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Documentation / power / video_extension.txt




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Based on kernel version 3.10. Page generated on 2013-07-08 20:17 EST.

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