usb gadget serial: split out generic serial function
David Brownell [Fri, 20 Jun 2008 01:18:50 +0000 (18:18 -0700)]
Split out the generic serial support into a "function driver".  This
closely mimics the ACM support, but with a MUCH simpler control model.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/DocBook/gadget.tmpl
drivers/usb/gadget/Makefile
drivers/usb/gadget/f_serial.c [new file with mode: 0644]
drivers/usb/gadget/u_serial.h

index b7e266c..ea3bc95 100644 (file)
@@ -557,6 +557,7 @@ Near-term plans include converting all of them, except for "gadgetfs".
 </para>
 
 !Edrivers/usb/gadget/f_acm.c
+!Edrivers/usb/gadget/f_serial.c
 
 </sect1>
 
index e438a01..47ecb3a 100644 (file)
@@ -26,7 +26,7 @@ C_UTILS =     composite.o usbstring.o config.o epautoconf.o
 
 g_zero-objs                    := zero.o f_sourcesink.o f_loopback.o $(C_UTILS)
 g_ether-objs                   := ether.o usbstring.o config.o epautoconf.o
-g_serial-objs                  := serial.o u_serial.o f_acm.o $(C_UTILS)
+g_serial-objs                  := serial.o u_serial.o f_acm.o f_serial.o $(C_UTILS)
 g_midi-objs                    := gmidi.o usbstring.o config.o epautoconf.o
 gadgetfs-objs                  := inode.o
 g_file_storage-objs            := file_storage.o usbstring.o config.o \
diff --git a/drivers/usb/gadget/f_serial.c b/drivers/usb/gadget/f_serial.c
new file mode 100644 (file)
index 0000000..1b6bde9
--- /dev/null
@@ -0,0 +1,296 @@
+/*
+ * f_serial.c - generic USB serial function driver
+ *
+ * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
+ * Copyright (C) 2008 by David Brownell
+ * Copyright (C) 2008 by Nokia Corporation
+ *
+ * This software is distributed under the terms of the GNU General
+ * Public License ("GPL") as published by the Free Software Foundation,
+ * either version 2 of that License or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include "u_serial.h"
+#include "gadget_chips.h"
+
+
+/*
+ * This function packages a simple "generic serial" port with no real
+ * control mechanisms, just raw data transfer over two bulk endpoints.
+ *
+ * Because it's not standardized, this isn't as interoperable as the
+ * CDC ACM driver.  However, for many purposes it's just as functional
+ * if you can arrange appropriate host side drivers.
+ */
+
+struct gser_descs {
+       struct usb_endpoint_descriptor  *in;
+       struct usb_endpoint_descriptor  *out;
+};
+
+struct f_gser {
+       struct gserial                  port;
+       u8                              data_id;
+       u8                              port_num;
+
+       struct usb_descriptor_header    **fs_function;
+       struct gser_descs               fs;
+       struct usb_descriptor_header    **hs_function;
+       struct gser_descs               hs;
+};
+
+static inline struct f_gser *func_to_gser(struct usb_function *f)
+{
+       return container_of(f, struct f_gser, port.func);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* interface descriptor: */
+
+static struct usb_interface_descriptor gser_interface_desc __initdata = {
+       .bLength =              USB_DT_INTERFACE_SIZE,
+       .bDescriptorType =      USB_DT_INTERFACE,
+       /* .bInterfaceNumber = DYNAMIC */
+       .bNumEndpoints =        2,
+       .bInterfaceClass =      USB_CLASS_VENDOR_SPEC,
+       .bInterfaceSubClass =   0,
+       .bInterfaceProtocol =   0,
+       /* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor gser_fs_in_desc __initdata = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bEndpointAddress =     USB_DIR_IN,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor gser_fs_out_desc __initdata = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bEndpointAddress =     USB_DIR_OUT,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *gser_fs_function[] __initdata = {
+       (struct usb_descriptor_header *) &gser_interface_desc,
+       (struct usb_descriptor_header *) &gser_fs_in_desc,
+       (struct usb_descriptor_header *) &gser_fs_out_desc,
+       NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor gser_hs_in_desc __initdata = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize =       __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor gser_hs_out_desc __initdata = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize =       __constant_cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *gser_hs_function[] __initdata = {
+       (struct usb_descriptor_header *) &gser_interface_desc,
+       (struct usb_descriptor_header *) &gser_hs_in_desc,
+       (struct usb_descriptor_header *) &gser_hs_out_desc,
+       NULL,
+};
+
+/* string descriptors: */
+
+static struct usb_string gser_string_defs[] = {
+       [0].s = "Generic Serial",
+       {  } /* end of list */
+};
+
+static struct usb_gadget_strings gser_string_table = {
+       .language =             0x0409, /* en-us */
+       .strings =              gser_string_defs,
+};
+
+static struct usb_gadget_strings *gser_strings[] = {
+       &gser_string_table,
+       NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+       struct f_gser           *gser = func_to_gser(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+
+       /* we know alt == 0, so this is an activation or a reset */
+
+       if (gser->port.in->driver_data) {
+               DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
+               gserial_disconnect(&gser->port);
+       } else {
+               DBG(cdev, "activate generic ttyGS%d\n", gser->port_num);
+               gser->port.in_desc = ep_choose(cdev->gadget,
+                               gser->hs.in, gser->fs.in);
