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Based on kernel version 3.13. Page generated on 2014-01-20 21:59 EST.

1	What:		/sys/class/backlight/<backlight>/bl_power
2	Date:		April 2005
3	KernelVersion:	2.6.12
4	Contact:	Richard Purdie <rpurdie@rpsys.net>
5	Description:
6			Control BACKLIGHT power, values are FB_BLANK_* from fb.h
7			 - FB_BLANK_UNBLANK (0)   : power on.
8			 - FB_BLANK_POWERDOWN (4) : power off
9	Users:		HAL
10	
11	What:		/sys/class/backlight/<backlight>/brightness
12	Date:		April 2005
13	KernelVersion:	2.6.12
14	Contact:	Richard Purdie <rpurdie@rpsys.net>
15	Description:
16			Control the brightness for this <backlight>. Values
17			are between 0 and max_brightness. This file will also
18			show the brightness level stored in the driver, which
19			may not be the actual brightness (see actual_brightness).
20	Users:		HAL
21	
22	What:		/sys/class/backlight/<backlight>/actual_brightness
23	Date:		March 2006
24	KernelVersion:	2.6.17
25	Contact:	Richard Purdie <rpurdie@rpsys.net>
26	Description:
27			Show the actual brightness by querying the hardware.
28	Users:		HAL
29	
30	What:		/sys/class/backlight/<backlight>/max_brightness
31	Date:		April 2005
32	KernelVersion:	2.6.12
33	Contact:	Richard Purdie <rpurdie@rpsys.net>
34	Description:
35			Maximum brightness for <backlight>.
36	Users:		HAL
37	
38	What:		/sys/class/backlight/<backlight>/type
39	Date:		September 2010
40	KernelVersion:	2.6.37
41	Contact:	Matthew Garrett <mjg@redhat.com>
42	Description:
43			The type of interface controlled by <backlight>.
44			"firmware": The driver uses a standard firmware interface
45			"platform": The driver uses a platform-specific interface
46			"raw": The driver controls hardware registers directly
47	
48			In the general case, when multiple backlight
49			interfaces are available for a single device, firmware
50			control should be preferred to platform control should
51			be preferred to raw control. Using a firmware
52			interface reduces the probability of confusion with
53			the hardware and the OS independently updating the
54			backlight state. Platform interfaces are mostly a
55			holdover from pre-standardisation of firmware
56			interfaces.
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