V4L/DVB (8145a): USB Video Class driver
Laurent Pinchart [Mon, 30 Jun 2008 18:04:50 +0000 (15:04 -0300)]
This driver supports video input devices compliant with the USB Video Class
specification. This means lots of currently manufactured webcams, and probably
most of the future ones.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

12 files changed:
MAINTAINERS
drivers/media/video/Kconfig
drivers/media/video/Makefile
drivers/media/video/uvc/Makefile [new file with mode: 0644]
drivers/media/video/uvc/uvc_ctrl.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_driver.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_isight.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_queue.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_status.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_v4l2.c [new file with mode: 0644]
drivers/media/video/uvc/uvc_video.c [new file with mode: 0644]
drivers/media/video/uvc/uvcvideo.h [new file with mode: 0644]

index 8f0ec46..e6c06fa 100644 (file)
@@ -4314,6 +4314,14 @@ L:       netdev@vger.kernel.org
 W:     http://www.linux-usb.org/usbnet
 S:     Maintained
 
+USB VIDEO CLASS
+P:     Laurent Pinchart
+M:     laurent.pinchart@skynet.be
+L:     linx-uvc-devel@berlios.de
+L:     video4linux-list@redhat.com
+W:     http://linux-uvc.berlios.de
+S:     Maintained
+
 USB W996[87]CF DRIVER
 P:     Luca Risolia
 M:     luca.risolia@studio.unibo.it
index 3b26fbd..5ccb0ae 100644 (file)
@@ -793,6 +793,14 @@ menuconfig V4L_USB_DRIVERS
 
 if V4L_USB_DRIVERS && USB
 
+config USB_VIDEO_CLASS
+       tristate "USB Video Class (UVC)"
+       ---help---
+         Support for the USB Video Class (UVC).  Currently only video
+         input devices, such as webcams, are supported.
+
+         For more information see: <http://linux-uvc.berlios.de/>
+
 source "drivers/media/video/pvrusb2/Kconfig"
 
 source "drivers/media/video/em28xx/Kconfig"
index dff0d6a..ecbbfaa 100644 (file)
@@ -136,6 +136,8 @@ obj-$(CONFIG_SOC_CAMERA_MT9V022)    += mt9v022.o
 
 obj-$(CONFIG_VIDEO_AU0828) += au0828/
 
+obj-$(CONFIG_USB_VIDEO_CLASS)  += uvc/
+
 EXTRA_CFLAGS += -Idrivers/media/dvb/dvb-core
 EXTRA_CFLAGS += -Idrivers/media/dvb/frontends
 EXTRA_CFLAGS += -Idrivers/media/common/tuners
diff --git a/drivers/media/video/uvc/Makefile b/drivers/media/video/uvc/Makefile
new file mode 100644 (file)
index 0000000..fb39bbf
--- /dev/null
@@ -0,0 +1,3 @@
+uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
+                 uvc_status.o uvc_isight.o
+obj-$(CONFIG_USB_VIDEO_CLASS) := uvcvideo.o
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
new file mode 100644 (file)
index 0000000..f0ee46d
--- /dev/null
@@ -0,0 +1,1256 @@
+/*
+ *      uvc_ctrl.c  --  USB Video Class driver - Controls
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include "uvcvideo.h"
+
+#define UVC_CTRL_NDATA         2
+#define UVC_CTRL_DATA_CURRENT  0
+#define UVC_CTRL_DATA_BACKUP   1
+
+/* ------------------------------------------------------------------------
+ * Control, formats, ...
+ */
+
+static struct uvc_control_info uvc_ctrls[] = {
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_BRIGHTNESS_CONTROL,
+               .index          = 0,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_CONTRAST_CONTROL,
+               .index          = 1,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_HUE_CONTROL,
+               .index          = 2,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE | UVC_CONTROL_AUTO_UPDATE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_SATURATION_CONTROL,
+               .index          = 3,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_SHARPNESS_CONTROL,
+               .index          = 4,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_GAMMA_CONTROL,
+               .index          = 5,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_BACKLIGHT_COMPENSATION_CONTROL,
+               .index          = 8,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_GAIN_CONTROL,
+               .index          = 9,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_POWER_LINE_FREQUENCY_CONTROL,
+               .index          = 10,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_HUE_AUTO_CONTROL,
+               .index          = 11,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_GET_DEF | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_AE_MODE_CONTROL,
+               .index          = 1,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_GET_DEF | UVC_CONTROL_GET_RES
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_AE_PRIORITY_CONTROL,
+               .index          = 2,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
+               .index          = 3,
+               .size           = 4,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_FOCUS_ABSOLUTE_CONTROL,
+               .index          = 5,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE | UVC_CONTROL_AUTO_UPDATE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_FOCUS_AUTO_CONTROL,
+               .index          = 17,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_GET_DEF | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
+               .index          = 12,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_GET_DEF | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
+               .index          = 6,
+               .size           = 2,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE | UVC_CONTROL_AUTO_UPDATE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
+               .index          = 13,
+               .size           = 1,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_CUR
+                               | UVC_CONTROL_GET_DEF | UVC_CONTROL_RESTORE,
+       },
+       {
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_COMPONENT_CONTROL,
+               .index          = 7,
+               .size           = 4,
+               .flags          = UVC_CONTROL_SET_CUR | UVC_CONTROL_GET_RANGE
+                               | UVC_CONTROL_RESTORE | UVC_CONTROL_AUTO_UPDATE,
+       },
+};
+
+static struct uvc_menu_info power_line_frequency_controls[] = {
+       { 0, "Disabled" },
+       { 1, "50 Hz" },
+       { 2, "60 Hz" },
+};
+
+static struct uvc_menu_info exposure_auto_controls[] = {
+       { 1, "Manual Mode" },
+       { 2, "Auto Mode" },
+       { 4, "Shutter Priority Mode" },
+       { 8, "Aperture Priority Mode" },
+};
+
+static struct uvc_control_mapping uvc_ctrl_mappings[] = {
+       {
+               .id             = V4L2_CID_BRIGHTNESS,
+               .name           = "Brightness",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_BRIGHTNESS_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_SIGNED,
+       },
+       {
+               .id             = V4L2_CID_CONTRAST,
+               .name           = "Contrast",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_CONTRAST_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_HUE,
+               .name           = "Hue",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_HUE_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_SIGNED,
+       },
+       {
+               .id             = V4L2_CID_SATURATION,
+               .name           = "Saturation",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_SATURATION_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_SHARPNESS,
+               .name           = "Sharpness",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_SHARPNESS_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_GAMMA,
+               .name           = "Gamma",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_GAMMA_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_BACKLIGHT_COMPENSATION,
+               .name           = "Backlight Compensation",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_BACKLIGHT_COMPENSATION_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_GAIN,
+               .name           = "Gain",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_GAIN_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_POWER_LINE_FREQUENCY,
+               .name           = "Power Line Frequency",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_POWER_LINE_FREQUENCY_CONTROL,
+               .size           = 2,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_MENU,
+               .data_type      = UVC_CTRL_DATA_TYPE_ENUM,
+               .menu_info      = power_line_frequency_controls,
+               .menu_count     = ARRAY_SIZE(power_line_frequency_controls),
+       },
+       {
+               .id             = V4L2_CID_HUE_AUTO,
+               .name           = "Hue, Auto",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_HUE_AUTO_CONTROL,
+               .size           = 1,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
+               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
+       },
+       {
+               .id             = V4L2_CID_EXPOSURE_AUTO,
+               .name           = "Exposure, Auto",
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_AE_MODE_CONTROL,
+               .size           = 4,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_MENU,
+               .data_type      = UVC_CTRL_DATA_TYPE_BITMASK,
+               .menu_info      = exposure_auto_controls,
+               .menu_count     = ARRAY_SIZE(exposure_auto_controls),
+       },
+       {
+               .id             = V4L2_CID_EXPOSURE_AUTO_PRIORITY,
+               .name           = "Exposure, Auto Priority",
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_AE_PRIORITY_CONTROL,
+               .size           = 1,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
+               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
+       },
+       {
+               .id             = V4L2_CID_EXPOSURE_ABSOLUTE,
+               .name           = "Exposure (Absolute)",
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
+               .size           = 32,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_AUTO_WHITE_BALANCE,
+               .name           = "White Balance Temperature, Auto",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
+               .size           = 1,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
+               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
+       },
+       {
+               .id             = V4L2_CID_WHITE_BALANCE_TEMPERATURE,
+               .name           = "White Balance Temperature",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_AUTO_WHITE_BALANCE,
+               .name           = "White Balance Component, Auto",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
+               .size           = 1,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
+               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
+       },
+       {
+               .id             = V4L2_CID_BLUE_BALANCE,
+               .name           = "White Balance Blue Component",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_COMPONENT_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_SIGNED,
+       },
+       {
+               .id             = V4L2_CID_RED_BALANCE,
+               .name           = "White Balance Red Component",
+               .entity         = UVC_GUID_UVC_PROCESSING,
+               .selector       = PU_WHITE_BALANCE_COMPONENT_CONTROL,
+               .size           = 16,
+               .offset         = 16,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_SIGNED,
+       },
+       {
+               .id             = V4L2_CID_FOCUS_ABSOLUTE,
+               .name           = "Focus (absolute)",
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_FOCUS_ABSOLUTE_CONTROL,
+               .size           = 16,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+       },
+       {
+               .id             = V4L2_CID_FOCUS_AUTO,
+               .name           = "Focus, Auto",
+               .entity         = UVC_GUID_UVC_CAMERA,
+               .selector       = CT_FOCUS_AUTO_CONTROL,
+               .size           = 1,
+               .offset         = 0,
+               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
+               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
+       },
+};
+
+/* ------------------------------------------------------------------------
+ * Utility functions
+ */
+
+static inline __u8 *uvc_ctrl_data(struct uvc_control *ctrl, int id)
+{
+       return ctrl->data + id * ctrl->info->size;
+}
+
+static inline int uvc_get_bit(const __u8 *data, int bit)
+{
+       return (data[bit >> 3] >> (bit & 7)) & 1;
+}
+
+/* Extract the bit string specified by mapping->offset and mapping->size
+ * from the little-endian data stored at 'data' and return the result as
+ * a signed 32bit integer. Sign extension will be performed if the mapping
+ * references a signed data type.
+ */
+static __s32 uvc_get_le_value(const __u8 *data,
+       struct uvc_control_mapping *mapping)
+{
+       int bits = mapping->size;
+       int offset = mapping->offset;
+       __s32 value = 0;
+       __u8 mask;
+
+       data += offset / 8;
+       offset &= 7;
+       mask = ((1LL << bits) - 1) << offset;
+
+       for (; bits > 0; data++) {
+               __u8 byte = *data & mask;
+               value |= offset > 0 ? (byte >> offset) : (byte << (-offset));
+               bits -= 8 - (offset > 0 ? offset : 0);
+               offset -= 8;
+               mask = (1 << bits) - 1;
+       }
+
+       /* Sign-extend the value if needed */
+       if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
+               value |= -(value & (1 << (mapping->size - 1)));
+
+       return value;
+}
+
+/* Set the bit string specified by mapping->offset and mapping->size
+ * in the little-endian data stored at 'data' to the value 'value'.
+ */
+static void uvc_set_le_value(__s32 value, __u8 *data,
+       struct uvc_control_mapping *mapping)
+{
+       int bits = mapping->size;
+       int offset = mapping->offset;
+       __u8 mask;
+
+       data += offset / 8;
+       offset &= 7;
+
+       for (; bits > 0; data++) {
+               mask = ((1LL << bits) - 1) << offset;
+               *data = (*data & ~mask) | ((value << offset) & mask);
+               value >>= offset ? offset : 8;
+               bits -= 8 - offset;
+               offset = 0;
+       }
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+static const __u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
+static const __u8 uvc_camera_guid[16] = UVC_GUID_UVC_CAMERA;
+static const __u8 uvc_media_transport_input_guid[16] =
+       UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
+
+static int uvc_entity_match_guid(struct uvc_entity *entity, __u8 guid[16])
+{
+       switch (UVC_ENTITY_TYPE(entity)) {
+       case ITT_CAMERA:
+               return memcmp(uvc_camera_guid, guid, 16) == 0;
+
+       case ITT_MEDIA_TRANSPORT_INPUT:
+               return memcmp(uvc_media_transport_input_guid, guid, 16) == 0;
+
+       case VC_PROCESSING_UNIT:
+               return memcmp(uvc_processing_guid, guid, 16) == 0;
+
+       case VC_EXTENSION_UNIT:
+               return memcmp(entity->extension.guidExtensionCode,
+                             guid, 16) == 0;
+
+       default:
+               return 0;
+       }
+}
+
+/* ------------------------------------------------------------------------
+ * UVC Controls
+ */
+
+static void __uvc_find_control(struct uvc_entity *entity, __u32 v4l2_id,
+       struct uvc_control_mapping **mapping, struct uvc_control **control,
+       int next)
+{
+       struct uvc_control *ctrl;
+       struct uvc_control_mapping *map;
+       unsigned int i;
+
+       if (entity == NULL)
+               return;
+
+       for (i = 0; i < entity->ncontrols; ++i) {
+               ctrl = &entity->controls[i];
+               if (ctrl->info == NULL)
+                       continue;
+
+               list_for_each_entry(map, &ctrl->info->mappings, list) {
+                       if ((map->id == v4l2_id) && !next) {
+                               *control = ctrl;
+                               *mapping = map;
+                               return;
+                       }
+
+                       if ((*mapping == NULL || (*mapping)->id > map->id) &&
+                           (map->id > v4l2_id) && next) {
+                               *control = ctrl;
+                               *mapping = map;
+                       }
+               }
+       }
+}
+
+struct uvc_control *uvc_find_control(struct uvc_video_device *video,
+       __u32 v4l2_id, struct uvc_control_mapping **mapping)
+{
+       struct uvc_control *ctrl = NULL;
+       struct uvc_entity *entity;
+       int next = v4l2_id & V4L2_CTRL_FLAG_NEXT_CTRL;
+
+       *mapping = NULL;
+
+       /* Mask the query flags. */
+       v4l2_id &= V4L2_CTRL_ID_MASK;
+
+       /* Find the control. */
+       __uvc_find_control(video->processing, v4l2_id, mapping, &ctrl, next);
+       if (ctrl && !next)
+               return ctrl;
+
+       list_for_each_entry(entity, &video->iterms, chain) {
+               __uvc_find_control(entity, v4l2_id, mapping, &ctrl, next);
+               if (ctrl && !next)
+                       return ctrl;
+       }
+
+       list_for_each_entry(entity, &video->extensions, chain) {
+               __uvc_find_control(entity, v4l2_id, mapping, &ctrl, next);
+               if (ctrl && !next)
+                       return ctrl;
+       }
+
+       if (ctrl == NULL && !next)
+               uvc_trace(UVC_TRACE_CONTROL, "Control 0x%08x not found.\n",
+                               v4l2_id);
+
+       return ctrl;
+}
+
+int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
+       struct v4l2_queryctrl *v4l2_ctrl)
+{
+       struct uvc_control *ctrl;
+       struct uvc_control_mapping *mapping;
+       struct uvc_menu_info *menu;
+       unsigned int i;
+       __u8 data[8];
+       int ret;
+
+       ctrl = uvc_find_control(video, v4l2_ctrl->id, &mapping);
+       if (ctrl == NULL)
+               return -EINVAL;
+
+       v4l2_ctrl->id = mapping->id;
+       v4l2_ctrl->type = mapping->v4l2_type;
+       strncpy(v4l2_ctrl->name, mapping->name, sizeof v4l2_ctrl->name);
+       v4l2_ctrl->flags = 0;
+
+       if (!(ctrl->info->flags & UVC_CONTROL_SET_CUR))
+               v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+       if (ctrl->info->flags & UVC_CONTROL_GET_DEF) {
+               if ((ret = uvc_query_ctrl(video->dev, GET_DEF, ctrl->entity->id,
+                               video->dev->intfnum, ctrl->info->selector,
+                               &data, ctrl->info->size)) < 0)
+                       return ret;
+               v4l2_ctrl->default_value = uvc_get_le_value(data, mapping);
+       }
+
+       if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
+               v4l2_ctrl->minimum = 0;
+               v4l2_ctrl->maximum = mapping->menu_count - 1;
+               v4l2_ctrl->step = 1;
+
+               menu = mapping->menu_info;
+               for (i = 0; i < mapping->menu_count; ++i, ++menu) {
+                       if (menu->value == v4l2_ctrl->default_value) {
+                               v4l2_ctrl->default_value = i;
+                               break;
+                       }
+               }
+
+               return 0;
+       }
+
+       if (ctrl->info->flags & UVC_CONTROL_GET_MIN) {
+               if ((ret = uvc_query_ctrl(video->dev, GET_MIN, ctrl->entity->id,
+                               video->dev->intfnum, ctrl->info->selector,
+                               &data, ctrl->info->size)) < 0)
+                       return ret;
+               v4l2_ctrl->minimum = uvc_get_le_value(data, mapping);
+       }
+       if (ctrl->info->flags & UVC_CONTROL_GET_MAX) {
+               if ((ret = uvc_query_ctrl(video->dev, GET_MAX, ctrl->entity->id,
+                               video->dev->intfnum, ctrl->info->selector,
+                               &data, ctrl->info->size)) < 0)
+                       return ret;
+               v4l2_ctrl->maximum = uvc_get_le_value(data, mapping);
+       }
+       if (ctrl->info->flags & UVC_CONTROL_GET_RES) {
+               if ((ret = uvc_query_ctrl(video->dev, GET_RES, ctrl->entity->id,
+                               video->dev->intfnum, ctrl->info->selector,
+                               &data, ctrl->info->size)) < 0)
+                       return ret;
+               v4l2_ctrl->step = uvc_get_le_value(data, mapping);
+       }
+
+       return 0;
+}
+
+
+/* --------------------------------------------------------------------------
+ * Control transactions
+ *
+ * To make extended set operations as atomic as the hardware allows, controls
+ * are handled using begin/commit/rollback operations.
+ *
+ * At the beginning of a set request, uvc_ctrl_begin should be called to
+ * initialize the request. This function acquires the control lock.
+ *
+ * When setting a control, the new value is stored in the control data field
+ * at position UVC_CTRL_DATA_CURRENT. The control is then marked as dirty for
+ * later processing. If the UVC and V4L2 control sizes differ, the current
+ * value is loaded from the hardware before storing the new value in the data
+ * field.
+ *
+ * After processing all controls in the transaction, uvc_ctrl_commit or
+ * uvc_ctrl_rollback must be called to apply the pending changes to the
+ * hardware or revert them. When applying changes, all controls marked as
+ * dirty will be modified in the UVC device, and the dirty flag will be
+ * cleared. When reverting controls, the control data field
+ * UVC_CTRL_DATA_CURRENT is reverted to its previous value
+ * (UVC_CTRL_DATA_BACKUP) for all dirty controls. Both functions release the
+ * control lock.
+ */
+int uvc_ctrl_begin(struct uvc_video_device *video)
+{
+       return mutex_lock_interruptible(&video->ctrl_mutex) ? -ERESTARTSYS : 0;
+}
+
+static int uvc_ctrl_commit_entity(struct uvc_device *dev,
+       struct uvc_entity *entity, int rollback)
+{
+       struct uvc_control *ctrl;
+       unsigned int i;
+       int ret;
+
+       if (entity == NULL)
+               return 0;
+
+       for (i = 0; i < entity->ncontrols; ++i) {
+               ctrl = &entity->controls[i];
+               if (ctrl->info == NULL || !ctrl->dirty)
+                       continue;
+
+               if (!rollback)
+                       ret = uvc_query_ctrl(dev, SET_CUR, ctrl->entity->id,
+                               dev->intfnum, ctrl->info->selector,
+                               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                               ctrl->info->size);
+               else
+                       ret = 0;
+
+               if (rollback || ret < 0)
+                       memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                              uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+                              ctrl->info->size);
+
+               if ((ctrl->info->flags & UVC_CONTROL_GET_CUR) == 0)
+                       ctrl->loaded = 0;
+
+               ctrl->dirty = 0;
+
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
+int __uvc_ctrl_commit(struct uvc_video_device *video, int rollback)
+{
+       struct uvc_entity *entity;
+       int ret = 0;
+
+       /* Find the control. */
+       ret = uvc_ctrl_commit_entity(video->dev, video->processing, rollback);
+       if (ret < 0)
+               goto done;
+
+       list_for_each_entry(entity, &video->iterms, chain) {
+               ret = uvc_ctrl_commit_entity(video->dev, entity, rollback);
+               if (ret < 0)
+                       goto done;
+       }
+
+       list_for_each_entry(entity, &video->extensions, chain) {
+               ret = uvc_ctrl_commit_entity(video->dev, entity, rollback);
+               if (ret < 0)
+                       goto done;
+       }
+
+done:
+       mutex_unlock(&video->ctrl_mutex);
+       return ret;
+}
+
+int uvc_ctrl_get(struct uvc_video_device *video,
+       struct v4l2_ext_control *xctrl)
+{
+       struct uvc_control *ctrl;
+       struct uvc_control_mapping *mapping;
+       struct uvc_menu_info *menu;
+       unsigned int i;
+       int ret;
+
+       ctrl = uvc_find_control(video, xctrl->id, &mapping);
+       if (ctrl == NULL || (ctrl->info->flags & UVC_CONTROL_GET_CUR) == 0)
+               return -EINVAL;
+
+       if (!ctrl->loaded) {
+               ret = uvc_query_ctrl(video->dev, GET_CUR, ctrl->entity->id,
+                               video->dev->intfnum, ctrl->info->selector,
+                               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                               ctrl->info->size);
+               if (ret < 0)
+                       return ret;
+
+               if ((ctrl->info->flags & UVC_CONTROL_AUTO_UPDATE) == 0)
+                       ctrl->loaded = 1;
+       }
+
+       xctrl->value = uvc_get_le_value(
+               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), mapping);
+
+       if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
+               menu = mapping->menu_info;
+               for (i = 0; i < mapping->menu_count; ++i, ++menu) {
+                       if (menu->value == xctrl->value) {
+                               xctrl->value = i;
+                               break;
+                       }
+               }
+       }
+
+       return 0;
+}
+
+int uvc_ctrl_set(struct uvc_video_device *video,
+       struct v4l2_ext_control *xctrl)
+{
+       struct uvc_control *ctrl;
+       struct uvc_control_mapping *mapping;
+       s32 value = xctrl->value;
+       int ret;
+
+       ctrl = uvc_find_control(video, xctrl->id, &mapping);
+       if (ctrl == NULL || (ctrl->info->flags & UVC_CONTROL_SET_CUR) == 0)
+               return -EINVAL;
+
+       if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
+               if (value < 0 || value >= mapping->menu_count)
+                       return -EINVAL;
+               value = mapping->menu_info[value].value;
+       }
+
+       if (!ctrl->loaded && (ctrl->info->size * 8) != mapping->size) {
+               if ((ctrl->info->flags & UVC_CONTROL_GET_CUR) == 0) {
+                       memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                               0, ctrl->info->size);
+               } else {
+                       ret = uvc_query_ctrl(video->dev, GET_CUR,
+                               ctrl->entity->id, video->dev->intfnum,
+                               ctrl->info->selector,
+                               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                               ctrl->info->size);
+                       if (ret < 0)
+                               return ret;
+               }
+
+               if ((ctrl->info->flags & UVC_CONTROL_AUTO_UPDATE) == 0)
+                       ctrl->loaded = 1;
+       }
+
+       if (!ctrl->dirty) {
+               memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+                      uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                      ctrl->info->size);
+       }
+
+       uvc_set_le_value(value,
+               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), mapping);
+
+       ctrl->dirty = 1;
+       ctrl->modified = 1;
+       return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Dynamic controls
+ */
+
+int uvc_xu_ctrl_query(struct uvc_video_device *video,
+       struct uvc_xu_control *xctrl, int set)
+{
+       struct uvc_entity *entity;
+       struct uvc_control *ctrl = NULL;
+       unsigned int i, found = 0;
+       __u8 *data;
+       int ret;
+
+       /* Find the extension unit. */
+       list_for_each_entry(entity, &video->extensions, chain) {
+               if (entity->id == xctrl->unit)
+                       break;
+       }
+
+       if (entity->id != xctrl->unit) {
+               uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
+                       xctrl->unit);
+               return -EINVAL;
+       }
+
+       /* Find the control. */
+       for (i = 0; i < entity->ncontrols; ++i) {
+               ctrl = &entity->controls[i];
+               if (ctrl->info == NULL)
+                       continue;
+
+               if (ctrl->info->selector == xctrl->selector) {
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (!found) {
+               uvc_trace(UVC_TRACE_CONTROL,
+                       "Control " UVC_GUID_FORMAT "/%u not found.\n",
+                       UVC_GUID_ARGS(entity->extension.guidExtensionCode),
+                       xctrl->selector);
+               return -EINVAL;
+       }
+
+       /* Validate control data size. */
+       if (ctrl->info->size != xctrl->size)
+               return -EINVAL;
+
+       if ((set && !(ctrl->info->flags & UVC_CONTROL_SET_CUR)) ||
+           (!set && !(ctrl->info->flags & UVC_CONTROL_GET_CUR)))
+               return -EINVAL;
+
+       if (mutex_lock_interruptible(&video->ctrl_mutex))
+               return -ERESTARTSYS;
+
+       memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+              uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+              xctrl->size);
+       data = uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT);
+
+       if (set && copy_from_user(data, xctrl->data, xctrl->size)) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+       ret = uvc_query_ctrl(video->dev, set ? SET_CUR : GET_CUR, xctrl->unit,
+                            video->dev->intfnum, xctrl->selector, data,
+                            xctrl->size);
+       if (ret < 0)
+               goto out;
+
+       if (!set && copy_to_user(xctrl->data, data, xctrl->size)) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+out:
+       if (ret)
+               memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+                      uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+                      xctrl->size);
+
+       mutex_unlock(&video->ctrl_mutex);
+       return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * Suspend/resume
+ */
+
+/*
+ * Restore control values after resume, skipping controls that haven't been
+ * changed.
+ *
+ * TODO
+ * - Don't restore modified controls that are back to their default value.
+ * - Handle restore order (Auto-Exposure Mode should be restored before
+ *   Exposure Time).
