diff --git a/arch/arm/boot/dts/gemini-dlink-dns-313.dts b/arch/arm/boot/dts/gemini-dlink-dns-313.dts
index 076b8d89befb..08568ce24d06 100644
--- a/arch/arm/boot/dts/gemini-dlink-dns-313.dts
+++ b/arch/arm/boot/dts/gemini-dlink-dns-313.dts
@@ -214,6 +214,56 @@ mux {
 						groups = "gpio1dgrp";
 					};
 				};
+				pinctrl-gmii {
+					mux {
+						function = "gmii";
+						groups = "gmii_gmac0_grp";
+					};
+					/*
+					 * In the vendor Linux tree, these values are set for the C3
+					 * version of the SL3512 ASIC with the comment "benson suggest"
+					 */
+					conf0 {
+						pins = "R8 GMAC0 RXDV", "U11 GMAC1 RXDV";
+						skew-delay = <0>;
+					};
+					conf1 {
+						pins = "T8 GMAC0 RXC";
+						skew-delay = <10>;
+					};
+					conf2 {
+						pins = "T11 GMAC1 RXC";
+						skew-delay = <15>;
+					};
+					conf3 {
+						pins = "P8 GMAC0 TXEN", "V11 GMAC1 TXEN";
+						skew-delay = <7>;
+					};
+					conf4 {
+						pins = "V7 GMAC0 TXC", "P10 GMAC1 TXC";
+						skew-delay = <10>;
+					};
+					conf5 {
+						/* The data lines all have default skew */
+						pins = "U8 GMAC0 RXD0", "V8 GMAC0 RXD1",
+						       "P9 GMAC0 RXD2", "R9 GMAC0 RXD3",
+						       "R11 GMAC1 RXD0", "P11 GMAC1 RXD1",
+						       "V12 GMAC1 RXD2", "U12 GMAC1 RXD3",
+						       "R10 GMAC1 TXD0", "T10 GMAC1 TXD1",
+						       "U10 GMAC1 TXD2", "V10 GMAC1 TXD3";
+						skew-delay = <7>;
+					};
+					conf6 {
+						pins = "U7 GMAC0 TXD0", "T7 GMAC0 TXD1",
+						       "R7 GMAC0 TXD2", "P7 GMAC0 TXD3";
+						skew-delay = <5>;
+					};
+					/* Set up drive strength on GMAC0 to 16 mA */
+					conf7 {
+						groups = "gmii_gmac0_grp";
+						drive-strength = <16>;
+					};
+				};
 			};
 		};
 
@@ -234,6 +284,18 @@ gpio1: gpio@4e000000 {
 			pinctrl-0 = <&gpio1_default_pins>;
 		};
 
+		ethernet@60000000 {
+			status = "okay";
+
+			ethernet-port@0 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy0>;
+			};
+			ethernet-port@1 {
+				/* Not used in this platform */
+			};
+		};
+
 		ata@63000000 {
 			status = "okay";
 		};
diff --git a/arch/arm/boot/dts/gemini-nas4220b.dts b/arch/arm/boot/dts/gemini-nas4220b.dts
index 943d2d07fac7..8bbb6f85d161 100644
--- a/arch/arm/boot/dts/gemini-nas4220b.dts
+++ b/arch/arm/boot/dts/gemini-nas4220b.dts
@@ -129,6 +129,50 @@ mux {
 						groups = "gpio1dgrp";
 					};
 				};
+				pinctrl-gmii {
+					mux {
+						function = "gmii";
+						groups = "gmii_gmac0_grp";
+					};
+					/* Settings come from OpenWRT */
+					conf0 {
+						pins = "R8 GMAC0 RXDV", "U11 GMAC1 RXDV";
+						skew-delay = <0>;
+					};
+					conf1 {
+						pins = "T8 GMAC0 RXC", "T11 GMAC1 RXC";
+						skew-delay = <15>;
+					};
+					conf2 {
+						pins = "P8 GMAC0 TXEN", "V11 GMAC1 TXEN";
+						skew-delay = <7>;
+					};
+					conf3 {
+						pins = "V7 GMAC0 TXC";
+						skew-delay = <11>;
+					};
+					conf4 {
+						pins = "P10 GMAC1 TXC";
+						skew-delay = <10>;
+					};
+					conf5 {
+						/* The data lines all have default skew */
+						pins = "U8 GMAC0 RXD0", "V8 GMAC0 RXD1",
+						       "P9 GMAC0 RXD2", "R9 GMAC0 RXD3",
+						       "U7 GMAC0 TXD0", "T7 GMAC0 TXD1",
+						       "R7 GMAC0 TXD2", "P7 GMAC0 TXD3",
+						       "R11 GMAC1 RXD0", "P11 GMAC1 RXD1",
+						       "V12 GMAC1 RXD2", "U12 GMAC1 RXD3",
+						       "R10 GMAC1 TXD0", "T10 GMAC1 TXD1",
+						       "U10 GMAC1 TXD2", "V10 GMAC1 TXD3";
+						skew-delay = <7>;
+					};
+					/* Set up drive strength on GMAC0 to 16 mA */
+					conf6 {
+						groups = "gmii_gmac0_grp";
+						drive-strength = <16>;
+					};
+				};
 			};
 		};
 
