Documentation/devicetree/bindings/clock/samsung,exynos990-clock.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/samsung,exynos990-clock.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Samsung Exynos990 SoC clock controller

maintainers:
  - Igor Belwon <igor.belwon@mentallysanemainliners.org>
  - Chanwoo Choi <cw00.choi@samsung.com>
  - Krzysztof Kozlowski <krzk@kernel.org>

description: |
  Exynos990 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 root tree
  is an external clock: OSCCLK (26 MHz). This 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 clocks of function blocks (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
  'include/dt-bindings/clock/samsung,exynos990.h' header.

properties:
  compatible:
    enum:
      - samsung,exynos990-cmu-hsi0
      - samsung,exynos990-cmu-top

  clocks:
    minItems: 1
    maxItems: 5

  clock-names:
    minItems: 1
    maxItems: 5

  "#clock-cells":
    const: 1

  reg:
    maxItems: 1

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

allOf:
  - if:
      properties:
        compatible:
          contains:
            const: samsung,exynos990-cmu-hsi0

    then:
      properties:
        clocks:
          items:
            - description: External reference clock (26 MHz)
            - description: CMU_HSI0 BUS clock (from CMU_TOP)
            - description: CMU_HSI0 USB31DRD clock (from CMU_TOP)
            - description: CMU_HSI0 USBDP_DEBUG clock (from CMU_TOP)
            - description: CMU_HSI0 DPGTC clock (from CMU_TOP)

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

  - if:
      properties:
        compatible:
          contains:
            const: samsung,exynos990-cmu-top

    then:
      properties:
        clocks:
          items:
            - description: External reference clock (26 MHz)

        clock-names:
          items:
            - const: oscclk

additionalProperties: false

examples:
  - |
    #include <dt-bindings/clock/samsung,exynos990.h>

    cmu_hsi0: clock-controller@10a00000 {
        compatible = "samsung,exynos990-cmu-hsi0";
        reg = <0x10a00000 0x8000>;
        #clock-cells = <1>;

        clocks = <&oscclk>,
                 <&cmu_top CLK_DOUT_CMU_HSI0_BUS>,
                 <&cmu_top CLK_DOUT_CMU_HSI0_USB31DRD>,
                 <&cmu_top CLK_DOUT_CMU_HSI0_USBDP_DEBUG>,
                 <&cmu_top CLK_DOUT_CMU_HSI0_DPGTC>;
        clock-names = "oscclk",
                      "bus",
                      "usb31drd",
                      "usbdp_debug",
                      "dpgtc";
    };

...