+ */
+int uvc_ctrl_resume_device(struct uvc_device *dev)
+{
+       struct uvc_control *ctrl;
+       struct uvc_entity *entity;
+       unsigned int i;
+       int ret;
+
+       /* Walk the entities list and restore controls when possible. */
+       list_for_each_entry(entity, &dev->entities, list) {
+
+               for (i = 0; i < entity->ncontrols; ++i) {
+                       ctrl = &entity->controls[i];
+
+                       if (ctrl->info == NULL || !ctrl->modified ||
+                           (ctrl->info->flags & UVC_CONTROL_RESTORE) == 0)
+                               continue;
+
+                       printk(KERN_INFO "restoring control " UVC_GUID_FORMAT
+                               "/%u/%u\n", UVC_GUID_ARGS(ctrl->info->entity),
+                               ctrl->info->index, ctrl->info->selector);
+                       ctrl->dirty = 1;
+               }
+
+               ret = uvc_ctrl_commit_entity(dev, entity, 0);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Control and mapping handling
+ */
+
+static void uvc_ctrl_add_ctrl(struct uvc_device *dev,
+       struct uvc_control_info *info)
+{
+       struct uvc_entity *entity;
+       struct uvc_control *ctrl = NULL;
+       int ret, found = 0;
+       unsigned int i;
+
+       list_for_each_entry(entity, &dev->entities, list) {
+               if (!uvc_entity_match_guid(entity, info->entity))
+                       continue;
+
+               for (i = 0; i < entity->ncontrols; ++i) {
+                       ctrl = &entity->controls[i];
+                       if (ctrl->index == info->index) {
+                               found = 1;
+                               break;
+                       }
+               }
+
+               if (found)
+                       break;
+       }
+
+       if (!found)
+               return;
+
+       if (UVC_ENTITY_TYPE(entity) == VC_EXTENSION_UNIT) {
+               /* Check if the device control information and length match
+                * the user supplied information.
+                */
+               __u32 flags;
+               __le16 size;
+               __u8 inf;
+
+               if ((ret = uvc_query_ctrl(dev, GET_LEN, ctrl->entity->id,
+                       dev->intfnum, info->selector, (__u8 *)&size, 2)) < 0) {
+                       uvc_trace(UVC_TRACE_CONTROL, "GET_LEN failed on "
+                               "control " UVC_GUID_FORMAT "/%u (%d).\n",
+                               UVC_GUID_ARGS(info->entity), info->selector,
+                               ret);
+                       return;
+               }
+
+               if (info->size != le16_to_cpu(size)) {
+                       uvc_trace(UVC_TRACE_CONTROL, "Control " UVC_GUID_FORMAT
+                               "/%u size doesn't match user supplied "
+                               "value.\n", UVC_GUID_ARGS(info->entity),
+                               info->selector);
+                       return;
+               }
+
+               if ((ret = uvc_query_ctrl(dev, GET_INFO, ctrl->entity->id,
+                       dev->intfnum, info->selector, &inf, 1)) < 0) {
+                       uvc_trace(UVC_TRACE_CONTROL, "GET_INFO failed on "
+                               "control " UVC_GUID_FORMAT "/%u (%d).\n",
+                               UVC_GUID_ARGS(info->entity), info->selector,
+                               ret);
+                       return;
+               }
+
+               flags = info->flags;
+               if (((flags & UVC_CONTROL_GET_CUR) && !(inf & (1 << 0))) ||
+                   ((flags & UVC_CONTROL_SET_CUR) && !(inf & (1 << 1)))) {
+                       uvc_trace(UVC_TRACE_CONTROL, "Control "
+                               UVC_GUID_FORMAT "/%u flags don't match "
+                               "supported operations.\n",
+                               UVC_GUID_ARGS(info->entity), info->selector);
+                       return;
+               }
+       }
+
+       ctrl->info = info;
+       ctrl->data = kmalloc(ctrl->info->size * UVC_CTRL_NDATA, GFP_KERNEL);
+       uvc_trace(UVC_TRACE_CONTROL, "Added control " UVC_GUID_FORMAT "/%u "
+               "to device %s entity %u\n", UVC_GUID_ARGS(ctrl->info->entity),
+               ctrl->info->selector, dev->udev->devpath, entity->id);
+}
+
+/*
+ * Add an item to the UVC control information list, and instantiate a control
+ * structure for each device that supports the control.
+ */
+int uvc_ctrl_add_info(struct uvc_control_info *info)
+{
+       struct uvc_control_info *ctrl;
+       struct uvc_device *dev;
+       int ret = 0;
+
+       /* Find matching controls by walking the devices, entities and
+        * controls list.
+        */
+       mutex_lock(&uvc_driver.ctrl_mutex);
+
+       /* First check if the list contains a control matching the new one.
+        * Bail out if it does.
+        */
+       list_for_each_entry(ctrl, &uvc_driver.controls, list) {
+               if (memcmp(ctrl->entity, info->entity, 16))
+                       continue;
+
+               if (ctrl->selector == info->selector) {
+                       uvc_trace(UVC_TRACE_CONTROL, "Control "
+                               UVC_GUID_FORMAT "/%u is already defined.\n",
+                               UVC_GUID_ARGS(info->entity), info->selector);
+                       ret = -EEXIST;
+                       goto end;
+               }
+               if (ctrl->index == info->index) {
+                       uvc_trace(UVC_TRACE_CONTROL, "Control "
+                               UVC_GUID_FORMAT "/%u would overwrite index "
+                               "%d.\n", UVC_GUID_ARGS(info->entity),
+                               info->selector, info->index);
+                       ret = -EEXIST;
+                       goto end;
+               }
+       }
+
+       list_for_each_entry(dev, &uvc_driver.devices, list)
+               uvc_ctrl_add_ctrl(dev, info);
+
+       INIT_LIST_HEAD(&info->mappings);
+       list_add_tail(&info->list, &uvc_driver.controls);
+end:
+       mutex_unlock(&uvc_driver.ctrl_mutex);
+       return ret;
+}
+
+int uvc_ctrl_add_mapping(struct uvc_control_mapping *mapping)
+{
+       struct uvc_control_info *info;
+       struct uvc_control_mapping *map;
+       int ret = -EINVAL;
+
+       if (mapping->id & ~V4L2_CTRL_ID_MASK) {
+               uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s' with "
+                       "invalid control id 0x%08x\n", mapping->name,
+                       mapping->id);
+               return -EINVAL;
+       }
+
+       mutex_lock(&uvc_driver.ctrl_mutex);
+       list_for_each_entry(info, &uvc_driver.controls, list) {
+               if (memcmp(info->entity, mapping->entity, 16) ||
+                       info->selector != mapping->selector)
+                       continue;
+
+               if (info->size * 8 < mapping->size + mapping->offset) {
+                       uvc_trace(UVC_TRACE_CONTROL, "Mapping '%s' would "
+                               "overflow control " UVC_GUID_FORMAT "/%u\n",
+                               mapping->name, UVC_GUID_ARGS(info->entity),
+                               info->selector);
+                       ret = -EOVERFLOW;
+                       goto end;
+               }
+
+               /* Check if the list contains a mapping matching the new one.
+                * Bail out if it does.
+                */
+               list_for_each_entry(map, &info->mappings, list) {
+                       if (map->id == mapping->id) {
+                               uvc_trace(UVC_TRACE_CONTROL, "Mapping '%s' is "
+                                       "already defined.\n", mapping->name);
+                               ret = -EEXIST;
+                               goto end;
+                       }
+               }
+
+               mapping->ctrl = info;
+               list_add_tail(&mapping->list, &info->mappings);
+               uvc_trace(UVC_TRACE_CONTROL, "Adding mapping %s to control "
+                       UVC_GUID_FORMAT "/%u.\n", mapping->name,
+                       UVC_GUID_ARGS(info->entity), info->selector);
+
+               ret = 0;
+               break;
+       }
+end:
+       mutex_unlock(&uvc_driver.ctrl_mutex);
+       return ret;
+}
+
+/*
+ * Initialize device controls.
+ */
+int uvc_ctrl_init_device(struct uvc_device *dev)
+{
+       struct uvc_control_info *info;
+       struct uvc_control *ctrl;
+       struct uvc_entity *entity;
+       unsigned int i;
+
+       /* Walk the entities list and instantiate controls */
+       list_for_each_entry(entity, &dev->entities, list) {
+               unsigned int bControlSize = 0, ncontrols = 0;
+               __u8 *bmControls = NULL;
+
+               if (UVC_ENTITY_TYPE(entity) == VC_EXTENSION_UNIT) {
+                       bmControls = entity->extension.bmControls;
+                       bControlSize = entity->extension.bControlSize;
+               } else if (UVC_ENTITY_TYPE(entity) == VC_PROCESSING_UNIT) {
+                       bmControls = entity->processing.bmControls;
+                       bControlSize = entity->processing.bControlSize;
+               } else if (UVC_ENTITY_TYPE(entity) == ITT_CAMERA) {
+                       bmControls = entity->camera.bmControls;
+                       bControlSize = entity->camera.bControlSize;
+               }
+
+               for (i = 0; i < bControlSize; ++i)
+                       ncontrols += hweight8(bmControls[i]);
+
+               if (ncontrols == 0)
+                       continue;
+
+               entity->controls = kzalloc(ncontrols*sizeof *ctrl, GFP_KERNEL);
+               if (entity->controls == NULL)
+                       return -ENOMEM;
+
+               entity->ncontrols = ncontrols;
+
+               ctrl = entity->controls;
+               for (i = 0; i < bControlSize * 8; ++i) {
+                       if (uvc_get_bit(bmControls, i) == 0)
+                               continue;
+
+                       ctrl->entity = entity;
+                       ctrl->index = i;
+                       ctrl++;
+               }
+       }
+
+       /* Walk the controls info list and associate them with the device
+        * controls, then add the device to the global device list. This has
+        * to be done while holding the controls lock, to make sure
+        * uvc_ctrl_add_info() will not get called in-between.
+        */
+       mutex_lock(&uvc_driver.ctrl_mutex);
+       list_for_each_entry(info, &uvc_driver.controls, list)
+               uvc_ctrl_add_ctrl(dev, info);
+
+       list_add_tail(&dev->list, &uvc_driver.devices);
+       mutex_unlock(&uvc_driver.ctrl_mutex);
+
+       return 0;
+}
+
+/*
+ * Cleanup device controls.
+ */
+void uvc_ctrl_cleanup_device(struct uvc_device *dev)
+{
+       struct uvc_entity *entity;
+       unsigned int i;
+
+       /* Remove the device from the global devices list */
+       mutex_lock(&uvc_driver.ctrl_mutex);
+       if (dev->list.next != NULL)
+               list_del(&dev->list);
+       mutex_unlock(&uvc_driver.ctrl_mutex);
+
+       list_for_each_entry(entity, &dev->entities, list) {
+               for (i = 0; i < entity->ncontrols; ++i)
+                       kfree(entity->controls[i].data);
+
+               kfree(entity->controls);
+       }
+}
+
+void uvc_ctrl_init(void)
+{
+       struct uvc_control_info *ctrl = uvc_ctrls;
+       struct uvc_control_info *cend = ctrl + ARRAY_SIZE(uvc_ctrls);
+       struct uvc_control_mapping *mapping = uvc_ctrl_mappings;
+       struct uvc_control_mapping *mend =
+               mapping + ARRAY_SIZE(uvc_ctrl_mappings);
+
+       for (; ctrl < cend; ++ctrl)
+               uvc_ctrl_add_info(ctrl);
+
+       for (; mapping < mend; ++mapping)
+               uvc_ctrl_add_mapping(mapping);
+}
diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
new file mode 100644 (file)
index 0000000..60ced58
--- /dev/null
@@ -0,0 +1,1955 @@
+/*
+ *      uvc_driver.c  --  USB Video Class driver
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+/*
+ * This driver aims to support video input devices compliant with the 'USB
+ * Video Class' specification.
+ *
+ * The driver doesn't support the deprecated v4l1 interface. It implements the
+ * mmap capture method only, and doesn't do any image format conversion in
+ * software. If your user-space application doesn't support YUYV or MJPEG, fix
+ * it :-). Please note that the MJPEG data have been stripped from their
+ * Huffman tables (DHT marker), you will need to add it back if your JPEG
+ * codec can't handle MJPEG data.
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+#define DRIVER_AUTHOR          "Laurent Pinchart <laurent.pinchart@skynet.be>"
+#define DRIVER_DESC            "USB Video Class driver"
+#ifndef DRIVER_VERSION
+#define DRIVER_VERSION         "v0.1.0"
+#endif
+
+static unsigned int uvc_quirks_param;
+unsigned int uvc_trace_param;
+
+/* ------------------------------------------------------------------------
+ * Control, formats, ...
+ */
+
+static struct uvc_format_desc uvc_fmts[] = {
+       {
+               .name           = "YUV 4:2:2 (YUYV)",
+               .guid           = UVC_GUID_FORMAT_YUY2,
+               .fcc            = V4L2_PIX_FMT_YUYV,
+       },
+       {
+               .name           = "YUV 4:2:0 (NV12)",
+               .guid           = UVC_GUID_FORMAT_NV12,
+               .fcc            = V4L2_PIX_FMT_NV12,
+       },
+       {
+               .name           = "MJPEG",
+               .guid           = UVC_GUID_FORMAT_MJPEG,
+               .fcc            = V4L2_PIX_FMT_MJPEG,
+       },
+       {
+               .name           = "YVU 4:2:0 (YV12)",
+               .guid           = UVC_GUID_FORMAT_YV12,
+               .fcc            = V4L2_PIX_FMT_YVU420,
+       },
+       {
+               .name           = "YUV 4:2:0 (I420)",
+               .guid           = UVC_GUID_FORMAT_I420,
+               .fcc            = V4L2_PIX_FMT_YUV420,
+       },
+       {
+               .name           = "YUV 4:2:2 (UYVY)",
+               .guid           = UVC_GUID_FORMAT_UYVY,
+               .fcc            = V4L2_PIX_FMT_UYVY,
+       },
+       {
+               .name           = "Greyscale",
+               .guid           = UVC_GUID_FORMAT_Y800,
+               .fcc            = V4L2_PIX_FMT_GREY,
+       },
+       {
+               .name           = "RGB Bayer",
+               .guid           = UVC_GUID_FORMAT_BY8,
+               .fcc            = V4L2_PIX_FMT_SBGGR8,
+       },
+};
+
+/* ------------------------------------------------------------------------
+ * Utility functions
+ */
+
+struct usb_host_endpoint *uvc_find_endpoint(struct usb_host_interface *alts,
+               __u8 epaddr)
+{
+       struct usb_host_endpoint *ep;
+       unsigned int i;
+
+       for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+               ep = &alts->endpoint[i];
+               if (ep->desc.bEndpointAddress == epaddr)
+                       return ep;
+       }
+
+       return NULL;
+}
+
+static struct uvc_format_desc *uvc_format_by_guid(const __u8 guid[16])
+{
+       unsigned int len = ARRAY_SIZE(uvc_fmts);
+       unsigned int i;
+
+       for (i = 0; i < len; ++i) {
+               if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
+                       return &uvc_fmts[i];
+       }
+
+       return NULL;
+}
+
+static __u32 uvc_colorspace(const __u8 primaries)
+{
+       static const __u8 colorprimaries[] = {
+               0,
+               V4L2_COLORSPACE_SRGB,
+               V4L2_COLORSPACE_470_SYSTEM_M,
+               V4L2_COLORSPACE_470_SYSTEM_BG,
+               V4L2_COLORSPACE_SMPTE170M,
+               V4L2_COLORSPACE_SMPTE240M,
+       };
+
+       if (primaries < ARRAY_SIZE(colorprimaries))
+               return colorprimaries[primaries];
+
+       return 0;
+}
+
+/* Simplify a fraction using a simple continued fraction decomposition. The
+ * idea here is to convert fractions such as 333333/10000000 to 1/30 using
+ * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
+ * arbitrary parameters to remove non-significative terms from the simple
+ * continued fraction decomposition. Using 8 and 333 for n_terms and threshold
+ * respectively seems to give nice results.
+ */
+void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
+               unsigned int n_terms, unsigned int threshold)
+{
+       uint32_t *an;
+       uint32_t x, y, r;
+       unsigned int i, n;
+
+       an = kmalloc(n_terms * sizeof *an, GFP_KERNEL);
+       if (an == NULL)
+               return;
+
+       /* Convert the fraction to a simple continued fraction. See
+        * http://mathforum.org/dr.math/faq/faq.fractions.html
+        * Stop if the current term is bigger than or equal to the given
+        * threshold.
+        */
+       x = *numerator;
+       y = *denominator;
+
+       for (n = 0; n < n_terms && y != 0; ++n) {
+               an[n] = x / y;
+               if (an[n] >= threshold) {
+                       if (n < 2)
+                               n++;
+                       break;
+               }
+
+               r = x - an[n] * y;
+               x = y;
+               y = r;
+       }
+
+       /* Expand the simple continued fraction back to an integer fraction. */
+       x = 0;
+       y = 1;
+
+       for (i = n; i > 0; --i) {
+               r = y;
+               y = an[i-1] * y + x;
+               x = r;
+       }
+
+       *numerator = y;
+       *denominator = x;
+       kfree(an);
+}
+
+/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
+ * to compute numerator / denominator * 10000000 using 32 bit fixed point
+ * arithmetic only.
+ */
+uint32_t uvc_fraction_to_interval(uint32_t numerator, uint32_t denominator)
+{
+       uint32_t multiplier;
+
+       /* Saturate the result if the operation would overflow. */
+       if (denominator == 0 ||
+           numerator/denominator >= ((uint32_t)-1)/10000000)
+               return (uint32_t)-1;
+
+       /* Divide both the denominator and the multiplier by two until
+        * numerator * multiplier doesn't overflow. If anyone knows a better
+        * algorithm please let me know.
+        */
+       multiplier = 10000000;
+       while (numerator > ((uint32_t)-1)/multiplier) {
+               multiplier /= 2;
+               denominator /= 2;
+       }
+
+       return denominator ? numerator * multiplier / denominator : 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+static struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id)
+{
+       struct uvc_entity *entity;
+
+       list_for_each_entry(entity, &dev->entities, list) {
+               if (entity->id == id)
+                       return entity;
+       }
+
+       return NULL;
+}
+
+static struct uvc_entity *uvc_entity_by_reference(struct uvc_device *dev,
+       int id, struct uvc_entity *entity)
+{
+       unsigned int i;
+
+       if (entity == NULL)
+               entity = list_entry(&dev->entities, struct uvc_entity, list);
+
+       list_for_each_entry_continue(entity, &dev->entities, list) {
+               switch (UVC_ENTITY_TYPE(entity)) {
+               case TT_STREAMING:
+                       if (entity->output.bSourceID == id)
+                               return entity;
+                       break;
+
+               case VC_PROCESSING_UNIT:
+                       if (entity->processing.bSourceID == id)
+                               return entity;
+                       break;
+
+               case VC_SELECTOR_UNIT:
+                       for (i = 0; i < entity->selector.bNrInPins; ++i)
+                               if (entity->selector.baSourceID[i] == id)
+                                       return entity;
+                       break;
+
+               case VC_EXTENSION_UNIT:
+                       for (i = 0; i < entity->extension.bNrInPins; ++i)
+                               if (entity->extension.baSourceID[i] == id)
+                                       return entity;
+                       break;
+               }
+       }
+
+       return NULL;
+}
+
+/* ------------------------------------------------------------------------
+ * Descriptors handling
+ */
+
+static int uvc_parse_format(struct uvc_device *dev,
+       struct uvc_streaming *streaming, struct uvc_format *format,
+       __u32 **intervals, unsigned char *buffer, int buflen)
+{
+       struct usb_interface *intf = streaming->intf;
+       struct usb_host_interface *alts = intf->cur_altsetting;
+       struct uvc_format_desc *fmtdesc;
+       struct uvc_frame *frame;
+       const unsigned char *start = buffer;
+       unsigned int interval;
+       unsigned int i, n;
+       __u8 ftype;
+
+       format->type = buffer[2];
+       format->index = buffer[3];
+
+       switch (buffer[2]) {
+       case VS_FORMAT_UNCOMPRESSED:
+       case VS_FORMAT_FRAME_BASED:
+               if (buflen < 27) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d FORMAT error\n",
+                              dev->udev->devnum,
+                              alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               /* Find the format descriptor from its GUID. */
+               fmtdesc = uvc_format_by_guid(&buffer[5]);
+
+               if (fmtdesc != NULL) {
+                       strncpy(format->name, fmtdesc->name,
+                               sizeof format->name);
+                       format->fcc = fmtdesc->fcc;
+               } else {
+                       uvc_printk(KERN_INFO, "Unknown video format "
+                               UVC_GUID_FORMAT "\n",
+                               UVC_GUID_ARGS(&buffer[5]));
+                       snprintf(format->name, sizeof format->name,
+                               UVC_GUID_FORMAT, UVC_GUID_ARGS(&buffer[5]));
+                       format->fcc = 0;
+               }
+
+               format->bpp = buffer[21];
+               if (buffer[2] == VS_FORMAT_UNCOMPRESSED) {
+                       ftype = VS_FRAME_UNCOMPRESSED;
+               } else {
+                       ftype = VS_FRAME_FRAME_BASED;
+                       if (buffer[27])
+                               format->flags = UVC_FMT_FLAG_COMPRESSED;
+               }
+               break;
+
+       case VS_FORMAT_MJPEG:
+               if (buflen < 11) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d FORMAT error\n",
+                              dev->udev->devnum,
+                              alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               strncpy(format->name, "MJPEG", sizeof format->name);
+               format->fcc = V4L2_PIX_FMT_MJPEG;
+               format->flags = UVC_FMT_FLAG_COMPRESSED;
+               format->bpp = 0;
+               ftype = VS_FRAME_MJPEG;
+               break;
+
+       case VS_FORMAT_DV:
+               if (buflen < 9) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d FORMAT error\n",
+                              dev->udev->devnum,
+                              alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               switch (buffer[8] & 0x7f) {
+               case 0:
+                       strncpy(format->name, "SD-DV", sizeof format->name);
+                       break;
+               case 1:
+                       strncpy(format->name, "SDL-DV", sizeof format->name);
+                       break;
+               case 2:
+                       strncpy(format->name, "HD-DV", sizeof format->name);
+                       break;
+               default:
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d: unknown DV format %u\n",
+                              dev->udev->devnum,
+                              alts->desc.bInterfaceNumber, buffer[8]);
+                       return -EINVAL;
+               }
+
+               strncat(format->name, buffer[8] & (1 << 7) ? " 60Hz" : " 50Hz",
+                       sizeof format->name);
+
+               format->fcc = V4L2_PIX_FMT_DV;
+               format->flags = UVC_FMT_FLAG_COMPRESSED | UVC_FMT_FLAG_STREAM;
+               format->bpp = 0;
+               ftype = 0;
+
+               /* Create a dummy frame descriptor. */
+               frame = &format->frame[0];
+               memset(&format->frame[0], 0, sizeof format->frame[0]);
+               frame->bFrameIntervalType = 1;
+               frame->dwDefaultFrameInterval = 1;
+               frame->dwFrameInterval = *intervals;
+               *(*intervals)++ = 1;
+               format->nframes = 1;
+               break;
+
+       case VS_FORMAT_MPEG2TS:
+       case VS_FORMAT_STREAM_BASED:
+               /* Not supported yet. */
+       default:
+               uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                      "interface %d unsupported format %u\n",
+                      dev->udev->devnum, alts->desc.bInterfaceNumber,
+                      buffer[2]);
+               return -EINVAL;
+       }
+
+       uvc_trace(UVC_TRACE_DESCR, "Found format %s.\n", format->name);
+
+       buflen -= buffer[0];
+       buffer += buffer[0];
+
+       /* Parse the frame descriptors. Only uncompressed, MJPEG and frame
+        * based formats have frame descriptors.
+        */
+       while (buflen > 2 && buffer[2] == ftype) {
+               frame = &format->frame[format->nframes];
+
+               if (ftype != VS_FRAME_FRAME_BASED)
+                       n = buflen > 25 ? buffer[25] : 0;
+               else
+                       n = buflen > 21 ? buffer[21] : 0;
+
+               n = n ? n : 3;
+
+               if (buflen < 26 + 4*n) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d FRAME error\n", dev->udev->devnum,
+                              alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               frame->bFrameIndex = buffer[3];
+               frame->bmCapabilities = buffer[4];
+               frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
+               frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
+               frame->dwMinBitRate = le32_to_cpup((__le32 *)&buffer[9]);
+               frame->dwMaxBitRate = le32_to_cpup((__le32 *)&buffer[13]);
+               if (ftype != VS_FRAME_FRAME_BASED) {
+                       frame->dwMaxVideoFrameBufferSize =
+                               le32_to_cpup((__le32 *)&buffer[17]);
+                       frame->dwDefaultFrameInterval =
+                               le32_to_cpup((__le32 *)&buffer[21]);
+                       frame->bFrameIntervalType = buffer[25];
+               } else {
+                       frame->dwMaxVideoFrameBufferSize = 0;
+                       frame->dwDefaultFrameInterval =
+                               le32_to_cpup((__le32 *)&buffer[17]);
+                       frame->bFrameIntervalType = buffer[21];
+               }
+               frame->dwFrameInterval = *intervals;
+
+               /* Several UVC chipsets screw up dwMaxVideoFrameBufferSize
+                * completely. Observed behaviours range from setting the
+                * value to 1.1x the actual frame size of hardwiring the
+                * 16 low bits to 0. This results in a higher than necessary
+                * memory usage as well as a wrong image size information. For
+                * uncompressed formats this can be fixed by computing the
+                * value from the frame size.
+                */
+               if (!(format->flags & UVC_FMT_FLAG_COMPRESSED))
+                       frame->dwMaxVideoFrameBufferSize = format->bpp
+                               * frame->wWidth * frame->wHeight / 8;
+
+               /* Some bogus devices report dwMinFrameInterval equal to
+                * dwMaxFrameInterval and have dwFrameIntervalStep set to
+                * zero. Setting all null intervals to 1 fixes the problem and
+                * some other divisions by zero which could happen.
+                */
+               for (i = 0; i < n; ++i) {
+                       interval = le32_to_cpup((__le32 *)&buffer[26+4*i]);
+                       *(*intervals)++ = interval ? interval : 1;
+               }
+
+               /* Make sure that the default frame interval stays between
+                * the boundaries.
