| 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 |
| |