Documentation/devicetree/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
      - google,gs101-cmu-hsi0
      - google,gs101-cmu-hsi2
      - google,gs101-cmu-peric0
      - google,gs101-cmu-peric1

  clocks:
    minItems: 1
    maxItems: 5

  clock-names:
    minItems: 1
    maxItems: 5

  "#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-hsi0

    then:
      properties:
        clocks:
          items:
            - description: External reference clock (24.576 MHz)
            - description: HSI0 bus clock (from CMU_TOP)
            - description: DPGTC (from CMU_TOP)
            - description: USB DRD controller clock (from CMU_TOP)
            - description: USB Display Port debug clock (from CMU_TOP)

        clock-names:
          items:
            - const: oscclk
            - const: bus
            - const: dpgtc
            - const: usb31drd
            - const: usbdpdbg

  - if:
      properties:
        compatible:
          contains:
            enum:
              - google,gs101-cmu-hsi2

    then:
      properties:
        clocks:
          items:
            - description: External reference clock (24.576 MHz)
            - description: High Speed Interface bus clock (from CMU_TOP)
            - description: High Speed Interface pcie clock (from CMU_TOP)
            - description: High Speed Interface ufs clock (from CMU_TOP)
            - description: High Speed Interface mmc clock (from CMU_TOP)

        clock-names:
          items:
            - const: oscclk
            - const: bus
            - const: pcie
            - const: ufs
            - const: mmc

  - 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

  - if:
      properties:
        compatible:
          contains:
            enum:
              - google,gs101-cmu-peric0
              - google,gs101-cmu-peric1

    then:
      properties:
        clocks:
          items:
            - description: External reference clock (24.576 MHz)
            - description: Connectivity Peripheral 0/1 bus clock (from CMU_TOP)
            - description: Connectivity Peripheral 0/1 IP clock (from CMU_TOP)

        clock-names:
          items:
            - const: oscclk
            - const: bus
            - const: ip

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";
    };

...