net: Add MDIO bus driver for the Allwinner EMAC

This patch adds a separate driver for the MDIO interface of the
Allwinner ethernet controllers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
new file mode 100644
index 000000000000..00b9f9a3ec1d
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
@@ -0,0 +1,26 @@
+* Allwinner A10 MDIO Ethernet Controller interface
+
+Required properties:
+- compatible: should be "allwinner,sun4i-mdio".
+- reg: address and length of the register set for the device.
+
+Optional properties:
+- phy-supply: phandle to a regulator if the PHY needs one
+
+Example at the SoC level:
+mdio@01c0b080 {
+	compatible = "allwinner,sun4i-mdio";
+	reg = <0x01c0b080 0x14>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+};
+
+And at the board level:
+
+mdio@01c0b080 {
+	phy-supply = <&reg_emac_3v3>;
+
+	phy0: ethernet-phy@0 {
+		reg = <0>;
+	};
+};