1STMicroelectronics Audio Digital Filter Sigma Delta modulators(DFSDM) 2 3The DFSDM allows PDM microphones capture through SPI interface. The Audio 4interface is seems as a sub block of the DFSDM device. 5For details on DFSDM bindings refer to ../iio/adc/st,stm32-dfsdm-adc.txt 6 7Required properties: 8 - compatible: "st,stm32h7-dfsdm-dai". 9 10 - #sound-dai-cells : Must be equal to 0 11 12 - io-channels : phandle to iio dfsdm instance node. 13 14Example of a sound card using audio DFSDM node. 15 16 sound_card { 17 compatible = "audio-graph-card"; 18 19 dais = <&cpu_port>; 20 }; 21 22 dfsdm: dfsdm@40017000 { 23 compatible = "st,stm32h7-dfsdm"; 24 reg = <0x40017000 0x400>; 25 clocks = <&rcc DFSDM1_CK>; 26 clock-names = "dfsdm"; 27 #interrupt-cells = <1>; 28 #address-cells = <1>; 29 #size-cells = <0>; 30 31 dfsdm_adc0: filter@0 { 32 compatible = "st,stm32-dfsdm-dmic"; 33 reg = <0>; 34 interrupts = <110>; 35 dmas = <&dmamux1 101 0x400 0x00>; 36 dma-names = "rx"; 37 st,adc-channels = <1>; 38 st,adc-channel-names = "dmic0"; 39 st,adc-channel-types = "SPI_R"; 40 st,adc-channel-clk-src = "CLKOUT"; 41 st,filter-order = <5>; 42 43 dfsdm_dai0: dfsdm-dai { 44 compatible = "st,stm32h7-dfsdm-dai"; 45 #sound-dai-cells = <0>; 46 io-channels = <&dfsdm_adc0 0>; 47 cpu_port: port { 48 dfsdm_endpoint: endpoint { 49 remote-endpoint = <&dmic0_endpoint>; 50 }; 51 }; 52 }; 53 }; 54 55 dmic0: dmic@0 { 56 compatible = "dmic-codec"; 57 #sound-dai-cells = <0>; 58 port { 59 dmic0_endpoint: endpoint { 60 remote-endpoint = <&dfsdm_endpoint>; 61 }; 62 }; 63 }; 64