ASoC: tegra: Add binding doc for ASRC module

This patch adds YAML schema for DT bindings of Asynchronous Sample Rate
Converter (ASRC) module. It will be registered as an ASoC component and
can be plugged into an audio path as per need via ALSA mixer controls.
The bindings are applicable on Tegra186 and later where the ASRC device
is present.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1648735412-32220-2-git-send-email-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/nvidia,tegra186-asrc.yaml

@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/nvidia,tegra186-asrc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Tegra186 ASRC Device Tree Bindings
+
+description: |
+  Asynchronous Sample Rate Converter (ASRC) converts the sampling frequency
+  of the input signal from one frequency to another. It can handle over a
+  wide range of sample rate ratios (freq_in/freq_out) from 1:24 to 24:1.
+  ASRC has two modes of operation. One where ratio can be programmed in SW
+  and the other where it gets the information from ratio estimator module.
+
+  It supports  sample rate conversions in the range of 8 to 192 kHz and
+  supports 6 streams upto 12 total channels. The input data size can be
+  16, 24 and 32 bits.
+
+maintainers:
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Mohan Kumar <mkumard@nvidia.com>
+  - Sameer Pujar <spujar@nvidia.com>
+
+allOf:
+  - $ref: name-prefix.yaml#
+
+properties:
+  $nodename:
+    pattern: "^asrc@[0-9a-f]*$"
+
+  compatible:
+    oneOf:
+      - const: nvidia,tegra186-asrc
+      - items:
+          - enum:
+              - nvidia,tegra234-asrc
+              - nvidia,tegra194-asrc
+          - const: nvidia,tegra186-asrc
+
+  reg:
+    maxItems: 1
+
+  sound-name-prefix:
+    pattern: "^ASRC[1-9]$"
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    description: |
+      ASRC has seven input ports and six output ports. Accordingly ACIF
+      (Audio Client Interfaces) port nodes are defined to represent the
+      ASRC inputs (port 0 to 6) and outputs (port 7 to 12). These are
+      connected to corresponding ports on AHUB (Audio Hub). Additional
+      input (port 6) is for receiving ratio information from estimator.
+
+    patternProperties:
+      '^port@[0-6]':
+        $ref: audio-graph-port.yaml#
+        unevaluatedProperties: false
+        description: ASRC ACIF input ports
+      '^port@[7-9]|1[1-2]':
+        $ref: audio-graph-port.yaml#
+        unevaluatedProperties: false
+        description: ASRC ACIF output ports
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+
+    asrc@2910000 {
+        compatible = "nvidia,tegra186-asrc";
+        reg = <0x2910000 0x2000>;
+        sound-name-prefix = "ASRC1";
+    };
+
+...

Documentation/devicetree/bindings/sound/nvidia,tegra210-ahub.yaml

@@ -106,6 +106,10 @@ patternProperties:
     type: object
     $ref: nvidia,tegra210-mixer.yaml#
 
+  '^asrc@[0-9a-f]+$':
+    type: object
+    $ref: nvidia,tegra186-asrc.yaml#
+
 required:
   - compatible
   - reg