ACPI video extensions ~~~~~~~~~~~~~~~~~~~~~ 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/TVO : 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