dt-bindings: clock: convert rockchip,rk3308-cru.txt to YAML

* Rockchip RK3308 Clock and Reset Unit

The RK3308 clock controller generates and supplies clock to various

controllers within the SoC and also implements a reset controller for SoC

peripherals.

Required Properties:

- compatible: CRU should be "rockchip,rk3308-cru"

- reg: physical base address of the controller and length of memory mapped

  region.

- #clock-cells: should be 1.

- #reset-cells: should be 1.

Optional Properties:

- rockchip,grf: phandle to the syscon managing the "general register files"

  If missing, pll rates are not changeable, due to the missing pll lock status.

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/rk3308-cru.h headers and can be

used in device tree sources. Similar macros exist for the reset sources in

these files.

External clocks:

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,

 - "mclk_i2s0_8ch_in", "mclk_i2s1_8ch_in", "mclk_i2s2_8ch_in",

   "mclk_i2s3_8ch_in", "mclk_i2s0_2ch_in",

   "mclk_i2s1_2ch_in" - external I2S or SPDIF clock - optional,

 - "mac_clkin" - external MAC clock - optional

Example: Clock controller node:

	cru: clock-controller@ff500000 {

		compatible = "rockchip,rk3308-cru";

		reg = <0x0 0xff500000 0x0 0x1000>;

		rockchip,grf = <&grf>;

		#clock-cells = <1>;

		#reset-cells = <1>;

	};

Example: UART controller node that consumes the clock generated by the clock

  controller:

	uart0: serial@ff0a0000 {

		compatible = "rockchip,rk3308-uart", "snps,dw-apb-uart";

		reg = <0x0 0xff0a0000 0x0 0x100>;

		interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;

		clocks = <&cru SCLK_UART0>, <&cru PCLK_UART0>;

		clock-names = "baudclk", "apb_pclk";

		reg-shift = <2>;

		reg-io-width = <4>;

		status = "disabled";

	};

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/clock/rockchip,rk3308-cru.yaml#

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

title: Rockchip RK3308 Clock and Reset Unit (CRU)

maintainers:

  - Elaine Zhang <zhangqing@rock-chips.com>

  - Heiko Stuebner <heiko@sntech.de>

description: |

  The RK3308 clock controller generates and supplies clocks to various

  controllers within the SoC and also implements a reset controller for SoC

  peripherals.

  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/rk3308-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

    - "mclk_i2s0_8ch_in", "mclk_i2s1_8ch_in",

      "mclk_i2s2_8ch_in", "mclk_i2s3_8ch_in",

      "mclk_i2s0_2ch_in", "mclk_i2s1_2ch_in" - external I2S or

                                               SPDIF clock        - optional

    - "mac_clkin"                            - external MAC clock - optional

properties:

  compatible:

    enum:

      - rockchip,rk3308-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@ff500000 {

      compatible = "rockchip,rk3308-cru";

      reg = <0xff500000 0x1000>;

      rockchip,grf = <&grf>;

      #clock-cells = <1>;

      #reset-cells = <1>;

    };