+                */
+               n -= frame->bFrameIntervalType ? 1 : 2;
+               frame->dwDefaultFrameInterval =
+                       min(frame->dwFrameInterval[n],
+                           max(frame->dwFrameInterval[0],
+                               frame->dwDefaultFrameInterval));
+
+               uvc_trace(UVC_TRACE_DESCR, "- %ux%u (%u.%u fps)\n",
+                       frame->wWidth, frame->wHeight,
+                       10000000/frame->dwDefaultFrameInterval,
+                       (100000000/frame->dwDefaultFrameInterval)%10);
+
+               format->nframes++;
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       if (buflen > 2 && buffer[2] == VS_STILL_IMAGE_FRAME) {
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       if (buflen > 2 && buffer[2] == VS_COLORFORMAT) {
+               if (buflen < 6) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+                              "interface %d COLORFORMAT error\n",
+                              dev->udev->devnum,
+                              alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               format->colorspace = uvc_colorspace(buffer[3]);
+
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       return buffer - start;
+}
+
+static int uvc_parse_streaming(struct uvc_device *dev,
+       struct usb_interface *intf)
+{
+       struct uvc_streaming *streaming = NULL;
+       struct uvc_format *format;
+       struct uvc_frame *frame;
+       struct usb_host_interface *alts = &intf->altsetting[0];
+       unsigned char *_buffer, *buffer = alts->extra;
+       int _buflen, buflen = alts->extralen;
+       unsigned int nformats = 0, nframes = 0, nintervals = 0;
+       unsigned int size, i, n, p;
+       __u32 *interval;
+       __u16 psize;
+       int ret = -EINVAL;
+
+       if (intf->cur_altsetting->desc.bInterfaceSubClass
+               != SC_VIDEOSTREAMING) {
+               uvc_trace(UVC_TRACE_DESCR, "device %d interface %d isn't a "
+                       "video streaming interface\n", dev->udev->devnum,
+                       intf->altsetting[0].desc.bInterfaceNumber);
+               return -EINVAL;
+       }
+
+       if (usb_driver_claim_interface(&uvc_driver.driver, intf, dev)) {
+               uvc_trace(UVC_TRACE_DESCR, "device %d interface %d is already "
+                       "claimed\n", dev->udev->devnum,
+                       intf->altsetting[0].desc.bInterfaceNumber);
+               return -EINVAL;
+       }
+
+       streaming = kzalloc(sizeof *streaming, GFP_KERNEL);
+       if (streaming == NULL) {
+               usb_driver_release_interface(&uvc_driver.driver, intf);
+               return -EINVAL;
+       }
+
+       mutex_init(&streaming->mutex);
+       streaming->intf = usb_get_intf(intf);
+       streaming->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+       /* The Pico iMage webcam has its class-specific interface descriptors
+        * after the endpoint descriptors.
+        */
+       if (buflen == 0) {
+               for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+                       struct usb_host_endpoint *ep = &alts->endpoint[i];
+
+                       if (ep->extralen == 0)
+                               continue;
+
+                       if (ep->extralen > 2 &&
+                           ep->extra[1] == USB_DT_CS_INTERFACE) {
+                               uvc_trace(UVC_TRACE_DESCR, "trying extra data "
+                                       "from endpoint %u.\n", i);
+                               buffer = alts->endpoint[i].extra;
+                               buflen = alts->endpoint[i].extralen;
+                               break;
+                       }
+               }
+       }
+
+       /* Skip the standard interface descriptors. */
+       while (buflen > 2 && buffer[1] != USB_DT_CS_INTERFACE) {
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       if (buflen <= 2) {
+               uvc_trace(UVC_TRACE_DESCR, "no class-specific streaming "
+                       "interface descriptors found.\n");
+               goto error;
+       }
+
+       /* Parse the header descriptor. */
+       if (buffer[2] == VS_OUTPUT_HEADER) {
+               uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+                       "%d OUTPUT HEADER descriptor is not supported.\n",
+                       dev->udev->devnum, alts->desc.bInterfaceNumber);
+               goto error;
+       } else if (buffer[2] == VS_INPUT_HEADER) {
+               p = buflen >= 5 ? buffer[3] : 0;
+               n = buflen >= 12 ? buffer[12] : 0;
+
+               if (buflen < 13 + p*n || buffer[2] != VS_INPUT_HEADER) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+                               "interface %d INPUT HEADER descriptor is "
+                               "invalid.\n", dev->udev->devnum,
+                               alts->desc.bInterfaceNumber);
+                       goto error;
+               }
+
+               streaming->header.bNumFormats = p;
+               streaming->header.bEndpointAddress = buffer[6];
+               streaming->header.bmInfo = buffer[7];
+               streaming->header.bTerminalLink = buffer[8];
+               streaming->header.bStillCaptureMethod = buffer[9];
+               streaming->header.bTriggerSupport = buffer[10];
+               streaming->header.bTriggerUsage = buffer[11];
+               streaming->header.bControlSize = n;
+
+               streaming->header.bmaControls = kmalloc(p*n, GFP_KERNEL);
+               if (streaming->header.bmaControls == NULL) {
+                       ret = -ENOMEM;
+                       goto error;
+               }
+
+               memcpy(streaming->header.bmaControls, &buffer[13], p*n);
+       } else {
+               uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+                       "%d HEADER descriptor not found.\n", dev->udev->devnum,
+                       alts->desc.bInterfaceNumber);
+               goto error;
+       }
+
+       buflen -= buffer[0];
+       buffer += buffer[0];
+
+       _buffer = buffer;
+       _buflen = buflen;
+
+       /* Count the format and frame descriptors. */
+       while (_buflen > 2) {
+               switch (_buffer[2]) {
+               case VS_FORMAT_UNCOMPRESSED:
+               case VS_FORMAT_MJPEG:
+               case VS_FORMAT_FRAME_BASED:
+                       nformats++;
+                       break;
+
+               case VS_FORMAT_DV:
+                       /* DV format has no frame descriptor. We will create a
+                        * dummy frame descriptor with a dummy frame interval.
+                        */
+                       nformats++;
+                       nframes++;
+                       nintervals++;
+                       break;
+
+               case VS_FORMAT_MPEG2TS:
+               case VS_FORMAT_STREAM_BASED:
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+                               "interface %d FORMAT %u is not supported.\n",
+                               dev->udev->devnum,
+                               alts->desc.bInterfaceNumber, _buffer[2]);
+                       break;
+
+               case VS_FRAME_UNCOMPRESSED:
+               case VS_FRAME_MJPEG:
+                       nframes++;
+                       if (_buflen > 25)
+                               nintervals += _buffer[25] ? _buffer[25] : 3;
+                       break;
+
+               case VS_FRAME_FRAME_BASED:
+                       nframes++;
+                       if (_buflen > 21)
+                               nintervals += _buffer[21] ? _buffer[21] : 3;
+                       break;
+               }
+
+               _buflen -= _buffer[0];
+               _buffer += _buffer[0];
+       }
+
+       if (nformats == 0) {
+               uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+                       "%d has no supported formats defined.\n",
+                       dev->udev->devnum, alts->desc.bInterfaceNumber);
+               goto error;
+       }
+
+       size = nformats * sizeof *format + nframes * sizeof *frame
+            + nintervals * sizeof *interval;
+       format = kzalloc(size, GFP_KERNEL);
+       if (format == NULL) {
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       frame = (struct uvc_frame *)&format[nformats];
+       interval = (__u32 *)&frame[nframes];
+
+       streaming->format = format;
+       streaming->nformats = nformats;
+
+       /* Parse the format descriptors. */
+       while (buflen > 2) {
+               switch (buffer[2]) {
+               case VS_FORMAT_UNCOMPRESSED:
+               case VS_FORMAT_MJPEG:
+               case VS_FORMAT_DV:
+               case VS_FORMAT_FRAME_BASED:
+                       format->frame = frame;
+                       ret = uvc_parse_format(dev, streaming, format,
+                               &interval, buffer, buflen);
+                       if (ret < 0)
+                               goto error;
+
+                       frame += format->nframes;
+                       format++;
+
+                       buflen -= ret;
+                       buffer += ret;
+                       continue;
+
+               default:
+                       break;
+               }
+
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       /* Parse the alternate settings to find the maximum bandwidth. */
+       for (i = 0; i < intf->num_altsetting; ++i) {
+               struct usb_host_endpoint *ep;
+               alts = &intf->altsetting[i];
+               ep = uvc_find_endpoint(alts,
+                               streaming->header.bEndpointAddress);
+               if (ep == NULL)
+                       continue;
+
+               psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+               psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+               if (psize > streaming->maxpsize)
+                       streaming->maxpsize = psize;
+       }
+
+       list_add_tail(&streaming->list, &dev->streaming);
+       return 0;
+
+error:
+       usb_driver_release_interface(&uvc_driver.driver, intf);
+       usb_put_intf(intf);
+       kfree(streaming->format);
+       kfree(streaming->header.bmaControls);
+       kfree(streaming);
+       return ret;
+}
+
+/* Parse vendor-specific extensions. */
+static int uvc_parse_vendor_control(struct uvc_device *dev,
+       const unsigned char *buffer, int buflen)
+{
+       struct usb_device *udev = dev->udev;
+       struct usb_host_interface *alts = dev->intf->cur_altsetting;
+       struct uvc_entity *unit;
+       unsigned int n, p;
+       int handled = 0;
+
+       switch (le16_to_cpu(dev->udev->descriptor.idVendor)) {
+       case 0x046d:            /* Logitech */
+               if (buffer[1] != 0x41 || buffer[2] != 0x01)
+                       break;
+
+               /* Logitech implements several vendor specific functions
+                * through vendor specific extension units (LXU).
+                *
+                * The LXU descriptors are similar to XU descriptors
+                * (see "USB Device Video Class for Video Devices", section
+                * 3.7.2.6 "Extension Unit Descriptor") with the following
+                * differences:
+                *
+                * ----------------------------------------------------------
+                * 0            bLength         1        Number
+                *      Size of this descriptor, in bytes: 24+p+n*2
+                * ----------------------------------------------------------
+                * 23+p+n       bmControlsType  N       Bitmap
+                *      Individual bits in the set are defined:
+                *      0: Absolute
+                *      1: Relative
+                *
+                *      This bitset is mapped exactly the same as bmControls.
+                * ----------------------------------------------------------
+                * 23+p+n*2     bReserved       1       Boolean
+                * ----------------------------------------------------------
+                * 24+p+n*2     iExtension      1       Index
+                *      Index of a string descriptor that describes this
+                *      extension unit.
+                * ----------------------------------------------------------
+                */
+               p = buflen >= 22 ? buffer[21] : 0;
+               n = buflen >= 25 + p ? buffer[22+p] : 0;
+
+               if (buflen < 25 + p + 2*n) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d EXTENSION_UNIT error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       break;
+               }
+
+               unit = kzalloc(sizeof *unit + p + 2*n, GFP_KERNEL);
+               if (unit == NULL)
+                       return -ENOMEM;
+
+               unit->id = buffer[3];
+               unit->type = VC_EXTENSION_UNIT;
+               memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+               unit->extension.bNumControls = buffer[20];
+               unit->extension.bNrInPins =
+                       le16_to_cpup((__le16 *)&buffer[21]);
+               unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
+               memcpy(unit->extension.baSourceID, &buffer[22], p);
+               unit->extension.bControlSize = buffer[22+p];
+               unit->extension.bmControls = (__u8 *)unit + sizeof *unit + p;
+               unit->extension.bmControlsType = (__u8 *)unit + sizeof *unit
+                                              + p + n;
+               memcpy(unit->extension.bmControls, &buffer[23+p], 2*n);
+
+               if (buffer[24+p+2*n] != 0)
+                       usb_string(udev, buffer[24+p+2*n], unit->name,
+                                  sizeof unit->name);
+               else
+                       sprintf(unit->name, "Extension %u", buffer[3]);
+
+               list_add_tail(&unit->list, &dev->entities);
+               handled = 1;
+               break;
+       }
+
+       return handled;
+}
+
+static int uvc_parse_standard_control(struct uvc_device *dev,
+       const unsigned char *buffer, int buflen)
+{
+       struct usb_device *udev = dev->udev;
+       struct uvc_entity *unit, *term;
+       struct usb_interface *intf;
+       struct usb_host_interface *alts = dev->intf->cur_altsetting;
+       unsigned int i, n, p, len;
+       __u16 type;
+
+       switch (buffer[2]) {
+       case VC_HEADER:
+               n = buflen >= 12 ? buffer[11] : 0;
+
+               if (buflen < 12 || buflen < 12 + n) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d HEADER error\n", udev->devnum,
+                               alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               dev->uvc_version = le16_to_cpup((__le16 *)&buffer[3]);
+               dev->clock_frequency = le32_to_cpup((__le32 *)&buffer[7]);
+
+               /* Parse all USB Video Streaming interfaces. */
+               for (i = 0; i < n; ++i) {
+                       intf = usb_ifnum_to_if(udev, buffer[12+i]);
+                       if (intf == NULL) {
+                               uvc_trace(UVC_TRACE_DESCR, "device %d "
+                                       "interface %d doesn't exists\n",
+                                       udev->devnum, i);
+                               continue;
+                       }
+
+                       uvc_parse_streaming(dev, intf);
+               }
+               break;
+
+       case VC_INPUT_TERMINAL:
+               if (buflen < 8) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d INPUT_TERMINAL error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               /* Make sure the terminal type MSB is not null, otherwise it
+                * could be confused with a unit.
+                */
+               type = le16_to_cpup((__le16 *)&buffer[4]);
+               if ((type & 0xff00) == 0) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d INPUT_TERMINAL %d has invalid "
+                               "type 0x%04x, skipping\n", udev->devnum,
+                               alts->desc.bInterfaceNumber,
+                               buffer[3], type);
+                       return 0;
+               }
+
+               n = 0;
+               p = 0;
+               len = 8;
+
+               if (type == ITT_CAMERA) {
+                       n = buflen >= 15 ? buffer[14] : 0;
+                       len = 15;
+
+               } else if (type == ITT_MEDIA_TRANSPORT_INPUT) {
+                       n = buflen >= 9 ? buffer[8] : 0;
+                       p = buflen >= 10 + n ? buffer[9+n] : 0;
+                       len = 10;
+               }
+
+               if (buflen < len + n + p) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d INPUT_TERMINAL error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               term = kzalloc(sizeof *term + n + p, GFP_KERNEL);
+               if (term == NULL)
+                       return -ENOMEM;
+
+               term->id = buffer[3];
+               term->type = type | UVC_TERM_INPUT;
+
+               if (UVC_ENTITY_TYPE(term) == ITT_CAMERA) {
+                       term->camera.bControlSize = n;
+                       term->camera.bmControls = (__u8 *)term + sizeof *term;
+                       term->camera.wObjectiveFocalLengthMin =
+                               le16_to_cpup((__le16 *)&buffer[8]);
+                       term->camera.wObjectiveFocalLengthMax =
+                               le16_to_cpup((__le16 *)&buffer[10]);
+                       term->camera.wOcularFocalLength =
+                               le16_to_cpup((__le16 *)&buffer[12]);
+                       memcpy(term->camera.bmControls, &buffer[15], n);
+               } else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT) {
+                       term->media.bControlSize = n;
+                       term->media.bmControls = (__u8 *)term + sizeof *term;
+                       term->media.bTransportModeSize = p;
+                       term->media.bmTransportModes = (__u8 *)term
+                                                    + sizeof *term + n;
+                       memcpy(term->media.bmControls, &buffer[9], n);
+                       memcpy(term->media.bmTransportModes, &buffer[10+n], p);
+               }
+
+               if (buffer[7] != 0)
+                       usb_string(udev, buffer[7], term->name,
+                                  sizeof term->name);
+               else if (UVC_ENTITY_TYPE(term) == ITT_CAMERA)
+                       sprintf(term->name, "Camera %u", buffer[3]);
+               else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT)
+                       sprintf(term->name, "Media %u", buffer[3]);
+               else
+                       sprintf(term->name, "Input %u", buffer[3]);
+
+               list_add_tail(&term->list, &dev->entities);
+               break;
+
+       case VC_OUTPUT_TERMINAL:
+               if (buflen < 9) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d OUTPUT_TERMINAL error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               /* Make sure the terminal type MSB is not null, otherwise it
+                * could be confused with a unit.
+                */
+               type = le16_to_cpup((__le16 *)&buffer[4]);
+               if ((type & 0xff00) == 0) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d OUTPUT_TERMINAL %d has invalid "
+                               "type 0x%04x, skipping\n", udev->devnum,
+                               alts->desc.bInterfaceNumber, buffer[3], type);
+                       return 0;
+               }
+
+               term = kzalloc(sizeof *term, GFP_KERNEL);
+               if (term == NULL)
+                       return -ENOMEM;
+
+               term->id = buffer[3];
+               term->type = type | UVC_TERM_OUTPUT;
+               term->output.bSourceID = buffer[7];
+
+               if (buffer[8] != 0)
+                       usb_string(udev, buffer[8], term->name,
+                                  sizeof term->name);
+               else
+                       sprintf(term->name, "Output %u", buffer[3]);
+
+               list_add_tail(&term->list, &dev->entities);
+               break;
+
+       case VC_SELECTOR_UNIT:
+               p = buflen >= 5 ? buffer[4] : 0;
+
+               if (buflen < 5 || buflen < 6 + p) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d SELECTOR_UNIT error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               unit = kzalloc(sizeof *unit + p, GFP_KERNEL);
+               if (unit == NULL)
+                       return -ENOMEM;
+
+               unit->id = buffer[3];
+               unit->type = buffer[2];
+               unit->selector.bNrInPins = buffer[4];
+               unit->selector.baSourceID = (__u8 *)unit + sizeof *unit;
+               memcpy(unit->selector.baSourceID, &buffer[5], p);
+
+               if (buffer[5+p] != 0)
+                       usb_string(udev, buffer[5+p], unit->name,
+                                  sizeof unit->name);
+               else
+                       sprintf(unit->name, "Selector %u", buffer[3]);
+
+               list_add_tail(&unit->list, &dev->entities);
+               break;
+
+       case VC_PROCESSING_UNIT:
+               n = buflen >= 8 ? buffer[7] : 0;
+               p = dev->uvc_version >= 0x0110 ? 10 : 9;
+
+               if (buflen < p + n) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d PROCESSING_UNIT error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               unit = kzalloc(sizeof *unit + n, GFP_KERNEL);
+               if (unit == NULL)
+                       return -ENOMEM;
+
+               unit->id = buffer[3];
+               unit->type = buffer[2];
+               unit->processing.bSourceID = buffer[4];
+               unit->processing.wMaxMultiplier =
+                       le16_to_cpup((__le16 *)&buffer[5]);
+               unit->processing.bControlSize = buffer[7];
+               unit->processing.bmControls = (__u8 *)unit + sizeof *unit;
+               memcpy(unit->processing.bmControls, &buffer[8], n);
+               if (dev->uvc_version >= 0x0110)
+                       unit->processing.bmVideoStandards = buffer[9+n];
+
+               if (buffer[8+n] != 0)
+                       usb_string(udev, buffer[8+n], unit->name,
+                                  sizeof unit->name);
+               else
+                       sprintf(unit->name, "Processing %u", buffer[3]);
+
+               list_add_tail(&unit->list, &dev->entities);
+               break;
+
+       case VC_EXTENSION_UNIT:
+               p = buflen >= 22 ? buffer[21] : 0;
+               n = buflen >= 24 + p ? buffer[22+p] : 0;
+
+               if (buflen < 24 + p + n) {
+                       uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+                               "interface %d EXTENSION_UNIT error\n",
+                               udev->devnum, alts->desc.bInterfaceNumber);
+                       return -EINVAL;
+               }
+
+               unit = kzalloc(sizeof *unit + p + n, GFP_KERNEL);
+               if (unit == NULL)
+                       return -ENOMEM;
+
+               unit->id = buffer[3];
+               unit->type = buffer[2];
+               memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+               unit->extension.bNumControls = buffer[20];
+               unit->extension.bNrInPins =
+                       le16_to_cpup((__le16 *)&buffer[21]);
+               unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
+               memcpy(unit->extension.baSourceID, &buffer[22], p);
+               unit->extension.bControlSize = buffer[22+p];
+               unit->extension.bmControls = (__u8 *)unit + sizeof *unit + p;
+               memcpy(unit->extension.bmControls, &buffer[23+p], n);
+
+               if (buffer[23+p+n] != 0)
+                       usb_string(udev, buffer[23+p+n], unit->name,
+                                  sizeof unit->name);
+               else
+                       sprintf(unit->name, "Extension %u", buffer[3]);
+
+               list_add_tail(&unit->list, &dev->entities);
+               break;
+
+       default:
+               uvc_trace(UVC_TRACE_DESCR, "Found an unknown CS_INTERFACE "
+                       "descriptor (%u)\n", buffer[2]);
+               break;
+       }
+
+       return 0;
+}
+
+static int uvc_parse_control(struct uvc_device *dev)
+{
+       struct usb_host_interface *alts = dev->intf->cur_altsetting;
+       unsigned char *buffer = alts->extra;
+       int buflen = alts->extralen;
+       int ret;
+
+       /* Parse the default alternate setting only, as the UVC specification
+        * defines a single alternate setting, the default alternate setting
+        * zero.
+        */
+
+       while (buflen > 2) {
+               if (uvc_parse_vendor_control(dev, buffer, buflen) ||
+                   buffer[1] != USB_DT_CS_INTERFACE)
+                       goto next_descriptor;
+
+               if ((ret = uvc_parse_standard_control(dev, buffer, buflen)) < 0)
+                       return ret;
+
+next_descriptor:
+               buflen -= buffer[0];
+               buffer += buffer[0];
+       }
+
+       /* Check if the optional status endpoint is present. */
+       if (alts->desc.bNumEndpoints == 1) {
+               struct usb_host_endpoint *ep = &alts->endpoint[0];
+               struct usb_endpoint_descriptor *desc = &ep->desc;
+
+               if (usb_endpoint_is_int_in(desc) &&
+                   le16_to_cpu(desc->wMaxPacketSize) >= 8 &&
+                   desc->bInterval != 0) {
+                       uvc_trace(UVC_TRACE_DESCR, "Found a Status endpoint "
+                               "(addr %02x).\n", desc->bEndpointAddress);
+                       dev->int_ep = ep;
+               }
+       }
+
+       return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * USB probe and disconnect
+ */
+
+/*
+ * Unregister the video devices.
+ */
+static void uvc_unregister_video(struct uvc_device *dev)
+{
+       if (dev->video.vdev) {
+               if (dev->video.vdev->minor == -1)
+                       video_device_release(dev->video.vdev);
+               else
+                       video_unregister_device(dev->video.vdev);
+               dev->video.vdev = NULL;
+       }
+}
+
+/*
+ * Scan the UVC descriptors to locate a chain starting at an Output Terminal
+ * and containing the following units:
+ *
+ * - a USB Streaming Output Terminal
+ * - zero or one Processing Unit
+ * - zero, one or mode single-input Selector Units
+ * - zero or one multiple-input Selector Units, provided all inputs are
+ *   connected to input terminals
+ * - zero, one or mode single-input Extension Units
+ * - one Camera Input Terminal, or one or more External terminals.
+ *
+ * A side forward scan is made on each detected entity to check for additional
+ * extension units.
+ */
+static int uvc_scan_chain_entity(struct uvc_video_device *video,
+       struct uvc_entity *entity)
+{
+       switch (UVC_ENTITY_TYPE(entity)) {
+       case VC_EXTENSION_UNIT:
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk(" <- XU %d", entity->id);
+
+               if (entity->extension.bNrInPins != 1) {
+                       uvc_trace(UVC_TRACE_DESCR, "Extension unit %d has more "
+                               "than 1 input pin.\n", entity->id);
+                       return -1;
+               }
+
+               list_add_tail(&entity->chain, &video->extensions);
+               break;
+
+       case VC_PROCESSING_UNIT:
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk(" <- PU %d", entity->id);
+
+               if (video->processing != NULL) {
+                       uvc_trace(UVC_TRACE_DESCR, "Found multiple "
+                               "Processing Units in chain.\n");
+                       return -1;
+               }
+
+               video->processing = entity;
+               break;
+
+       case VC_SELECTOR_UNIT:
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk(" <- SU %d", entity->id);
+
+               /* Single-input selector units are ignored. */
+               if (entity->selector.bNrInPins == 1)
+                       break;
+
+               if (video->selector != NULL) {
+                       uvc_trace(UVC_TRACE_DESCR, "Found multiple Selector "
+                               "Units in chain.\n");
+                       return -1;
+               }
+
+               video->selector = entity;
+               break;
+
+       case ITT_VENDOR_SPECIFIC:
+       case ITT_CAMERA:
+       case ITT_MEDIA_TRANSPORT_INPUT:
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk(" <- IT %d\n", entity->id);
+
+               list_add_tail(&entity->chain, &video->iterms);
+               break;
+
+       default:
+               uvc_trace(UVC_TRACE_DESCR, "Unsupported entity type "
+                       "0x%04x found in chain.\n", UVC_ENTITY_TYPE(entity));
+               return -1;
+       }
+
+       return 0;
+}
+
+static int uvc_scan_chain_forward(struct uvc_video_device *video,
+       struct uvc_entity *entity, struct uvc_entity *prev)
+{
+       struct uvc_entity *forward;
+       int found;
+
+       /* Forward scan */
+       forward = NULL;
+       found = 0;
+
+       while (1) {
+               forward = uvc_entity_by_reference(video->dev, entity->id,
+                       forward);
+               if (forward == NULL)
+                       break;
+
+               if (UVC_ENTITY_TYPE(forward) != VC_EXTENSION_UNIT ||
+                   forward == prev)
+                       continue;
+
+               if (forward->extension.bNrInPins != 1) {
+                       uvc_trace(UVC_TRACE_DESCR, "Extension unit %d has"
+                               "more than 1 input pin.\n", entity->id);
+                       return -1;
+               }
+
+               list_add_tail(&forward->chain, &video->extensions);
+               if (uvc_trace_param & UVC_TRACE_PROBE) {
+                       if (!found)
+                               printk(" (-> XU");
+
+                       printk(" %d", forward->id);
+                       found = 1;
+               }
+       }
+       if (found)
+               printk(")");
+
+       return 0;
+}
+
+static int uvc_scan_chain_backward(struct uvc_video_device *video,
+       struct uvc_entity *entity)
+{
+       struct uvc_entity *term;
+       int id = -1, i;
+
+       switch (UVC_ENTITY_TYPE(entity)) {
+       case VC_EXTENSION_UNIT:
+               id = entity->extension.baSourceID[0];
+               break;
+
+       case VC_PROCESSING_UNIT:
+               id = entity->processing.bSourceID;
+               break;
+
+       case VC_SELECTOR_UNIT:
+               /* Single-input selector units are ignored. */
+               if (entity->selector.bNrInPins == 1) {
+                       id = entity->selector.baSourceID[0];
+                       break;
+               }
+
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk(" <- IT");
+
+               video->selector = entity;
+               for (i = 0; i < entity->selector.bNrInPins; ++i) {
+                       id = entity->selector.baSourceID[i];
+                       term = uvc_entity_by_id(video->dev, id);
+                       if (term == NULL || !UVC_ENTITY_IS_ITERM(term)) {
+                               uvc_trace(UVC_TRACE_DESCR, "Selector unit %d "
+                                       "input %d isn't connected to an "
+                                       "input terminal\n", entity->id, i);
+                               return -1;
+                       }
+
+                       if (uvc_trace_param & UVC_TRACE_PROBE)
+                               printk(" %d", term->id);
+
+                       list_add_tail(&term->chain, &video->iterms);
+                       uvc_scan_chain_forward(video, term, entity);
+               }
+
+               if (uvc_trace_param & UVC_TRACE_PROBE)
+                       printk("\n");
+
+               id = 0;
+               break;
+       }
+
+       return id;
+}
+
+static int uvc_scan_chain(struct uvc_video_device *video)
+{
+       struct uvc_entity *entity, *prev;
+       int id;
+
+       entity = video->oterm;
+       uvc_trace(UVC_TRACE_PROBE, "Scanning UVC chain: OT %d", entity->id);
+       id = entity->output.bSourceID;
+       while (id != 0) {
+               prev = entity;
+               entity = uvc_entity_by_id(video->dev, id);
+               if (entity == NULL) {
+                       uvc_trace(UVC_TRACE_DESCR, "Found reference to "
+                               "unknown entity %d.\n", id);
+                       return -1;
+               }
+
+               /* Process entity */
+               if (uvc_scan_chain_entity(video, entity) < 0)
+                       return -1;
+
+               /* Forward scan */
+               if (uvc_scan_chain_forward(video, entity, prev) < 0)
+                       return -1;
+
+               /* Stop when a terminal is found. */
+               if (!UVC_ENTITY_IS_UNIT(entity))
+                       break;
+
+               /* Backward scan */
+               id = uvc_scan_chain_backward(video, entity);
+               if (id < 0)
+                       return id;
+       }
+
+       /* Initialize the video buffers queue. */
+       uvc_queue_init(&video->queue);
+
+       return 0;
+}
+
+/*
+ * Register the video devices.
