SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 ACPI_VIDEO_COMPONENT            0x08000000
  42 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  43
  44 static long acpi_video_support;
  45 static bool acpi_video_caps_checked;
  46
  47 static acpi_status
  48 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
  49                           void **retyurn_value)
  50 {
  51         long *cap = context;
  52         acpi_handle h_dummy;
  53
  54         if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
  55             ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
  56                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
  57                                   "support\n"));
  58                 *cap |= ACPI_VIDEO_BACKLIGHT;
  59                 /* We have backlight support, no need to scan further */
  60                 return AE_CTRL_TERMINATE;
  61         }
  62         return 0;
  63 }
  64
  65 /* Returns true if the device is a video device which can be handled by
  66  * video.ko.
  67  * The device will get a Linux specific CID added in scan.c to
  68  * identify the device as an ACPI graphics device
  69  * Be aware that the graphics device may not be physically present
  70  * Use acpi_video_get_capabilities() to detect general ACPI video
  71  * capabilities of present cards
  72  */
  73 long acpi_is_video_device(struct acpi_device *device)
  74 {
  75         acpi_handle h_dummy;
  76         long video_caps = 0;
  77
  78         if (!device)
  79                 return 0;
  80
  81         /* Does this device able to support video switching ? */
  82         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
  83             ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
  84                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
  85
  86         /* Does this device able to retrieve a video ROM ? */
  87         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
  88                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
  89
  90         /* Does this device able to configure which video head to be POSTed ? */
  91         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
  92             ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
  93             ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
  94                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
  95
  96         /* Only check for backlight functionality if one of the above hit. */
  97         if (video_caps)
  98                 acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
  99                                     ACPI_UINT32_MAX, acpi_backlight_cap_match,
 100                                     &video_caps, NULL);
 101
 102         return video_caps;
 103 }
 104 EXPORT_SYMBOL(acpi_is_video_device);
 105
 106 static acpi_status
 107 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
 108 {
 109         long *cap = context;
 110         struct device *dev;
 111         struct acpi_device *acpi_dev;
 112
 113         const struct acpi_device_id video_ids[] = {
 114                 {ACPI_VIDEO_HID, 0},
 115                 {"", 0},
 116         };
 117         if (acpi_bus_get_device(handle, &acpi_dev))
 118                 return AE_OK;
 119
 120         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
 121                 dev = acpi_get_physical_pci_device(handle);
 122                 if (!dev)
 123                         return AE_OK;
 124                 put_device(dev);
 125                 *cap |= acpi_is_video_device(acpi_dev);
 126         }
 127         return AE_OK;
 128 }
 129
 130 /*
 131  * Returns the video capabilities of a specific ACPI graphics device
 132  *
 133  * if NULL is passed as argument all ACPI devices are enumerated and
 134  * all graphics capabilities of physically present devices are
 135  * summerized and returned. This is cached and done only once.
 136  */
 137 long acpi_video_get_capabilities(acpi_handle graphics_handle)
 138 {
 139         long caps = 0;
 140         struct acpi_device *tmp_dev;
 141         acpi_status status;
 142
 143         if (acpi_video_caps_checked && graphics_handle == NULL)
 144                 return acpi_video_support;
 145
 146         if (!graphics_handle) {
 147                 /* Only do the global walk through all graphics devices once */
 148                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 149                                     ACPI_UINT32_MAX, find_video,
 150                                     &caps, NULL);
 151                 /* There might be boot param flags set already... */
 152                 acpi_video_support |= caps;
 153                 acpi_video_caps_checked = 1;
 154                 /* Add blacklists here. Be careful to use the right *DMI* bits
 155                  * to still be able to override logic via boot params, e.g.:
 156                  *
 157                  *   if (dmi_name_in_vendors("XY")) {
 158                  *      acpi_video_support |=
 159                  *              ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR;
 160                  *      acpi_video_support |=
 161                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 162                  *}
 163                  */
 164         } else {
 165                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
 166                 if (ACPI_FAILURE(status)) {
 167                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
 168                         return 0;
 169                 }
 170                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
 171                                     ACPI_UINT32_MAX, find_video,
 172                                     &caps, NULL);
 173         }
 174         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
 175                           graphics_handle ? caps : acpi_video_support,
 176                           graphics_handle ? "on device " : "in general",
 177                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
 178         return caps;
 179 }
 180 EXPORT_SYMBOL(acpi_video_get_capabilities);
 181
 182 /* Returns true if video.ko can do backlight switching */
 183 int acpi_video_backlight_support(void)
 184 {
 185         /*
 186          * We must check whether the ACPI graphics device is physically plugged
 187          * in. Therefore this must be called after binding PCI and ACPI devices
 188          */
 189         if (!acpi_video_caps_checked)
 190                 acpi_video_get_capabilities(NULL);
 191
 192         /* First check for boot param -> highest prio */
 193         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
 194                 return 0;
 195         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
 196                 return 1;
 197
 198         /* Then check for DMI blacklist -> second highest prio */
 199         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
 200                 return 0;
 201         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
 202                 return 1;
 203
 204         /* Then go the default way */
 205         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
 206 }
 207 EXPORT_SYMBOL(acpi_video_backlight_support);
 208
 209 /*
 210  * Returns true if video.ko can do display output switching.
 211  * This does not work well/at all with binary graphics drivers
 212  * which disable system io ranges and do it on their own.
 213  */
 214 int acpi_video_display_switch_support(void)
 215 {
 216         if (!acpi_video_caps_checked)
 217                 acpi_video_get_capabilities(NULL);
 218
 219         if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR)
 220                 return 0;
 221         else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO)
 222                 return 1;
 223
 224         if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR)
 225                 return 0;
 226         else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO)
 227                 return 1;
 228
 229         return acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING;
 230 }
 231 EXPORT_SYMBOL(acpi_video_display_switch_support);
 232
 233 /*
 234  * Use acpi_display_output=vendor/video or acpi_backlight=vendor/video
 235  * To force that backlight or display output switching is processed by vendor
 236  * specific acpi drivers or video.ko driver.
 237  */
 238 int __init acpi_backlight(char *str)
 239 {
 240         if (str == NULL || *str == '\0')
 241                 return 1;
 242         else {
 243                 if (!strcmp("vendor", str))
 244                         acpi_video_support |=
 245                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
 246                 if (!strcmp("video", str))
 247                         acpi_video_support |=
 248                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
 249         }
 250         return 1;
 251 }
 252 __setup("acpi_backlight=", acpi_backlight);
 253
 254 int __init acpi_display_output(char *str)
 255 {
 256         if (str == NULL || *str == '\0')
 257                 return 1;
 258         else {
 259                 if (!strcmp("vendor", str))
 260                         acpi_video_support |=
 261                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR;
 262                 if (!strcmp("video", str))
 263                         acpi_video_support |=
 264                                 ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
 265         }
 266         return 1;
 267 }
 268 __setup("acpi_display_output=", acpi_display_output);