| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | |