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Diffstat (limited to 'Documentation/power/video_extension.txt')
| -rw-r--r-- | Documentation/power/video_extension.txt | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/power/video_extension.txt b/Documentation/power/video_extension.txt new file mode 100644 index 00000000000..8e33d7c82c4 --- /dev/null +++ b/Documentation/power/video_extension.txt @@ -0,0 +1,34 @@ +This driver implement the ACPI Extensions For Display Adapters +for integrated graphics devices on motherboard, as specified in +ACPI 2.0 Specification, Appendix B, allowing to perform some basic +control like defining the video POST device, retrieving EDID information +or to setup a video output, etc. Note that this is an ref. implementation only. +It may or may not work for your integrated video device. + +Interfaces exposed to userland through /proc/acpi/video: + +VGA/info : display the supported video bus device capability like ,Video ROM, CRT/LCD/TV. +VGA/ROM : Used to get a copy of the display devices' ROM data (up to 4k). +VGA/POST_info : Used to determine what options are implemented. +VGA/POST : Used to get/set POST device. +VGA/DOS : Used to get/set ownership of output switching: + Please refer ACPI spec B.4.1 _DOS +VGA/CRT : CRT output +VGA/LCD : LCD output +VGA/TV : TV output +VGA/*/brightness : Used to get/set brightness of output device + +Notify event through /proc/acpi/event: + +#define ACPI_VIDEO_NOTIFY_SWITCH 0x80 +#define ACPI_VIDEO_NOTIFY_PROBE 0x81 +#define ACPI_VIDEO_NOTIFY_CYCLE 0x82 +#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83 +#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84 + +#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x82 +#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x83 +#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x84 +#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x85 +#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x86 + |