dt-bindings: hwmon: Convert aspeed,ast2400-pwm-tacho to DT schema

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/hwmon/aspeed,ast2400-pwm-tacho.yaml#

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

title: ASPEED AST2400/AST2500 PWM and Fan Tacho controller

maintainers:

  - Joel Stanley <joel@jms.id.au>

  - Andrew Jeffery <andrew@codeconstruct.com.au>

description: >

  The ASPEED PWM controller can support up to 8 PWM outputs. The ASPEED Fan

  Tacho controller can support up to 16 Fan tachometer inputs.

  There can be up to 8 fans supported. Each fan can have 1 PWM output and

  1-2 Fan tach inputs.

properties:

  compatible:

    enum:

      - aspeed,ast2400-pwm-tacho

      - aspeed,ast2500-pwm-tacho

  reg:

    maxItems: 1

  '#address-cells':

    const: 1

  '#size-cells':

    const: 0

  '#cooling-cells':

    const: 2

  clocks:

    maxItems: 1

  resets:

    maxItems: 1

patternProperties:

  '^fan@[0-7]$':

    description: Fan subnode

    type: object

    additionalProperties: false

    properties:

      reg:

        description: PWM source port index (0 = PWM A, ..., 7 = PWM H)

        maximum: 7

      cooling-levels:

        description: PWM duty cycle values for cooling states

        $ref: /schemas/types.yaml#/definitions/uint8-array

        minItems: 1

        maxItems: 16  # Should be enough

      aspeed,fan-tach-ch:

        description: Fan tachometer input channel

        $ref: /schemas/types.yaml#/definitions/uint8-array

        minItems: 1

        maxItems: 2

        items:

          maximum: 15

    required:

      - reg

      - aspeed,fan-tach-ch

required:

  - compatible

  - reg

  - '#address-cells'

  - '#size-cells'

  - clocks

  - resets

additionalProperties: false

examples:

  - |

    #include <dt-bindings/clock/aspeed-clock.h>

    fan-controller@1e786000 {

        compatible = "aspeed,ast2500-pwm-tacho";

        reg = <0x1e786000 0x1000>;

        #address-cells = <1>;

        #size-cells = <0>;

        #cooling-cells = <2>;

        clocks = <&syscon ASPEED_CLK_APB>;

        resets = <&syscon ASPEED_RESET_PWM>;

        fan@0 {

            reg = <0x00>;

            cooling-levels = /bits/ 8 <125 151 177 203 229 255>;

            aspeed,fan-tach-ch = /bits/ 8 <0x00>;

        };

        fan@1 {

            reg = <0x01>;

            aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;

        };

    };

ASPEED AST2400/AST2500 PWM and Fan Tacho controller device driver

The ASPEED PWM controller can support upto 8 PWM outputs. The ASPEED Fan Tacho

controller can support upto 16 Fan tachometer inputs.

There can be upto 8 fans supported. Each fan can have one PWM output and

one/two Fan tach inputs.

Required properties for pwm-tacho node:

- #address-cells : should be 1.

- #size-cells : should be 1.

- #cooling-cells: should be 2.

- reg : address and length of the register set for the device.

- pinctrl-names : a pinctrl state named "default" must be defined.

- pinctrl-0 : phandle referencing pin configuration of the PWM ports.

- compatible : should be "aspeed,ast2400-pwm-tacho" for AST2400 and

	       "aspeed,ast2500-pwm-tacho" for AST2500.

- clocks : phandle to clock provider with the clock number in the second cell

- resets : phandle to reset controller with the reset number in the second cell

fan subnode format:

===================

Under fan subnode there can upto 8 child nodes, with each child node

representing a fan. If there are 8 fans each fan can have one PWM port and

one/two Fan tach inputs.

For PWM port can be configured cooling-levels to create cooling device.

Cooling device could be bound to a thermal zone for the thermal control.

Required properties for each child node:

- reg : should specify PWM source port.

	integer value in the range 0 to 7 with 0 indicating PWM port A and

	7 indicating PWM port H.

- cooling-levels: PWM duty cycle values in a range from 0 to 255

                  which correspond to thermal cooling states.

- aspeed,fan-tach-ch : should specify the Fan tach input channel.

                integer value in the range 0 through 15, with 0 indicating

		Fan tach channel 0 and 15 indicating Fan tach channel 15.

		At least one Fan tach input channel is required.

Examples:

pwm_tacho: pwmtachocontroller@1e786000 {

	#address-cells = <1>;

	#size-cells = <1>;

	#cooling-cells = <2>;

	reg = <0x1E786000 0x1000>;

	compatible = "aspeed,ast2500-pwm-tacho";

	clocks = <&syscon ASPEED_CLK_APB>;

	resets = <&syscon ASPEED_RESET_PWM>;

	pinctrl-names = "default";

	pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;

	fan@0 {

		reg = <0x00>;

		cooling-levels = /bits/ 8 <125 151 177 203 229 255>;

		aspeed,fan-tach-ch = /bits/ 8 <0x00>;

	};

	fan@1 {

		reg = <0x01>;

		aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;

	};

};