Documentation/devicetree/bindings/clock/rockchip,rk3288-cru.yaml

# SPDX-License-Identifier: (GPL-2.0+ OR MIT)
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/rockchip,rk3288-cru.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Rockchip RK3288 Clock and Reset Unit (CRU)

maintainers:
  - Elaine Zhang <zhangqing@rock-chips.com>
  - Heiko Stuebner <heiko@sntech.de>

description: |
  The RK3288 clock controller generates and supplies clocks to various
  controllers within the SoC and also implements a reset controller for SoC
  peripherals.

  A revision of this SoC is available: rk3288w. The clock tree is a bit
  different so another dt-compatible is available. Noticed that it is only
  setting the difference but there is no automatic revision detection. This
  should be performed by boot loaders.

  Each clock is assigned an identifier and client nodes can use this identifier
  to specify the clock which they consume. All available clocks are defined as
  preprocessor macros in the dt-bindings/clock/rk3288-cru.h headers and can be
  used in device tree sources. Similar macros exist for the reset sources in
  these files.

  There are several clocks that are generated outside the SoC. It is expected
  that they are defined using standard clock bindings with following
  clock-output-names:
    - "xin24m"      - crystal input               - required,
    - "xin32k"      - rtc clock                   - optional,
    - "ext_i2s"     - external I2S clock          - optional,
    - "ext_hsadc"   - external HSADC clock        - optional,
    - "ext_edp_24m" - external display port clock - optional,
    - "ext_vip"     - external VIP clock          - optional,
    - "ext_isp"     - external ISP clock          - optional,
    - "ext_jtag"    - external JTAG clock         - optional

properties:
  compatible:
    enum:
      - rockchip,rk3288-cru
      - rockchip,rk3288w-cru

  reg:
    maxItems: 1

  "#clock-cells":
    const: 1

  "#reset-cells":
    const: 1

  clocks:
    maxItems: 1

  clock-names:
    const: xin24m

  rockchip,grf:
    $ref: /schemas/types.yaml#/definitions/phandle
    description:
      Phandle to the syscon managing the "general register files" (GRF),
      if missing pll rates are not changeable, due to the missing pll
      lock status.

required:
  - compatible
  - reg
  - "#clock-cells"
  - "#reset-cells"

additionalProperties: false

examples:
  - |
    cru: clock-controller@ff760000 {
      compatible = "rockchip,rk3288-cru";
      reg = <0xff760000 0x1000>;
      rockchip,grf = <&grf>;
      #clock-cells = <1>;
      #reset-cells = <1>;
    };