xref: /linux/Documentation/devicetree/bindings/leds/backlight/lp855x-backlight.yaml (revision 42874e4eb35bdfc54f8514685e50434098ba4f6c) 
1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/leds/backlight/lp855x-backlight.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Texas Instruments LP855X backlight controllers
8
9maintainers:
10  - Artur Weber <aweber.kernel@gmail.com>
11
12properties:
13  compatible:
14    enum:
15      - ti,lp8550
16      - ti,lp8551
17      - ti,lp8552
18      - ti,lp8553
19      - ti,lp8555
20      - ti,lp8556
21      - ti,lp8557
22
23  reg:
24    maxItems: 1
25
26  dev-ctrl:
27    $ref: /schemas/types.yaml#/definitions/uint8
28    description:
29      Value of device control register. This is a device-specific value.
30
31  bl-name:
32    $ref: /schemas/types.yaml#/definitions/string
33    description: Backlight device name.
34
35  init-brt:
36    $ref: /schemas/types.yaml#/definitions/uint8
37    description: Initial value of backlight brightness.
38
39  power-supply:
40    description: Regulator which controls the 3V rail.
41
42  enable-supply:
43    description: Regulator which controls the EN/VDDIO input.
44
45  pwms:
46    maxItems: 1
47    description: |
48      PWM channel to use for controlling the backlight; setting this
49      enables the PWM-based backlight control mode.
50
51  pwm-names: true
52
53  pwm-period:
54    $ref: /schemas/types.yaml#/definitions/uint32
55    description:
56      PWM period value. Deprecated; set the period value in the pwms
57      property instead.
58    deprecated: true
59
60patternProperties:
61  "^rom-[0-9a-f]{2}h$":
62    type: object
63    description: Nodes containing the values of configuration registers.
64    additionalProperties: false
65    properties:
66      rom-addr:
67        $ref: /schemas/types.yaml#/definitions/uint8
68        description: Register address of ROM area to be updated.
69
70      rom-val:
71        $ref: /schemas/types.yaml#/definitions/uint8
72        description: Value to write to the ROM register.
73
74required:
75  - compatible
76  - reg
77  - dev-ctrl
78
79unevaluatedProperties: false
80
81examples:
82  - |
83    i2c {
84        #address-cells = <1>;
85        #size-cells = <0>;
86
87        backlight@2c {
88            compatible = "ti,lp8555";
89            reg = <0x2c>;
90
91            dev-ctrl = /bits/ 8 <0x00>;
92
93            pwms = <&pwm 0 10000>;
94            pwm-names = "lp8555";
95
96            /* 4V OV, 4 output LED0 string enabled */
97            rom-14h {
98              rom-addr = /bits/ 8 <0x14>;
99              rom-val = /bits/ 8 <0xcf>;
100            };
101
102            /* Heavy smoothing, 24ms ramp time step */
103            rom-15h {
104              rom-addr = /bits/ 8 <0x15>;
105              rom-val = /bits/ 8 <0xc7>;
106            };
107
108            /* 4 output LED1 string enabled */
109            rom-19h {
110              rom-addr = /bits/ 8 <0x19>;
111              rom-val = /bits/ 8 <0x0f>;
112            };
113        };
114    };
115  - |
116    i2c {
117        #address-cells = <1>;
118        #size-cells = <0>;
119
120        backlight@2c {
121            compatible = "ti,lp8556";
122            reg = <0x2c>;
123
124            bl-name = "lcd-bl";
125            dev-ctrl = /bits/ 8 <0x85>;
126            init-brt = /bits/ 8 <0x10>;
127        };
128      };
129  - |
130    i2c {
131        #address-cells = <1>;
132        #size-cells = <0>;
133
134        backlight@2c {
135            compatible = "ti,lp8557";
136            reg = <0x2c>;
137            enable-supply = <&backlight_vddio>;
138            power-supply = <&backlight_vdd>;
139
140            dev-ctrl = /bits/ 8 <0x41>;
141            init-brt = /bits/ 8 <0x0a>;
142
143            /* 4V OV, 4 output LED string enabled */
144            rom-14h {
145              rom-addr = /bits/ 8 <0x14>;
146              rom-val = /bits/ 8 <0xcf>;
147            };
148        };
149    };
150