ASoC: dt-bindings: wcd938x-sdw: add bindings for wcd938x-sdw

Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC
connected over SoundWire. This device has two SoundWire devices RX and
TX respectively. This bindings is for those slave devices on WCD9380/WCD9385.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210609090943.7896-5-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/qcom,wcd938x-sdw.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/qcom,wcd938x-sdw.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Bindings for Qualcomm SoundWire Slave devices on WCD9380/WCD9385
+
+maintainers:
+  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+
+description: |
+  Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC.
+  It has RX and TX Soundwire slave devices. This bindings is for the
+  slave devices.
+
+properties:
+  compatible:
+    const: sdw20217010d00
+
+  reg:
+    maxItems: 1
+
+  qcom,tx-port-mapping:
+    description: |
+      Specifies static port mapping between slave and master tx ports.
+      In the order of slave port index.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 4
+    maxItems: 4
+
+  qcom,rx-port-mapping:
+    description: |
+      Specifies static port mapping between slave and master rx ports.
+      In the order of slave port index.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 5
+    maxItems: 5
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    soundwire@3210000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03210000 0x2000>;
+        wcd938x_rx: codec@0,4 {
+            compatible = "sdw20217010d00";
+            reg  = <0 4>;
+            qcom,rx-port-mapping = <1 2 3 4 5>;
+        };
+    };
+
+    soundwire@3230000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03230000 0x2000>;
+        wcd938x_tx: codec@0,3 {
+            compatible = "sdw20217010d00";
+            reg  = <0 3>;
+            qcom,tx-port-mapping = <2 3 4 5>;
+        };
+    };
+
+...