ACPI: EC: add another DMI check for ASUS hardware
[linux-2.6.git] / drivers / acpi / video_detect.c
1 /*
2  *  Copyright (C) 2008       SuSE Linux Products GmbH
3  *                           Thomas Renninger <trenn@suse.de>
4  *
5  *  May be copied or modified under the terms of the GNU General Public License
6  *
7  * video_detect.c:
8  * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
9  * There a Linux specific (Spec does not provide a HID for video devices) is
10  * assigned
11  *
12  * After PCI devices are glued with ACPI devices
13  * acpi_get_pci_dev() can be called to identify ACPI graphics
14  * devices for which a real graphics card is plugged in
15  *
16  * Now acpi_video_get_capabilities() can be called to check which
17  * capabilities the graphics cards plugged in support. The check for general
18  * video capabilities will be triggered by the first caller of
19  * acpi_video_get_capabilities(NULL); which will happen when the first
20  * backlight switching supporting driver calls:
21  * acpi_video_backlight_support();
22  *
23  * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
24  * are available, video.ko should be used to handle the device.
25  *
26  * Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi,
27  * sony_acpi,... can take care about backlight brightness.
28  *
29  * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
30  * this file will not be compiled, acpi_video_get_capabilities() and
31  * acpi_video_backlight_support() will always return 0 and vendor specific
32  * drivers always can handle backlight.
33  *
34  */
35
36 #include <linux/acpi.h>
37 #include <linux/dmi.h>
38 #include <linux/pci.h>
39
40 #define PREFIX "ACPI: "
41
42 ACPI_MODULE_NAME("video");
43 #define _COMPONENT              ACPI_VIDEO_COMPONENT
44
45 static long acpi_video_support;
46 static bool acpi_video_caps_checked;
47
48 static acpi_status
49 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
50                           void **retyurn_value)
51 {
52         long *cap = context;
53         acpi_handle h_dummy;
54
55         if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
56             ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
58                                   "support\n"));
59                 *cap |= ACPI_VIDEO_BACKLIGHT;
60                 if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
61                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
62                                 "cannot determine initial brightness\n");
63                 /* We have backlight support, no need to scan further */
64                 return AE_CTRL_TERMINATE;
65         }
66         return 0;
67 }
68
69 /* Returns true if the device is a video device which can be handled by
70  * video.ko.
71  * The device will get a Linux specific CID added in scan.c to
72  * identify the device as an ACPI graphics device
73  * Be aware that the graphics device may not be physically present
74  * Use acpi_video_get_capabilities() to detect general ACPI video
75  * capabilities of present cards
76  */
77 long acpi_is_video_device(struct acpi_device *device)
78 {
79         acpi_handle h_dummy;
80         long video_caps = 0;
81
82         if (!device)
83                 return 0;
84
85         /* Is this device able to support video switching ? */
86         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) ||
87             ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
88                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
89
90         /* Is this device able to retrieve a video ROM ? */
91         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
92                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
93
94         /* Is this device able to configure which video head to be POSTed ? */
95         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
96             ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
97             ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
98                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
99
100         /* Only check for backlight functionality if one of the above hit. */
101         if (video_caps)
102                 acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
103                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
104                                     &video_caps, NULL);
105
106         return video_caps;
107 }
108 EXPORT_SYMBOL(acpi_is_video_device);
109
110 static acpi_status
111 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
112 {
113         long *cap = context;
114         struct pci_dev *dev;
115         struct acpi_device *acpi_dev;
116
117         const struct acpi_device_id video_ids[] = {
118                 {ACPI_VIDEO_HID, 0},
119                 {"", 0},
120         };
121         if (acpi_bus_get_device(handle, &acpi_dev))
122                 return AE_OK;
123
124         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
125                 dev = acpi_get_pci_dev(handle);
126                 if (!dev)
127                         return AE_OK;
128                 pci_dev_put(dev);
129                 *cap |= acpi_is_video_device(acpi_dev);
130         }
131         return AE_OK;
132 }
133
134 /*
135  * Returns the video capabilities of a specific ACPI graphics device
136  *
137  * if NULL is passed as argument all ACPI devices are enumerated and
138  * all graphics capabilities of physically present devices are
139  * summarized and returned. This is cached and done only once.
140  */
141 long acpi_video_get_capabilities(acpi_handle graphics_handle)
142 {
143         long caps = 0;
144         struct acpi_device *tmp_dev;
145         acpi_status status;
146
147         if (acpi_video_caps_checked && graphics_handle == NULL)
148                 return acpi_video_support;
149
150         if (!graphics_handle) {
151                 /* Only do the global walk through all graphics devices once */
152                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
153                                     ACPI_UINT32_MAX, find_video, NULL,
154                                     &caps, NULL);
155                 /* There might be boot param flags set already... */
156                 acpi_video_support |= caps;
157                 acpi_video_caps_checked = 1;
158                 /* Add blacklists here. Be careful to use the right *DMI* bits
159                  * to still be able to override logic via boot params, e.g.:
160                  *
161                  *   if (dmi_name_in_vendors("XY")) {
162                  *      acpi_video_support |=
163                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
164                  *}
165                  */
166         } else {
167                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
168                 if (ACPI_FAILURE(status)) {
169                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
170                         return 0;
171                 }
172                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
173                                     ACPI_UINT32_MAX, find_video, NULL,
174                                     &caps, NULL);
175         }
176         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
177                           graphics_handle ? caps : acpi_video_support,
178                           graphics_handle ? "on device " : "in general",
179                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
180         return caps;
181 }
182 EXPORT_SYMBOL(acpi_video_get_capabilities);
183
184 /* Returns true if video.ko can do backlight switching */
185 int acpi_video_backlight_support(void)
186 {
187         /*
188          * We must check whether the ACPI graphics device is physically plugged
189          * in. Therefore this must be called after binding PCI and ACPI devices
190          */
191         if (!acpi_video_caps_checked)
192                 acpi_video_get_capabilities(NULL);
193
194         /* First check for boot param -> highest prio */
195         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
196                 return 0;
197         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
198                 return 1;
199
200         /* Then check for DMI blacklist -> second highest prio */
201         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
202                 return 0;
203         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
204                 return 1;
205
206         /* Then go the default way */
207         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
208 }
209 EXPORT_SYMBOL(acpi_video_backlight_support);
210
211 /*
212  * Use acpi_backlight=vendor/video to force that backlight switching
213  * is processed by vendor specific acpi drivers or video.ko driver.
214  */
215 static int __init acpi_backlight(char *str)
216 {
217         if (str == NULL || *str == '\0')
218                 return 1;
219         else {
220                 if (!strcmp("vendor", str))
221                         acpi_video_support |=
222                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
223                 if (!strcmp("video", str))
224                         acpi_video_support |=
225                                 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
226         }
227         return 1;
228 }
229 __setup("acpi_backlight=", acpi_backlight);