+ *
+ * The driver currently supports a single video device per control interface
+ * only. The terminal and units must match the following structure:
+ *
+ * ITT_CAMERA -> VC_PROCESSING_UNIT -> VC_EXTENSION_UNIT{0,n} -> TT_STREAMING
+ *
+ * The Extension Units, if present, must have a single input pin. The
+ * Processing Unit and Extension Units can be in any order. Additional
+ * Extension Units connected to the main chain as single-unit branches are
+ * also supported.
+ */
+static int uvc_register_video(struct uvc_device *dev)
+{
+       struct video_device *vdev;
+       struct uvc_entity *term;
+       int found = 0, ret;
+
+       /* Check if the control interface matches the structure we expect. */
+       list_for_each_entry(term, &dev->entities, list) {
+               struct uvc_streaming *streaming;
+
+               if (UVC_ENTITY_TYPE(term) != TT_STREAMING)
+                       continue;
+
+               memset(&dev->video, 0, sizeof dev->video);
+               mutex_init(&dev->video.ctrl_mutex);
+               INIT_LIST_HEAD(&dev->video.iterms);
+               INIT_LIST_HEAD(&dev->video.extensions);
+               dev->video.oterm = term;
+               dev->video.dev = dev;
+               if (uvc_scan_chain(&dev->video) < 0)
+                       continue;
+
+               list_for_each_entry(streaming, &dev->streaming, list) {
+                       if (streaming->header.bTerminalLink == term->id) {
+                               dev->video.streaming = streaming;
+                               found = 1;
+                               break;
+                       }
+               }
+
+               if (found)
+                       break;
+       }
+
+       if (!found) {
+               uvc_printk(KERN_INFO, "No valid video chain found.\n");
+               return -1;
+       }
+
+       if (uvc_trace_param & UVC_TRACE_PROBE) {
+               uvc_printk(KERN_INFO, "Found a valid video chain (");
+               list_for_each_entry(term, &dev->video.iterms, chain) {
+                       printk("%d", term->id);
+                       if (term->chain.next != &dev->video.iterms)
+                               printk(",");
+               }
+               printk(" -> %d).\n", dev->video.oterm->id);
+       }
+
+       /* Initialize the streaming interface with default streaming
+        * parameters.
+        */
+       if ((ret = uvc_video_init(&dev->video)) < 0) {
+               uvc_printk(KERN_ERR, "Failed to initialize the device "
+                       "(%d).\n", ret);
+               return ret;
+       }
+
+       /* Register the device with V4L. */
+       vdev = video_device_alloc();
+       if (vdev == NULL)
+               return -1;
+
+       /* We already hold a reference to dev->udev. The video device will be
+        * unregistered before the reference is released, so we don't need to
+        * get another one.
+        */
+       vdev->dev = &dev->intf->dev;
+       vdev->type = 0;
+       vdev->type2 = 0;
+       vdev->minor = -1;
+       vdev->fops = &uvc_fops;
+       vdev->release = video_device_release;
+       strncpy(vdev->name, dev->name, sizeof vdev->name);
+
+       /* Set the driver data before calling video_register_device, otherwise
+        * uvc_v4l2_open might race us.
+        *
+        * FIXME: usb_set_intfdata hasn't been called so far. Is that a
+        *        problem ? Does any function which could be called here get
+        *        a pointer to the usb_interface ?
+        */
+       dev->video.vdev = vdev;
+       video_set_drvdata(vdev, &dev->video);
+
+       if (video_register_device(vdev, VFL_TYPE_GRABBER, -1) < 0) {
+               dev->video.vdev = NULL;
+               video_device_release(vdev);
+               return -1;
+       }
+
+       return 0;
+}
+
+/*
+ * Delete the UVC device.
+ *
+ * Called by the kernel when the last reference to the uvc_device structure
+ * is released.
+ *
+ * Unregistering the video devices is done here because every opened instance
+ * must be closed before the device can be unregistered. An alternative would
+ * have been to use another reference count for uvc_v4l2_open/uvc_release, and
+ * unregister the video devices on disconnect when that reference count drops
+ * to zero.
+ *
+ * As this function is called after or during disconnect(), all URBs have
+ * already been canceled by the USB core. There is no need to kill the
+ * interrupt URB manually.
+ */
+void uvc_delete(struct kref *kref)
+{
+       struct uvc_device *dev = container_of(kref, struct uvc_device, kref);
+       struct list_head *p, *n;
+
+       /* Unregister the video device */
+       uvc_unregister_video(dev);
+       usb_put_intf(dev->intf);
+       usb_put_dev(dev->udev);
+
+       uvc_status_cleanup(dev);
+       uvc_ctrl_cleanup_device(dev);
+
+       list_for_each_safe(p, n, &dev->entities) {
+               struct uvc_entity *entity;
+               entity = list_entry(p, struct uvc_entity, list);
+               kfree(entity);
+       }
+
+       list_for_each_safe(p, n, &dev->streaming) {
+               struct uvc_streaming *streaming;
+               streaming = list_entry(p, struct uvc_streaming, list);
+               usb_driver_release_interface(&uvc_driver.driver,
+                       streaming->intf);
+               usb_put_intf(streaming->intf);
+               kfree(streaming->format);
+               kfree(streaming->header.bmaControls);
+               kfree(streaming);
+       }
+
+       kfree(dev);
+}
+
+static int uvc_probe(struct usb_interface *intf,
+                    const struct usb_device_id *id)
+{
+       struct usb_device *udev = interface_to_usbdev(intf);
+       struct uvc_device *dev;
+       int ret;
+
+       if (id->idVendor && id->idProduct)
+               uvc_trace(UVC_TRACE_PROBE, "Probing known UVC device %s "
+                               "(%04x:%04x)\n", udev->devpath, id->idVendor,
+                               id->idProduct);
+       else
+               uvc_trace(UVC_TRACE_PROBE, "Probing generic UVC device %s\n",
+                               udev->devpath);
+
+       /* Allocate memory for the device and initialize it */
+       if ((dev = kzalloc(sizeof *dev, GFP_KERNEL)) == NULL)
+               return -ENOMEM;
+
+       INIT_LIST_HEAD(&dev->entities);
+       INIT_LIST_HEAD(&dev->streaming);
+       kref_init(&dev->kref);
+
+       dev->udev = usb_get_dev(udev);
+       dev->intf = usb_get_intf(intf);
+       dev->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+       dev->quirks = id->driver_info | uvc_quirks_param;
+
+       if (udev->product != NULL)
+               strncpy(dev->name, udev->product, sizeof dev->name);
+       else
+               snprintf(dev->name, sizeof dev->name,
+                       "UVC Camera (%04x:%04x)",
+                       le16_to_cpu(udev->descriptor.idVendor),
+                       le16_to_cpu(udev->descriptor.idProduct));
+
+       /* Parse the Video Class control descriptor */
+       if (uvc_parse_control(dev) < 0) {
+               uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC "
+                       "descriptors.\n");
+               goto error;
+       }
+
+       uvc_printk(KERN_INFO, "Found UVC %u.%02u device %s (%04x:%04x)\n",
+               dev->uvc_version >> 8, dev->uvc_version & 0xff,
+               udev->product ? udev->product : "<unnamed>",
+               le16_to_cpu(udev->descriptor.idVendor),
+               le16_to_cpu(udev->descriptor.idProduct));
+
+       if (uvc_quirks_param != 0) {
+               uvc_printk(KERN_INFO, "Forcing device quirks 0x%x by module "
+                       "parameter for testing purpose.\n", uvc_quirks_param);
+               uvc_printk(KERN_INFO, "Please report required quirks to the "
+                       "linux-uvc-devel mailing list.\n");
+       }
+
+       /* Initialize controls */
+       if (uvc_ctrl_init_device(dev) < 0)
+               goto error;
+
+       /* Register the video devices */
+       if (uvc_register_video(dev) < 0)
+               goto error;
+
+       /* Save our data pointer in the interface data */
+       usb_set_intfdata(intf, dev);
+
+       /* Initialize the interrupt URB */
+       if ((ret = uvc_status_init(dev)) < 0) {
+               uvc_printk(KERN_INFO, "Unable to initialize the status "
+                       "endpoint (%d), status interrupt will not be "
+                       "supported.\n", ret);
+       }
+
+       uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
+       return 0;
+
+error:
+       kref_put(&dev->kref, uvc_delete);
+       return -ENODEV;
+}
+
+static void uvc_disconnect(struct usb_interface *intf)
+{
+       struct uvc_device *dev = usb_get_intfdata(intf);
+
+       /* Set the USB interface data to NULL. This can be done outside the
+        * lock, as there's no other reader.
+        */
+       usb_set_intfdata(intf, NULL);
+
+       if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOSTREAMING)
+               return;
+
+       /* uvc_v4l2_open() might race uvc_disconnect(). A static driver-wide
+        * lock is needed to prevent uvc_disconnect from releasing its
+        * reference to the uvc_device instance after uvc_v4l2_open() received
+        * the pointer to the device (video_devdata) but before it got the
+        * chance to increase the reference count (kref_get).
+        */
+       mutex_lock(&uvc_driver.open_mutex);
+
+       dev->state |= UVC_DEV_DISCONNECTED;
+       kref_put(&dev->kref, uvc_delete);
+
+       mutex_unlock(&uvc_driver.open_mutex);
+}
+
+static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
+{
+       struct uvc_device *dev = usb_get_intfdata(intf);
+
+       uvc_trace(UVC_TRACE_SUSPEND, "Suspending interface %u\n",
+               intf->cur_altsetting->desc.bInterfaceNumber);
+
+       /* Controls are cached on the fly so they don't need to be saved. */
+       if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL)
+               return uvc_status_suspend(dev);
+
+       if (dev->video.streaming->intf != intf) {
+               uvc_trace(UVC_TRACE_SUSPEND, "Suspend: video streaming USB "
+                               "interface mismatch.\n");
+               return -EINVAL;
+       }
+
+       return uvc_video_suspend(&dev->video);
+}
+
+static int uvc_resume(struct usb_interface *intf)
+{
+       struct uvc_device *dev = usb_get_intfdata(intf);
+       int ret;
+
+       uvc_trace(UVC_TRACE_SUSPEND, "Resuming interface %u\n",
+               intf->cur_altsetting->desc.bInterfaceNumber);
+
+       if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL) {
+               if ((ret = uvc_ctrl_resume_device(dev)) < 0)
+                       return ret;
+
+               return uvc_status_resume(dev);
+       }
+
+       if (dev->video.streaming->intf != intf) {
+               uvc_trace(UVC_TRACE_SUSPEND, "Resume: video streaming USB "
+                               "interface mismatch.\n");
+               return -EINVAL;
+       }
+
+       return uvc_video_resume(&dev->video);
+}
+
+/* ------------------------------------------------------------------------
+ * Driver initialization and cleanup
+ */
+
+/*
+ * The Logitech cameras listed below have their interface class set to
+ * VENDOR_SPEC because they don't announce themselves as UVC devices, even
+ * though they are compliant.
+ */
+static struct usb_device_id uvc_ids[] = {
+       /* ALi M5606 (Clevo M540SR) */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x0402,
+         .idProduct            = 0x5606,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Creative Live! Optia */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x041e,
+         .idProduct            = 0x4057,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Microsoft Lifecam NX-6000 */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x045e,
+         .idProduct            = 0x00f8,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Microsoft Lifecam VX-7000 */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x045e,
+         .idProduct            = 0x0723,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Logitech Quickcam Fusion */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c1,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Logitech Quickcam Orbit MP */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c2,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Logitech Quickcam Pro for Notebook */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c3,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Logitech Quickcam Pro 5000 */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c5,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Logitech Quickcam OEM Dell Notebook */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c6,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Logitech Quickcam OEM Cisco VT Camera II */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x046d,
+         .idProduct            = 0x08c7,
+         .bInterfaceClass      = USB_CLASS_VENDOR_SPEC,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0 },
+       /* Apple Built-In iSight */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x05ac,
+         .idProduct            = 0x8501,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX
+                               | UVC_QUIRK_BUILTIN_ISIGHT },
+       /* Genesys Logic USB 2.0 PC Camera */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x05e3,
+         .idProduct            = 0x0505,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_STREAM_NO_FID },
+       /* Silicon Motion SM371 */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x090c,
+         .idProduct            = 0xb371,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* MT6227 */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x0e8d,
+         .idProduct            = 0x0004,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Syntek (HP Spartan) */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x174f,
+         .idProduct            = 0x5212,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_STREAM_NO_FID },
+       /* Syntek (Asus U3S) */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x174f,
+         .idProduct            = 0x8a33,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_STREAM_NO_FID },
+       /* Ecamm Pico iMage */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x18cd,
+         .idProduct            = 0xcafe,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_EXTRAFIELDS },
+       /* Bodelin ProScopeHR */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_DEV_HI
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x19ab,
+         .idProduct            = 0x1000,
+         .bcdDevice_hi         = 0x0126,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_STATUS_INTERVAL },
+       /* SiGma Micro USB Web Camera */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x1c4f,
+         .idProduct            = 0x3000,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX
+                               | UVC_QUIRK_IGNORE_SELECTOR_UNIT},
+       /* Acer OEM Webcam - Unknown vendor */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x5986,
+         .idProduct            = 0x0100,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Packard Bell OEM Webcam */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x5986,
+         .idProduct            = 0x0101,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Acer Crystal Eye webcam */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x5986,
+         .idProduct            = 0x0102,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Acer OrbiCam - Unknown vendor */
+       { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x5986,
+         .idProduct            = 0x0200,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_PROBE_MINMAX },
+       /* Generic USB Video Class */
+       { USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
+       {}
+};
+
+MODULE_DEVICE_TABLE(usb, uvc_ids);
+
+struct uvc_driver uvc_driver = {
+       .driver = {
+               .name           = "uvcvideo",
+               .probe          = uvc_probe,
+               .disconnect     = uvc_disconnect,
+               .suspend        = uvc_suspend,
+               .resume         = uvc_resume,
+               .id_table       = uvc_ids,
+               .supports_autosuspend = 1,
+       },
+};
+
+static int __init uvc_init(void)
+{
+       int result;
+
+       INIT_LIST_HEAD(&uvc_driver.devices);
+       INIT_LIST_HEAD(&uvc_driver.controls);
+       mutex_init(&uvc_driver.open_mutex);
+       mutex_init(&uvc_driver.ctrl_mutex);
+
+       uvc_ctrl_init();
+
+       result = usb_register(&uvc_driver.driver);
+       if (result == 0)
+               printk(KERN_INFO DRIVER_DESC " (" DRIVER_VERSION ")\n");
+       return result;
+}
+
+static void __exit uvc_cleanup(void)
+{
+       usb_deregister(&uvc_driver.driver);
+}
+
+module_init(uvc_init);
+module_exit(uvc_cleanup);
+
+module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(quirks, "Forced device quirks");
+module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(trace, "Trace level bitmask");
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
diff --git a/drivers/media/video/uvc/uvc_isight.c b/drivers/media/video/uvc/uvc_isight.c
new file mode 100644 (file)
index 0000000..37bdefd
--- /dev/null
@@ -0,0 +1,134 @@
+/*
+ *      uvc_isight.c  --  USB Video Class driver - iSight support
+ *
+ *     Copyright (C) 2006-2007
+ *             Ivan N. Zlatev <contact@i-nz.net>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/usb.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include "uvcvideo.h"
+
+/* Built-in iSight webcams implements most of UVC 1.0 except a
+ * different packet format. Instead of sending a header at the
+ * beginning of each isochronous transfer payload, the webcam sends a
+ * single header per image (on its own in a packet), followed by
+ * packets containing data only.
+ *
+ * Offset   Size (bytes)       Description
+ * ------------------------------------------------------------------
+ * 0x00        1       Header length
+ * 0x01        1       Flags (UVC-compliant)
+ * 0x02        4       Always equal to '11223344'
+ * 0x06        8       Always equal to 'deadbeefdeadface'
+ * 0x0e        16      Unknown
+ *
+ * The header can be prefixed by an optional, unknown-purpose byte.
+ */
+
+static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
+               const __u8 *data, unsigned int len)
+{
+       static const __u8 hdr[] = {
+               0x11, 0x22, 0x33, 0x44,
+               0xde, 0xad, 0xbe, 0xef,
+               0xde, 0xad, 0xfa, 0xce
+       };
+
+       unsigned int maxlen, nbytes;
+       __u8 *mem;
+       int is_header = 0;
+
+       if (buf == NULL)
+               return 0;
+
+       if ((len >= 14 && memcmp(&data[2], hdr, 12) == 0) ||
+           (len >= 15 && memcmp(&data[3], hdr, 12) == 0)) {
+               uvc_trace(UVC_TRACE_FRAME, "iSight header found\n");
+               is_header = 1;
+       }
+
+       /* Synchronize to the input stream by waiting for a header packet. */
+       if (buf->state != UVC_BUF_STATE_ACTIVE) {
+               if (!is_header) {
+                       uvc_trace(UVC_TRACE_FRAME, "Dropping packet (out of "
+                                 "sync).\n");
+                       return 0;
+               }
+
+               buf->state = UVC_BUF_STATE_ACTIVE;
+       }
+
+       /* Mark the buffer as done if we're at the beginning of a new frame.
+        *
+        * Empty buffers (bytesused == 0) don't trigger end of frame detection
+        * as it doesn't make sense to return an empty buffer.
+        */
+       if (is_header && buf->buf.bytesused != 0) {
+               buf->state = UVC_BUF_STATE_DONE;
+               return -EAGAIN;
+       }
+
+       /* Copy the video data to the buffer. Skip header packets, as they
+        * contain no data.
+        */
+       if (!is_header) {
+               maxlen = buf->buf.length - buf->buf.bytesused;
+               mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
+               nbytes = min(len, maxlen);
+               memcpy(mem, data, nbytes);
+               buf->buf.bytesused += nbytes;
+
+               if (len > maxlen || buf->buf.bytesused == buf->buf.length) {
+                       uvc_trace(UVC_TRACE_FRAME, "Frame complete "
+                                 "(overflow).\n");
+                       buf->state = UVC_BUF_STATE_DONE;
+               }
+       }
+
+       return 0;
+}
+
+void uvc_video_decode_isight(struct urb *urb, struct uvc_video_device *video,
+               struct uvc_buffer *buf)
+{
+       int ret, i;
+
+       for (i = 0; i < urb->number_of_packets; ++i) {
+               if (urb->iso_frame_desc[i].status < 0) {
+                       uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
+                                 "lost (%d).\n",
+                                 urb->iso_frame_desc[i].status);
+               }
+
+               /* Decode the payload packet.
+                * uvc_video_decode is entered twice when a frame transition
+                * has been detected because the end of frame can only be
+                * reliably detected when the first packet of the new frame
+                * is processed. The first pass detects the transition and
+                * closes the previous frame's buffer, the second pass
+                * processes the data of the first payload of the new frame.
+                */
+               do {
+                       ret = isight_decode(&video->queue, buf,
+                                       urb->transfer_buffer +
+                                       urb->iso_frame_desc[i].offset,
+                                       urb->iso_frame_desc[i].actual_length);
+
+                       if (buf == NULL)
+                               break;
+
+                       if (buf->state == UVC_BUF_STATE_DONE ||
+                           buf->state == UVC_BUF_STATE_ERROR)
+                               buf = uvc_queue_next_buffer(&video->queue, buf);
+               } while (ret == -EAGAIN);
+       }
+}
diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
new file mode 100644 (file)
index 0000000..0923f0e
--- /dev/null
@@ -0,0 +1,477 @@
+/*
+ *      uvc_queue.c  --  USB Video Class driver - Buffers management
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * Video buffers queue management.
+ *
+ * Video queues is initialized by uvc_queue_init(). The function performs
+ * basic initialization of the uvc_video_queue struct and never fails.
+ *
+ * Video buffer allocation and freeing are performed by uvc_alloc_buffers and
+ * uvc_free_buffers respectively. The former acquires the video queue lock,
+ * while the later must be called with the lock held (so that allocation can
+ * free previously allocated buffers). Trying to free buffers that are mapped
+ * to user space will return -EBUSY.
+ *
+ * Video buffers are managed using two queues. However, unlike most USB video
+ * drivers which use an in queue and an out queue, we use a main queue which
+ * holds all queued buffers (both 'empty' and 'done' buffers), and an irq
+ * queue which holds empty buffers. This design (copied from video-buf)
+ * minimizes locking in interrupt, as only one queue is shared between
+ * interrupt and user contexts.
+ *
+ * Use cases
+ * ---------
+ *
+ * Unless stated otherwise, all operations which modify the irq buffers queue
+ * are protected by the irq spinlock.
+ *
+ * 1. The user queues the buffers, starts streaming and dequeues a buffer.
+ *
+ *    The buffers are added to the main and irq queues. Both operations are
+ *    protected by the queue lock, and the latert is protected by the irq
+ *    spinlock as well.
+ *
+ *    The completion handler fetches a buffer from the irq queue and fills it
+ *    with video data. If no buffer is available (irq queue empty), the handler
+ *    returns immediately.
+ *
+ *    When the buffer is full, the completion handler removes it from the irq
+ *    queue, marks it as ready (UVC_BUF_STATE_DONE) and wake its wait queue.
+ *    At that point, any process waiting on the buffer will be woken up. If a
+ *    process tries to dequeue a buffer after it has been marked ready, the
+ *    dequeing will succeed immediately.
+ *
+ * 2. Buffers are queued, user is waiting on a buffer and the device gets
+ *    disconnected.
+ *
+ *    When the device is disconnected, the kernel calls the completion handler
+ *    with an appropriate status code. The handler marks all buffers in the
+ *    irq queue as being erroneous (UVC_BUF_STATE_ERROR) and wakes them up so
+ *    that any process waiting on a buffer gets woken up.
+ *
+ *    Waking up up the first buffer on the irq list is not enough, as the
+ *    process waiting on the buffer might restart the dequeue operation
+ *    immediately.
+ *
+ */
+
+void uvc_queue_init(struct uvc_video_queue *queue)
+{
+       mutex_init(&queue->mutex);
+       spin_lock_init(&queue->irqlock);
+       INIT_LIST_HEAD(&queue->mainqueue);
+       INIT_LIST_HEAD(&queue->irqqueue);
+}
+
+/*
+ * Allocate the video buffers.
+ *
+ * Pages are reserved to make sure they will not be swaped, as they will be
+ * filled in URB completion handler.
+ *
+ * Buffers will be individually mapped, so they must all be page aligned.
+ */
+int uvc_alloc_buffers(struct uvc_video_queue *queue, unsigned int nbuffers,
+               unsigned int buflength)
+{
+       unsigned int bufsize = PAGE_ALIGN(buflength);
+       unsigned int i;
+       void *mem = NULL;
+       int ret;
+
+       if (nbuffers > UVC_MAX_VIDEO_BUFFERS)
+               nbuffers = UVC_MAX_VIDEO_BUFFERS;
+
+       mutex_lock(&queue->mutex);
+
+       if ((ret = uvc_free_buffers(queue)) < 0)
+               goto done;
+
+       /* Bail out if no buffers should be allocated. */
+       if (nbuffers == 0)
+               goto done;
+
+       /* Decrement the number of buffers until allocation succeeds. */
+       for (; nbuffers > 0; --nbuffers) {
+               mem = vmalloc_32(nbuffers * bufsize);
+               if (mem != NULL)
+                       break;
+       }
+
+       if (mem == NULL) {
+               ret = -ENOMEM;
+               goto done;
+       }
+
+       for (i = 0; i < nbuffers; ++i) {
+               memset(&queue->buffer[i], 0, sizeof queue->buffer[i]);
+               queue->buffer[i].buf.index = i;
+               queue->buffer[i].buf.m.offset = i * bufsize;
+               queue->buffer[i].buf.length = buflength;
+               queue->buffer[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+               queue->buffer[i].buf.sequence = 0;
+               queue->buffer[i].buf.field = V4L2_FIELD_NONE;
+               queue->buffer[i].buf.memory = V4L2_MEMORY_MMAP;
+               queue->buffer[i].buf.flags = 0;
+               init_waitqueue_head(&queue->buffer[i].wait);
+       }
+
+       queue->mem = mem;
+       queue->count = nbuffers;
+       queue->buf_size = bufsize;
+       ret = nbuffers;
+
+done:
+       mutex_unlock(&queue->mutex);
+       return ret;
+}
+
+/*
+ * Free the video buffers.
+ *
+ * This function must be called with the queue lock held.
