Add bindings that describes audio settings to support
Digital Filter for pulse density modulation(PDM) microphone.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
.../devicetree/bindings/sound/st,stm32-adfsdm.txt | 62 ++++++++++++++++++++++
1 file changed, 62 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..2782cda
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt
@@ -0,0 +1,62 @@
+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";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ dfsdm_adc0: dfsdm-adc@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>;
+ };
+ };
+ };
--
2.7.4
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