This patch adds documentation of device tree bindings for the STM32 SAI ASoC driver.
Signed-off-by: olivier moysan olivier.moysan@st.com --- .../devicetree/bindings/sound/st,stm32-sai.txt | 89 ++++++++++++++++++++++ 1 file changed, 89 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..c59a3d7 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/st,stm32-sai.txt @@ -0,0 +1,89 @@ +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 "x8k" and "x11k" + "x8k": SAI parent clock for sampling rates multiple of 8kHz. + "x11k": SAI parent clock for sampling rates multiple of 11.025kHz. + - interrupts: cpu DAI interrupt line shared by SAI sub-blocks + +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: +sound_card { + compatible = "audio-graph-card"; + dais = <&sai1b_port>; +}; + +sai1: sai1@40015800 { + compatible = "st,stm32f4-sai"; + #address-cells = <1>; + #size-cells = <1>; + ranges; + reg = <0x40015800 0x4>; + clocks = <&rcc 1 CLK_SAIQ_PDIV>, <&rcc 1 CLK_I2SQ_PDIV>; + clock-names = "x8k", "x11k"; + interrupts = <87>; + + sai1b: audio-controller@40015824 { + #sound-dai-cells = <0>; + compatible = "st,stm32-sai-sub-b"; + reg = <0x40015824 0x1C>; + clocks = <&rcc 1 CLK_SAI2>; + clock-names = "sai_ck"; + dmas = <&dma2 5 0 0x400 0x0>; + dma-names = "tx"; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_sai1b>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + sai1b_port: port@0 { + reg = <0>; + cpu_endpoint: endpoint { + remote-endpoint = <&codec_endpoint>; + audio-graph-card,format = "i2s"; + audio-graph-card,bitclock-master = <&codec_endpoint>; + audio-graph-card,frame-master = <&codec_endpoint>; + }; + }; + }; + }; +}; + +audio-codec { + codec_port: port { + codec_endpoint: endpoint { + remote-endpoint = <&cpu_endpoint>; + }; + }; +};