+ */
+int uvc_free_buffers(struct uvc_video_queue *queue)
+{
+       unsigned int i;
+
+       for (i = 0; i < queue->count; ++i) {
+               if (queue->buffer[i].vma_use_count != 0)
+                       return -EBUSY;
+       }
+
+       if (queue->count) {
+               vfree(queue->mem);
+               queue->count = 0;
+       }
+
+       return 0;
+}
+
+static void __uvc_query_buffer(struct uvc_buffer *buf,
+               struct v4l2_buffer *v4l2_buf)
+{
+       memcpy(v4l2_buf, &buf->buf, sizeof *v4l2_buf);
+
+       if (buf->vma_use_count)
+               v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED;
+
+       switch (buf->state) {
+       case UVC_BUF_STATE_ERROR:
+       case UVC_BUF_STATE_DONE:
+               v4l2_buf->flags |= V4L2_BUF_FLAG_DONE;
+               break;
+       case UVC_BUF_STATE_QUEUED:
+       case UVC_BUF_STATE_ACTIVE:
+               v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
+               break;
+       case UVC_BUF_STATE_IDLE:
+       default:
+               break;
+       }
+}
+
+int uvc_query_buffer(struct uvc_video_queue *queue,
+               struct v4l2_buffer *v4l2_buf)
+{
+       int ret = 0;
+
+       mutex_lock(&queue->mutex);
+       if (v4l2_buf->index >= queue->count) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       __uvc_query_buffer(&queue->buffer[v4l2_buf->index], v4l2_buf);
+
+done:
+       mutex_unlock(&queue->mutex);
+       return ret;
+}
+
+/*
+ * Queue a video buffer. Attempting to queue a buffer that has already been
+ * queued will return -EINVAL.
+ */
+int uvc_queue_buffer(struct uvc_video_queue *queue,
+       struct v4l2_buffer *v4l2_buf)
+{
+       struct uvc_buffer *buf;
+       unsigned long flags;
+       int ret = 0;
+
+       uvc_trace(UVC_TRACE_CAPTURE, "Queuing buffer %u.\n", v4l2_buf->index);
+
+       if (v4l2_buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+           v4l2_buf->memory != V4L2_MEMORY_MMAP) {
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
+                       "and/or memory (%u).\n", v4l2_buf->type,
+                       v4l2_buf->memory);
+               return -EINVAL;
+       }
+
+       mutex_lock(&queue->mutex);
+       if (v4l2_buf->index >= queue->count)  {
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Out of range index.\n");
+               ret = -EINVAL;
+               goto done;
+       }
+
+       buf = &queue->buffer[v4l2_buf->index];
+       if (buf->state != UVC_BUF_STATE_IDLE) {
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state "
+                       "(%u).\n", buf->state);
+               ret = -EINVAL;
+               goto done;
+       }
+
+       spin_lock_irqsave(&queue->irqlock, flags);
+       if (queue->flags & UVC_QUEUE_DISCONNECTED) {
+               spin_unlock_irqrestore(&queue->irqlock, flags);
+               ret = -ENODEV;
+               goto done;
+       }
+       buf->state = UVC_BUF_STATE_QUEUED;
+       buf->buf.bytesused = 0;
+       list_add_tail(&buf->stream, &queue->mainqueue);
+       list_add_tail(&buf->queue, &queue->irqqueue);
+       spin_unlock_irqrestore(&queue->irqlock, flags);
+
+done:
+       mutex_unlock(&queue->mutex);
+       return ret;
+}
+
+static int uvc_queue_waiton(struct uvc_buffer *buf, int nonblocking)
+{
+       if (nonblocking) {
+               return (buf->state != UVC_BUF_STATE_QUEUED &&
+                       buf->state != UVC_BUF_STATE_ACTIVE)
+                       ? 0 : -EAGAIN;
+       }
+
+       return wait_event_interruptible(buf->wait,
+               buf->state != UVC_BUF_STATE_QUEUED &&
+               buf->state != UVC_BUF_STATE_ACTIVE);
+}
+
+/*
+ * Dequeue a video buffer. If nonblocking is false, block until a buffer is
+ * available.
+ */
+int uvc_dequeue_buffer(struct uvc_video_queue *queue,
+               struct v4l2_buffer *v4l2_buf, int nonblocking)
+{
+       struct uvc_buffer *buf;
+       int ret = 0;
+
+       if (v4l2_buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+           v4l2_buf->memory != V4L2_MEMORY_MMAP) {
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
+                       "and/or memory (%u).\n", v4l2_buf->type,
+                       v4l2_buf->memory);
+               return -EINVAL;
+       }
+
+       mutex_lock(&queue->mutex);
+       if (list_empty(&queue->mainqueue)) {
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Empty buffer queue.\n");
+               ret = -EINVAL;
+               goto done;
+       }
+
+       buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
+       if ((ret = uvc_queue_waiton(buf, nonblocking)) < 0)
+               goto done;
+
+       uvc_trace(UVC_TRACE_CAPTURE, "Dequeuing buffer %u (%u, %u bytes).\n",
+               buf->buf.index, buf->state, buf->buf.bytesused);
+
+       switch (buf->state) {
+       case UVC_BUF_STATE_ERROR:
+               uvc_trace(UVC_TRACE_CAPTURE, "[W] Corrupted data "
+                       "(transmission error).\n");
+               ret = -EIO;
+       case UVC_BUF_STATE_DONE:
+               buf->state = UVC_BUF_STATE_IDLE;
+               break;
+
+       case UVC_BUF_STATE_IDLE:
+       case UVC_BUF_STATE_QUEUED:
+       case UVC_BUF_STATE_ACTIVE:
+       default:
+               uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state %u "
+                       "(driver bug?).\n", buf->state);
+               ret = -EINVAL;
+               goto done;
+       }
+
+       list_del(&buf->stream);
+       __uvc_query_buffer(buf, v4l2_buf);
+
+done:
+       mutex_unlock(&queue->mutex);
+       return ret;
+}
+
+/*
+ * Poll the video queue.
+ *
+ * This function implements video queue polling and is intended to be used by
+ * the device poll handler.
+ */
+unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
+               poll_table *wait)
+{
+       struct uvc_buffer *buf;
+       unsigned int mask = 0;
+
+       mutex_lock(&queue->mutex);
+       if (list_empty(&queue->mainqueue)) {
+               mask |= POLLERR;
+               goto done;
+       }
+       buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
+
+       poll_wait(file, &buf->wait, wait);
+       if (buf->state == UVC_BUF_STATE_DONE ||
+           buf->state == UVC_BUF_STATE_ERROR)
+               mask |= POLLIN | POLLRDNORM;
+
+done:
+       mutex_unlock(&queue->mutex);
+       return mask;
+}
+
+/*
+ * Enable or disable the video buffers queue.
+ *
+ * The queue must be enabled before starting video acquisition and must be
+ * disabled after stopping it. This ensures that the video buffers queue
+ * state can be properly initialized before buffers are accessed from the
+ * interrupt handler.
+ *
+ * Enabling the video queue initializes parameters (such as sequence number,
+ * sync pattern, ...). If the queue is already enabled, return -EBUSY.
+ *
+ * Disabling the video queue cancels the queue and removes all buffers from
+ * the main queue.
+ *
+ * This function can't be called from interrupt context. Use
+ * uvc_queue_cancel() instead.
+ */
+int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
+{
+       unsigned int i;
+       int ret = 0;
+
+       mutex_lock(&queue->mutex);
+       if (enable) {
+               if (uvc_queue_streaming(queue)) {
+                       ret = -EBUSY;
+                       goto done;
+               }
+               queue->sequence = 0;
+               queue->flags |= UVC_QUEUE_STREAMING;
+       } else {
+               uvc_queue_cancel(queue, 0);
+               INIT_LIST_HEAD(&queue->mainqueue);
+
+               for (i = 0; i < queue->count; ++i)
+                       queue->buffer[i].state = UVC_BUF_STATE_IDLE;
+
+               queue->flags &= ~UVC_QUEUE_STREAMING;
+       }
+
+done:
+       mutex_unlock(&queue->mutex);
+       return ret;
+}
+
+/*
+ * Cancel the video buffers queue.
+ *
+ * Cancelling the queue marks all buffers on the irq queue as erroneous,
+ * wakes them up and remove them from the queue.
+ *
+ * If the disconnect parameter is set, further calls to uvc_queue_buffer will
+ * fail with -ENODEV.
+ *
+ * This function acquires the irq spinlock and can be called from interrupt
+ * context.
+ */
+void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
+{
+       struct uvc_buffer *buf;
+       unsigned long flags;
+
+       spin_lock_irqsave(&queue->irqlock, flags);
+       while (!list_empty(&queue->irqqueue)) {
+               buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                      queue);
+               list_del(&buf->queue);
+               buf->state = UVC_BUF_STATE_ERROR;
+               wake_up(&buf->wait);
+       }
+       /* This must be protected by the irqlock spinlock to avoid race
+        * conditions between uvc_queue_buffer and the disconnection event that
+        * could result in an interruptible wait in uvc_dequeue_buffer. Do not
+        * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
+        * state outside the queue code.
+        */
+       if (disconnect)
+               queue->flags |= UVC_QUEUE_DISCONNECTED;
+       spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+               struct uvc_buffer *buf)
+{
+       struct uvc_buffer *nextbuf;
+       unsigned long flags;
+
+       if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
+           buf->buf.length != buf->buf.bytesused) {
+               buf->state = UVC_BUF_STATE_QUEUED;
+               buf->buf.bytesused = 0;
+               return buf;
+       }
+
+       spin_lock_irqsave(&queue->irqlock, flags);
+       list_del(&buf->queue);
+       if (!list_empty(&queue->irqqueue))
+               nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                          queue);
+       else
+               nextbuf = NULL;
+       spin_unlock_irqrestore(&queue->irqlock, flags);
+
+       buf->buf.sequence = queue->sequence++;
+       do_gettimeofday(&buf->buf.timestamp);
+
+       wake_up(&buf->wait);
+       return nextbuf;
+}
diff --git a/drivers/media/video/uvc/uvc_status.c b/drivers/media/video/uvc/uvc_status.c
new file mode 100644 (file)
index 0000000..be9084e
--- /dev/null
@@ -0,0 +1,207 @@
+/*
+ *      uvc_status.c  --  USB Video Class driver - Status endpoint
+ *
+ *      Copyright (C) 2007-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+
+#include "uvcvideo.h"
+
+/* --------------------------------------------------------------------------
+ * Input device
+ */
+static int uvc_input_init(struct uvc_device *dev)
+{
+       struct usb_device *udev = dev->udev;
+       struct input_dev *input;
+       char *phys = NULL;
+       int ret;
+
+       input = input_allocate_device();
+       if (input == NULL)
+               return -ENOMEM;
+
+       phys = kmalloc(6 + strlen(udev->bus->bus_name) + strlen(udev->devpath),
+                       GFP_KERNEL);
+       if (phys == NULL) {
+               ret = -ENOMEM;
+               goto error;
+       }
+       sprintf(phys, "usb-%s-%s", udev->bus->bus_name, udev->devpath);
+
+       input->name = dev->name;
+       input->phys = phys;
+       usb_to_input_id(udev, &input->id);
+       input->dev.parent = &dev->intf->dev;
+
+       set_bit(EV_KEY, input->evbit);
+       set_bit(BTN_0, input->keybit);
+
+       if ((ret = input_register_device(input)) < 0)
+               goto error;
+
+       dev->input = input;
+       return 0;
+
+error:
+       input_free_device(input);
+       kfree(phys);
+       return ret;
+}
+
+static void uvc_input_cleanup(struct uvc_device *dev)
+{
+       if (dev->input)
+               input_unregister_device(dev->input);
+}
+
+/* --------------------------------------------------------------------------
+ * Status interrupt endpoint
+ */
+static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len)
+{
+       if (len < 3) {
+               uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
+                               "received.\n");
+               return;
+       }
+
+       if (data[2] == 0) {
+               if (len < 4)
+                       return;
+               uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
+                       data[1], data[3] ? "pressed" : "released", len);
+               if (dev->input)
+                       input_report_key(dev->input, BTN_0, data[3]);
+       } else {
+               uvc_trace(UVC_TRACE_STATUS, "Stream %u error event %02x %02x "
+                       "len %d.\n", data[1], data[2], data[3], len);
+       }
+}
+
+static void uvc_event_control(struct uvc_device *dev, __u8 *data, int len)
+{
+       char *attrs[3] = { "value", "info", "failure" };
+
+       if (len < 6 || data[2] != 0 || data[4] > 2) {
+               uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
+                               "received.\n");
+               return;
+       }
+
+       uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
+               data[1], data[3], attrs[data[4]], len);
+}
+
+static void uvc_status_complete(struct urb *urb)
+{
+       struct uvc_device *dev = urb->context;
+       int len, ret;
+
+       switch (urb->status) {
+       case 0:
+               break;
+
+       case -ENOENT:           /* usb_kill_urb() called. */
+       case -ECONNRESET:       /* usb_unlink_urb() called. */
+       case -ESHUTDOWN:        /* The endpoint is being disabled. */
+       case -EPROTO:           /* Device is disconnected (reported by some
+                                * host controller). */
+               return;
+
+       default:
+               uvc_printk(KERN_WARNING, "Non-zero status (%d) in status "
+                       "completion handler.\n", urb->status);
+               return;
+       }
+
+       len = urb->actual_length;
+       if (len > 0) {
+               switch (dev->status[0] & 0x0f) {
+               case UVC_STATUS_TYPE_CONTROL:
+                       uvc_event_control(dev, dev->status, len);
+                       break;
+
+               case UVC_STATUS_TYPE_STREAMING:
+                       uvc_event_streaming(dev, dev->status, len);
+                       break;
+
+               default:
+                       uvc_printk(KERN_INFO, "unknown event type %u.\n",
+                               dev->status[0]);
+                       break;
+               }
+       }
+
+       /* Resubmit the URB. */
+       urb->interval = dev->int_ep->desc.bInterval;
+       if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+               uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
+                       ret);
+       }
+}
+
+int uvc_status_init(struct uvc_device *dev)
+{
+       struct usb_host_endpoint *ep = dev->int_ep;
+       unsigned int pipe;
+       int interval;
+
+       if (ep == NULL)
+               return 0;
+
+       uvc_input_init(dev);
+
+       dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
+       if (dev->int_urb == NULL)
+               return -ENOMEM;
+
+       pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
+
+       /* For high-speed interrupt endpoints, the bInterval value is used as
+        * an exponent of two. Some developers forgot about it.
+        */
+       interval = ep->desc.bInterval;
+       if (interval > 16 && dev->udev->speed == USB_SPEED_HIGH &&
+           (dev->quirks & UVC_QUIRK_STATUS_INTERVAL))
+               interval = fls(interval) - 1;
+
+       usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
+               dev->status, sizeof dev->status, uvc_status_complete,
+               dev, interval);
+
+       return usb_submit_urb(dev->int_urb, GFP_KERNEL);
+}
+
+void uvc_status_cleanup(struct uvc_device *dev)
+{
+       usb_kill_urb(dev->int_urb);
+       usb_free_urb(dev->int_urb);
+       uvc_input_cleanup(dev);
+}
+
+int uvc_status_suspend(struct uvc_device *dev)
+{
+       usb_kill_urb(dev->int_urb);
+       return 0;
+}
+
+int uvc_status_resume(struct uvc_device *dev)
+{
+       if (dev->int_urb == NULL)
+               return 0;
+
+       return usb_submit_urb(dev->int_urb, GFP_KERNEL);
+}
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
new file mode 100644 (file)
index 0000000..2e0a665
--- /dev/null
@@ -0,0 +1,1105 @@
+/*
+ *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * V4L2 interface
+ */
+
+/*
+ * Mapping V4L2 controls to UVC controls can be straighforward if done well.
+ * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
+ * must be grouped (for instance the Red Balance, Blue Balance and Do White
+ * Balance V4L2 controls use the White Balance Component UVC control) or
+ * otherwise translated. The approach we take here is to use a translation
+ * table for the controls which can be mapped directly, and handle the others
+ * manually.
+ */
+static int uvc_v4l2_query_menu(struct uvc_video_device *video,
+       struct v4l2_querymenu *query_menu)
+{
+       struct uvc_menu_info *menu_info;
+       struct uvc_control_mapping *mapping;
+       struct uvc_control *ctrl;
+
+       ctrl = uvc_find_control(video, query_menu->id, &mapping);
+       if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
+               return -EINVAL;
+
+       if (query_menu->index >= mapping->menu_count)
+               return -EINVAL;
+
+       menu_info = &mapping->menu_info[query_menu->index];
+       strncpy(query_menu->name, menu_info->name, 32);
+       return 0;
+}
+
+/*
+ * Find the frame interval closest to the requested frame interval for the
+ * given frame format and size. This should be done by the device as part of
+ * the Video Probe and Commit negotiation, but some hardware don't implement
+ * that feature.
+ */
+static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
+{
+       unsigned int i;
+
+       if (frame->bFrameIntervalType) {
+               __u32 best = -1, dist;
+
+               for (i = 0; i < frame->bFrameIntervalType; ++i) {
+                       dist = interval > frame->dwFrameInterval[i]
+                            ? interval - frame->dwFrameInterval[i]
+                            : frame->dwFrameInterval[i] - interval;
+
+                       if (dist > best)
+                               break;
+
+                       best = dist;
+               }
+
+               interval = frame->dwFrameInterval[i-1];
+       } else {
+               const __u32 min = frame->dwFrameInterval[0];
+               const __u32 max = frame->dwFrameInterval[1];
+               const __u32 step = frame->dwFrameInterval[2];
+
+               interval = min + (interval - min + step/2) / step * step;
+               if (interval > max)
+                       interval = max;
+       }
+
+       return interval;
+}
+
+static int uvc_v4l2_try_format(struct uvc_video_device *video,
+       struct v4l2_format *fmt, struct uvc_streaming_control *probe,
+       struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
+{
+       struct uvc_format *format = NULL;
+       struct uvc_frame *frame = NULL;
+       __u16 rw, rh;
+       unsigned int d, maxd;
+       unsigned int i;
+       __u32 interval;
+       int ret = 0;
+       __u8 *fcc;
+
+       if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
+       uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
+                       fmt->fmt.pix.pixelformat,
+                       fcc[0], fcc[1], fcc[2], fcc[3],
+                       fmt->fmt.pix.width, fmt->fmt.pix.height);
+
+       /* Check if the hardware supports the requested format. */
+       for (i = 0; i < video->streaming->nformats; ++i) {
+               format = &video->streaming->format[i];
+               if (format->fcc == fmt->fmt.pix.pixelformat)
+                       break;
+       }
+
+       if (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
+               uvc_trace(UVC_TRACE_FORMAT, "Unsupported format 0x%08x.\n",
+                               fmt->fmt.pix.pixelformat);
+               return -EINVAL;
+       }
+
+       /* Find the closest image size. The distance between image sizes is
+        * the size in pixels of the non-overlapping regions between the
+        * requested size and the frame-specified size.
+        */
+       rw = fmt->fmt.pix.width;
+       rh = fmt->fmt.pix.height;
+       maxd = (unsigned int)-1;
+
+       for (i = 0; i < format->nframes; ++i) {
+               __u16 w = format->frame[i].wWidth;
+               __u16 h = format->frame[i].wHeight;
+
+               d = min(w, rw) * min(h, rh);
+               d = w*h + rw*rh - 2*d;
+               if (d < maxd) {
+                       maxd = d;
+                       frame = &format->frame[i];
+               }
+
+               if (maxd == 0)
+                       break;
+       }
+
+       if (frame == NULL) {
+               uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
+                               fmt->fmt.pix.width, fmt->fmt.pix.height);
+               return -EINVAL;
+       }
+
+       /* Use the default frame interval. */
+       interval = frame->dwDefaultFrameInterval;
+       uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
+               "(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
+               (100000000/interval)%10);
+
+       /* Set the format index, frame index and frame interval. */
+       memset(probe, 0, sizeof *probe);
+       probe->bmHint = 1;      /* dwFrameInterval */
+       probe->bFormatIndex = format->index;
+       probe->bFrameIndex = frame->bFrameIndex;
+       probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
+       /* Some webcams stall the probe control set request when the
+        * dwMaxVideoFrameSize field is set to zero. The UVC specification
+        * clearly states that the field is read-only from the host, so this
+        * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
+        * the webcam to work around the problem.
+        *
+        * The workaround could probably be enabled for all webcams, so the
+        * quirk can be removed if needed. It's currently useful to detect
+        * webcam bugs and fix them before they hit the market (providing
+        * developers test their webcams with the Linux driver as well as with
+        * the Windows driver).
+        */
+       if (video->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
+               probe->dwMaxVideoFrameSize =
+                       video->streaming->ctrl.dwMaxVideoFrameSize;
+
+       /* Probe the device */
+       if ((ret = uvc_probe_video(video, probe)) < 0)
+               goto done;
+
+       fmt->fmt.pix.width = frame->wWidth;
+       fmt->fmt.pix.height = frame->wHeight;
+       fmt->fmt.pix.field = V4L2_FIELD_NONE;
+       fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+       fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
+       fmt->fmt.pix.colorspace = format->colorspace;
+       fmt->fmt.pix.priv = 0;
+
+       if (uvc_format != NULL)
+               *uvc_format = format;
+       if (uvc_frame != NULL)
+               *uvc_frame = frame;
+
+done:
+       return ret;
+}
+
+static int uvc_v4l2_get_format(struct uvc_video_device *video,
+       struct v4l2_format *fmt)
+{
+       struct uvc_format *format = video->streaming->cur_format;
+       struct uvc_frame *frame = video->streaming->cur_frame;
+
+       if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       if (format == NULL || frame == NULL)
+               return -EINVAL;
+
+       fmt->fmt.pix.pixelformat = format->fcc;
+       fmt->fmt.pix.width = frame->wWidth;
+       fmt->fmt.pix.height = frame->wHeight;
+       fmt->fmt.pix.field = V4L2_FIELD_NONE;
+       fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+       fmt->fmt.pix.sizeimage = video->streaming->ctrl.dwMaxVideoFrameSize;
+       fmt->fmt.pix.colorspace = format->colorspace;
+       fmt->fmt.pix.priv = 0;
+
+       return 0;
+}
+
+static int uvc_v4l2_set_format(struct uvc_video_device *video,
+       struct v4l2_format *fmt)
+{
+       struct uvc_streaming_control probe;
+       struct uvc_format *format;
+       struct uvc_frame *frame;
+       int ret;
+
+       if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       if (uvc_queue_streaming(&video->queue))
+               return -EBUSY;
+
+       ret = uvc_v4l2_try_format(video, fmt, &probe, &format, &frame);
+       if (ret < 0)
+               return ret;
+
+       if ((ret = uvc_set_video_ctrl(video, &probe, 0)) < 0)
+               return ret;
+
+       memcpy(&video->streaming->ctrl, &probe, sizeof probe);
+       video->streaming->cur_format = format;
+       video->streaming->cur_frame = frame;
+
+       return 0;
+}
+
+static int uvc_v4l2_get_streamparm(struct uvc_video_device *video,
+               struct v4l2_streamparm *parm)
+{
+       uint32_t numerator, denominator;
+
+       if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       numerator = video->streaming->ctrl.dwFrameInterval;
+       denominator = 10000000;
+       uvc_simplify_fraction(&numerator, &denominator, 8, 333);
+
+       memset(parm, 0, sizeof *parm);
+       parm->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+       parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
+       parm->parm.capture.capturemode = 0;
+       parm->parm.capture.timeperframe.numerator = numerator;
+       parm->parm.capture.timeperframe.denominator = denominator;
+       parm->parm.capture.extendedmode = 0;
+       parm->parm.capture.readbuffers = 0;
+
+       return 0;
+}
+
+static int uvc_v4l2_set_streamparm(struct uvc_video_device *video,
+               struct v4l2_streamparm *parm)
+{
+       struct uvc_frame *frame = video->streaming->cur_frame;
+       struct uvc_streaming_control probe;
+       uint32_t interval;
+       int ret;
+
+       if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       if (uvc_queue_streaming(&video->queue))
+               return -EBUSY;
+
+       memcpy(&probe, &video->streaming->ctrl, sizeof probe);
+       interval = uvc_fraction_to_interval(
+                       parm->parm.capture.timeperframe.numerator,
+                       parm->parm.capture.timeperframe.denominator);
+
+       uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
+                       parm->parm.capture.timeperframe.numerator,
+                       parm->parm.capture.timeperframe.denominator,
+                       interval);
+       probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);
+
+       /* Probe the device with the new settings. */
+       if ((ret = uvc_probe_video(video, &probe)) < 0)
+               return ret;
+
+       /* Commit the new settings. */
+       if ((ret = uvc_set_video_ctrl(video, &probe, 0)) < 0)
+               return ret;
+
+       memcpy(&video->streaming->ctrl, &probe, sizeof probe);
+
+       /* Return the actual frame period. */
+       parm->parm.capture.timeperframe.numerator = probe.dwFrameInterval;
+       parm->parm.capture.timeperframe.denominator = 10000000;
+       uvc_simplify_fraction(&parm->parm.capture.timeperframe.numerator,
+                               &parm->parm.capture.timeperframe.denominator,
+                               8, 333);
+
+       return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Privilege management
+ */
+
+/*
+ * Privilege management is the multiple-open implementation basis. The current
+ * implementation is completely transparent for the end-user and doesn't
+ * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
+ * Those ioctls enable finer control on the device (by making possible for a
+ * user to request exclusive access to a device), but are not mature yet.
+ * Switching to the V4L2 priority mechanism might be considered in the future
+ * if this situation changes.
+ *
+ * Each open instance of a UVC device can either be in a privileged or
+ * unprivileged state. Only a single instance can be in a privileged state at
+ * a given time. Trying to perform an operation which requires privileges will
+ * automatically acquire the required privileges if possible, or return -EBUSY
+ * otherwise. Privileges are dismissed when closing the instance.
