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This patch adds documentation of device tree bindings for the STM32 SAI ASoC driver. Signed-off-by: olivier moysan <[email protected]> Signed-off-by: Mark Brown <[email protected]>
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STMicroelectronics STM32 Serial Audio Interface (SAI). | ||
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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. | ||
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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 | ||
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Optional properties: | ||
- resets: Reference to a reset controller asserting the SAI | ||
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SAI subnodes: | ||
Two subnodes corresponding to SAI sub-block instances A et B can be defined. | ||
Subnode can be omitted for unsused sub-block. | ||
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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 | ||
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Example: | ||
sound_card { | ||
compatible = "audio-graph-card"; | ||
dais = <&sai1b_port>; | ||
}; | ||
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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>; | ||
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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>; | ||
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ports { | ||
#address-cells = <1>; | ||
#size-cells = <0>; | ||
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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>; | ||
}; | ||
}; | ||
}; | ||
}; | ||
}; | ||
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audio-codec { | ||
codec_port: port { | ||
codec_endpoint: endpoint { | ||
remote-endpoint = <&cpu_endpoint>; | ||
}; | ||
}; | ||
}; |