@@ -143,6 +187,18 @@ gpio1: gpio@4e000000 {
 			pinctrl-0 = <&gpio1_default_pins>;
 		};
 
+		ethernet@60000000 {
+			status = "okay";
+
+			ethernet-port@0 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy0>;
+			};
+			ethernet-port@1 {
+				/* Not used in this platform */
+			};
+		};
+
 		ata@63000000 {
 			status = "okay";
 		};
diff --git a/arch/arm/boot/dts/gemini-rut1xx.dts b/arch/arm/boot/dts/gemini-rut1xx.dts
index fd55528bba56..15f20178642c 100644
--- a/arch/arm/boot/dts/gemini-rut1xx.dts
+++ b/arch/arm/boot/dts/gemini-rut1xx.dts
@@ -114,5 +114,17 @@ gpio1: gpio@4e000000 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&gpio1_default_pins>;
 		};
+
+		ethernet@60000000 {
+			status = "okay";
+
+			ethernet-port@0 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy0>;
+			};
+			ethernet-port@1 {
+				/* Not used in this platform */
+			};
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/gemini-wbd111.dts b/arch/arm/boot/dts/gemini-wbd111.dts
index 389cb2b275c7..b4ec9ad85d72 100644
--- a/arch/arm/boot/dts/gemini-wbd111.dts
+++ b/arch/arm/boot/dts/gemini-wbd111.dts
@@ -160,5 +160,17 @@ pci@50000000 {
 				<0x6000 0 0 3 &pci_intc 1>,
 				<0x6000 0 0 4 &pci_intc 2>;
 		};
+
+		ethernet@60000000 {
+			status = "okay";
+
+			ethernet-port@0 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy0>;
+			};
+			ethernet-port@1 {
+				/* Not used in this platform */
+			};
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/gemini-wbd222.dts b/arch/arm/boot/dts/gemini-wbd222.dts
index 2f00e88292ac..6d25bcc046e7 100644
--- a/arch/arm/boot/dts/gemini-wbd222.dts
+++ b/arch/arm/boot/dts/gemini-wbd222.dts
@@ -136,6 +136,13 @@ mux {
 						"gpio0bgrp";
 					};
 				};
+				pinctrl-gmii {
+					/* This platform use both the ethernet ports */
+					mux {
+						function = "gmii";
+						groups = "gmii_gmac0_grp", "gmii_gmac1_grp";
+					};
+				};
 			};
 		};
 
@@ -165,5 +172,18 @@ pci@50000000 {
 				<0x6000 0 0 3 &pci_intc 1>,
 				<0x6000 0 0 4 &pci_intc 2>;
 		};
+
+		ethernet@60000000 {
+			status = "okay";
+
+			ethernet-port@0 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy0>;
+			};
+			ethernet-port@1 {
+				phy-mode = "rgmii";
+				phy-handle = <&phy1>;
+			};
+		};
 	};
 };