ASoC: google: dt-bindings: Add sc7180-trogdor machine bindings

Add devicetree bindings documentation file for sc7180 sound card.
Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20201027032234.1705835-2-cychiang@chromium.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/google,sc7180-trogdor.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/google,sc7180-trogdor.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google SC7180-Trogdor ASoC sound card driver
+
+maintainers:
+  - Rohit kumar <rohitkr@codeaurora.org>
+  - Cheng-Yi Chiang <cychiang@chromium.org>
+
+description:
+  This binding describes the SC7180 sound card which uses LPASS for audio.
+
+properties:
+  compatible:
+    const: google,sc7180-trogdor
+
+  audio-routing:
+    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+    description:
+      A list of the connections between audio components. Each entry is a
+      pair of strings, the first being the connection's sink, the second
+      being the connection's source.
+
+  model:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: User specified audio sound card name
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^dai-link(@[0-9])?$":
+    description:
+      Each subnode represents a dai link. Subnodes of each dai links would be
+      cpu/codec dais.
+
+    type: object
+
+    properties:
+      link-name:
+        description: Indicates dai-link name and PCM stream name.
+        $ref: /schemas/types.yaml#/definitions/string
+        maxItems: 1
+
+      reg:
+        description: dai link address.
+
+      cpu:
+        description: Holds subnode which indicates cpu dai.
+        type: object
+        properties:
+          sound-dai: true
+
+      codec:
+        description: Holds subnode which indicates codec dai.
+        type: object
+        properties:
+          sound-dai: true
+
+    required:
+      - link-name
+      - cpu
+      - codec
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - model
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+
+  - |
+    sound {
+        compatible = "google,sc7180-trogdor";
+        model = "sc7180-rt5682-max98357a-1mic";
+
+        audio-routing =
+                    "Headphone Jack", "HPOL",
+                    "Headphone Jack", "HPOR";
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dai-link@0 {
+            link-name = "MultiMedia0";
+            reg = <0>;
+            cpu {
+                sound-dai = <&lpass_cpu 0>;
+            };
+
+            codec {
+                sound-dai = <&alc5682 0>;
+            };
+        };
+
+        dai-link@1 {
+            link-name = "MultiMedia1";
+            reg = <1>;
+            cpu {
+                sound-dai = <&lpass_cpu 1>;
+            };
+
+            codec {
+                sound-dai = <&max98357a>;
+            };
+        };
+
+        dai-link@2 {
+            link-name = "MultiMedia2";
+            reg = <2>;
+            cpu {
+                sound-dai = <&lpass_hdmi 0>;
+            };
+
+            codec {
+                sound-dai = <&msm_dp>;
+            };
+        };
+    };