dt-bindings: asoc: Add ADAU7118 documentation

Document the ADAU7118 8 channel PDM to I2S/TDM converter devicetree
bindings.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20191010074234.7344-2-nuno.sa@analog.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/adi,adau7118.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/adi,adau7118.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+
+title: Analog Devices ADAU7118 8 Channel PDM to I2S/TDM Converter
+
+maintainers:
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |
+  Analog Devices ADAU7118 8 Channel PDM to I2S/TDM Converter over I2C or HW
+  standalone mode.
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ADAU7118.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,adau7118
+
+  reg:
+    maxItems: 1
+
+  "#sound-dai-cells":
+    const: 0
+
+  IOVDD-supply:
+    description: Digital Input/Output Power Supply.
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+
+  DVDD-supply:
+    description: Internal Core Digital Power Supply.
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+
+  adi,decimation-ratio:
+    description: |
+      This property set's the decimation ratio of PDM to PCM audio data.
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - enum: [64, 32, 16]
+        default: 64
+
+  adi,pdm-clk-map:
+    description: |
+      The ADAU7118 has two PDM clocks for the four Inputs. Each input must be
+      assigned to one of these two clocks. This property set's the mapping
+      between the clocks and the inputs.
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+      - minItems: 4
+        maxItems: 4
+        items:
+          maximum: 1
+        default: [0, 0, 1, 1]
+
+required:
+  - "#sound-dai-cells"
+  - compatible
+  - IOVDD-supply
+  - DVDD-supply
+
+examples:
+  - |
+    i2c0 {
+        /* example with i2c support */
+        #address-cells = <1>;
+        #size-cells = <0>;
+        status = "okay";
+        adau7118_codec: adau7118-codec@14 {
+                compatible = "adi,adau7118";
+                reg = <14>;
+                #sound-dai-cells = <0>;
+                status = "okay";
+                IOVDD-supply = <&supply>;
+                DVDD-supply = <&supply>;
+                adi,pdm-clk-map = <1 1 0 0>;
+                adi,decimation-ratio = <16>;
+        };
+    };
+
+    /* example with hw standalone mode */
+    adau7118_codec_hw: adau7118-codec-hw {
+            compatible = "adi,adau7118";
+            #sound-dai-cells = <0>;
+            status = "okay";
+            IOVDD-supply = <&supply>;
+            DVDD-supply = <&supply>;
+    };