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Commit | Line | Data |
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3c4c1b69 CC |
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 | |
bb7ca747 MG |
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. |