105 lines
2.7 KiB
YAML
105 lines
2.7 KiB
YAML
# SPDX-License-Identifier: GPL-2.0-only
|
|
%YAML 1.2
|
|
---
|
|
$id: http://devicetree.org/schemas/leds/backlight/pwm-backlight.yaml#
|
|
$schema: http://devicetree.org/meta-schemas/core.yaml#
|
|
|
|
title: pwm-backlight
|
|
|
|
maintainers:
|
|
- Lee Jones <lee@kernel.org>
|
|
- Daniel Thompson <daniel.thompson@linaro.org>
|
|
- Jingoo Han <jingoohan1@gmail.com>
|
|
|
|
properties:
|
|
compatible:
|
|
const: pwm-backlight
|
|
|
|
pwms:
|
|
maxItems: 1
|
|
|
|
pwm-names: true
|
|
|
|
power-supply:
|
|
description: regulator for supply voltage
|
|
|
|
enable-gpios:
|
|
description:
|
|
Contains a single GPIO specifier for the GPIO which enables and disables
|
|
the backlight.
|
|
maxItems: 1
|
|
|
|
post-pwm-on-delay-ms:
|
|
description:
|
|
Delay in ms between setting an initial (non-zero) PWM and enabling the
|
|
backlight using GPIO.
|
|
|
|
pwm-off-delay-ms:
|
|
description:
|
|
Delay in ms between disabling the backlight using GPIO and setting PWM
|
|
value to 0.
|
|
|
|
brightness-levels:
|
|
description:
|
|
Array of distinct brightness levels. Typically these are in the range
|
|
from 0 to 255, but any range starting at 0 will do. The actual brightness
|
|
level (PWM duty cycle) will be interpolated from these values. 0 means a
|
|
0% duty cycle (darkest/off), while the last value in the array represents
|
|
a 100% duty cycle (brightest).
|
|
$ref: /schemas/types.yaml#/definitions/uint32-array
|
|
|
|
default-brightness-level:
|
|
description:
|
|
The default brightness level (index into the array defined by the
|
|
"brightness-levels" property).
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
|
|
|
num-interpolated-steps:
|
|
description:
|
|
Number of interpolated steps between each value of brightness-levels
|
|
table. This way a high resolution pwm duty cycle can be used without
|
|
having to list out every possible value in the brightness-level array.
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
|
|
|
dependencies:
|
|
default-brightness-level: [brightness-levels]
|
|
num-interpolated-steps: [brightness-levels]
|
|
|
|
required:
|
|
- compatible
|
|
- pwms
|
|
- power-supply
|
|
|
|
additionalProperties: false
|
|
|
|
examples:
|
|
- |
|
|
backlight {
|
|
compatible = "pwm-backlight";
|
|
pwms = <&pwm 0 5000000>;
|
|
|
|
brightness-levels = <0 4 8 16 32 64 128 255>;
|
|
default-brightness-level = <6>;
|
|
|
|
power-supply = <&vdd_bl_reg>;
|
|
enable-gpios = <&gpio 58 0>;
|
|
post-pwm-on-delay-ms = <10>;
|
|
pwm-off-delay-ms = <10>;
|
|
};
|
|
|
|
- |
|
|
// Example using num-interpolation-steps:
|
|
backlight {
|
|
compatible = "pwm-backlight";
|
|
pwms = <&pwm 0 5000000>;
|
|
|
|
brightness-levels = <0 2048 4096 8192 16384 65535>;
|
|
num-interpolated-steps = <2048>;
|
|
default-brightness-level = <4096>;
|
|
|
|
power-supply = <&vdd_bl_reg>;
|
|
enable-gpios = <&gpio 58 0>;
|
|
};
|
|
|
|
...
|