+ *
+ * Operations which require privileges are:
+ *
+ * - VIDIOC_S_INPUT
+ * - VIDIOC_S_PARM
+ * - VIDIOC_S_FMT
+ * - VIDIOC_TRY_FMT
+ * - VIDIOC_REQBUFS
+ */
+static int uvc_acquire_privileges(struct uvc_fh *handle)
+{
+       int ret = 0;
+
+       /* Always succeed if the handle is already privileged. */
+       if (handle->state == UVC_HANDLE_ACTIVE)
+               return 0;
+
+       /* Check if the device already has a privileged handle. */
+       mutex_lock(&uvc_driver.open_mutex);
+       if (atomic_inc_return(&handle->device->active) != 1) {
+               atomic_dec(&handle->device->active);
+               ret = -EBUSY;
+               goto done;
+       }
+
+       handle->state = UVC_HANDLE_ACTIVE;
+
+done:
+       mutex_unlock(&uvc_driver.open_mutex);
+       return ret;
+}
+
+static void uvc_dismiss_privileges(struct uvc_fh *handle)
+{
+       if (handle->state == UVC_HANDLE_ACTIVE)
+               atomic_dec(&handle->device->active);
+
+       handle->state = UVC_HANDLE_PASSIVE;
+}
+
+static int uvc_has_privileges(struct uvc_fh *handle)
+{
+       return handle->state == UVC_HANDLE_ACTIVE;
+}
+
+/* ------------------------------------------------------------------------
+ * V4L2 file operations
+ */
+
+static int uvc_v4l2_open(struct inode *inode, struct file *file)
+{
+       struct video_device *vdev;
+       struct uvc_video_device *video;
+       struct uvc_fh *handle;
+       int ret = 0;
+
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
+       mutex_lock(&uvc_driver.open_mutex);
+       vdev = video_devdata(file);
+       video = video_get_drvdata(vdev);
+
+       if (video->dev->state & UVC_DEV_DISCONNECTED) {
+               ret = -ENODEV;
+               goto done;
+       }
+
+       ret = usb_autopm_get_interface(video->dev->intf);
+       if (ret < 0)
+               goto done;
+
+       /* Create the device handle. */
+       handle = kzalloc(sizeof *handle, GFP_KERNEL);
+       if (handle == NULL) {
+               usb_autopm_put_interface(video->dev->intf);
+               ret = -ENOMEM;
+               goto done;
+       }
+
+       handle->device = video;
+       handle->state = UVC_HANDLE_PASSIVE;
+       file->private_data = handle;
+
+       kref_get(&video->dev->kref);
+
+done:
+       mutex_unlock(&uvc_driver.open_mutex);
+       return ret;
+}
+
+static int uvc_v4l2_release(struct inode *inode, struct file *file)
+{
+       struct video_device *vdev = video_devdata(file);
+       struct uvc_video_device *video = video_get_drvdata(vdev);
+       struct uvc_fh *handle = (struct uvc_fh *)file->private_data;
+
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");
+
+       /* Only free resources if this is a privileged handle. */
+       if (uvc_has_privileges(handle)) {
+               uvc_video_enable(video, 0);
+
+               mutex_lock(&video->queue.mutex);
+               if (uvc_free_buffers(&video->queue) < 0)
+                       uvc_printk(KERN_ERR, "uvc_v4l2_release: Unable to "
+                                       "free buffers.\n");
+               mutex_unlock(&video->queue.mutex);
+       }
+
+       /* Release the file handle. */
+       uvc_dismiss_privileges(handle);
+       kfree(handle);
+       file->private_data = NULL;
+
+       usb_autopm_put_interface(video->dev->intf);
+       kref_put(&video->dev->kref, uvc_delete);
+       return 0;
+}
+
+static int uvc_v4l2_do_ioctl(struct inode *inode, struct file *file,
+                    unsigned int cmd, void *arg)
+{
+       struct video_device *vdev = video_devdata(file);
+       struct uvc_video_device *video = video_get_drvdata(vdev);
+       struct uvc_fh *handle = (struct uvc_fh *)file->private_data;
+       int ret = 0;
+
+       if (uvc_trace_param & UVC_TRACE_IOCTL)
+               v4l_printk_ioctl(cmd);
+
+       switch (cmd) {
+       /* Query capabilities */
+       case VIDIOC_QUERYCAP:
+       {
+               struct v4l2_capability *cap = arg;
+
+               memset(cap, 0, sizeof *cap);
+               strncpy(cap->driver, "uvcvideo", sizeof cap->driver);
+               strncpy(cap->card, vdev->name, 32);
+               strncpy(cap->bus_info, video->dev->udev->bus->bus_name,
+                       sizeof cap->bus_info);
+               cap->version = DRIVER_VERSION_NUMBER;
+               cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
+                                 | V4L2_CAP_STREAMING;
+               break;
+       }
+
+       /* Get, Set & Query control */
+       case VIDIOC_QUERYCTRL:
+               return uvc_query_v4l2_ctrl(video, arg);
+
+       case VIDIOC_G_CTRL:
+       {
+               struct v4l2_control *ctrl = arg;
+               struct v4l2_ext_control xctrl;
+
+               memset(&xctrl, 0, sizeof xctrl);
+               xctrl.id = ctrl->id;
+
+               uvc_ctrl_begin(video);
+               ret = uvc_ctrl_get(video, &xctrl);
+               uvc_ctrl_rollback(video);
+               if (ret >= 0)
+                       ctrl->value = xctrl.value;
+               break;
+       }
+
+       case VIDIOC_S_CTRL:
+       {
+               struct v4l2_control *ctrl = arg;
+               struct v4l2_ext_control xctrl;
+
+               memset(&xctrl, 0, sizeof xctrl);
+               xctrl.id = ctrl->id;
+               xctrl.value = ctrl->value;
+
+               uvc_ctrl_begin(video);
+               ret = uvc_ctrl_set(video, &xctrl);
+               if (ret < 0) {
+                       uvc_ctrl_rollback(video);
+                       return ret;
+               }
+               ret = uvc_ctrl_commit(video);
+               break;
+       }
+
+       case VIDIOC_QUERYMENU:
+               return uvc_v4l2_query_menu(video, arg);
+
+       case VIDIOC_G_EXT_CTRLS:
+       {
+               struct v4l2_ext_controls *ctrls = arg;
+               struct v4l2_ext_control *ctrl = ctrls->controls;
+               unsigned int i;
+
+               uvc_ctrl_begin(video);
+               for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+                       ret = uvc_ctrl_get(video, ctrl);
+                       if (ret < 0) {
+                               uvc_ctrl_rollback(video);
+                               ctrls->error_idx = i;
+                               return ret;
+                       }
+               }
+               ctrls->error_idx = 0;
+               ret = uvc_ctrl_rollback(video);
+               break;
+       }
+
+       case VIDIOC_S_EXT_CTRLS:
+       case VIDIOC_TRY_EXT_CTRLS:
+       {
+               struct v4l2_ext_controls *ctrls = arg;
+               struct v4l2_ext_control *ctrl = ctrls->controls;
+               unsigned int i;
+
+               ret = uvc_ctrl_begin(video);
+               if (ret < 0)
+                       return ret;
+
+               for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+                       ret = uvc_ctrl_set(video, ctrl);
+                       if (ret < 0) {
+                               uvc_ctrl_rollback(video);
+                               ctrls->error_idx = i;
+                               return ret;
+                       }
+               }
+
+               ctrls->error_idx = 0;
+
+               if (cmd == VIDIOC_S_EXT_CTRLS)
+                       ret = uvc_ctrl_commit(video);
+               else
+                       ret = uvc_ctrl_rollback(video);
+               break;
+       }
+
+       /* Get, Set & Enum input */
+       case VIDIOC_ENUMINPUT:
+       {
+               const struct uvc_entity *selector = video->selector;
+               struct v4l2_input *input = arg;
+               struct uvc_entity *iterm = NULL;
+               u32 index = input->index;
+               int pin = 0;
+
+               if (selector == NULL ||
+                   (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+                       if (index != 0)
+                               return -EINVAL;
+                       iterm = list_first_entry(&video->iterms,
+                                       struct uvc_entity, chain);
+                       pin = iterm->id;
+               } else if (pin < selector->selector.bNrInPins) {
+                       pin = selector->selector.baSourceID[index];
+                       list_for_each_entry(iterm, video->iterms.next, chain) {
+                               if (iterm->id == pin)
+                                       break;
+                       }
+               }
+
+               if (iterm == NULL || iterm->id != pin)
+                       return -EINVAL;
+
+               memset(input, 0, sizeof *input);
+               input->index = index;
+               strncpy(input->name, iterm->name, sizeof input->name);
+               if (UVC_ENTITY_TYPE(iterm) == ITT_CAMERA)
+                       input->type = V4L2_INPUT_TYPE_CAMERA;
+               break;
+       }
+
+       case VIDIOC_G_INPUT:
+       {
+               u8 input;
+
+               if (video->selector == NULL ||
+                   (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+                       *(int *)arg = 0;
+                       break;
+               }
+
+               ret = uvc_query_ctrl(video->dev, GET_CUR, video->selector->id,
+                       video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
+                       &input, 1);
+               if (ret < 0)
+                       return ret;
+
+               *(int *)arg = input - 1;
+               break;
+       }
+
+       case VIDIOC_S_INPUT:
+       {
+               u8 input = *(u32 *)arg + 1;
+
+               if ((ret = uvc_acquire_privileges(handle)) < 0)
+                       return ret;
+
+               if (video->selector == NULL ||
+                   (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+                       if (input != 1)
+                               return -EINVAL;
+                       break;
+               }
+
+               if (input > video->selector->selector.bNrInPins)
+                       return -EINVAL;
+
+               return uvc_query_ctrl(video->dev, SET_CUR, video->selector->id,
+                       video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
+                       &input, 1);
+       }
+
+       /* Try, Get, Set & Enum format */
+       case VIDIOC_ENUM_FMT:
+       {
+               struct v4l2_fmtdesc *fmt = arg;
+               struct uvc_format *format;
+
+               if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+                   fmt->index >= video->streaming->nformats)
+                       return -EINVAL;
+
+               format = &video->streaming->format[fmt->index];
+               fmt->flags = 0;
+               if (format->flags & UVC_FMT_FLAG_COMPRESSED)
+                       fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
+               strncpy(fmt->description, format->name,
+                       sizeof fmt->description);
+               fmt->description[sizeof fmt->description - 1] = 0;
+               fmt->pixelformat = format->fcc;
+               break;
+       }
+
+       case VIDIOC_TRY_FMT:
+       {
+               struct uvc_streaming_control probe;
+
+               if ((ret = uvc_acquire_privileges(handle)) < 0)
+                       return ret;
+
+               return uvc_v4l2_try_format(video, arg, &probe, NULL, NULL);
+       }
+
+       case VIDIOC_S_FMT:
+               if ((ret = uvc_acquire_privileges(handle)) < 0)
+                       return ret;
+
+               return uvc_v4l2_set_format(video, arg);
+
+       case VIDIOC_G_FMT:
+               return uvc_v4l2_get_format(video, arg);
+
+       /* Frame size enumeration */
+       case VIDIOC_ENUM_FRAMESIZES:
+       {
+               struct v4l2_frmsizeenum *fsize = arg;
+               struct uvc_format *format = NULL;
+               struct uvc_frame *frame;
+               int i;
+
+               /* Look for the given pixel format */
+               for (i = 0; i < video->streaming->nformats; i++) {
+                       if (video->streaming->format[i].fcc ==
+                                       fsize->pixel_format) {
+                               format = &video->streaming->format[i];
+                               break;
+                       }
+               }
+               if (format == NULL)
+                       return -EINVAL;
+
+               if (fsize->index >= format->nframes)
+                       return -EINVAL;
+
+               frame = &format->frame[fsize->index];
+               fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+               fsize->discrete.width = frame->wWidth;
+               fsize->discrete.height = frame->wHeight;
+               break;
+       }
+
+       /* Frame interval enumeration */
+       case VIDIOC_ENUM_FRAMEINTERVALS:
+       {
+               struct v4l2_frmivalenum *fival = arg;
+               struct uvc_format *format = NULL;
+               struct uvc_frame *frame = NULL;
+               int i;
+
+               /* Look for the given pixel format and frame size */
+               for (i = 0; i < video->streaming->nformats; i++) {
+                       if (video->streaming->format[i].fcc ==
+                                       fival->pixel_format) {
+                               format = &video->streaming->format[i];
+                               break;
+                       }
+               }
+               if (format == NULL)
+                       return -EINVAL;
+
+               for (i = 0; i < format->nframes; i++) {
+                       if (format->frame[i].wWidth == fival->width &&
+                           format->frame[i].wHeight == fival->height) {
+                               frame = &format->frame[i];
+                               break;
+                       }
+               }
+               if (frame == NULL)
+                       return -EINVAL;
+
+               if (frame->bFrameIntervalType) {
+                       if (fival->index >= frame->bFrameIntervalType)
+                               return -EINVAL;
+
+                       fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+                       fival->discrete.numerator =
+                               frame->dwFrameInterval[fival->index];
+                       fival->discrete.denominator = 10000000;
+                       uvc_simplify_fraction(&fival->discrete.numerator,
+                               &fival->discrete.denominator, 8, 333);
+               } else {
+                       fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
+                       fival->stepwise.min.numerator =
+                               frame->dwFrameInterval[0];
+                       fival->stepwise.min.denominator = 10000000;
+                       fival->stepwise.max.numerator =
+                               frame->dwFrameInterval[1];
+                       fival->stepwise.max.denominator = 10000000;
+                       fival->stepwise.step.numerator =
+                               frame->dwFrameInterval[2];
+                       fival->stepwise.step.denominator = 10000000;
+                       uvc_simplify_fraction(&fival->stepwise.min.numerator,
+                               &fival->stepwise.min.denominator, 8, 333);
+                       uvc_simplify_fraction(&fival->stepwise.max.numerator,
+                               &fival->stepwise.max.denominator, 8, 333);
+                       uvc_simplify_fraction(&fival->stepwise.step.numerator,
+                               &fival->stepwise.step.denominator, 8, 333);
+               }
+               break;
+       }
+
+       /* Get & Set streaming parameters */
+       case VIDIOC_G_PARM:
+               return uvc_v4l2_get_streamparm(video, arg);
+
+       case VIDIOC_S_PARM:
+               if ((ret = uvc_acquire_privileges(handle)) < 0)
+                       return ret;
+
+               return uvc_v4l2_set_streamparm(video, arg);
+
+       /* Cropping and scaling */
+       case VIDIOC_CROPCAP:
+       {
+               struct v4l2_cropcap *ccap = arg;
+               struct uvc_frame *frame = video->streaming->cur_frame;
+
+               if (ccap->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+                       return -EINVAL;
+
+               ccap->bounds.left = 0;
+               ccap->bounds.top = 0;
+               ccap->bounds.width = frame->wWidth;
+               ccap->bounds.height = frame->wHeight;
+
+               ccap->defrect = ccap->bounds;
+
+               ccap->pixelaspect.numerator = 1;
+               ccap->pixelaspect.denominator = 1;
+               break;
+       }
+
+       case VIDIOC_G_CROP:
+       case VIDIOC_S_CROP:
+               return -EINVAL;
+
+       /* Buffers & streaming */
+       case VIDIOC_REQBUFS:
+       {
+               struct v4l2_requestbuffers *rb = arg;
+               unsigned int bufsize =
+                       video->streaming->ctrl.dwMaxVideoFrameSize;
+
+               if (rb->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+                   rb->memory != V4L2_MEMORY_MMAP)
+                       return -EINVAL;
+
+               if ((ret = uvc_acquire_privileges(handle)) < 0)
+                       return ret;
+
+               ret = uvc_alloc_buffers(&video->queue, rb->count, bufsize);
+               if (ret < 0)
+                       return ret;
+
+               if (!(video->streaming->cur_format->flags &
+                   UVC_FMT_FLAG_COMPRESSED))
+                       video->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
+
+               rb->count = ret;
+               ret = 0;
+               break;
+       }
+
+       case VIDIOC_QUERYBUF:
+       {
+               struct v4l2_buffer *buf = arg;
+
+               if (buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+                       return -EINVAL;
+
+               if (!uvc_has_privileges(handle))
+                       return -EBUSY;
+
+               return uvc_query_buffer(&video->queue, buf);
+       }
+
+       case VIDIOC_QBUF:
+               if (!uvc_has_privileges(handle))
+                       return -EBUSY;
+
+               return uvc_queue_buffer(&video->queue, arg);
+
+       case VIDIOC_DQBUF:
+               if (!uvc_has_privileges(handle))
+                       return -EBUSY;
+
+               return uvc_dequeue_buffer(&video->queue, arg,
+                       file->f_flags & O_NONBLOCK);
+
+       case VIDIOC_STREAMON:
+       {
+               int *type = arg;
+
+               if (*type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+                       return -EINVAL;
+
+               if (!uvc_has_privileges(handle))
+                       return -EBUSY;
+
+               if ((ret = uvc_video_enable(video, 1)) < 0)
+                       return ret;
+               break;
+       }
+
+       case VIDIOC_STREAMOFF:
+       {
+               int *type = arg;
+
+               if (*type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+                       return -EINVAL;
+
+               if (!uvc_has_privileges(handle))
+                       return -EBUSY;
+
+               return uvc_video_enable(video, 0);
+       }
+
+       /* Analog video standards make no sense for digital cameras. */
+       case VIDIOC_ENUMSTD:
+       case VIDIOC_QUERYSTD:
+       case VIDIOC_G_STD:
+       case VIDIOC_S_STD:
+
+       case VIDIOC_OVERLAY:
+
+       case VIDIOC_ENUMAUDIO:
+       case VIDIOC_ENUMAUDOUT:
+
+       case VIDIOC_ENUMOUTPUT:
+               uvc_trace(UVC_TRACE_IOCTL, "Unsupported ioctl 0x%08x\n", cmd);
+               return -EINVAL;
+
+       /* Dynamic controls. */
+       case UVCIOC_CTRL_ADD:
+       {
+               struct uvc_xu_control_info *xinfo = arg;
+               struct uvc_control_info *info;
+
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+
+               info = kmalloc(sizeof *info, GFP_KERNEL);
+               if (info == NULL)
+                       return -ENOMEM;
+
+               memcpy(info->entity, xinfo->entity, sizeof info->entity);
+               info->index = xinfo->index;
+               info->selector = xinfo->selector;
+               info->size = xinfo->size;
+               info->flags = xinfo->flags;
+
+               info->flags |= UVC_CONTROL_GET_MIN | UVC_CONTROL_GET_MAX |
+                               UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF;
+
+               ret = uvc_ctrl_add_info(info);
+               if (ret < 0)
+                       kfree(info);
+               break;
+       }
+
+       case UVCIOC_CTRL_MAP:
+       {
+               struct uvc_xu_control_mapping *xmap = arg;
+               struct uvc_control_mapping *map;
+
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+
+               map = kmalloc(sizeof *map, GFP_KERNEL);
+               if (map == NULL)
+                       return -ENOMEM;
+
+               map->id = xmap->id;
+               memcpy(map->name, xmap->name, sizeof map->name);
+               memcpy(map->entity, xmap->entity, sizeof map->entity);
+               map->selector = xmap->selector;
+               map->size = xmap->size;
+               map->offset = xmap->offset;
+               map->v4l2_type = xmap->v4l2_type;
+               map->data_type = xmap->data_type;
+
+               ret = uvc_ctrl_add_mapping(map);
+               if (ret < 0)
+                       kfree(map);
+               break;
+       }
+
+       case UVCIOC_CTRL_GET:
+               return uvc_xu_ctrl_query(video, arg, 0);
+
+       case UVCIOC_CTRL_SET:
+               return uvc_xu_ctrl_query(video, arg, 1);
+
+       default:
+               if ((ret = v4l_compat_translate_ioctl(inode, file, cmd, arg,
+                       uvc_v4l2_do_ioctl)) == -ENOIOCTLCMD)
+                       uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n",
+                                 cmd);
+               return ret;
+       }
+
+       return ret;
+}
+
+static int uvc_v4l2_ioctl(struct inode *inode, struct file *file,
+                    unsigned int cmd, unsigned long arg)
+{
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_ioctl\n");
+       return video_usercopy(inode, file, cmd, arg, uvc_v4l2_do_ioctl);
+}
+
+static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
+                   size_t count, loff_t *ppos)
+{
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
+       return -ENODEV;
+}
+
+/*
+ * VMA operations.
+ */
+static void uvc_vm_open(struct vm_area_struct *vma)
+{
+       struct uvc_buffer *buffer = vma->vm_private_data;
+       buffer->vma_use_count++;
+}
+
+static void uvc_vm_close(struct vm_area_struct *vma)
+{
+       struct uvc_buffer *buffer = vma->vm_private_data;
+       buffer->vma_use_count--;
+}
+
+static struct vm_operations_struct uvc_vm_ops = {
+       .open           = uvc_vm_open,
+       .close          = uvc_vm_close,
+};
+
+static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+       struct video_device *vdev = video_devdata(file);
+       struct uvc_video_device *video = video_get_drvdata(vdev);
+       struct uvc_buffer *buffer;
+       struct page *page;
+       unsigned long addr, start, size;
+       unsigned int i;
+       int ret = 0;
+
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");
+
+       start = vma->vm_start;
+       size = vma->vm_end - vma->vm_start;
+
+       mutex_lock(&video->queue.mutex);
+
+       for (i = 0; i < video->queue.count; ++i) {
+               buffer = &video->queue.buffer[i];
+               if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
+                       break;
+       }
+
+       if (i == video->queue.count || size != video->queue.buf_size) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       /*
+        * VM_IO marks the area as being an mmaped region for I/O to a
+        * device. It also prevents the region from being core dumped.
+        */
+       vma->vm_flags |= VM_IO;
+
+       addr = (unsigned long)video->queue.mem + buffer->buf.m.offset;
+       while (size > 0) {
+               page = vmalloc_to_page((void *)addr);
+               if ((ret = vm_insert_page(vma, start, page)) < 0)
+                       goto done;
+
+               start += PAGE_SIZE;
+               addr += PAGE_SIZE;
+               size -= PAGE_SIZE;
+       }
+
+       vma->vm_ops = &uvc_vm_ops;
+       vma->vm_private_data = buffer;
+       uvc_vm_open(vma);
+
+done:
+       mutex_unlock(&video->queue.mutex);
+       return ret;
+}
+
+static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
+{
+       struct video_device *vdev = video_devdata(file);
+       struct uvc_video_device *video = video_get_drvdata(vdev);
+
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");
+
+       return uvc_queue_poll(&video->queue, file, wait);
+}
+
+struct file_operations uvc_fops = {
+       .owner          = THIS_MODULE,
+       .open           = uvc_v4l2_open,
+       .release        = uvc_v4l2_release,
+       .ioctl          = uvc_v4l2_ioctl,
+       .compat_ioctl   = v4l_compat_ioctl32,
+       .llseek         = no_llseek,
+       .read           = uvc_v4l2_read,
+       .mmap           = uvc_v4l2_mmap,
+       .poll           = uvc_v4l2_poll,
+};
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
new file mode 100644 (file)
index 0000000..6faf1fb
--- /dev/null
@@ -0,0 +1,934 @@
+/*
+ *      uvc_video.c  --  USB Video Class driver - Video handling
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+#include <asm/unaligned.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * UVC Controls
+ */
+
+static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+                       __u8 intfnum, __u8 cs, void *data, __u16 size,
+                       int timeout)
+{
+       __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+       unsigned int pipe;
+       int ret;
+
+       pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
+                             : usb_sndctrlpipe(dev->udev, 0);
+       type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
+
+       ret = usb_control_msg(dev->udev, pipe, query, type, cs << 8,
+                       unit << 8 | intfnum, data, size, timeout);
+
+       if (ret != size) {
+               uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u "
+                       "(unit %u) : %d (exp. %u).\n", query, cs, unit, ret,
+                       size);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+                       __u8 intfnum, __u8 cs, void *data, __u16 size)
+{
+       return __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
+                               UVC_CTRL_CONTROL_TIMEOUT);
+}
+
+static void uvc_fixup_buffer_size(struct uvc_video_device *video,
+       struct uvc_streaming_control *ctrl)
+{
+       struct uvc_format *format;
+       struct uvc_frame *frame;
+
+       if (ctrl->bFormatIndex <= 0 ||
+           ctrl->bFormatIndex > video->streaming->nformats)
+               return;
+
+       format = &video->streaming->format[ctrl->bFormatIndex - 1];
+
+       if (ctrl->bFrameIndex <= 0 ||
+           ctrl->bFrameIndex > format->nframes)
+               return;
+
+       frame = &format->frame[ctrl->bFrameIndex - 1];
+
+       if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
+            (ctrl->dwMaxVideoFrameSize == 0 &&
+             video->dev->uvc_version < 0x0110))
+               ctrl->dwMaxVideoFrameSize =
+                       frame->dwMaxVideoFrameBufferSize;
+}
+
+static int uvc_get_video_ctrl(struct uvc_video_device *video,
+       struct uvc_streaming_control *ctrl, int probe, __u8 query)
+{
+       __u8 data[34];
+       __u8 size;
+       int ret;
+
+       size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
+       ret = __uvc_query_ctrl(video->dev, query, 0, video->streaming->intfnum,
+               probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, &data, size,
+               UVC_CTRL_STREAMING_TIMEOUT);
+
+       if (ret < 0)
+               return ret;
+
+       ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
+       ctrl->bFormatIndex = data[2];
+       ctrl->bFrameIndex = data[3];
+       ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
+       ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
+       ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
+       ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
+       ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
+       ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
+       ctrl->dwMaxVideoFrameSize =
+               le32_to_cpu(get_unaligned((__le32 *)&data[18]));
+       ctrl->dwMaxPayloadTransferSize =
+               le32_to_cpu(get_unaligned((__le32 *)&data[22]));
+
+       if (size == 34) {
+               ctrl->dwClockFrequency =
+                       le32_to_cpu(get_unaligned((__le32 *)&data[26]));
+               ctrl->bmFramingInfo = data[30];
+               ctrl->bPreferedVersion = data[31];
+               ctrl->bMinVersion = data[32];
+               ctrl->bMaxVersion = data[33];
+       } else {
+               ctrl->dwClockFrequency = video->dev->clock_frequency;
+               ctrl->bmFramingInfo = 0;
+               ctrl->bPreferedVersion = 0;
+               ctrl->bMinVersion = 0;
+               ctrl->bMaxVersion = 0;
+       }
+
+       /* Some broken devices return a null or wrong dwMaxVideoFrameSize.
+        * Try to get the value from the format and frame descriptor.
+        */
+       uvc_fixup_buffer_size(video, ctrl);
+
+       return 0;
+}
+
+int uvc_set_video_ctrl(struct uvc_video_device *video,
+       struct uvc_streaming_control *ctrl, int probe)
+{
+       __u8 data[34];
+       __u8 size;
+
+       size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
+       memset(data, 0, sizeof data);
+
+       *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
+       data[2] = ctrl->bFormatIndex;
+       data[3] = ctrl->bFrameIndex;
+       *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
+       *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
+       *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
+       *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
+       *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
+       *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
+       /* Note: Some of the fields below are not required for IN devices (see
+        * UVC spec, 4.3.1.1), but we still copy them in case support for OUT
+        * devices is added in the future. */
+       put_unaligned(cpu_to_le32(ctrl->dwMaxVideoFrameSize),
+               (__le32 *)&data[18]);
+       put_unaligned(cpu_to_le32(ctrl->dwMaxPayloadTransferSize),
+               (__le32 *)&data[22]);
+
+       if (size == 34) {
+               put_unaligned(cpu_to_le32(ctrl->dwClockFrequency),
+                       (__le32 *)&data[26]);
+               data[30] = ctrl->bmFramingInfo;
+               data[31] = ctrl->bPreferedVersion;
+               data[32] = ctrl->bMinVersion;
+               data[33] = ctrl->bMaxVersion;
+       }
+
+       return __uvc_query_ctrl(video->dev, SET_CUR, 0,
+               video->streaming->intfnum,
+               probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, &data, size,
+               UVC_CTRL_STREAMING_TIMEOUT);
+}
+
+int uvc_probe_video(struct uvc_video_device *video,
+       struct uvc_streaming_control *probe)
+{
+       struct uvc_streaming_control probe_min, probe_max;
+       __u16 bandwidth;
+       unsigned int i;
+       int ret;
+
+       mutex_lock(&video->streaming->mutex);
+
+       /* Perform probing. The device should adjust the requested values
+        * according to its capabilities. However, some devices, namely the
+        * first generation UVC Logitech webcams, don't implement the Video
+        * Probe control properly, and just return the needed bandwidth. For
+        * that reason, if the needed bandwidth exceeds the maximum available
+        * bandwidth, try to lower the quality.
