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