Re: [PATCH v2 2/4] dt-bindings: add bindings for rk3328 clock controller

[Rob Herring]

On Mon, Dec 19, 2016 at 09:56:11AM +0800, Elaine Zhang wrote:
> Add devicetree bindings for Rockchip cru which found on
> Rockchip SoCs.
> 
> Signed-off-by: Elaine Zhang <zhangqing@xxxxxxxxxxxxxx>
> ---
>  .../bindings/clock/rockchip,rk3328-cru.txt         | 57 ++++++++++++++++++++++
>  1 file changed, 57 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/rockchip,rk3328-cru.txt
> 
> diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3328-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3328-cru.txt
> new file mode 100644
> index 000000000000..20053494d49f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/rockchip,rk3328-cru.txt
> @@ -0,0 +1,57 @@
> +* Rockchip RK3328 Clock and Reset Unit
> +
> +The RK3328 clock controller generates and supplies clock to various
> +controllers within the SoC and also implements a reset controller for SoC
> +peripherals.
> +
> +Required Properties:
> +
> +- compatible: should be "rockchip,rk3328-cru"

The example shows other compatibles. IMO, I would drop them rather than 
add them here.

> +- 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/rk3328-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,
> + - "clkin_i2s" - external I2S clock - optional,
> + - "gmac_clkin" - external GMAC clock - optional
> + - "phy_50m_out" - output clock of the pll in the mac phy
> +
> +Example: Clock controller node:
> +
> +	cru: clock-controller@ff440000 {
> +		compatible = "rockchip,rk3328-cru", "rockchip,cru", "syscon";
> +		reg = <0x0 0xff440000 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@ff120000 {
> +		compatible = "snps,dw-apb-uart";
> +		reg = <0xff120000 0x100>;
> +		interrupts = <GIC_SPI 56 IRQ_TYPE_LEVEL_HIGH>;
> +		reg-shift = <2>;
> +		reg-io-width = <4>;
> +		clocks = <&cru SCLK_UART0>;
> +	};
> -- 
> 1.9.1
> 
>