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 --- .../devicetree/bindings/sound/st,stm32-adfsdm.txt | 63 ++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt
diff --git a/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt b/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt new file mode 100644 index 0000000..864f5b0 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt @@ -0,0 +1,63 @@ +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>; + }; + }; + };