dt-bindings: rtc: Convert Allwinner A31 RTC to a schema

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/rtc/allwinner,sun6i-a31-rtc.yaml#

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

title: Allwinner A31 RTC Device Tree Bindings

maintainers:

  - Chen-Yu Tsai <wens@csie.org>

  - Maxime Ripard <maxime.ripard@bootlin.com>

properties:

  "#clock-cells":

    const: 1

  compatible:

    oneOf:

      - const: allwinner,sun6i-a31-rtc

      - const: allwinner,sun8i-a23-rtc

      - const: allwinner,sun8i-h3-rtc

      - items:

          - const: allwinner,sun8i-r40-rtc

          - const: allwinner,sun8i-h3-rtc

      - const: allwinner,sun8i-v3-rtc

      - const: allwinner,sun50i-h5-rtc

      - items:

          - const: allwinner,sun50i-a64-rtc

          - const: allwinner,sun8i-h3-rtc

  reg:

    maxItems: 1

  interrupts:

    items:

      - description: RTC Alarm 0

      - description: RTC Alarm 1

  clocks:

    maxItems: 1

  clock-output-names:

    minItems: 1

    maxItems: 3

    description:

      The RTC provides up to three clocks

        - the Low Frequency Oscillator or LOSC, at index 0,

        - the Low Frequency Oscillator External output (X32KFOUT in

          the datasheet), at index 1,

        - the Internal Oscillator, at index 2.

allOf:

  - $ref: "rtc.yaml#"

  - if:

      properties:

        compatible:

          contains:

            const: allwinner,sun6i-a31-rtc

    then:

      properties:

        clock-output-names:

          minItems: 1

          maxItems: 1

  - if:

      properties:

        compatible:

          contains:

            enum:

              - allwinner,sun8i-a23-rtc

              - allwinner,sun8i-v3-rtc

    then:

      properties:

        clock-output-names:

          minItems: 2

          maxItems: 2

  - if:

      properties:

        compatible:

          contains:

            enum:

              - allwinner,sun8i-h3-rtc

              - allwinner,sun50i-h5-rtc

    then:

      properties:

        clock-output-names:

          minItems: 3

          maxItems: 3

required:

  - "#clock-cells"

  - compatible

  - reg

  - interrupts

  - clocks

  - clock-output-names

additionalProperties: false

examples:

  - |

    rtc: rtc@1f00000 {

        compatible = "allwinner,sun6i-a31-rtc";

        reg = <0x01f00000 0x400>;

        interrupts = <0 40 4>, <0 41 4>;

        clock-output-names = "osc32k";

        clocks = <&ext_osc32k>;

        #clock-cells = <1>;

    };

...

* sun6i Real Time Clock

RTC controller for the Allwinner A31

Required properties:

- compatible	: Should be one of the following combinations:

		    - "allwinner,sun6i-a31-rtc"

		    - "allwinner,sun8i-a23-rtc"

		    - "allwinner,sun8i-h3-rtc"

		    - "allwinner,sun8i-r40-rtc", "allwinner,sun8i-h3-rtc"

		    - "allwinner,sun8i-v3-rtc"

		    - "allwinner,sun50i-a64-rtc", "allwinner,sun8i-h3-rtc"

		    - "allwinner,sun50i-h5-rtc"

		  Where there are two or more compatible strings, this

		  denotes the hardware covered by the most specific one

		  is backward-compatible with the latter ones, and the

		  implementation for the latter ones can be used, albeit

		  with reduced functionality.

- reg		: physical base address of the controller and length of

		  memory mapped region.

- interrupts	: IRQ lines for the RTC alarm 0 and alarm 1, in that order.

Required properties for new device trees

- clocks	: phandle to the 32kHz external oscillator

- clock-output-names : names of up to three clock outputs. See below.

- #clock-cells  : must be equal to 1.

The RTC provides the following clocks at the given indices:

- 0: LOSC

- 1: LOSC external output, known as X32KFOUT in the datasheet.

     This clock is not available on the A31 and is deprecated for old

     device trees still using the "allwinner,sun6i-a31-rtc" compatible.

- 2: InternalOSC, or internal RC oscillator (A64/H3/H5 only)

Example:

rtc: rtc@1f00000 {

	compatible = "allwinner,sun6i-a31-rtc";

	reg = <0x01f00000 0x400>;

	interrupts = <0 40 4>, <0 41 4>;

	clock-output-names = "osc32k";

	clocks = <&ext_osc32k>;

	#clock-cells = <1>;

};