As the ethernet controller of SG2044 and SG2042 only supports
RGMII phy. Add phy-mode property to restrict the value.

Also, since SG2042 has internal rx delay in its mac, make
only "rgmii-txid" and "rgmii-id" valid for phy-mode.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
---
 .../bindings/net/sophgo,sg2044-dwmac.yaml       | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/sophgo,sg2044-dwmac.yaml b/Documentation/devicetree/bindings/net/sophgo,sg2044-dwmac.yaml
index ce21979a2d9a..0f1523dc0e36 100644
--- a/Documentation/devicetree/bindings/net/sophgo,sg2044-dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/sophgo,sg2044-dwmac.yaml
@@ -52,6 +52,13 @@ properties:
   interrupt-names:
     maxItems: 1

+  phy-mode:
+    enum:
+      - rgmii
+      - rgmii-rxid
+      - rgmii-txid
+      - rgmii-id
+
   resets:
     maxItems: 1

@@ -70,6 +77,16 @@ required:

 allOf:
   - $ref: snps,dwmac.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: sophgo,sg2042-dwmac
+    then:
+      phy-mode:
+        enum:
+          - rgmii-txid
+          - rgmii-id

 unevaluatedProperties: false

--
2.51.1.dirty