[alsa-devel] [PATCH v4 1/7] dt-bindings: clk: at91: add an I2S mux clock

[Rob Herring]

On Fri, May 25, 2018 at 03:34:22PM +0300, Codrin Ciubotariu wrote:
> The I2S mux clock can be used to select the I2S input clock. The
> available parents are the peripheral and the generated clocks.
> 
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu at microchip.com>
> ---
>  .../devicetree/bindings/clock/at91-clock.txt       | 34 ++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
> index 51c259a..1c46b3c 100644
> --- a/Documentation/devicetree/bindings/clock/at91-clock.txt
> +++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
> @@ -90,6 +90,8 @@ Required properties:
>  	"atmel,sama5d2-clk-audio-pll-pmc"
>  		at91 audio pll output on AUDIOPLLCLK that feeds the PMC
>  		and can be used by peripheral clock or generic clock
> +	"atmel,sama5d2-clk-i2s-mux":
> +		at91 I2S clock source selection

Is this boolean or takes some values. If latter, what are valid values?

>  
>  Required properties for SCKC node:
>  - reg : defines the IO memory reserved for the SCKC.
> @@ -507,3 +509,35 @@ For example:
>  			atmel,clk-output-range = <0 83000000>;
>  		};
>  	};
> +
> +Required properties for I2S mux clocks:
> +- #size-cells : shall be 0 (reg is used to encode I2S bus id).
> +- #address-cells : shall be 1 (reg is used to encode I2S bus id).
> +- name: device tree node describing a specific mux clock.
> +	* #clock-cells : from common clock binding; shall be set to 0.
> +	* clocks : shall be the mux clock parent phandles; shall be 2 phandles:
> +	  peripheral and generated clock; the first phandle shall belong to the
> +	  peripheral clock and the second one shall belong to the generated
> +	  clock; "clock-indices" property can be user to specify
> +	  the correct order.
> +	* reg: I2S bus id of the corresponding mux clock.
> +	  e.g. reg = <0>; for i2s0, reg = <1>; for i2s1
> +
> +For example:
> +	i2s_clkmux {

What is this a child of?

> +		compatible = "atmel,sama5d2-clk-i2s-mux";
> +		#address-cells = <1>;
> +		#size-cells = <0>;

How do you address this block? My guess is you don't because it is just 
part of some other block and you are just creating this node to 
instantiate a driver. Just make the node for the actual h/w block a 
clock provider and define the clock ids (0 and 1).

> +
> +		i2s0muxck: i2s0_muxclk {
> +			clocks = <&i2s0_clk>, <&i2s0_gclk>;
> +			#clock-cells = <0>;
> +			reg = <0>;
> +		};
> +
> +		i2s1muxck: i2s1_muxclk {
> +			clocks = <&i2s1_clk>, <&i2s1_gclk>;
> +			#clock-cells = <0>;
> +			reg = <1>;
> +		};
> +	};
> -- 
> 2.7.4
>