+1.2. Using the central MDIO PCIe endpoint device
+
+In this case, the mdio node should be defined as another PCIe
+endpoint node, at the same level with the ENETC port nodes.
+
+Required properties:
+
+- reg : Specifies PCIe Device Number and Function
+ Number of the ENETC endpoint device, according
+ to parent node bindings.
+- compatible : Should be "fsl,enetc-mdio".
+
+The remaining required mdio bus properties are standard, their bindings
+already defined in Documentation/devicetree/bindings/net/mdio.txt.
+
+Example:
+
+ ethernet@0,0 {
+ compatible = "fsl,enetc";
+ reg = <0x000000 0 0 0 0>;
+ phy-handle = <&sgmii_phy0>;
+ phy-connection-type = "sgmii";
+ };
+
+ mdio@0,3 {
+ compatible = "fsl,enetc-mdio";
+ reg = <0x000300 0 0 0 0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ sgmii_phy0: ethernet-phy@2 {
+ reg = <0x2>;
+ };
+ };
+
+2. The ENETC port is an internal port or has a fixed-link external
+connection