dt-bindings: leds: Convert pwm to yaml

LED connected to PWM

Required properties:

- compatible : should be "pwm-leds".

Each LED is represented as a sub-node of the pwm-leds device.  Each

node's name represents the name of the corresponding LED.

LED sub-node properties:

- pwms : PWM property to point to the PWM device (phandle)/port (id) and to

  specify the period time to be used: <&phandle id period_ns>;

- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device

  For the pwms and pwm-names property please refer to:

  Documentation/devicetree/bindings/pwm/pwm.txt

- max-brightness : Maximum brightness possible for the LED

- active-low : (optional) For PWMs where the LED is wired to supply

  rather than ground.

- label :  (optional)

  see Documentation/devicetree/bindings/leds/common.txt

- linux,default-trigger :  (optional)

  see Documentation/devicetree/bindings/leds/common.txt

Example:

twl_pwm: pwm {

	/* provides two PWMs (id 0, 1 for PWM1 and PWM2) */

	compatible = "ti,twl6030-pwm";

	#pwm-cells = <2>;

};

twl_pwmled: pwmled {

	/* provides one PWM (id 0 for Charing indicator LED) */

	compatible = "ti,twl6030-pwmled";

	#pwm-cells = <2>;

};

pwmleds {

	compatible = "pwm-leds";

	kpad {

		label = "omap4::keypad";

		pwms = <&twl_pwm 0 7812500>;

		max-brightness = <127>;

	};

	charging {

		label = "omap4:green:chrg";

		pwms = <&twl_pwmled 0 7812500>;

		max-brightness = <255>;

	};

};

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/leds/leds-pwm.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: LEDs connected to PWM

maintainers:

  - Pavel Machek <pavel@ucw.cz>

description:

  Each LED is represented as a sub-node of the pwm-leds device.  Each

  node's name represents the name of the corresponding LED.

properties:

  compatible:

    const: pwm-leds

patternProperties:

  "^led(-[0-9a-f]+)?$":

    type: object

    $ref: common.yaml#

    properties:

      pwms:

        maxItems: 1

      pwm-names: true

      max-brightness:

        description:

          Maximum brightness possible for the LED

        $ref: /schemas/types.yaml#/definitions/uint32

      active-low:

        description:

          For PWMs where the LED is wired to supply rather than ground.

        type: boolean

    required:

      - pwms

      - max-brightness

additionalProperties: false

examples:

  - |

    #include <dt-bindings/leds/common.h>

    led-controller {

        compatible = "pwm-leds";

        led-1 {

            label = "omap4::keypad";

            pwms = <&twl_pwm 0 7812500>;

            max-brightness = <127>;

        };

        led-2 {

            color = <LED_COLOR_ID_GREEN>;

            function = LED_FUNCTION_CHARGING;

            pwms = <&twl_pwmled 0 7812500>;

            max-brightness = <255>;

        };

    };

...