+        */
+       if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0)
+               goto done;
+
+       /* Get the minimum and maximum values for compression settings. */
+       if (!(video->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
+               ret = uvc_get_video_ctrl(video, &probe_min, 1, GET_MIN);
+               if (ret < 0)
+                       goto done;
+               ret = uvc_get_video_ctrl(video, &probe_max, 1, GET_MAX);
+               if (ret < 0)
+                       goto done;
+
+               probe->wCompQuality = probe_max.wCompQuality;
+       }
+
+       for (i = 0; i < 2; ++i) {
+               if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0 ||
+                   (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
+                       goto done;
+
+               if (video->streaming->intf->num_altsetting == 1)
+                       break;
+
+               bandwidth = probe->dwMaxPayloadTransferSize;
+               if (bandwidth <= video->streaming->maxpsize)
+                       break;
+
+               if (video->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
+                       ret = -ENOSPC;
+                       goto done;
+               }
+
+               /* TODO: negotiate compression parameters */
+               probe->wKeyFrameRate = probe_min.wKeyFrameRate;
+               probe->wPFrameRate = probe_min.wPFrameRate;
+               probe->wCompQuality = probe_max.wCompQuality;
+               probe->wCompWindowSize = probe_min.wCompWindowSize;
+       }
+
+done:
+       mutex_unlock(&video->streaming->mutex);
+       return ret;
+}
+
+/* ------------------------------------------------------------------------
+ * Video codecs
+ */
+
+/* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
+#define UVC_STREAM_EOH (1 << 7)
+#define UVC_STREAM_ERR (1 << 6)
+#define UVC_STREAM_STI (1 << 5)
+#define UVC_STREAM_RES (1 << 4)
+#define UVC_STREAM_SCR (1 << 3)
+#define UVC_STREAM_PTS (1 << 2)
+#define UVC_STREAM_EOF (1 << 1)
+#define UVC_STREAM_FID (1 << 0)
+
+/* Video payload decoding is handled by uvc_video_decode_start(),
+ * uvc_video_decode_data() and uvc_video_decode_end().
+ *
+ * uvc_video_decode_start is called with URB data at the start of a bulk or
+ * isochronous payload. It processes header data and returns the header size
+ * in bytes if successful. If an error occurs, it returns a negative error
+ * code. The following error codes have special meanings.
+ *
+ * - EAGAIN informs the caller that the current video buffer should be marked
+ *   as done, and that the function should be called again with the same data
+ *   and a new video buffer. This is used when end of frame conditions can be
+ *   reliably detected at the beginning of the next frame only.
+ *
+ * If an error other than -EAGAIN is returned, the caller will drop the current
+ * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
+ * made until the next payload. -ENODATA can be used to drop the current
+ * payload if no other error code is appropriate.
+ *
+ * uvc_video_decode_data is called for every URB with URB data. It copies the
+ * data to the video buffer.
+ *
+ * uvc_video_decode_end is called with header data at the end of a bulk or
+ * isochronous payload. It performs any additional header data processing and
+ * returns 0 or a negative error code if an error occured. As header data have
+ * already been processed by uvc_video_decode_start, this functions isn't
+ * required to perform sanity checks a second time.
+ *
+ * For isochronous transfers where a payload is always transfered in a single
+ * URB, the three functions will be called in a row.
+ *
+ * To let the decoder process header data and update its internal state even
+ * when no video buffer is available, uvc_video_decode_start must be prepared
+ * to be called with a NULL buf parameter. uvc_video_decode_data and
+ * uvc_video_decode_end will never be called with a NULL buffer.
+ */
+static int uvc_video_decode_start(struct uvc_video_device *video,
+               struct uvc_buffer *buf, const __u8 *data, int len)
+{
+       __u8 fid;
+
+       /* Sanity checks:
+        * - packet must be at least 2 bytes long
+        * - bHeaderLength value must be at least 2 bytes (see above)
+        * - bHeaderLength value can't be larger than the packet size.
+        */
+       if (len < 2 || data[0] < 2 || data[0] > len)
+               return -EINVAL;
+
+       /* Skip payloads marked with the error bit ("error frames"). */
+       if (data[1] & UVC_STREAM_ERR) {
+               uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
+                         "set).\n");
+               return -ENODATA;
+       }
+
+       fid = data[1] & UVC_STREAM_FID;
+
+       /* Store the payload FID bit and return immediately when the buffer is
+        * NULL.
+        */
+       if (buf == NULL) {
+               video->last_fid = fid;
+               return -ENODATA;
+       }
+
+       /* Synchronize to the input stream by waiting for the FID bit to be
+        * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
+        * queue->last_fid is initialized to -1, so the first isochronous
+        * frame will always be in sync.
+        *
+        * If the device doesn't toggle the FID bit, invert video->last_fid
+        * when the EOF bit is set to force synchronisation on the next packet.
+        */
+       if (buf->state != UVC_BUF_STATE_ACTIVE) {
+               if (fid == video->last_fid) {
+                       uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
+                               "sync).\n");
+                       if ((video->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
+                           (data[1] & UVC_STREAM_EOF))
+                               video->last_fid ^= UVC_STREAM_FID;
+                       return -ENODATA;
+               }
+
+               /* TODO: Handle PTS and SCR. */
+               buf->state = UVC_BUF_STATE_ACTIVE;
+       }
+
+       /* Mark the buffer as done if we're at the beginning of a new frame.
+        * End of frame detection is better implemented by checking the EOF
+        * bit (FID bit toggling is delayed by one frame compared to the EOF
+        * bit), but some devices don't set the bit at end of frame (and the
+        * last payload can be lost anyway). We thus must check if the FID has
+        * been toggled.
+        *
+        * queue->last_fid is initialized to -1, so the first isochronous
+        * frame will never trigger an end of frame detection.
+        *
+        * Empty buffers (bytesused == 0) don't trigger end of frame detection
+        * as it doesn't make sense to return an empty buffer. This also
+        * avoids detecting and of frame conditions at FID toggling if the
+        * previous payload had the EOF bit set.
+        */
+       if (fid != video->last_fid && buf->buf.bytesused != 0) {
+               uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
+                               "toggled).\n");
+               buf->state = UVC_BUF_STATE_DONE;
+               return -EAGAIN;
+       }
+
+       video->last_fid = fid;
+
+       return data[0];
+}
+
+static void uvc_video_decode_data(struct uvc_video_device *video,
+               struct uvc_buffer *buf, const __u8 *data, int len)
+{
+       struct uvc_video_queue *queue = &video->queue;
+       unsigned int maxlen, nbytes;
+       void *mem;
+
+       if (len <= 0)
+               return;
+
+       /* Copy the video data to the buffer. */
+       maxlen = buf->buf.length - buf->buf.bytesused;
+       mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
+       nbytes = min((unsigned int)len, maxlen);
+       memcpy(mem, data, nbytes);
+       buf->buf.bytesused += nbytes;
+
+       /* Complete the current frame if the buffer size was exceeded. */
+       if (len > maxlen) {
+               uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
+               buf->state = UVC_BUF_STATE_DONE;
+       }
+}
+
+static void uvc_video_decode_end(struct uvc_video_device *video,
+               struct uvc_buffer *buf, const __u8 *data, int len)
+{
+       /* Mark the buffer as done if the EOF marker is set. */
+       if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
+               uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
+               if (data[0] == len)
+                       uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
+               buf->state = UVC_BUF_STATE_DONE;
+               if (video->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
+                       video->last_fid ^= UVC_STREAM_FID;
+       }
+}
+
+/* ------------------------------------------------------------------------
+ * URB handling
+ */
+
+/*
+ * Completion handler for video URBs.
+ */
+static void uvc_video_decode_isoc(struct urb *urb,
+       struct uvc_video_device *video, struct uvc_buffer *buf)
+{
+       u8 *mem;
+       int ret, i;
+
+       for (i = 0; i < urb->number_of_packets; ++i) {
+               if (urb->iso_frame_desc[i].status < 0) {
+                       uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
+                               "lost (%d).\n", urb->iso_frame_desc[i].status);
+                       continue;
+               }
+
+               /* Decode the payload header. */
+               mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+               do {
+                       ret = uvc_video_decode_start(video, buf, mem,
+                               urb->iso_frame_desc[i].actual_length);
+                       if (ret == -EAGAIN)
+                               buf = uvc_queue_next_buffer(&video->queue, buf);
+               } while (ret == -EAGAIN);
+
+               if (ret < 0)
+                       continue;
+
+               /* Decode the payload data. */
+               uvc_video_decode_data(video, buf, mem + ret,
+                       urb->iso_frame_desc[i].actual_length - ret);
+
+               /* Process the header again. */
+               uvc_video_decode_end(video, buf, mem, ret);
+
+               if (buf->state == UVC_BUF_STATE_DONE ||
+                   buf->state == UVC_BUF_STATE_ERROR)
+                       buf = uvc_queue_next_buffer(&video->queue, buf);
+       }
+}
+
+static void uvc_video_decode_bulk(struct urb *urb,
+       struct uvc_video_device *video, struct uvc_buffer *buf)
+{
+       u8 *mem;
+       int len, ret;
+
+       mem = urb->transfer_buffer;
+       len = urb->actual_length;
+       video->bulk.payload_size += len;
+
+       /* If the URB is the first of its payload, decode and save the
+        * header.
+        */
+       if (video->bulk.header_size == 0) {
+               do {
+                       ret = uvc_video_decode_start(video, buf, mem, len);
+                       if (ret == -EAGAIN)
+                               buf = uvc_queue_next_buffer(&video->queue, buf);
+               } while (ret == -EAGAIN);
+
+               /* If an error occured skip the rest of the payload. */
+               if (ret < 0 || buf == NULL) {
+                       video->bulk.skip_payload = 1;
+                       return;
+               }
+
+               video->bulk.header_size = ret;
+               memcpy(video->bulk.header, mem, video->bulk.header_size);
+
+               mem += ret;
+               len -= ret;
+       }
+
+       /* The buffer queue might have been cancelled while a bulk transfer
+        * was in progress, so we can reach here with buf equal to NULL. Make
+        * sure buf is never dereferenced if NULL.
+        */
+
+       /* Process video data. */
+       if (!video->bulk.skip_payload && buf != NULL)
+               uvc_video_decode_data(video, buf, mem, len);
+
+       /* Detect the payload end by a URB smaller than the maximum size (or
+        * a payload size equal to the maximum) and process the header again.
+        */
+       if (urb->actual_length < urb->transfer_buffer_length ||
+           video->bulk.payload_size >= video->bulk.max_payload_size) {
+               if (!video->bulk.skip_payload && buf != NULL) {
+                       uvc_video_decode_end(video, buf, video->bulk.header,
+                               video->bulk.header_size);
+                       if (buf->state == UVC_BUF_STATE_DONE ||
+                           buf->state == UVC_BUF_STATE_ERROR)
+                               buf = uvc_queue_next_buffer(&video->queue, buf);
+               }
+
+               video->bulk.header_size = 0;
+               video->bulk.skip_payload = 0;
+               video->bulk.payload_size = 0;
+       }
+}
+
+static void uvc_video_complete(struct urb *urb)
+{
+       struct uvc_video_device *video = urb->context;
+       struct uvc_video_queue *queue = &video->queue;
+       struct uvc_buffer *buf = NULL;
+       unsigned long flags;
+       int ret;
+
+       switch (urb->status) {
+       case 0:
+               break;
+
+       default:
+               uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
+                       "completion handler.\n", urb->status);
+
+       case -ENOENT:           /* usb_kill_urb() called. */
+               if (video->frozen)
+                       return;
+
+       case -ECONNRESET:       /* usb_unlink_urb() called. */
+       case -ESHUTDOWN:        /* The endpoint is being disabled. */
+               uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
+               return;
+       }
+
+       spin_lock_irqsave(&queue->irqlock, flags);
+       if (!list_empty(&queue->irqqueue))
+               buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                      queue);
+       spin_unlock_irqrestore(&queue->irqlock, flags);
+
+       video->decode(urb, video, buf);
+
+       if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+               uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
+                       ret);
+       }
+}
+
+/*
+ * Uninitialize isochronous/bulk URBs and free transfer buffers.
+ */
+static void uvc_uninit_video(struct uvc_video_device *video)
+{
+       struct urb *urb;
+       unsigned int i;
+
+       for (i = 0; i < UVC_URBS; ++i) {
+               if ((urb = video->urb[i]) == NULL)
+                       continue;
+
+               usb_kill_urb(urb);
+               /* urb->transfer_buffer_length is not touched by USB core, so
+                * we can use it here as the buffer length.
+                */
+               if (video->urb_buffer[i]) {
+                       usb_buffer_free(video->dev->udev,
+                               urb->transfer_buffer_length,
+                               video->urb_buffer[i], urb->transfer_dma);
+                       video->urb_buffer[i] = NULL;
+               }
+
+               usb_free_urb(urb);
+               video->urb[i] = NULL;
+       }
+}
+
+/*
+ * Initialize isochronous URBs and allocate transfer buffers. The packet size
+ * is given by the endpoint.
+ */
+static int uvc_init_video_isoc(struct uvc_video_device *video,
+       struct usb_host_endpoint *ep)
+{
+       struct urb *urb;
+       unsigned int npackets, i, j;
+       __u16 psize;
+       __u32 size;
+
+       /* Compute the number of isochronous packets to allocate by dividing
+        * the maximum video frame size by the packet size. Limit the result
+        * to UVC_MAX_ISO_PACKETS.
+        */
+       psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+       psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+
+       size = video->streaming->ctrl.dwMaxVideoFrameSize;
+       if (size > UVC_MAX_FRAME_SIZE)
+               return -EINVAL;
+
+       npackets = (size + psize - 1) / psize;
+       if (npackets > UVC_MAX_ISO_PACKETS)
+               npackets = UVC_MAX_ISO_PACKETS;
+
+       size = npackets * psize;
+
+       for (i = 0; i < UVC_URBS; ++i) {
+               urb = usb_alloc_urb(npackets, GFP_KERNEL);
+               if (urb == NULL) {
+                       uvc_uninit_video(video);
+                       return -ENOMEM;
+               }
+
+               video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev,
+                       size, GFP_KERNEL, &urb->transfer_dma);
+               if (video->urb_buffer[i] == NULL) {
+                       usb_free_urb(urb);
+                       uvc_uninit_video(video);
+                       return -ENOMEM;
+               }
+
+               urb->dev = video->dev->udev;
+               urb->context = video;
+               urb->pipe = usb_rcvisocpipe(video->dev->udev,
+                               ep->desc.bEndpointAddress);
+               urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+               urb->interval = ep->desc.bInterval;
+               urb->transfer_buffer = video->urb_buffer[i];
+               urb->complete = uvc_video_complete;
+               urb->number_of_packets = npackets;
+               urb->transfer_buffer_length = size;
+
+               for (j = 0; j < npackets; ++j) {
+                       urb->iso_frame_desc[j].offset = j * psize;
+                       urb->iso_frame_desc[j].length = psize;
+               }
+
+               video->urb[i] = urb;
+       }
+
+       return 0;
+}
+
+/*
+ * Initialize bulk URBs and allocate transfer buffers. The packet size is
+ * given by the endpoint.
+ */
+static int uvc_init_video_bulk(struct uvc_video_device *video,
+       struct usb_host_endpoint *ep)
+{
+       struct urb *urb;
+       unsigned int pipe, i;
+       __u16 psize;
+       __u32 size;
+
+       /* Compute the bulk URB size. Some devices set the maximum payload
+        * size to a value too high for memory-constrained devices. We must
+        * then transfer the payload accross multiple URBs. To be consistant
+        * with isochronous mode, allocate maximum UVC_MAX_ISO_PACKETS per bulk
+        * URB.
+        */
+       psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
+       size = video->streaming->ctrl.dwMaxPayloadTransferSize;
+       video->bulk.max_payload_size = size;
+       if (size > psize * UVC_MAX_ISO_PACKETS)
+               size = psize * UVC_MAX_ISO_PACKETS;
+
+       pipe = usb_rcvbulkpipe(video->dev->udev, ep->desc.bEndpointAddress);
+
+       for (i = 0; i < UVC_URBS; ++i) {
+               urb = usb_alloc_urb(0, GFP_KERNEL);
+               if (urb == NULL) {
+                       uvc_uninit_video(video);
+                       return -ENOMEM;
+               }
+
+               video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev,
+                       size, GFP_KERNEL, &urb->transfer_dma);
+               if (video->urb_buffer[i] == NULL) {
+                       usb_free_urb(urb);
+                       uvc_uninit_video(video);
+                       return -ENOMEM;
+               }
+
+               usb_fill_bulk_urb(urb, video->dev->udev, pipe,
+                       video->urb_buffer[i], size, uvc_video_complete,
+                       video);
+               urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+
+               video->urb[i] = urb;
+       }
+
+       return 0;
+}
+
+/*
+ * Initialize isochronous/bulk URBs and allocate transfer buffers.
+ */
+static int uvc_init_video(struct uvc_video_device *video)
+{
+       struct usb_interface *intf = video->streaming->intf;
+       struct usb_host_interface *alts;
+       struct usb_host_endpoint *ep = NULL;
+       int intfnum = video->streaming->intfnum;
+       unsigned int bandwidth, psize, i;
+       int ret;
+
+       video->last_fid = -1;
+       video->bulk.header_size = 0;
+       video->bulk.skip_payload = 0;
+       video->bulk.payload_size = 0;
+
+       if (intf->num_altsetting > 1) {
+               /* Isochronous endpoint, select the alternate setting. */
+               bandwidth = video->streaming->ctrl.dwMaxPayloadTransferSize;
+
+               if (bandwidth == 0) {
+                       uvc_printk(KERN_WARNING, "device %s requested null "
+                               "bandwidth, defaulting to lowest.\n",
+                               video->vdev->name);
+                       bandwidth = 1;
+               }
+
+               for (i = 0; i < intf->num_altsetting; ++i) {
+                       alts = &intf->altsetting[i];
+                       ep = uvc_find_endpoint(alts,
+                               video->streaming->header.bEndpointAddress);
+                       if (ep == NULL)
+                               continue;
+
+                       /* Check if the bandwidth is high enough. */
+                       psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+                       psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+                       if (psize >= bandwidth)
+                               break;
+               }
+
+               if (i >= intf->num_altsetting)
+                       return -EIO;
+
+               if ((ret = usb_set_interface(video->dev->udev, intfnum, i)) < 0)
+                       return ret;
+
+               ret = uvc_init_video_isoc(video, ep);
+       } else {
+               /* Bulk endpoint, proceed to URB initialization. */
+               ep = uvc_find_endpoint(&intf->altsetting[0],
+                               video->streaming->header.bEndpointAddress);
+               if (ep == NULL)
+                       return -EIO;
+
+               ret = uvc_init_video_bulk(video, ep);
+       }
+
+       if (ret < 0)
+               return ret;
+
+       /* Submit the URBs. */
+       for (i = 0; i < UVC_URBS; ++i) {
+               if ((ret = usb_submit_urb(video->urb[i], GFP_KERNEL)) < 0) {
+                       uvc_printk(KERN_ERR, "Failed to submit URB %u "
+                                       "(%d).\n", i, ret);
+                       uvc_uninit_video(video);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Suspend/resume
+ */
+
+/*
+ * Stop streaming without disabling the video queue.
+ *
+ * To let userspace applications resume without trouble, we must not touch the
+ * video buffers in any way. We mark the device as frozen to make sure the URB
+ * completion handler won't try to cancel the queue when we kill the URBs.
+ */
+int uvc_video_suspend(struct uvc_video_device *video)
+{
+       if (!uvc_queue_streaming(&video->queue))
+               return 0;
+
+       video->frozen = 1;
+       uvc_uninit_video(video);
+       usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
+       return 0;
+}
+
+/*
+ * Reconfigure the video interface and restart streaming if it was enable
+ * before suspend.
+ *
+ * If an error occurs, disable the video queue. This will wake all pending
+ * buffers, making sure userspace applications are notified of the problem
+ * instead of waiting forever.
+ */
+int uvc_video_resume(struct uvc_video_device *video)
+{
+       int ret;
+
+       video->frozen = 0;
+
+       if ((ret = uvc_set_video_ctrl(video, &video->streaming->ctrl, 0)) < 0) {
+               uvc_queue_enable(&video->queue, 0);
+               return ret;
+       }
+
+       if (!uvc_queue_streaming(&video->queue))
+               return 0;
+
+       if ((ret = uvc_init_video(video)) < 0)
+               uvc_queue_enable(&video->queue, 0);
+
+       return ret;
+}
+
+/* ------------------------------------------------------------------------
+ * Video device
+ */
+
+/*
+ * Initialize the UVC video device by retrieving the default format and
+ * committing it.
+ *
+ * Some cameras (namely the Fuji Finepix) set the format and frame
+ * indexes to zero. The UVC standard doesn't clearly make this a spec
+ * violation, so try to silently fix the values if possible.
+ *
+ * This function is called before registering the device with V4L.
+ */
+int uvc_video_init(struct uvc_video_device *video)
+{
+       struct uvc_streaming_control *probe = &video->streaming->ctrl;
+       struct uvc_format *format = NULL;
+       struct uvc_frame *frame = NULL;
+       unsigned int i;
+       int ret;
+
+       if (video->streaming->nformats == 0) {
+               uvc_printk(KERN_INFO, "No supported video formats found.\n");
+               return -EINVAL;
+       }
+
+       /* Alternate setting 0 should be the default, yet the XBox Live Vision
+        * Cam (and possibly other devices) crash or otherwise misbehave if
+        * they don't receive a SET_INTERFACE request before any other video
+        * control request.
+        */
+       usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
+
+       /* Some webcams don't suport GET_DEF request on the probe control. We
+        * fall back to GET_CUR if GET_DEF fails.
+        */
+       if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 &&
+           (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
+               return ret;
+
+       /* Check if the default format descriptor exists. Use the first
+        * available format otherwise.
+        */
+       for (i = video->streaming->nformats; i > 0; --i) {
+               format = &video->streaming->format[i-1];
+               if (format->index == probe->bFormatIndex)
+                       break;
+       }
+
+       if (format->nframes == 0) {
+               uvc_printk(KERN_INFO, "No frame descriptor found for the "
+                       "default format.\n");
+               return -EINVAL;
+       }
+
+       /* Zero bFrameIndex might be correct. Stream-based formats (including
+        * MPEG-2 TS and DV) do not support frames but have a dummy frame
+        * descriptor with bFrameIndex set to zero. If the default frame
+        * descriptor is not found, use the first avalable frame.
+        */
+       for (i = format->nframes; i > 0; --i) {
+               frame = &format->frame[i-1];
+               if (frame->bFrameIndex == probe->bFrameIndex)
+                       break;
+       }
+
+       /* Commit the default settings. */
+       probe->bFormatIndex = format->index;
+       probe->bFrameIndex = frame->bFrameIndex;
+       if ((ret = uvc_set_video_ctrl(video, probe, 0)) < 0)
+               return ret;
+
+       video->streaming->cur_format = format;
+       video->streaming->cur_frame = frame;
+       atomic_set(&video->active, 0);
+
+       /* Select the video decoding function */
+       if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
+               video->decode = uvc_video_decode_isight;
+       else if (video->streaming->intf->num_altsetting > 1)
+               video->decode = uvc_video_decode_isoc;
+       else
+               video->decode = uvc_video_decode_bulk;
+
+       return 0;
+}
+
+/*
+ * Enable or disable the video stream.
