ASoC: dt-bindings: document WCD939x Audio Codec

Document the Qualcomm WCD9390/WCD9395 Audio Codec and the
Soundwire devices than can be found on Qualcomm SM8650 based platforms.

The Qualcomm WCD9390/WCD9395 Audio Codec communicates
with the host SoC over 2 Soundwire links to provide:
- 4 ADC inputs for up to 5 Analog Microphones
- 4 DMIC inputs for up to 8 Digital Microphones
- 4 Microphone BIAS
- Stereo Headphone output
- Mono EAR output
- MBHC engine for Headset Detection

The WCD9390/WCD9395 IC has separate I2C subsystem for USB-C
DP Altmode/Audio Accessory mode Mux which is not documented
here but requires port/endpoint graph and properties to handle
Altmode/Audio Accessory switch and orientation.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://msgid.link/r/20231219-topic-sm8650-upstream-wcd939x-codec-v4-2-1c3bbff2d7ab@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/qcom,wcd939x-sdw.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/qcom,wcd939x-sdw.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm SoundWire devices on WCD9390/WCD9395
+
+maintainers:
+  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+
+description: |
+  Qualcomm WCD9390/WCD9395 Codec is a standalone Hi-Fi audio codec IC.
+  It has RX and TX Soundwire devices. This bindings is for the devices.
+
+properties:
+  compatible:
+    const: sdw20217010e00
+
+  reg:
+    maxItems: 1
+
+  qcom,tx-port-mapping:
+    description: |
+      Specifies static port mapping between device and host tx ports.
+      In the order of the device port index.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 4
+    maxItems: 4
+
+  qcom,rx-port-mapping:
+    description: |
+      Specifies static port mapping between device and host rx ports.
+      In the order of device port index.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 6
+    maxItems: 6
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    soundwire@3210000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03210000 0x2000>;
+        wcd938x_rx: codec@0,4 {
+            compatible = "sdw20217010e00";
+            reg = <0 4>;
+            qcom,rx-port-mapping = <1 2 3 4 5 6>;
+        };
+    };
+
+    soundwire@3230000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03230000 0x2000>;
+        wcd938x_tx: codec@0,3 {
+            compatible = "sdw20217010e00";
+            reg = <0 3>;
+            qcom,tx-port-mapping = <2 3 4 5>;
+        };
+    };
+
+...

Documentation/devicetree/bindings/sound/qcom,wcd939x.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/qcom,wcd939x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm WCD9380/WCD9385 Audio Codec
+
+maintainers:
+  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+
+description: |
+  Qualcomm WCD9390/WCD9395 Codec is a standalone Hi-Fi audio codec IC.
+  It has RX and TX Soundwire devices.
+  The WCD9390/WCD9395 IC has a functionally separate USB-C Mux subsystem
+  accessible over an I2C interface.
+  The Audio Headphone and Microphone data path between the Codec and the USB-C Mux
+  subsystems are external to the IC, thus requiring DT port-endpoint graph description
+  to handle USB-C altmode & orientation switching for Audio Accessory Mode.
+
+allOf:
+  - $ref: dai-common.yaml#
+  - $ref: qcom,wcd93xx-common.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - const: qcom,wcd9390-codec
+      - items:
+          - const: qcom,wcd9395-codec
+          - const: qcom,wcd9390-codec
+
+  mode-switch:
+    description: Flag the port as possible handler of altmode switching
+    type: boolean
+
+  orientation-switch:
+    description: Flag the port as possible handler of orientation switching
+    type: boolean
+
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+    description:
+      A port node to link the WCD939x Codec node to USB MUX subsystems for the
+      purpose of handling altmode muxing and orientation switching to detect and
+      enable Audio Accessory Mode.
+
+required:
+  - compatible
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    codec {
+        compatible = "qcom,wcd9390-codec";
+        reset-gpios = <&tlmm 32 IRQ_TYPE_NONE>;
+        #sound-dai-cells = <1>;
+        qcom,tx-device = <&wcd939x_tx>;
+        qcom,rx-device = <&wcd939x_rx>;
+        qcom,micbias1-microvolt = <1800000>;
+        qcom,micbias2-microvolt = <1800000>;
+        qcom,micbias3-microvolt = <1800000>;
+        qcom,micbias4-microvolt = <1800000>;
+        qcom,hphl-jack-type-normally-closed;
+        qcom,ground-jack-type-normally-closed;
+        qcom,mbhc-buttons-vthreshold-microvolt = <75000 150000 237000 500000 500000 500000 500000 500000>;
+        qcom,mbhc-headphone-vthreshold-microvolt = <50000>;
+    };
+
+    /* ... */
+
+    soundwire@3210000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03210000 0x2000>;
+        wcd939x_rx: codec@0,4 {
+            compatible = "sdw20217010e00";
+            reg = <0 4>;
+            qcom,rx-port-mapping = <1 2 3 4 5 6>;
+        };
+    };
+
+    soundwire@3230000 {
+        #address-cells = <2>;
+        #size-cells = <0>;
+        reg = <0x03230000 0x2000>;
+        wcd938x_tx: codec@0,3 {
+            compatible = "sdw20217010e00";
+            reg = <0 3>;
+            qcom,tx-port-mapping = <2 3 4 5>;
+        };
+    };
+
+...