Documentation/power/video_extension.txt

   1 This driver implement the ACPI Extensions For Display Adapters
   2 for integrated graphics devices on motherboard, as specified in
   3 ACPI 2.0 Specification, Appendix B, allowing to perform some basic
   4 control like defining the video POST device, retrieving EDID information
   5 or to setup a video output, etc.  Note that this is an ref. implementation only.
   6 It may or may not work for your integrated video device.
   7
   8 Interfaces exposed to userland through /proc/acpi/video:
   9
  10 VGA/info : display the supported video bus device capability like ,Video ROM, CRT/LCD/TV.
  11 VGA/ROM :  Used to get a copy of the display devices' ROM data (up to 4k).
  12 VGA/POST_info : Used to determine what options are implemented.
  13 VGA/POST : Used to get/set POST device.
  14 VGA/DOS : Used to get/set ownership of output switching:
  15         Please refer ACPI spec B.4.1 _DOS
  16 VGA/CRT : CRT output
  17 VGA/LCD : LCD output
  18 VGA/TV : TV output
  19 VGA/*/brightness : Used to get/set brightness of output device
  20
  21 Notify event through /proc/acpi/event:
  22
  23 #define ACPI_VIDEO_NOTIFY_SWITCH        0x80
  24 #define ACPI_VIDEO_NOTIFY_PROBE         0x81
  25 #define ACPI_VIDEO_NOTIFY_CYCLE         0x82
  26 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT   0x83
  27 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT   0x84
  28
  29 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS      0x82
  30 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x83
  31 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x84
  32 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x85
  33 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x86
  34