linux/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt
Arnaud Pouliquen a71615792d
ASoC: add bindings for stm32 DFSDM filter
Add bindings that describes audio settings to support
Digital Filter for pulse density modulation(PDM) microphone.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-01-10 10:52:04 +00:00

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STMicroelectronics Audio Digital Filter Sigma Delta modulators(DFSDM)
The DFSDM allows PDM microphones capture through SPI interface. The Audio
interface is seems as a sub block of the DFSDM device.
For details on DFSDM bindings refer to ../iio/adc/st,stm32-dfsdm-adc.txt
Required properties:
- compatible: "st,stm32h7-dfsdm-dai".
- #sound-dai-cells : Must be equal to 0
- io-channels : phandle to iio dfsdm instance node.
Example of a sound card using audio DFSDM node.
sound_card {
compatible = "audio-graph-card";
dais = <&cpu_port>;
};
dfsdm: dfsdm@40017000 {
compatible = "st,stm32h7-dfsdm";
reg = <0x40017000 0x400>;
clocks = <&rcc DFSDM1_CK>;
clock-names = "dfsdm";
#interrupt-cells = <1>;
#address-cells = <1>;
#size-cells = <0>;
dfsdm_adc0: filter@0 {
compatible = "st,stm32-dfsdm-dmic";
reg = <0>;
interrupts = <110>;
dmas = <&dmamux1 101 0x400 0x00>;
dma-names = "rx";
st,adc-channels = <1>;
st,adc-channel-names = "dmic0";
st,adc-channel-types = "SPI_R";
st,adc-channel-clk-src = "CLKOUT";
st,filter-order = <5>;
dfsdm_dai0: dfsdm-dai {
compatible = "st,stm32h7-dfsdm-dai";
#sound-dai-cells = <0>;
io-channels = <&dfsdm_adc0 0>;
cpu_port: port {
dfsdm_endpoint: endpoint {
remote-endpoint = <&dmic0_endpoint>;
};
};
};
};
dmic0: dmic@0 {
compatible = "dmic-codec";
#sound-dai-cells = <0>;
port {
dmic0_endpoint: endpoint {
remote-endpoint = <&dfsdm_endpoint>;
};
};
};