MLK-16784-2 documentation: sound: add documentation for PDM

Add documentation for micfil IP.

Signed-off-by: Cosmin-Gabriel Samoila <cosmin.samoila@nxp.com>
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>

diff --git a/Documentation/devicetree/bindings/sound/fsl,micfil.txt b/Documentation/devicetree/bindings/sound/fsl,micfil.txt
new file mode 100644 (file)
index 0000000..d7830af
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+++ b/Documentation/devicetree/bindings/sound/fsl,micfil.txt
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+Freescale MICFIL PDM Interface (MICFIL).
+
+The MICFIL digital interface provides a 16-bit audio signal from a PDM
+microphone bitstream in a configurable output sampling rate.
+
+Required properties:
+
+  - compatible         : Compatible list, contains "fsl,imx8mm-micfil"
+
+  - reg                        : Offset and length of the register set for the device.
+
+  - interrupts         : Contains the micfil interrupts.
+
+  - clocks             : Must contain an entry for each entry in clock-names.
+
+  - clock-names                : Must include the "ipg_clk" for register access and
+                         "ipg_clk_app" for internal micfil clock.
+
+  - dmas               : Generic dma devicetree binding as described in
+                         Documentation/devicetree/bindings/dma/dma.txt.
+
+  - dma-names          : One "rx" dma must be configured.
+
+Example:
+micfil: micfil@30080000 {
+       compatible = "fsl,imx8mm-micfil";
+       reg = <0x0 0x30080000 0x0 0x10000>;
+       interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>,
+                    <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>,
+                    <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>,
+                    <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+       clocks = <&clk IMX8MM_CLK_PDM_IPG>,
+                <&clk IMX8MM_CLK_PDM_ROOT>;
+       clock-names = "ipg_clk", "ipg_clk_app";
+       dmas = <&sdma2 24 26 0x80000000>;
+       dma-names = "rx";
+       status = "disabled";
+};