netdev/of/phy: Add MDIO bus multiplexer driven by GPIO lines.

The GPIO pins select which sub bus is connected to the master.

Initially tested with an sn74cbtlv3253 switch device wired into the
MDIO bus.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 127 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/mdio-mux-gpio.txt b/Documentation/devicetree/bindings/net/mdio-mux-gpio.txt
new file mode 100644
index 00000000000..79384113c2b
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mdio-mux-gpio.txt
@@ -0,0 +1,127 @@
+Properties for an MDIO bus multiplexer/switch controlled by GPIO pins.
+
+This is a special case of a MDIO bus multiplexer.  One or more GPIO
+lines are used to control which child bus is connected.
+
+Required properties in addition to the generic multiplexer properties:
+
+- compatible : mdio-mux-gpio.
+- gpios : GPIO specifiers for each GPIO line.  One or more must be specified.
+
+
+Example :
+
+	/* The parent MDIO bus. */
+	smi1: mdio@1180000001900 {
+		compatible = "cavium,octeon-3860-mdio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x11800 0x00001900 0x0 0x40>;
+	};
+
+	/*
+	   An NXP sn74cbtlv3253 dual 1-of-4 switch controlled by a
+	   pair of GPIO lines.  Child busses 2 and 3 populated with 4
+	   PHYs each.
+	 */
+	mdio-mux {
+		compatible = "mdio-mux-gpio";
+		gpios = <&gpio1 3 0>, <&gpio1 4 0>;
+		mdio-parent-bus = <&smi1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		mdio@2 {
+			reg = <2>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			phy11: ethernet-phy@1 {
+				reg = <1>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <10 8>; /* Pin 10, active low */
+			};
+			phy12: ethernet-phy@2 {
+				reg = <2>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <10 8>; /* Pin 10, active low */
+			};
+			phy13: ethernet-phy@3 {
+				reg = <3>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <10 8>; /* Pin 10, active low */
+			};
+			phy14: ethernet-phy@4 {
+				reg = <4>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <10 8>; /* Pin 10, active low */
+			};
+		};
+
+		mdio@3 {
+			reg = <3>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			phy21: ethernet-phy@1 {
+				reg = <1>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <12 8>; /* Pin 12, active low */
+			};
+			phy22: ethernet-phy@2 {
+				reg = <2>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <12 8>; /* Pin 12, active low */
+			};
+			phy23: ethernet-phy@3 {
+				reg = <3>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <12 8>; /* Pin 12, active low */
+			};
+			phy24: ethernet-phy@4 {
+				reg = <4>;
+				compatible = "marvell,88e1149r";
+				marvell,reg-init = <3 0x10 0 0x5777>,
+					<3 0x11 0 0x00aa>,
+					<3 0x12 0 0x4105>,
+					<3 0x13 0 0x0a60>;
+				interrupt-parent = <&gpio>;
+				interrupts = <12 8>; /* Pin 12, active low */
+			};
+		};
+	};