blob: 3ab175a3f5cb34ee4b25b9adfa2430ff93baba30 [file] [log] [blame]
David Brazdil0f672f62019-12-10 10:32:29 +00001What: /sys/class/backlight/<backlight>/scale
2Date: July 2019
3KernelVersion: 5.4
4Contact: Daniel Thompson <daniel.thompson@linaro.org>
5Description:
6 Description of the scale of the brightness curve.
7
8 The human eye senses brightness approximately logarithmically,
9 hence linear changes in brightness are perceived as being
10 non-linear. To achieve a linear perception of brightness changes
11 controls like sliders need to apply a logarithmic mapping for
12 backlights with a linear brightness curve.
13
14 Possible values of the attribute are:
15
16 unknown
17 The scale of the brightness curve is unknown.
18
19 linear
20 The brightness changes linearly with each step. Brightness
21 controls should apply a logarithmic mapping for a linear
22 perception.
23
24 non-linear
25 The brightness changes non-linearly with each step. Brightness
26 controls should use a linear mapping for a linear perception.