ASoC: dt-bindings: document Microchip's ASRC Sound Card

Add DT bindings for the new Sound Card that can be used to enable ASRC
present in sama7g5 SoCs.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

Author: Codrin Ciubotariu

Documentation/devicetree/bindings/sound/microchip,asrc-card.yaml

@@ -0,0 +1,162 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/microchip,asrc-card.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sound Card driver for Microchip's Asynchronous Sample Rate Converter
+
+maintainers:
+  - Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
+
+description:
+  Sound Card driver to be used with Microchip's ASRC. It is able to register
+  the ASRC as Front-End and makes the rest of the audio IPs behave as
+  Back-ends and as normal PCMs as well. The ASRC use is optional though.
+
+definitions:
+  model:
+    description: User specified audio sound card name.
+    $ref: /schemas/types.yaml#/definitions/string
+
+  audio-routing:
+    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.
+    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+
+  dai-tdm-slot-num:
+    description: see tdm-slot.txt.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  dai-tdm-slot-width:
+    description: see tdm-slot.txt.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  frame-master:
+    description: Indicates dai-link frame master.
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  bitclock-master:
+    description: Indicates dai-link bit clock master
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  label:
+    maxItems: 1
+
+  format:
+    description: audio format.
+    items:
+      enum:
+        - i2s
+        - right_j
+        - left_j
+        - dsp_a
+        - dsp_b
+        - pdm
+
+  convert-rate:
+    description: Front-End to Back-End rate convert.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  convert-channels:
+    description: Front-end to Back-end channels convert.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  convert-sample-format:
+    description: Front-end to Back-end sample format convert.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  dai:
+    type: object
+    properties:
+      sound-dai:
+        maxItems: 1
+
+      # common properties
+      frame-master:
+        $ref: /schemas/types.yaml#/definitions/flag
+      bitclock-master:
+        $ref: /schemas/types.yaml#/definitions/flag
+      dai-tdm-slot-num:
+        $ref: "#/definitions/dai-tdm-slot-num"
+      dai-tdm-slot-width:
+        $ref: "#/definitions/dai-tdm-slot-width"
+    required:
+      - sound-dai
+properties:
+  compatible:
+    const: microchip,sama7g5-asrc-card
+
+  "#address-cells":
+    const: 1
+  "#size-cells":
+    const: 0
+
+  label:
+    $ref: "#/definitions/label"
+
+patternProperties:
+  "^microchip,dai-link(@[0-9a-f]+)?$":
+    description: |
+      Container for dai-link level properties and the CPU and CODEC sub-nodes.
+      This container may be omitted when the card has only one DAI link.
+    type: object
+    properties:
+
+      # common properties
+      microchip,frame-master:
+        $ref: "#/definitions/frame-master"
+      microchip,bitclock-master:
+        $ref: "#/definitions/bitclock-master"
+      microchip,format:
+        $ref: "#/definitions/format"
+      microchip,convert-rate:
+        $ref: "#/definitions/convert-rate"
+      microchip,convert-channels:
+        $ref: "#/definitions/convert-channels"
+      microchip,convert-sample-format:
+        $ref: "#/definitions/convert-sample-format"
+
+    patternProperties:
+      "^cpu(@[0-9a-f]+)?":
+        $ref: "#/definitions/dai"
+      "^codec(@[0-9a-f]+)?":
+        $ref: "#/definitions/dai"
+    additionalProperties: false
+
+required:
+  - compatible
+  - microchip,model
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/sound/microchip,asrc-card.h>
+
+    sound: sound {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        compatible = "microchip,asrc-card";
+        microchip,model = "mchp-asrc-card @ sama5g7 EK";
+
+        microchip,audio-asrc = <&asrc 0>, <&asrc 1>, <&asrc 2>, <&asrc 3>;
+
+        microchip,dai-link@0 {
+            reg = <0>;
+            microchip,format = "i2s";
+            microchip,frame-master = <&dailink_master>;
+            microchip,bitclock-master = <&dailink_master>;
+            microchip,convert-channels = <2>;
+            microchip,convert-rate = <48000>;
+            microchip,convert-sample-format = <MCHP_ASRC_PCM_FORMAT_S24_LE>;
+            dailink_master: cpu {
+                sound-dai = <&i2s0>;
+            };
+            codec {
+                sound-dai = <&wm8731>;
+            };
+        };
+    };

include/dt-bindings/sound/microchip,asrc-card.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DT_BINDINGS_MICROCHIP_ASRC_CARD_H__
+#define __DT_BINDINGS_MICROCHIP_ASRC_CARD_H__
+
+/* formats to be used for Back-ends of Microhip's ASRC */
+/* must be kept in-sync with include/uapi/sound/asound.h */
+#define MCHP_ASRC_PCM_FORMAT_S8		0
+#define MCHP_ASRC_PCM_FORMAT_S16_LE	2
+#define MCHP_ASRC_PCM_FORMAT_S24_LE	6
+#define MCHP_ASRC_PCM_FORMAT_S32_LE	10
+
+#endif /* __DT_BINDINGS_MICROCHIP_ASRC_CARD_H__ */