1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 %YAML 1.2 2 %YAML 1.2
3 --- 3 ---
4 $id: http://devicetree.org/schemas/leds/backli 4 $id: http://devicetree.org/schemas/leds/backlight/pwm-backlight.yaml#
5 $schema: http://devicetree.org/meta-schemas/co 5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6 6
7 title: pwm-backlight 7 title: pwm-backlight
8 8
9 maintainers: 9 maintainers:
10 - Lee Jones <lee@kernel.org> 10 - Lee Jones <lee@kernel.org>
11 - Daniel Thompson <daniel.thompson@linaro.org 11 - Daniel Thompson <daniel.thompson@linaro.org>
12 - Jingoo Han <jingoohan1@gmail.com> 12 - Jingoo Han <jingoohan1@gmail.com>
13 13
14 allOf: 14 allOf:
15 - $ref: common.yaml# 15 - $ref: common.yaml#
16 16
17 properties: 17 properties:
18 compatible: 18 compatible:
19 const: pwm-backlight 19 const: pwm-backlight
20 20
21 pwms: 21 pwms:
22 maxItems: 1 22 maxItems: 1
23 23
24 pwm-names: true 24 pwm-names: true
25 25
26 power-supply: 26 power-supply:
27 description: regulator for supply voltage 27 description: regulator for supply voltage
28 28
29 enable-gpios: 29 enable-gpios:
30 description: 30 description:
31 Contains a single GPIO specifier for the 31 Contains a single GPIO specifier for the GPIO which enables and disables
32 the backlight. 32 the backlight.
33 maxItems: 1 33 maxItems: 1
34 34
35 post-pwm-on-delay-ms: 35 post-pwm-on-delay-ms:
36 description: 36 description:
37 Delay in ms between setting an initial ( 37 Delay in ms between setting an initial (non-zero) PWM and enabling the
38 backlight using GPIO. 38 backlight using GPIO.
39 39
40 pwm-off-delay-ms: 40 pwm-off-delay-ms:
41 description: 41 description:
42 Delay in ms between disabling the backli 42 Delay in ms between disabling the backlight using GPIO and setting PWM
43 value to 0. 43 value to 0.
44 44
45 num-interpolated-steps: 45 num-interpolated-steps:
46 description: 46 description:
47 Number of interpolated steps between eac 47 Number of interpolated steps between each value of brightness-levels
48 table. This way a high resolution pwm du 48 table. This way a high resolution pwm duty cycle can be used without
49 having to list out every possible value 49 having to list out every possible value in the brightness-level array.
50 $ref: /schemas/types.yaml#/definitions/uin 50 $ref: /schemas/types.yaml#/definitions/uint32
51 51
52 dependencies: 52 dependencies:
53 default-brightness-level: [brightness-levels 53 default-brightness-level: [brightness-levels]
54 num-interpolated-steps: [brightness-levels] 54 num-interpolated-steps: [brightness-levels]
55 55
56 required: 56 required:
57 - compatible 57 - compatible
58 - pwms 58 - pwms
59 59
60 unevaluatedProperties: false 60 unevaluatedProperties: false
61 61
62 examples: 62 examples:
63 - | 63 - |
64 backlight { 64 backlight {
65 compatible = "pwm-backlight"; 65 compatible = "pwm-backlight";
66 pwms = <&pwm 0 5000000>; 66 pwms = <&pwm 0 5000000>;
67 67
68 brightness-levels = <0 4 8 16 32 64 12 68 brightness-levels = <0 4 8 16 32 64 128 255>;
69 default-brightness-level = <6>; 69 default-brightness-level = <6>;
70 70
71 power-supply = <&vdd_bl_reg>; 71 power-supply = <&vdd_bl_reg>;
72 enable-gpios = <&gpio 58 0>; 72 enable-gpios = <&gpio 58 0>;
73 post-pwm-on-delay-ms = <10>; 73 post-pwm-on-delay-ms = <10>;
74 pwm-off-delay-ms = <10>; 74 pwm-off-delay-ms = <10>;
75 }; 75 };
76 76
77 - | 77 - |
78 // Example using num-interpolation-steps: 78 // Example using num-interpolation-steps:
79 backlight { 79 backlight {
80 compatible = "pwm-backlight"; 80 compatible = "pwm-backlight";
81 pwms = <&pwm 0 5000000>; 81 pwms = <&pwm 0 5000000>;
82 82
83 brightness-levels = <0 2048 4096 8192 83 brightness-levels = <0 2048 4096 8192 16384 65535>;
84 num-interpolated-steps = <2048>; 84 num-interpolated-steps = <2048>;
85 default-brightness-level = <4096>; 85 default-brightness-level = <4096>;
86 86
87 power-supply = <&vdd_bl_reg>; 87 power-supply = <&vdd_bl_reg>;
88 enable-gpios = <&gpio 58 0>; 88 enable-gpios = <&gpio 58 0>;
89 }; 89 };
90 90
91 ... 91 ...
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