Re: [PATCH v3 3/4] net: stmmac: register parent MDIO node for sun8i-h3-emac

[Andrew Lunn]

> All muxes are mostly always represented the same way afaik, or do you
> want to simply introduce a new compatible / property?

+      	  mdio-mux {
+		compatible = "allwinner,sun8i-h3-mdio-switch";
+		mdio-parent-bus = <&mdio_parent>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		internal_mdio: mdio@1 {
			reg = <1>;
-			clocks = <&ccu CLK_BUS_EPHY>;
-			resets = <&ccu RST_BUS_EPHY>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			int_mii_phy: ethernet-phy@1 {
+				compatible = "ethernet-phy-ieee802.3-c22";
+				reg = <1>;
+				clocks = <&ccu CLK_BUS_EPHY>;
+				resets = <&ccu RST_BUS_EPHY>;
+				phy-is-integrated;
+			};
+		};
+		mdio: mdio@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <0>;
 		};
 		
Hi Maxim

Anybody who knows the MDIO-mux code/binding, knows that it is a run
time mux. You swap the mux per MDIO transaction. You can access all
the PHY and switches on the mux'ed MDIO bus.

However here, it is effectively a boot-time MUX. You cannot change it
on the fly. What happens when somebody has a phandle to a PHY on the
internal and a phandle to a phy on the external? Does the driver at
least return -EINVAL, or -EBUSY? Is there a representation which
eliminates this possibility?

   Andrew