+ */
+int uvc_video_enable(struct uvc_video_device *video, int enable)
+{
+       int ret;
+
+       if (!enable) {
+               uvc_uninit_video(video);
+               usb_set_interface(video->dev->udev,
+                       video->streaming->intfnum, 0);
+               uvc_queue_enable(&video->queue, 0);
+               return 0;
+       }
+
+       if ((ret = uvc_queue_enable(&video->queue, 1)) < 0)
+               return ret;
+
+       return uvc_init_video(video);
+}
diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
new file mode 100644 (file)
index 0000000..a995a78
--- /dev/null
@@ -0,0 +1,796 @@
+#ifndef _USB_VIDEO_H_
+#define _USB_VIDEO_H_
+
+#include <linux/kernel.h>
+#include <linux/videodev2.h>
+
+
+/*
+ * Dynamic controls
+ */
+
+/* Data types for UVC control data */
+#define UVC_CTRL_DATA_TYPE_RAW         0
+#define UVC_CTRL_DATA_TYPE_SIGNED      1
+#define UVC_CTRL_DATA_TYPE_UNSIGNED    2
+#define UVC_CTRL_DATA_TYPE_BOOLEAN     3
+#define UVC_CTRL_DATA_TYPE_ENUM                4
+#define UVC_CTRL_DATA_TYPE_BITMASK     5
+
+/* Control flags */
+#define UVC_CONTROL_SET_CUR    (1 << 0)
+#define UVC_CONTROL_GET_CUR    (1 << 1)
+#define UVC_CONTROL_GET_MIN    (1 << 2)
+#define UVC_CONTROL_GET_MAX    (1 << 3)
+#define UVC_CONTROL_GET_RES    (1 << 4)
+#define UVC_CONTROL_GET_DEF    (1 << 5)
+/* Control should be saved at suspend and restored at resume. */
+#define UVC_CONTROL_RESTORE    (1 << 6)
+/* Control can be updated by the camera. */
+#define UVC_CONTROL_AUTO_UPDATE        (1 << 7)
+
+#define UVC_CONTROL_GET_RANGE  (UVC_CONTROL_GET_CUR | UVC_CONTROL_GET_MIN | \
+                                UVC_CONTROL_GET_MAX | UVC_CONTROL_GET_RES | \
+                                UVC_CONTROL_GET_DEF)
+
+struct uvc_xu_control_info {
+       __u8 entity[16];
+       __u8 index;
+       __u8 selector;
+       __u16 size;
+       __u32 flags;
+};
+
+struct uvc_xu_control_mapping {
+       __u32 id;
+       __u8 name[32];
+       __u8 entity[16];
+       __u8 selector;
+
+       __u8 size;
+       __u8 offset;
+       enum v4l2_ctrl_type v4l2_type;
+       __u32 data_type;
+};
+
+struct uvc_xu_control {
+       __u8 unit;
+       __u8 selector;
+       __u16 size;
+       __u8 __user *data;
+};
+
+#define UVCIOC_CTRL_ADD                _IOW('U', 1, struct uvc_xu_control_info)
+#define UVCIOC_CTRL_MAP                _IOWR('U', 2, struct uvc_xu_control_mapping)
+#define UVCIOC_CTRL_GET                _IOWR('U', 3, struct uvc_xu_control)
+#define UVCIOC_CTRL_SET                _IOW('U', 4, struct uvc_xu_control)
+
+#ifdef __KERNEL__
+
+#include <linux/poll.h>
+
+/* --------------------------------------------------------------------------
+ * UVC constants
+ */
+
+#define SC_UNDEFINED                    0x00
+#define SC_VIDEOCONTROL                 0x01
+#define SC_VIDEOSTREAMING               0x02
+#define SC_VIDEO_INTERFACE_COLLECTION   0x03
+
+#define PC_PROTOCOL_UNDEFINED           0x00
+
+#define CS_UNDEFINED                    0x20
+#define CS_DEVICE                       0x21
+#define CS_CONFIGURATION                0x22
+#define CS_STRING                       0x23
+#define CS_INTERFACE                    0x24
+#define CS_ENDPOINT                     0x25
+
+/* VideoControl class specific interface descriptor */
+#define VC_DESCRIPTOR_UNDEFINED         0x00
+#define VC_HEADER                       0x01
+#define VC_INPUT_TERMINAL               0x02
+#define VC_OUTPUT_TERMINAL              0x03
+#define VC_SELECTOR_UNIT                0x04
+#define VC_PROCESSING_UNIT              0x05
+#define VC_EXTENSION_UNIT               0x06
+
+/* VideoStreaming class specific interface descriptor */
+#define VS_UNDEFINED                    0x00
+#define VS_INPUT_HEADER                 0x01
+#define VS_OUTPUT_HEADER                0x02
+#define VS_STILL_IMAGE_FRAME            0x03
+#define VS_FORMAT_UNCOMPRESSED          0x04
+#define VS_FRAME_UNCOMPRESSED           0x05
+#define VS_FORMAT_MJPEG                 0x06
+#define VS_FRAME_MJPEG                  0x07
+#define VS_FORMAT_MPEG2TS               0x0a
+#define VS_FORMAT_DV                    0x0c
+#define VS_COLORFORMAT                  0x0d
+#define VS_FORMAT_FRAME_BASED           0x10
+#define VS_FRAME_FRAME_BASED            0x11
+#define VS_FORMAT_STREAM_BASED          0x12
+
+/* Endpoint type */
+#define EP_UNDEFINED                    0x00
+#define EP_GENERAL                      0x01
+#define EP_ENDPOINT                     0x02
+#define EP_INTERRUPT                    0x03
+
+/* Request codes */
+#define RC_UNDEFINED                    0x00
+#define SET_CUR                         0x01
+#define GET_CUR                         0x81
+#define GET_MIN                         0x82
+#define GET_MAX                         0x83
+#define GET_RES                         0x84
+#define GET_LEN                         0x85
+#define GET_INFO                        0x86
+#define GET_DEF                         0x87
+
+/* VideoControl interface controls */
+#define VC_CONTROL_UNDEFINED            0x00
+#define VC_VIDEO_POWER_MODE_CONTROL     0x01
+#define VC_REQUEST_ERROR_CODE_CONTROL   0x02
+
+/* Terminal controls */
+#define TE_CONTROL_UNDEFINED            0x00
+
+/* Selector Unit controls */
+#define SU_CONTROL_UNDEFINED            0x00
+#define SU_INPUT_SELECT_CONTROL         0x01
+
+/* Camera Terminal controls */
+#define CT_CONTROL_UNDEFINED                           0x00
+#define CT_SCANNING_MODE_CONTROL                       0x01
+#define CT_AE_MODE_CONTROL                             0x02
+#define CT_AE_PRIORITY_CONTROL                         0x03
+#define CT_EXPOSURE_TIME_ABSOLUTE_CONTROL               0x04
+#define CT_EXPOSURE_TIME_RELATIVE_CONTROL               0x05
+#define CT_FOCUS_ABSOLUTE_CONTROL                      0x06
+#define CT_FOCUS_RELATIVE_CONTROL                      0x07
+#define CT_FOCUS_AUTO_CONTROL                          0x08
+#define CT_IRIS_ABSOLUTE_CONTROL                       0x09
+#define CT_IRIS_RELATIVE_CONTROL                       0x0a
+#define CT_ZOOM_ABSOLUTE_CONTROL                       0x0b
+#define CT_ZOOM_RELATIVE_CONTROL                       0x0c
+#define CT_PANTILT_ABSOLUTE_CONTROL                    0x0d
+#define CT_PANTILT_RELATIVE_CONTROL                    0x0e
+#define CT_ROLL_ABSOLUTE_CONTROL                       0x0f
+#define CT_ROLL_RELATIVE_CONTROL                       0x10
+#define CT_PRIVACY_CONTROL                             0x11
+
+/* Processing Unit controls */
+#define PU_CONTROL_UNDEFINED                           0x00
+#define PU_BACKLIGHT_COMPENSATION_CONTROL               0x01
+#define PU_BRIGHTNESS_CONTROL                          0x02
+#define PU_CONTRAST_CONTROL                            0x03
+#define PU_GAIN_CONTROL                                0x04
+#define PU_POWER_LINE_FREQUENCY_CONTROL                0x05
+#define PU_HUE_CONTROL                                 0x06
+#define PU_SATURATION_CONTROL                          0x07
+#define PU_SHARPNESS_CONTROL                           0x08
+#define PU_GAMMA_CONTROL                               0x09
+#define PU_WHITE_BALANCE_TEMPERATURE_CONTROL            0x0a
+#define PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL       0x0b
+#define PU_WHITE_BALANCE_COMPONENT_CONTROL              0x0c
+#define PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL         0x0d
+#define PU_DIGITAL_MULTIPLIER_CONTROL                  0x0e
+#define PU_DIGITAL_MULTIPLIER_LIMIT_CONTROL             0x0f
+#define PU_HUE_AUTO_CONTROL                            0x10
+#define PU_ANALOG_VIDEO_STANDARD_CONTROL                0x11
+#define PU_ANALOG_LOCK_STATUS_CONTROL                  0x12
+
+#define LXU_MOTOR_PANTILT_RELATIVE_CONTROL             0x01
+#define LXU_MOTOR_PANTILT_RESET_CONTROL                        0x02
+#define LXU_MOTOR_FOCUS_MOTOR_CONTROL                  0x03
+
+/* VideoStreaming interface controls */
+#define VS_CONTROL_UNDEFINED            0x00
+#define VS_PROBE_CONTROL                0x01
+#define VS_COMMIT_CONTROL               0x02
+#define VS_STILL_PROBE_CONTROL          0x03
+#define VS_STILL_COMMIT_CONTROL         0x04
+#define VS_STILL_IMAGE_TRIGGER_CONTROL  0x05
+#define VS_STREAM_ERROR_CODE_CONTROL    0x06
+#define VS_GENERATE_KEY_FRAME_CONTROL   0x07
+#define VS_UPDATE_FRAME_SEGMENT_CONTROL 0x08
+#define VS_SYNC_DELAY_CONTROL           0x09
+
+#define TT_VENDOR_SPECIFIC              0x0100
+#define TT_STREAMING                    0x0101
+
+/* Input Terminal types */
+#define ITT_VENDOR_SPECIFIC             0x0200
+#define ITT_CAMERA                      0x0201
+#define ITT_MEDIA_TRANSPORT_INPUT       0x0202
+
+/* Output Terminal types */
+#define OTT_VENDOR_SPECIFIC             0x0300
+#define OTT_DISPLAY                     0x0301
+#define OTT_MEDIA_TRANSPORT_OUTPUT      0x0302
+
+/* External Terminal types */
+#define EXTERNAL_VENDOR_SPECIFIC        0x0400
+#define COMPOSITE_CONNECTOR             0x0401
+#define SVIDEO_CONNECTOR                0x0402
+#define COMPONENT_CONNECTOR             0x0403
+
+#define UVC_TERM_INPUT                 0x0000
+#define UVC_TERM_OUTPUT                        0x8000
+
+#define UVC_ENTITY_TYPE(entity)                ((entity)->type & 0x7fff)
+#define UVC_ENTITY_IS_UNIT(entity)     (((entity)->type & 0xff00) == 0)
+#define UVC_ENTITY_IS_TERM(entity)     (((entity)->type & 0xff00) != 0)
+#define UVC_ENTITY_IS_ITERM(entity) \
+       (((entity)->type & 0x8000) == UVC_TERM_INPUT)
+#define UVC_ENTITY_IS_OTERM(entity) \
+       (((entity)->type & 0x8000) == UVC_TERM_OUTPUT)
+
+#define UVC_STATUS_TYPE_CONTROL                1
+#define UVC_STATUS_TYPE_STREAMING      2
+
+/* ------------------------------------------------------------------------
+ * GUIDs
+ */
+#define UVC_GUID_UVC_CAMERA \
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}
+#define UVC_GUID_UVC_OUTPUT \
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}
+#define UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT \
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03}
+#define UVC_GUID_UVC_PROCESSING \
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01}
+#define UVC_GUID_UVC_SELECTOR \
+       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02}
+
+#define UVC_GUID_LOGITECH_DEV_INFO \
+       {0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
+        0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x1e}
+#define UVC_GUID_LOGITECH_USER_HW \
+       {0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
+        0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x1f}
+#define UVC_GUID_LOGITECH_VIDEO \
+       {0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
+        0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x50}
+#define UVC_GUID_LOGITECH_MOTOR \
+       {0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
+        0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x56}
+
+#define UVC_GUID_FORMAT_MJPEG \
+       { 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_YUY2 \
+       { 'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_NV12 \
+       { 'N',  'V',  '1',  '2', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_YV12 \
+       { 'Y',  'V',  '1',  '2', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_I420 \
+       { 'I',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_UYVY \
+       { 'U',  'Y',  'V',  'Y', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y800 \
+       { 'Y',  '8',  '0',  '0', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_BY8 \
+       { 'B',  'Y',  '8',  ' ', 0x00, 0x00, 0x10, 0x00, \
+        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+
+
+/* ------------------------------------------------------------------------
+ * Driver specific constants.
+ */
+
+#define DRIVER_VERSION_NUMBER  KERNEL_VERSION(0, 1, 0)
+
+/* Number of isochronous URBs. */
+#define UVC_URBS               5
+/* Maximum number of packets per isochronous URB. */
+#define UVC_MAX_ISO_PACKETS    40
+/* Maximum frame size in bytes, for sanity checking. */
+#define UVC_MAX_FRAME_SIZE     (16*1024*1024)
+/* Maximum number of video buffers. */
+#define UVC_MAX_VIDEO_BUFFERS  32
+
+#define UVC_CTRL_CONTROL_TIMEOUT       300
+#define UVC_CTRL_STREAMING_TIMEOUT     1000
+
+/* Devices quirks */
+#define UVC_QUIRK_STATUS_INTERVAL      0x00000001
+#define UVC_QUIRK_PROBE_MINMAX         0x00000002
+#define UVC_QUIRK_PROBE_EXTRAFIELDS    0x00000004
+#define UVC_QUIRK_BUILTIN_ISIGHT       0x00000008
+#define UVC_QUIRK_STREAM_NO_FID                0x00000010
+#define UVC_QUIRK_IGNORE_SELECTOR_UNIT 0x00000020
+
+/* Format flags */
+#define UVC_FMT_FLAG_COMPRESSED                0x00000001
+#define UVC_FMT_FLAG_STREAM            0x00000002
+
+/* ------------------------------------------------------------------------
+ * Structures.
+ */
+
+struct uvc_device;
+
+/* TODO: Put the most frequently accessed fields at the beginning of
+ * structures to maximize cache efficiency.
+ */
+struct uvc_streaming_control {
+       __u16 bmHint;
+       __u8  bFormatIndex;
+       __u8  bFrameIndex;
+       __u32 dwFrameInterval;
+       __u16 wKeyFrameRate;
+       __u16 wPFrameRate;
+       __u16 wCompQuality;
+       __u16 wCompWindowSize;
+       __u16 wDelay;
+       __u32 dwMaxVideoFrameSize;
+       __u32 dwMaxPayloadTransferSize;
+       __u32 dwClockFrequency;
+       __u8  bmFramingInfo;
+       __u8  bPreferedVersion;
+       __u8  bMinVersion;
+       __u8  bMaxVersion;
+};
+
+struct uvc_menu_info {
+       __u32 value;
+       __u8 name[32];
+};
+
+struct uvc_control_info {
+       struct list_head list;
+       struct list_head mappings;
+
+       __u8 entity[16];
+       __u8 index;
+       __u8 selector;
+
+       __u16 size;
+       __u32 flags;
+};
+
+struct uvc_control_mapping {
+       struct list_head list;
+
+       struct uvc_control_info *ctrl;
+
+       __u32 id;
+       __u8 name[32];
+       __u8 entity[16];
+       __u8 selector;
+
+       __u8 size;
+       __u8 offset;
+       enum v4l2_ctrl_type v4l2_type;
+       __u32 data_type;
+
+       struct uvc_menu_info *menu_info;
+       __u32 menu_count;
+};
+
+struct uvc_control {
+       struct uvc_entity *entity;
+       struct uvc_control_info *info;
+
+       __u8 index;     /* Used to match the uvc_control entry with a
+                          uvc_control_info. */
+       __u8 dirty : 1,
+            loaded : 1,
+            modified : 1;
+
+       __u8 *data;
+};
+
+struct uvc_format_desc {
+       char *name;
+       __u8 guid[16];
+       __u32 fcc;
+};
+
+/* The term 'entity' refers to both UVC units and UVC terminals.
+ *
+ * The type field is either the terminal type (wTerminalType in the terminal
+ * descriptor), or the unit type (bDescriptorSubtype in the unit descriptor).
+ * As the bDescriptorSubtype field is one byte long, the type value will
+ * always have a null MSB for units. All terminal types defined by the UVC
+ * specification have a non-null MSB, so it is safe to use the MSB to
+ * differentiate between units and terminals as long as the descriptor parsing
+ * code makes sure terminal types have a non-null MSB.
+ *
+ * For terminals, the type's most significant bit stores the terminal
+ * direction (either UVC_TERM_INPUT or UVC_TERM_OUTPUT). The type field should
+ * always be accessed with the UVC_ENTITY_* macros and never directly.
+ */
+
+struct uvc_entity {
+       struct list_head list;          /* Entity as part of a UVC device. */
+       struct list_head chain;         /* Entity as part of a video device
+                                        * chain. */
+       __u8 id;
+       __u16 type;
+       char name[64];
+
+       union {
+               struct {
+                       __u16 wObjectiveFocalLengthMin;
+                       __u16 wObjectiveFocalLengthMax;
+                       __u16 wOcularFocalLength;
+                       __u8  bControlSize;
+                       __u8  *bmControls;
+               } camera;
+
+               struct {
+                       __u8  bControlSize;
+                       __u8  *bmControls;
+                       __u8  bTransportModeSize;
+                       __u8  *bmTransportModes;
+               } media;
+
+               struct {
+                       __u8  bSourceID;
+               } output;
+
+               struct {
+                       __u8  bSourceID;
+                       __u16 wMaxMultiplier;
+                       __u8  bControlSize;
+                       __u8  *bmControls;
+                       __u8  bmVideoStandards;
+               } processing;
+
+               struct {
+                       __u8  bNrInPins;
+                       __u8  *baSourceID;
+               } selector;
+
+               struct {
+                       __u8  guidExtensionCode[16];
+                       __u8  bNumControls;
+                       __u8  bNrInPins;
+                       __u8  *baSourceID;
+                       __u8  bControlSize;
+                       __u8  *bmControls;
+                       __u8  *bmControlsType;
+               } extension;
+       };
+
+       unsigned int ncontrols;
+       struct uvc_control *controls;
+};
+
+struct uvc_frame {
+       __u8  bFrameIndex;
+       __u8  bmCapabilities;
+       __u16 wWidth;
+       __u16 wHeight;
+       __u32 dwMinBitRate;
+       __u32 dwMaxBitRate;
+       __u32 dwMaxVideoFrameBufferSize;
+       __u8  bFrameIntervalType;
+       __u32 dwDefaultFrameInterval;
+       __u32 *dwFrameInterval;
+};
+
+struct uvc_format {
+       __u8 type;
+       __u8 index;
+       __u8 bpp;
+       __u8 colorspace;
+       __u32 fcc;
+       __u32 flags;
+
+       char name[32];
+
+       unsigned int nframes;
+       struct uvc_frame *frame;
+};
+
+struct uvc_streaming_header {
+       __u8 bNumFormats;
+       __u8 bEndpointAddress;
+       __u8 bTerminalLink;
+       __u8 bControlSize;
+       __u8 *bmaControls;
+       /* The following fields are used by input headers only. */
+       __u8 bmInfo;
+       __u8 bStillCaptureMethod;
+       __u8 bTriggerSupport;
+       __u8 bTriggerUsage;
+};
+
+struct uvc_streaming {
+       struct list_head list;
+
+       struct usb_interface *intf;
+       int intfnum;
+       __u16 maxpsize;
+
+       struct uvc_streaming_header header;
+
+       unsigned int nformats;
+       struct uvc_format *format;
+
+       struct uvc_streaming_control ctrl;
+       struct uvc_format *cur_format;
+       struct uvc_frame *cur_frame;
+
+       struct mutex mutex;
+};
+
+enum uvc_buffer_state {
+       UVC_BUF_STATE_IDLE       = 0,
+       UVC_BUF_STATE_QUEUED     = 1,
+       UVC_BUF_STATE_ACTIVE     = 2,
+       UVC_BUF_STATE_DONE       = 3,
+       UVC_BUF_STATE_ERROR      = 4,
+};
+
+struct uvc_buffer {
+       unsigned long vma_use_count;
+       struct list_head stream;
+
+       /* Touched by interrupt handler. */
+       struct v4l2_buffer buf;
+       struct list_head queue;
+       wait_queue_head_t wait;
+       enum uvc_buffer_state state;
+};
+
+#define UVC_QUEUE_STREAMING            (1 << 0)
+#define UVC_QUEUE_DISCONNECTED         (1 << 1)
+#define UVC_QUEUE_DROP_INCOMPLETE      (1 << 2)
+
+struct uvc_video_queue {
+       void *mem;
+       unsigned int flags;
+       __u32 sequence;
+
+       unsigned int count;
+       unsigned int buf_size;
+       struct uvc_buffer buffer[UVC_MAX_VIDEO_BUFFERS];
+       struct mutex mutex;     /* protects buffers and mainqueue */
+       spinlock_t irqlock;     /* protects irqqueue */
+
+       struct list_head mainqueue;
+       struct list_head irqqueue;
+};
+
+struct uvc_video_device {
+       struct uvc_device *dev;
+       struct video_device *vdev;
+       atomic_t active;
+       unsigned int frozen : 1;
+
+       struct list_head iterms;
+       struct uvc_entity *oterm;
+       struct uvc_entity *processing;
+       struct uvc_entity *selector;
+       struct list_head extensions;
+       struct mutex ctrl_mutex;
+
+       struct uvc_video_queue queue;
+
+       /* Video streaming object, must always be non-NULL. */
+       struct uvc_streaming *streaming;
+
+       void (*decode) (struct urb *urb, struct uvc_video_device *video,
+                       struct uvc_buffer *buf);
+
+       /* Context data used by the bulk completion handler. */
+       struct {
+               __u8 header[256];
+               unsigned int header_size;
+               int skip_payload;
+               __u32 payload_size;
+               __u32 max_payload_size;
+       } bulk;
+
+       struct urb *urb[UVC_URBS];
+       char *urb_buffer[UVC_URBS];
+
+       __u8 last_fid;
+};
+
+enum uvc_device_state {
+       UVC_DEV_DISCONNECTED = 1,
+};
+
+struct uvc_device {
+       struct usb_device *udev;
+       struct usb_interface *intf;
+       __u32 quirks;
+       int intfnum;
+       char name[32];
+
+       enum uvc_device_state state;
+       struct kref kref;
+       struct list_head list;
+
+       /* Video control interface */
+       __u16 uvc_version;
+       __u32 clock_frequency;
+
+       struct list_head entities;
+
+       struct uvc_video_device video;
+
+       /* Status Interrupt Endpoint */
+       struct usb_host_endpoint *int_ep;
+       struct urb *int_urb;
+       __u8 status[16];
+       struct input_dev *input;
+
+       /* Video Streaming interfaces */
+       struct list_head streaming;
+};
+
+enum uvc_handle_state {
+       UVC_HANDLE_PASSIVE      = 0,
+       UVC_HANDLE_ACTIVE       = 1,
+};
+
+struct uvc_fh {
+       struct uvc_video_device *device;
+       enum uvc_handle_state state;
+};
+
+struct uvc_driver {
+       struct usb_driver driver;
+
+       struct mutex open_mutex;        /* protects from open/disconnect race */
+
+       struct list_head devices;       /* struct uvc_device list */
+       struct list_head controls;      /* struct uvc_control_info list */
+       struct mutex ctrl_mutex;        /* protects controls and devices
+                                          lists */
+};
+
+/* ------------------------------------------------------------------------
+ * Debugging, printing and logging
+ */
+
+#define UVC_TRACE_PROBE                (1 << 0)
+#define UVC_TRACE_DESCR                (1 << 1)
+#define UVC_TRACE_CONTROL      (1 << 2)
+#define UVC_TRACE_FORMAT       (1 << 3)
+#define UVC_TRACE_CAPTURE      (1 << 4)
+#define UVC_TRACE_CALLS                (1 << 5)
+#define UVC_TRACE_IOCTL                (1 << 6)
+#define UVC_TRACE_FRAME                (1 << 7)
+#define UVC_TRACE_SUSPEND      (1 << 8)
+#define UVC_TRACE_STATUS       (1 << 9)
+
+extern unsigned int uvc_trace_param;
+
+#define uvc_trace(flag, msg...) \
+       do { \
+               if (uvc_trace_param & flag) \
+                       printk(KERN_DEBUG "uvcvideo: " msg); \
+       } while (0)
+
+#define uvc_printk(level, msg...) \
+       printk(level "uvcvideo: " msg)
+
+#define UVC_GUID_FORMAT "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-" \
+                       "%02x%02x%02x%02x%02x%02x"
+#define UVC_GUID_ARGS(guid) \
+       (guid)[3],  (guid)[2],  (guid)[1],  (guid)[0], \
+       (guid)[5],  (guid)[4], \
+       (guid)[7],  (guid)[6], \
+       (guid)[8],  (guid)[9], \
+       (guid)[10], (guid)[11], (guid)[12], \
+       (guid)[13], (guid)[14], (guid)[15]
+
+/* --------------------------------------------------------------------------
+ * Internal functions.
+ */
+
+/* Core driver */
+extern struct uvc_driver uvc_driver;
+extern void uvc_delete(struct kref *kref);
+
+/* Video buffers queue management. */
+extern void uvc_queue_init(struct uvc_video_queue *queue);
+extern int uvc_alloc_buffers(struct uvc_video_queue *queue,
+               unsigned int nbuffers, unsigned int buflength);
+extern int uvc_free_buffers(struct uvc_video_queue *queue);
+extern int uvc_query_buffer(struct uvc_video_queue *queue,
+               struct v4l2_buffer *v4l2_buf);
+extern int uvc_queue_buffer(struct uvc_video_queue *queue,
+               struct v4l2_buffer *v4l2_buf);
+extern int uvc_dequeue_buffer(struct uvc_video_queue *queue,
+               struct v4l2_buffer *v4l2_buf, int nonblocking);
+extern int uvc_queue_enable(struct uvc_video_queue *queue, int enable);
+extern void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
+extern struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+               struct uvc_buffer *buf);
+extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
+               struct file *file, poll_table *wait);
+static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
+{
+       return queue->flags & UVC_QUEUE_STREAMING;
+}
+
+/* V4L2 interface */
+extern struct file_operations uvc_fops;
+
+/* Video */
+extern int uvc_video_init(struct uvc_video_device *video);
+extern int uvc_video_suspend(struct uvc_video_device *video);
+extern int uvc_video_resume(struct uvc_video_device *video);
+extern int uvc_video_enable(struct uvc_video_device *video, int enable);
+extern int uvc_probe_video(struct uvc_video_device *video,
+               struct uvc_streaming_control *probe);
+extern int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+               __u8 intfnum, __u8 cs, void *data, __u16 size);
+extern int uvc_set_video_ctrl(struct uvc_video_device *video,
+               struct uvc_streaming_control *ctrl, int probe);
+
+/* Status */
+extern int uvc_status_init(struct uvc_device *dev);
+extern void uvc_status_cleanup(struct uvc_device *dev);
+extern int uvc_status_suspend(struct uvc_device *dev);
+extern int uvc_status_resume(struct uvc_device *dev);
+
+/* Controls */
+extern struct uvc_control *uvc_find_control(struct uvc_video_device *video,
+               __u32 v4l2_id, struct uvc_control_mapping **mapping);
+extern int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
+               struct v4l2_queryctrl *v4l2_ctrl);
+
+extern int uvc_ctrl_add_info(struct uvc_control_info *info);
+extern int uvc_ctrl_add_mapping(struct uvc_control_mapping *mapping);
+extern int uvc_ctrl_init_device(struct uvc_device *dev);
+extern void uvc_ctrl_cleanup_device(struct uvc_device *dev);
+extern int uvc_ctrl_resume_device(struct uvc_device *dev);
+extern void uvc_ctrl_init(void);
+
+extern int uvc_ctrl_begin(struct uvc_video_device *video);
+extern int __uvc_ctrl_commit(struct uvc_video_device *video, int rollback);
+static inline int uvc_ctrl_commit(struct uvc_video_device *video)
+{
+       return __uvc_ctrl_commit(video, 0);
+}
+static inline int uvc_ctrl_rollback(struct uvc_video_device *video)
+{
+       return __uvc_ctrl_commit(video, 1);
+}
+
+extern int uvc_ctrl_get(struct uvc_video_device *video,
+               struct v4l2_ext_control *xctrl);
+extern int uvc_ctrl_set(struct uvc_video_device *video,
+               struct v4l2_ext_control *xctrl);
+
+extern int uvc_xu_ctrl_query(struct uvc_video_device *video,
+               struct uvc_xu_control *ctrl, int set);
+
+/* Utility functions */
+extern void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
+               unsigned int n_terms, unsigned int threshold);
+extern uint32_t uvc_fraction_to_interval(uint32_t numerator,
+               uint32_t denominator);
+extern struct usb_host_endpoint *uvc_find_endpoint(
+               struct usb_host_interface *alts, __u8 epaddr);
+
+/* Quirks support */
+void uvc_video_decode_isight(struct urb *urb, struct uvc_video_device *video,
+               struct uvc_buffer *buf);
+
+#endif /* __KERNEL__ */
+
+#endif