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1# SPDX-License-Identifier: GPL-2.0-only2%YAML 1.23---4$id: http://devicetree.org/schemas/leds/backlight/pwm-backlight.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: pwm-backlight8 9maintainers:10 - Lee Jones <lee@kernel.org>11 - Daniel Thompson <daniel.thompson@linaro.org>12 - Jingoo Han <jingoohan1@gmail.com>13 14allOf:15 - $ref: common.yaml#16 17properties:18 compatible:19 const: pwm-backlight20 21 pwms:22 maxItems: 123 24 pwm-names: true25 26 power-supply:27 description: regulator for supply voltage28 29 enable-gpios:30 description:31 Contains a single GPIO specifier for the GPIO which enables and disables32 the backlight.33 maxItems: 134 35 post-pwm-on-delay-ms:36 description:37 Delay in ms between setting an initial (non-zero) PWM and enabling the38 backlight using GPIO.39 40 pwm-off-delay-ms:41 description:42 Delay in ms between disabling the backlight using GPIO and setting PWM43 value to 0.44 45 num-interpolated-steps:46 description:47 Number of interpolated steps between each value of brightness-levels48 table. This way a high resolution pwm duty cycle can be used without49 having to list out every possible value in the brightness-level array.50 $ref: /schemas/types.yaml#/definitions/uint3251 52dependencies:53 default-brightness-level: [brightness-levels]54 num-interpolated-steps: [brightness-levels]55 56required:57 - compatible58 - pwms59 60unevaluatedProperties: false61 62examples:63 - |64 backlight {65 compatible = "pwm-backlight";66 pwms = <&pwm 0 5000000>;67 68 brightness-levels = <0 4 8 16 32 64 128 255>;69 default-brightness-level = <6>;70 71 power-supply = <&vdd_bl_reg>;72 enable-gpios = <&gpio 58 0>;73 post-pwm-on-delay-ms = <10>;74 pwm-off-delay-ms = <10>;75 };76 77 - |78 // Example using num-interpolation-steps:79 backlight {80 compatible = "pwm-backlight";81 pwms = <&pwm 0 5000000>;82 83 brightness-levels = <0 2048 4096 8192 16384 65535>;84 num-interpolated-steps = <2048>;85 default-brightness-level = <4096>;86 87 power-supply = <&vdd_bl_reg>;88 enable-gpios = <&gpio 58 0>;89 };90 91...92