dt-bindings: net: dsa: mediatek,mt7530: define phy-mode per switch

Define acceptable phy-mode values for the CPU ports of mt7530 and mt7531
switches. Remove relevant information from the description of the binding.
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml

@@ -49,17 +49,6 @@ description: |
   * mt7621: phy-mode = "rgmii-txid";
   * mt7623: phy-mode = "rgmii";
 
-  CPU-Ports need a phy-mode property:
-    Allowed values on mt7530 and mt7621:
-      - "rgmii"
-      - "trgmii"
-    On mt7531:
-      - "1000base-x"
-      - "2500base-x"
-      - "rgmii"
-      - "sgmii"
-
-
 properties:
   compatible:
     oneOf:
@@ -164,6 +153,65 @@ required:
   - compatible
   - reg
 
+$defs:
+  mt7530-dsa-port:
+    patternProperties:
+      "^(ethernet-)?ports$":
+        patternProperties:
+          "^(ethernet-)?port@[0-9]+$":
+            if:
+              properties:
+                label:
+                  const: cpu
+            then:
+              if:
+                properties:
+                  reg:
+                    const: 5
+              then:
+                properties:
+                  phy-mode:
+                    enum:
+                      - gmii
+                      - mii
+                      - rgmii
+              else:
+                properties:
+                  phy-mode:
+                    enum:
+                      - rgmii
+                      - trgmii
+
+  mt7531-dsa-port:
+    patternProperties:
+      "^(ethernet-)?ports$":
+        patternProperties:
+          "^(ethernet-)?port@[0-9]+$":
+            if:
+              properties:
+                label:
+                  const: cpu
+            then:
+              if:
+                properties:
+                  reg:
+                    const: 5
+              then:
+                properties:
+                  phy-mode:
+                    enum:
+                      - 1000base-x
+                      - 2500base-x
+                      - rgmii
+                      - sgmii
+              else:
+                properties:
+                  phy-mode:
+                    enum:
+                      - 1000base-x
+                      - 2500base-x
+                      - sgmii
+
 allOf:
   - $ref: dsa.yaml#
   - if:
@@ -185,6 +233,7 @@ allOf:
         compatible:
           const: mediatek,mt7530
     then:
+      $ref: "#/$defs/mt7530-dsa-port"
       required:
         - core-supply
         - io-supply
@@ -194,6 +243,7 @@ allOf:
         compatible:
           const: mediatek,mt7531
     then:
+      $ref: "#/$defs/mt7531-dsa-port"
       properties:
         mediatek,mcm: false
 
@@ -202,6 +252,7 @@ allOf:
         compatible:
           const: mediatek,mt7621
     then:
+      $ref: "#/$defs/mt7530-dsa-port"
       required:
         - mediatek,mcm