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| -rw-r--r-- | Documentation/devicetree/bindings/sound/st,stm32-sai.txt | 107 |
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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 000000000..c42b91e52 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/st,stm32-sai.txt @@ -0,0 +1,107 @@ +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" or "st,stm32h7-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 "pclk" "x8k" and "x11k" + "pclk": Clock which feeds the peripheral bus interface. + Mandatory for "st,stm32h7-sai" compatible. + Not used for "st,stm32f4-sai" compatible. + "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. + If the SAI shares a master clock, with another SAI set as MCLK + clock provider, SAI provider phandle must be specified here. + - clock-names: Must contain "sai_ck". + Must also contain "MCLK", if SAI shares a master clock, + with a SAI set as MCLK clock provider. + - dmas: see Documentation/devicetree/bindings/dma/st,stm32-dma.yaml + - 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/st,stm32-pinctrl.yaml + +SAI subnodes Optional properties: + - st,sync: specify synchronization mode. + By default SAI sub-block is in asynchronous mode. + This property sets SAI sub-block as slave of another SAI sub-block. + Must contain the phandle and index of the sai sub-block providing + the synchronization. + - st,iec60958: support S/PDIF IEC6958 protocol for playback + IEC60958 protocol is not available for capture. + By default, custom protocol is assumed, meaning that protocol is + configured according to protocol defined in related DAI link node, + such as i2s, left justified, right justified, dsp and pdm protocols. + Note: ac97 protocol is not supported by SAI driver + - #clock-cells: should be 0. This property must be present if the SAI device + is a master clock provider, according to clocks bindings, described in + Documentation/devicetree/bindings/clock/clock-bindings.txt. + +The device node should contain one 'port' child node with one child 'endpoint' +node, according to the bindings defined in Documentation/devicetree/bindings/ +graph.txt. + +Example: +sound_card { + compatible = "audio-graph-card"; + dais = <&sai1b_port>; +}; + +sai1: sai1@40015800 { + compatible = "st,stm32h7-sai"; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x40015800 0x400>; + reg = <0x40015800 0x4>; + clocks = <&rcc SAI1_CK>, <&rcc PLL1_Q>, <&rcc PLL2_P>; + clock-names = "pclk", "x8k", "x11k"; + interrupts = <87>; + + sai1a: audio-controller@40015804 { + compatible = "st,stm32-sai-sub-a"; + reg = <0x4 0x1C>; + clocks = <&rcc SAI1_CK>; + clock-names = "sai_ck"; + dmas = <&dmamux1 1 87 0x400 0x0>; + dma-names = "tx"; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_sai1a>; + + sai1b_port: port { + cpu_endpoint: endpoint { + remote-endpoint = <&codec_endpoint>; + format = "i2s"; + }; + }; + }; +}; + +audio-codec { + codec_port: port { + codec_endpoint: endpoint { + remote-endpoint = <&cpu_endpoint>; + }; + }; +}; |