Add documentation of device tree bindings for STM32 SPI/I2S.
Signed-off-by: olivier moysan olivier.moysan@st.com --- .../devicetree/bindings/sound/st,stm32h7-i2s.txt | 71 ++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 Documentation/devicetree/bindings/sound/st,stm32h7-i2s.txt
diff --git a/Documentation/devicetree/bindings/sound/st,stm32h7-i2s.txt b/Documentation/devicetree/bindings/sound/st,stm32h7-i2s.txt new file mode 100644 index 0000000..b99467a --- /dev/null +++ b/Documentation/devicetree/bindings/sound/st,stm32h7-i2s.txt @@ -0,0 +1,71 @@ +STMicroelectronics STM32 SPI/I2S Controller + +The SPI/I2S block supports I2S/PCM protocols when configured on I2S mode. +Only some SPI instances support I2S. + +Required properties: + - compatible: Must be "st,stm32h7-i2s" + - #sound-dai-cells: Must be 1. (one parameter) + This parameter allows to specify CPU DAI index in soundcard CPU dai link. + index 0: playback DAI + index 1: capture DAI + index 2: full duplex DAI + - reg: Offset and length of the device's register set. + - interrupts: Must contain the interrupt line id. + - clocks: Must contain phandle and clock specifier pairs for each entry + in clock-names. + - clock-names: Must contain "i2sclk", "pclk", "x8k" and "x11k". + "i2sclk": clock which feeds the internal clock generator + "pclk": clock which feeds the peripheral bus interface + "x8k": I2S parent clock for sampling rates multiple of 8kHz. + "x11k": I2S parent clock for sampling rates multiple of 11.025kHz. + - dmas: DMA specifiers for tx and rx dma. + See Documentation/devicetree/bindings/dma/stm32-dma.txt. + - dma-names: Identifier for each DMA request line. Must be "tx" and "rx". + - pinctrl-names: should contain only value "default" + - pinctrl-0: see Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt + +Optional properties: + - resets: Reference to a reset controller asserting the reset controller + +Example: +sound_card { + compatible = "audio-graph-card"; + dais = <&i2s2_port 0>; +}; + +i2s2: audio-controller@40003800 { + compatible = "st,stm32h7-i2s"; + #sound-dai-cells = <1>; + reg = <0x40003800 0x400>; + interrupts = <36>; + clocks = <&rcc PCLK1>, <&rcc SPI2_CK>, <&rcc PLL1_Q>, <&rcc PLL2_P>; + clock-names = "pclk", "i2sclk", "x8k", "x11k"; + dmas = <&dmamux2 2 39 0x400 0x1>, + <&dmamux2 3 40 0x400 0x1>; + dma-names = "rx", "tx"; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_i2s2>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + i2s2_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>; + }; + }; +};