Bindings/clock/google,gs101-clock.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/google,gs101-clock.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Google GS101 SoC clock controller

maintainers:
  - Peter Griffin <peter.griffin@linaro.org>

description: |
  Google GS101 clock controller is comprised of several CMU units, generating
  clocks for different domains. Those CMU units are modeled as separate device
  tree nodes, and might depend on each other. The root clock in that clock tree
  is OSCCLK (24.576 MHz). That external clock must be defined as a fixed-rate
  clock in dts.

  CMU_TOP is a top-level CMU, where all base clocks are prepared using PLLs and
  dividers; all other leaf clocks (other CMUs) are usually derived from CMU_TOP.

  Each clock is assigned an identifier and client nodes can use this identifier
  to specify the clock which they consume. All clocks available for usage
  in clock consumer nodes are defined as preprocessor macros in
  'dt-bindings/clock/gs101.h' header.

properties:
  compatible:
    enum:
      - google,gs101-cmu-top
      - google,gs101-cmu-apm
      - google,gs101-cmu-misc

  clocks:
    minItems: 1
    maxItems: 2

  clock-names:
    minItems: 1
    maxItems: 2

  "#clock-cells":
    const: 1

  reg:
    maxItems: 1

required:
  - compatible
  - "#clock-cells"
  - clocks
  - clock-names
  - reg

allOf:
  - if:
      properties:
        compatible:
          contains:
            enum:
              - google,gs101-cmu-top
              - google,gs101-cmu-apm
    then:
      properties:
        clocks:
          items:
            - description: External reference clock (24.576 MHz)

        clock-names:
          items:
            - const: oscclk

  - if:
      properties:
        compatible:
          contains:
            const: google,gs101-cmu-misc

    then:
      properties:
        clocks:
          items:
            - description: Misc bus clock (from CMU_TOP)
            - description: Misc sss clock (from CMU_TOP)

        clock-names:
          items:
            - const: bus
            - const: sss

additionalProperties: false

examples:
  # Clock controller node for CMU_TOP
  - |
    #include <dt-bindings/clock/google,gs101.h>

    cmu_top: clock-controller@1e080000 {
        compatible = "google,gs101-cmu-top";
        reg = <0x1e080000 0x8000>;
        #clock-cells = <1>;
        clocks = <&ext_24_5m>;
        clock-names = "oscclk";
    };

...