+               gser->port.out_desc = ep_choose(cdev->gadget,
+                               gser->hs.out, gser->fs.out);
+       }
+       gserial_connect(&gser->port, gser->port_num);
+       return 0;
+}
+
+static void gser_disable(struct usb_function *f)
+{
+       struct f_gser   *gser = func_to_gser(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+
+       DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num);
+       gserial_disconnect(&gser->port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* serial function driver setup/binding */
+
+static int __init
+gser_bind(struct usb_configuration *c, struct usb_function *f)
+{
+       struct usb_composite_dev *cdev = c->cdev;
+       struct f_gser           *gser = func_to_gser(f);
+       int                     status;
+       struct usb_ep           *ep;
+
+       /* allocate instance-specific interface IDs */
+       status = usb_interface_id(c, f);
+       if (status < 0)
+               goto fail;
+       gser->data_id = status;
+       gser_interface_desc.bInterfaceNumber = status;
+
+       status = -ENODEV;
+
+       /* allocate instance-specific endpoints */
+       ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
+       if (!ep)
+               goto fail;
+       gser->port.in = ep;
+       ep->driver_data = cdev; /* claim */
+
+       ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
+       if (!ep)
+               goto fail;
+       gser->port.out = ep;
+       ep->driver_data = cdev; /* claim */
+
+       /* copy descriptors, and track endpoint copies */
+       f->descriptors = usb_copy_descriptors(gser_fs_function);
+
+       gser->fs.in = usb_find_endpoint(gser_fs_function,
+                       f->descriptors, &gser_fs_in_desc);
+       gser->fs.out = usb_find_endpoint(gser_fs_function,
+                       f->descriptors, &gser_fs_out_desc);
+
+
+       /* support all relevant hardware speeds... we expect that when
+        * hardware is dual speed, all bulk-capable endpoints work at
+        * both speeds
+        */
+       if (gadget_is_dualspeed(c->cdev->gadget)) {
+               gser_hs_in_desc.bEndpointAddress =
+                               gser_fs_in_desc.bEndpointAddress;
+               gser_hs_out_desc.bEndpointAddress =
+                               gser_fs_out_desc.bEndpointAddress;
+
+               /* copy descriptors, and track endpoint copies */
+               f->hs_descriptors = usb_copy_descriptors(gser_hs_function);
+
+               gser->hs.in = usb_find_endpoint(gser_hs_function,
+                               f->hs_descriptors, &gser_hs_in_desc);
+               gser->hs.out = usb_find_endpoint(gser_hs_function,
+                               f->hs_descriptors, &gser_hs_out_desc);
+       }
+
+       DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
+                       gser->port_num,
+                       gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+                       gser->port.in->name, gser->port.out->name);
+       return 0;
+
+fail:
+       /* we might as well release our claims on endpoints */
+       if (gser->port.out)
+               gser->port.out->driver_data = NULL;
+       if (gser->port.in)
+               gser->port.in->driver_data = NULL;
+
+       ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+       return status;
+}
+
+static void
+gser_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+       if (gadget_is_dualspeed(c->cdev->gadget))
+               usb_free_descriptors(f->hs_descriptors);
+       usb_free_descriptors(f->descriptors);
+       kfree(func_to_gser(f));
+}
+
+/**
+ * gser_bind_config - add a generic serial function to a configuration
+ * @c: the configuration to support the serial instance
+ * @port_num: /dev/ttyGS* port this interface will use
+ * Context: single threaded during gadget setup
+ *
+ * Returns zero on success, else negative errno.
+ *
+ * Caller must have called @gserial_setup() with enough ports to
+ * handle all the ones it binds.  Caller is also responsible
+ * for calling @gserial_cleanup() before module unload.
+ */
+int __init gser_bind_config(struct usb_configuration *c, u8 port_num)
+{
+       struct f_gser   *gser;
+       int             status;
+
+       /* REVISIT might want instance-specific strings to help
+        * distinguish instances ...
+        */
+
+       /* maybe allocate device-global string ID */
+       if (gser_string_defs[0].id == 0) {
+               status = usb_string_id(c->cdev);
+               if (status < 0)
+                       return status;
+               gser_string_defs[0].id = status;
+       }
+
+       /* allocate and initialize one new instance */
+       gser = kzalloc(sizeof *gser, GFP_KERNEL);
+       if (!gser)
+               return -ENOMEM;
+
+       gser->port_num = port_num;
+
+       gser->port.func.name = "gser";
+       gser->port.func.strings = gser_strings;
+       gser->port.func.bind = gser_bind;
+       gser->port.func.unbind = gser_unbind;
+       gser->port.func.set_alt = gser_set_alt;
+       gser->port.func.disable = gser_disable;
+
+       status = usb_add_function(c, &gser->port.func);
+       if (status)
+               kfree(gser);
+       return status;
+}
index 83b45a3..f9ce300 100644 (file)
@@ -58,5 +58,6 @@ void gserial_disconnect(struct gserial *);
 
 /* functions are bound to configurations by a config or gadget driver */
 int acm_bind_config(struct usb_configuration *c, u8 port_num);
+int gser_bind_config(struct usb_configuration *c, u8 port_num);
 
 #endif /* __U_SERIAL_H */