ASoC: wm8731: Convert DT bindings to YAML format

Convert the WM8731 DT bindings to YAML format, including addition of
documentation for the regulator and clock bindings which the driver has
had for some time but which were not covered in the bindings document.
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220325153121.1598494-7-broonie@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/wlf,wm8731.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/wlf,wm8731.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Wolfson Microelectromics WM8731 audio CODEC
+
+maintainers:
+  - patches@opensource.cirrus.com
+
+description: |
+  Wolfson Microelectronics WM8731 audio CODEC
+
+  Pins on the device (for linking into audio routes):
+    * LOUT: Left Channel Line Output
+    * ROUT: Right Channel Line Output
+    * LHPOUT: Left Channel Headphone Output
+    * RHPOUT: Right Channel Headphone Output
+    * LLINEIN: Left Channel Line Input
+    * RLINEIN: Right Channel Line Input
+    * MICIN: Microphone Input
+
+properties:
+  compatible:
+    enum:
+      - wlf,wm8731
+
+  reg:
+    maxItems: 1
+
+  "#sound-dai-cells":
+    const: 0
+
+  clocks:
+    description: Clock provider for MCLK pin.
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: mclk
+
+  AVDD-supply:
+    description: Analog power supply regulator on the AVDD pin.
+
+  HPVDD-supply:
+    description: Headphone power supply regulator on the HPVDD pin.
+
+  DBVDD-supply:
+    description: Digital buffer supply regulator for the DBVDD pin.
+
+  DCVDD-supply:
+    description: Digital core supply regulator for the DCVDD pin.
+
+  spi-max-frequency: true
+
+additionalProperties: false
+
+required:
+  - reg
+  - compatible
+  - AVDD-supply
+  - HPVDD-supply
+  - DBVDD-supply
+  - DCVDD-supply
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        wm8731_i2c: codec@0 {
+            compatible = "wlf,wm8731";
+            reg = <0>;
+            spi-max-frequency = <12500000>;
+
+            AVDD-supply = <&avdd_reg>;
+            HPVDD-supply = <&hpvdd_reg>;
+            DCVDD-supply = <&dcvdd_reg>;
+            DBVDD-supply = <&dbvdd_reg>;
+        };
+    };
+  - |
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        wm8731_spi: codec@1b {
+            compatible = "wlf,wm8731";
+            reg = <0x1b>;
+
+            AVDD-supply = <&avdd_reg>;
+            HPVDD-supply = <&hpvdd_reg>;
+            DCVDD-supply = <&dcvdd_reg>;
+            DBVDD-supply = <&dbvdd_reg>;
+        };
+    };

Documentation/devicetree/bindings/sound/wm8731.txt

-WM8731 audio CODEC
-
-This device supports both I2C and SPI (configured with pin strapping
-on the board).
-
-Required properties:
-
-  - compatible : "wlf,wm8731"
-
-  - reg : the I2C address of the device for I2C, the chip select
-          number for SPI.
-
-Example:
-
-wm8731: codec@1a {
-	compatible = "wlf,wm8731";
-	reg = <0x1a>;
-};
-
-Available audio endpoints for an audio-routing table:
- * LOUT: Left Channel Line Output
- * ROUT: Right Channel Line Output
- * LHPOUT: Left Channel Headphone Output
- * RHPOUT: Right Channel Headphone Output
- * LLINEIN: Left Channel Line Input
- * RLINEIN: Right Channel Line Input
- * MICIN: Microphone Input