summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-class-backlight
blob: 3ab175a3f5cb34ee4b25b9adfa2430ff93baba30 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
What:		/sys/class/backlight/<backlight>/scale
Date:		July 2019
KernelVersion:	5.4
Contact:	Daniel Thompson <daniel.thompson@linaro.org>
Description:
		Description of the scale of the brightness curve.

		The human eye senses brightness approximately logarithmically,
		hence linear changes in brightness are perceived as being
		non-linear. To achieve a linear perception of brightness changes
		controls like sliders need to apply a logarithmic mapping for
		backlights with a linear brightness curve.

		Possible values of the attribute are:

		unknown
		  The scale of the brightness curve is unknown.

		linear
		  The brightness changes linearly with each step. Brightness
		  controls should apply a logarithmic mapping for a linear
		  perception.

		non-linear
		  The brightness changes non-linearly with each step. Brightness
		  controls should use a linear mapping for a linear perception.