diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt
index 58307d0931c8..5b8c58903077 100644
--- a/Documentation/devicetree/bindings/net/phy.txt
+++ b/Documentation/devicetree/bindings/net/phy.txt
@@ -21,10 +21,18 @@ Optional Properties:
   elements.
 - max-speed: Maximum PHY supported speed (10, 100, 1000...)
 
+  If the phy's identifier is known then the list may contain an entry
+  of the form: "ethernet-phy-idAAAA.BBBB" where
+     AAAA - The value of the 16 bit Phy Identifier 1 register as
+            4 hex digits. This is the chip vendor OUI bits 3:18
+     BBBB - The value of the 16 bit Phy Identifier 2 register as
+            4 hex digits. This is the chip vendor OUI bits 19:24,
+            followed by 10 bits of a vendor specific ID.
+
 Example:
 
 ethernet-phy@0 {
-	compatible = "ethernet-phy-ieee802.3-c22";
+	compatible = "ethernet-phy-id0141.0e90", "ethernet-phy-ieee802.3-c22";
 	interrupt-parent = <40000>;
 	interrupts = <35 1>;
 	reg = <0>;