dt-bindings: i2c: Add Apple I2C controller bindings

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

%YAML 1.2

---

$id: "http://devicetree.org/schemas/i2c/apple,i2c.yaml#"

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

title: Apple/PASemi I2C controller

maintainers:

  - Sven Peter <sven@svenpeter.dev>

description: |

  Apple SoCs such as the M1 come with a I2C controller based on the one found

  in machines with P. A. Semi's PWRficient processors.

  The bus is used to communicate with e.g. USB PD chips or the speaker

  amp.

allOf:

  - $ref: /schemas/i2c/i2c-controller.yaml#

properties:

  compatible:

    enum:

      - apple,t8103-i2c

      - apple,i2c

  reg:

    maxItems: 1

  clocks:

    items:

      - description: I2C bus reference clock

  interrupts:

    maxItems: 1

  clock-frequency:

    description: |

      Desired I2C bus clock frequency in Hz. If not specified, 100 kHz will be

      used. This frequency is generated by dividing the reference clock.

      Allowed values are between ref_clk/(16*4) and ref_clk/(16*255).

required:

  - compatible

  - reg

  - clocks

  - interrupts

unevaluatedProperties: false

examples:

  - |

    i2c@35010000 {

      compatible = "apple,t8103-i2c";

      reg = <0x35010000 0x4000>;

      interrupt-parent = <&aic>;

      interrupts = <0 627 4>;

      clocks = <&ref_clk>;

      #address-cells = <1>;

      #size-cells = <0>;

    };