[alsa-devel] [RESEND PATCH v2 1/2] ASoC: stm32: add bindings for SAI

[Rob Herring]

On Tue, Mar 07, 2017 at 10:44:31AM +0100, olivier moysan wrote:
> This patch adds documentation of device tree bindings for the
> STM32 SAI ASoC driver.
> 
> Signed-off-by: olivier moysan <olivier.moysan at st.com>
> ---
>  .../devicetree/bindings/sound/st,stm32-sai.txt     | 79 ++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/sound/st,stm32-sai.txt
> 
> diff --git a/Documentation/devicetree/bindings/sound/st,stm32-sai.txt b/Documentation/devicetree/bindings/sound/st,stm32-sai.txt
> new file mode 100644
> index 0000000..b3be26d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/st,stm32-sai.txt
> @@ -0,0 +1,79 @@
> +STMicroelectronics STM32 Serial Audio Interface (SAI).
> +
> +The SAI interface (Serial Audio Interface) offers a wide set of audio protocols
> +as I2S standards, LSB or MSB-justified, PCM/DSP, TDM, and AC'97.
> +The SAI contains two independent audio sub-blocks. Each sub-block has
> +its own clock generator and I/O lines controller.
> +
> +Required properties:
> +  - compatible: Should be "st,stm32f4-sai"
> +  - reg: Base address and size of SAI common register set.
> +  - clocks: Must contain phandle and clock specifier pairs for each entry
> +	in clock-names.
> +  - clock-names: Must contain "clk_x8k" and "clk_x11k"
> +	"clk_x8k": SAI parent clock for sampling rates multiple of 8kHz.
> +	"clk_x11k": SAI parent clock for sampling rates multiple of 11.025kHz.

clk_ is redundant.

> +  - interrupts: cpu DAI interrupt line shared by SAI sub-blocks
> +
> +Note: Each SAI controller should have an alias correctly numbered
> +in "aliases" node, to provide explicit name to CPU DAI.

No, it shouldn't. Why do you need that?


> +
> +Optional properties:
> +  - resets: Reference to a reset controller asserting the SAI
> +
> +SAI subnodes:
> +Two subnodes corresponding to SAI sub-block instances A et B can be defined.
> +Subnode can be omitted for unsused sub-block.
> +
> +SAI subnodes required properties:
> +  - compatible: Should be "st,stm32-sai-sub-a" or "st,stm32-sai-sub-b"
> +	for SAI sub-block A or B respectively.
> +  - reg: Base address and size of SAI sub-block register set.
> +  - clocks: Must contain one phandle and clock specifier pair
> +	for sai_ck which feeds the internal clock generator.
> +  - clock-names: Must contain "sai_ck".
> +  - dmas: see Documentation/devicetree/bindings/dma/stm32-dma.txt
> +  - dma-names: identifier string for each DMA request line
> +	"tx": if sai sub-block is configured as playback DAI
> +	"rx": if sai sub-block is configured as capture DAI
> +  - pinctrl-names: should contain only value "default"
> +  - pinctrl-0: see Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
> +
> +Example:
> +sai1: sai1 at 40015800 {
> +	compatible = "st,stm32f4-sai";
> +	reg = <0x40015800 0x400>;
> +	clocks = <&rcc 1 CLK_SAIQ_PDIV>, <&rcc 1 CLK_I2SQ_PDIV>;
> +	clock-names = "clk_x8k", "clk_x11k";
> +	interrupts = <87>;
> +	resets = <&rcc 310>;
> +
> +	sai1b: sai at 1 {

unit address needs a reg property.

audio-controller at 1

> +		#sound-dai-cells = <0>;
> +		compatible = "st,stm32-sai-sub-b";
> +		clocks = <&rcc 1 CLK_SAI2>;
> +		clock-names = "sai_ck";
> +		dmas = <&dma2 5 0 0x400 0x1>;
> +		dma-names = "tx";
> +	};
> +};
> +
> +sound {
> +	compatible = "simple-audio-card";

Perhaps you want to use the graph-card here. It's getting close to 
merging.

> +	simple-audio-card,name = "STM32-Sound-Card";
> +	status = "okay";
> +
> +	simple-audio-card,dai-link at 0 {
> +		format = "i2s";
> +		cpu {
> +			sound-dai = <&sai1b>;
> +		};
> +		codec {
> +			sound-dai = <&codec>;
> +		};
> +	};
> +};
> +
> +aliases {
> +	sai1 = &sai1;
> +};
> -- 
> 1.9.1
>