[PATCH v3 1/5] ASoC: dt-bindings: fsl,imx-asrc: update port binding to support multiple paths

[shengjiu.wang at oss.nxp.com]

From: Shengjiu Wang <shengjiu.wang at nxp.com>

The i.MX ASRC hardware supports up to three conversion pairs (A, B, C).
The existing binding exposed only a single generic audio-graph port,
which cannot represent independent conversion paths when multiple pairs
are in use simultaneously.

Add a ports container that enumerates up to three sub-ports, each
representing an independent conversion path:
  port at 0 -- conversion path 0
  port at 1 -- conversion path 1
  port at 2 -- conversion path 2

Each sub-port references audio-graph-port.yaml as before. Hardware pairs
are allocated dynamically at stream open time; each active stream
direction (playback or capture) on a port consumes one hardware pair.

For backwards compatibility, keep the old single port property but mark
it deprecated. A schema constraint (not: required: [port, ports]) ensures
that both forms cannot be used at the same time. The binding example is
updated to show the preferred ports form.

No existing upstream DTS file for fsl,imx-asrc uses the previously
documented single 'port' node, so this change does not break any
in-tree device tree.

Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
---
 .../bindings/sound/fsl,imx-asrc.yaml          | 45 ++++++++++++++++---
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/fsl,imx-asrc.yaml b/Documentation/devicetree/bindings/sound/fsl,imx-asrc.yaml
index 608defc93c1e..67d2826eef3f 100644
--- a/Documentation/devicetree/bindings/sound/fsl,imx-asrc.yaml
+++ b/Documentation/devicetree/bindings/sound/fsl,imx-asrc.yaml
@@ -78,9 +78,19 @@ properties:
   power-domains:
     maxItems: 1
 
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    patternProperties:
+      "^port@[0-2]$":
+        $ref: audio-graph-port.yaml#
+        unevaluatedProperties: false
+        description: port for an independent conversion path
+
   port:
     $ref: audio-graph-port.yaml#
     unevaluatedProperties: false
+    deprecated: true
+    description: deprecated, use ports instead
 
   fsl,asrc-rate:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -125,6 +135,10 @@ required:
   - fsl,asrc-width
 
 allOf:
+  - not:
+      required:
+        - port
+        - ports
   - $ref: dai-common.yaml#
   - if:
       properties:
@@ -180,11 +194,32 @@ examples:
         fsl,asrc-rate = <48000>;
         fsl,asrc-width = <16>;
 
-        port {
-            playback-only;
+        ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            port at 0 {
+                reg = <0>;
+                playback-only;
+                endpoint {
+                    remote-endpoint = <&fe00_ep>;
+                };
+            };
+
+            port at 1 {
+                reg = <1>;
+                capture-only;
+                endpoint {
+                    remote-endpoint = <&fe01_ep>;
+                };
+            };
 
-            asrc_endpoint: endpoint {
-                remote-endpoint = <&fe00_ep>;
+            port at 2 {
+                reg = <2>;
+                capture-only;
+                endpoint {
+                    remote-endpoint = <&fe02_ep>;
+                };
             };
-       };
+        };
     };
-- 
2.34.1