Documentation/devicetree/bindings/leds/backlight/lp855x-backlight.yaml

   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
   7 title: Texas Instruments LP855X backlight controllers
   8
   9 maintainers:
  10   - Artur Weber <aweber.kernel@gmail.com>
  11
  12 properties:
  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     $ref: /schemas/types.yaml#/definitions/uint32
  55     description:
  56       PWM period value. Deprecated; set the period value in the pwms
  57       property instead.
  58     deprecated: true
  59
  60 patternProperties:
  61   "^rom-[0-9a-f]{2}h$":
  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
  74 required:
  75   - compatible
  76   - reg
  77   - dev-ctrl
  78
  79 unevaluatedProperties: false
  80
  81 examples:
  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     };