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

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/leds/backlight/lp855x-backlight.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Texas Instruments LP855X backlight controllers

maintainers:
  - Artur Weber <aweber.kernel@gmail.com>

properties:
  compatible:
    enum:
      - ti,lp8550
      - ti,lp8551
      - ti,lp8552
      - ti,lp8553
      - ti,lp8555
      - ti,lp8556
      - ti,lp8557

  reg:
    maxItems: 1

  dev-ctrl:
    $ref: /schemas/types.yaml#/definitions/uint8
    description:
      Value of device control register. This is a device-specific value.

  bl-name:
    $ref: /schemas/types.yaml#/definitions/string
    description: Backlight device name.

  init-brt:
    $ref: /schemas/types.yaml#/definitions/uint8
    description: Initial value of backlight brightness.

  power-supply:
    description: Regulator which controls the 3V rail.

  enable-supply:
    description: Regulator which controls the EN/VDDIO input.

  pwms:
    maxItems: 1
    description: |
      PWM channel to use for controlling the backlight; setting this
      enables the PWM-based backlight control mode.

  pwm-names: true

  pwm-period:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      PWM period value. Deprecated; set the period value in the pwms
      property instead.
    deprecated: true

patternProperties:
  "^rom-[0-9a-f]{2}h$":
    type: object
    description: Nodes containing the values of configuration registers.
    additionalProperties: false
    properties:
      rom-addr:
        $ref: /schemas/types.yaml#/definitions/uint8
        description: Register address of ROM area to be updated.

      rom-val:
        $ref: /schemas/types.yaml#/definitions/uint8
        description: Value to write to the ROM register.

required:
  - compatible
  - reg
  - dev-ctrl

unevaluatedProperties: false

examples:
  - |
    i2c {
        #address-cells = <1>;
        #size-cells = <0>;

        backlight@2c {
            compatible = "ti,lp8555";
            reg = <0x2c>;

            dev-ctrl = /bits/ 8 <0x00>;

            pwms = <&pwm 0 10000>;
            pwm-names = "lp8555";

            /* 4V OV, 4 output LED0 string enabled */
            rom-14h {
              rom-addr = /bits/ 8 <0x14>;
              rom-val = /bits/ 8 <0xcf>;
            };

            /* Heavy smoothing, 24ms ramp time step */
            rom-15h {
              rom-addr = /bits/ 8 <0x15>;
              rom-val = /bits/ 8 <0xc7>;
            };

            /* 4 output LED1 string enabled */
            rom-19h {
              rom-addr = /bits/ 8 <0x19>;
              rom-val = /bits/ 8 <0x0f>;
            };
        };
    };
  - |
    i2c {
        #address-cells = <1>;
        #size-cells = <0>;

        backlight@2c {
            compatible = "ti,lp8556";
            reg = <0x2c>;

            bl-name = "lcd-bl";
            dev-ctrl = /bits/ 8 <0x85>;
            init-brt = /bits/ 8 <0x10>;
        };
      };
  - |
    i2c {
        #address-cells = <1>;
        #size-cells = <0>;

        backlight@2c {
            compatible = "ti,lp8557";
            reg = <0x2c>;
            enable-supply = <&backlight_vddio>;
            power-supply = <&backlight_vdd>;

            dev-ctrl = /bits/ 8 <0x41>;
            init-brt = /bits/ 8 <0x0a>;

            /* 4V OV, 4 output LED string enabled */
            rom-14h {
              rom-addr = /bits/ 8 <0x14>;
              rom-val = /bits/ 8 <0xcf>;
            };
        };
    };