Merge branch 'psd' into release
[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  * assinged
11  *
12  * After PCI devices are glued with ACPI devices
13  * acpi_get_physical_pci_device() 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 (or display output) 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 and display output
28  * switching.
29  *
30  * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
31  * this file will not be compiled, acpi_video_get_capabilities() and
32  * acpi_video_backlight_support() will always return 0 and vendor specific
33  * drivers always can handle backlight.
34  *
35  */
36
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39
40 ACPI_MODULE_NAME("video");
41 #define _COMPONENT              ACPI_VIDEO_COMPONENT
42
43 static long acpi_video_support;
44 static bool acpi_video_caps_checked;
45
46 static acpi_status
47 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
48                           void **retyurn_value)
49 {
50         long *cap = context;
51         acpi_handle h_dummy;
52
53         if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
54             ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
55                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
56                                   "support\n"));
57                 *cap |= ACPI_VIDEO_BACKLIGHT;
58                 /* We have backlight support, no need to scan further */
59                 return AE_CTRL_TERMINATE;
60         }
61         return 0;
62 }
63
64 /* Returns true if the device is a video device which can be handled by
65  * video.ko.
66  * The device will get a Linux specific CID added in scan.c to
67  * identify the device as an ACPI graphics device
68  * Be aware that the graphics device may not be physically present
69  * Use acpi_video_get_capabilities() to detect general ACPI video
70  * capabilities of present cards
71  */
72 long acpi_is_video_device(struct acpi_device *device)
73 {
74         acpi_handle h_dummy;
75         long video_caps = 0;
76
77         if (!device)
78                 return 0;
79
80         /* Does this device able to support video switching ? */
81         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
82             ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
83                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
84
85         /* Does this device able to retrieve a video ROM ? */
86         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
87                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
88
89         /* Does this device able to configure which video head to be POSTed ? */
90         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
91             ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
92             ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
93                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
94
95         /* Only check for backlight functionality if one of the above hit. */
96         if (video_caps)
97                 acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
98                                     ACPI_UINT32_MAX, acpi_backlight_cap_match,
99                                     &video_caps, NULL);
100
101         return video_caps;
102 }
103 EXPORT_SYMBOL(acpi_is_video_device);
104
105 static acpi_status
106 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
107 {
108         long *cap = context;
109         struct device *dev;
110         struct acpi_device *acpi_dev;
111
112         const struct acpi_device_id video_ids[] = {
113                 {ACPI_VIDEO_HID, 0},
114                 {"", 0},
115         };
116         if (acpi_bus_get_device(handle, &acpi_dev))
117                 return AE_OK;
118
119         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
120                 dev = acpi_get_physical_pci_device(handle);
121                 if (!dev)
122                         return AE_OK;
123                 put_device(dev);
124                 *cap |= acpi_is_video_device(acpi_dev);
125         }
126         return AE_OK;
127 }
128
129 /*
130  * Returns the video capabilities of a specific ACPI graphics device
131  *
132  * if NULL is passed as argument all ACPI devices are enumerated and
133  * all graphics capabilities of physically present devices are
134  * summerized and returned. This is cached and done only once.
135  */
136 long acpi_video_get_capabilities(acpi_handle graphics_handle)
137 {
138         long caps = 0;
139         struct acpi_device *tmp_dev;
140         acpi_status status;
141
142         if (acpi_video_caps_checked && graphics_handle == NULL)
143                 return acpi_video_support;
144
145         if (!graphics_handle) {
146                 /* Only do the global walk through all graphics devices once */
147                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
148                                     ACPI_UINT32_MAX, find_video,
149                                     &caps, NULL);
150                 /* There might be boot param flags set already... */
151                 acpi_video_support |= caps;
152                 acpi_video_caps_checked = 1;
153                 /* Add blacklists here. Be careful to use the right *DMI* bits
154                  * to still be able to override logic via boot params, e.g.:
155                  *
156                  *   if (dmi_name_in_vendors("XY")) {
157                  *      acpi_video_support |=
158                  *              ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR;
159                  *      acpi_video_support |=
160                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
161                  *}
162                  */
163         } else {
164                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
165                 if (ACPI_FAILURE(status)) {
166                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
167                         return 0;
168                 }
169                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
170                                     ACPI_UINT32_MAX, find_video,
171                                     &caps, NULL);
172         }
173         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
174                           graphics_handle ? caps : acpi_video_support,
175                           graphics_handle ? "on device " : "in general",
176                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
177         return caps;
178 }
179 EXPORT_SYMBOL(acpi_video_get_capabilities);
180
181 /* Returns true if video.ko can do backlight switching */
182 int acpi_video_backlight_support(void)
183 {
184         /*
185          * We must check whether the ACPI graphics device is physically plugged
186          * in. Therefore this must be called after binding PCI and ACPI devices
187          */
188         if (!acpi_video_caps_checked)
189                 acpi_video_get_capabilities(NULL);
190
191         /* First check for boot param -> highest prio */
192         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
193                 return 0;
194         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
195                 return 1;
196
197         /* Then check for DMI blacklist -> second highest prio */
198         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
199                 return 0;
200         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
201                 return 1;
202
203         /* Then go the default way */
204         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
205 }
206 EXPORT_SYMBOL(acpi_video_backlight_support);
207
208 /*
209  * Returns true if video.ko can do display output switching.
210  * This does not work well/at all with binary graphics drivers
211  * which disable system io ranges and do it on their own.
212  */
213 int acpi_video_display_switch_support(void)
214 {
215         if (!acpi_video_caps_checked)
216                 acpi_video_get_capabilities(NULL);
217
218         if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR)
219                 return 0;
220         else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO)
221                 return 1;
222
223         if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR)
224                 return 0;
225         else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO)
226                 return 1;
227
228         return acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING;
229 }
230 EXPORT_SYMBOL(acpi_video_display_switch_support);
231
232 /*
233  * Use acpi_display_output=vendor/video or acpi_backlight=vendor/video
234  * To force that backlight or display output switching is processed by vendor
235  * specific acpi drivers or video.ko driver.
236  */
237 static int __init acpi_backlight(char *str)
238 {
239         if (str == NULL || *str == '\0')
240                 return 1;
241         else {
242                 if (!strcmp("vendor", str))
243                         acpi_video_support |=
244                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
245                 if (!strcmp("video", str))
246                         acpi_video_support |=
247                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
248         }
249         return 1;
250 }
251 __setup("acpi_backlight=", acpi_backlight);
252
253 static int __init acpi_display_output(char *str)
254 {
255         if (str == NULL || *str == '\0')
256                 return 1;
257         else {
258                 if (!strcmp("vendor", str))
259                         acpi_video_support |=
260                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR;
261                 if (!strcmp("video", str))
262                         acpi_video_support |=
263                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
264         }
265         return 1;
266 }
267 __setup("acpi_display_output=", acpi_display_output);