tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1pwm-backlight bindings
2
3Required properties:
4 - compatible: "pwm-backlight"
5 - pwms: OF device-tree PWM specification (see PWM binding[0])
6 - brightness-levels: Array of distinct brightness levels. Typically these
7 are in the range from 0 to 255, but any range starting at 0 will do.
8 The actual brightness level (PWM duty cycle) will be interpolated
9 from these values. 0 means a 0% duty cycle (darkest/off), while the
10 last value in the array represents a 100% duty cycle (brightest).
11 - default-brightness-level: the default brightness level (index into the
12 array defined by the "brightness-levels" property)
13 - power-supply: regulator for supply voltage
14
15Optional properties:
16 - pwm-names: a list of names for the PWM devices specified in the
17 "pwms" property (see PWM binding[0])
18 - enable-gpios: contains a single GPIO specifier for the GPIO which enables
19 and disables the backlight (see GPIO binding[1])
20
21[0]: Documentation/devicetree/bindings/pwm/pwm.txt
22[1]: Documentation/devicetree/bindings/gpio/gpio.txt
23
24Example:
25
26 backlight {
27 compatible = "pwm-backlight";
28 pwms = <&pwm 0 5000000>;
29
30 brightness-levels = <0 4 8 16 32 64 128 255>;
31 default-brightness-level = <6>;
32
33 power-supply = <&vdd_bl_reg>;
34 enable-gpios = <&gpio 58 0>;
35 };