From: Conor Dooley <conor.dooley@microchip.com>

Ryan added cdns,refclk-ext with the intent of decoupling the source of
the reference clock on sama7g5 (and related platforms) from the
compatible. Unfortunately, the default for sama7g5-emac is an external
reference clock, so this property had no effect there, so that
compatibility with older devicetrees is preserved.
Replace cdns,refclk-ext with one that supports both default states and
therefore is usable for sama7g5-emac.

For now, limit it to only the platforms that have USRIO controlled
reference clock selection, but this could be generalised in the future.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../devicetree/bindings/net/cdns,macb.yaml    | 39 ++++++++++++++++---
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/cdns,macb.yaml b/Documentation/devicetree/bindings/net/cdns,macb.yaml
index cb14c35ba9969..a492357570edd 100644
--- a/Documentation/devicetree/bindings/net/cdns,macb.yaml
+++ b/Documentation/devicetree/bindings/net/cdns,macb.yaml
@@ -120,12 +120,14 @@ properties:
   power-domains:
     maxItems: 1
 
-  cdns,refclk-ext:
-    type: boolean
+  cdns,refclk-source:
+    $ref: /schemas/types.yaml#/definitions/string
+    enum:
+      - internal
+      - external
     description:
-      This selects if the REFCLK for RMII is provided by an external source.
-      For RGMII mode this selects if the 125MHz REF clock is provided by an external
-      source.
+      Select whether or not the refclk for RGMII or RMII is provided by an
+      internal or external source. The default is device specific.
 
   cdns,rx-watermark:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -196,6 +198,33 @@ allOf:
       required:
         - phys
 
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              enum:
+                - microchip,sama7g5-gem
+                - microchip,sama7g5-emac
+    then:
+      properties:
+        cdns,refclk-source: false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,sama7g5-emac
+    then:
+      properties:
+        cdns,refclk-source:
+          default: external
+    else:
+      properties:
+        cdns,refclk-source:
+          default: internal
+
 unevaluatedProperties: false
 
 examples:
-- 
2.51.0