diff --git a/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml b/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
index ecf3d7d968c80ba9821a90dcc93ecd218d9d9e39..2cf229a076f0f5169ca8148f73048cceca55042b 100644
--- a/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
+++ b/Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
@@ -48,6 +48,10 @@ properties:
       - const: mclk_rx
       - const: hclk
 
+  port:
+    $ref: audio-graph-port.yaml#
+    unevaluatedProperties: false
+
   resets:
     maxItems: 1