diff --git a/arch/mips/cavium-octeon/octeon-platform.c b/arch/mips/cavium-octeon/octeon-platform.c
index be711dd2d9185542b912c3d05317dba12879cb7f..febfdd73309fc4f66abeef68066578597079bedd 100644
--- a/arch/mips/cavium-octeon/octeon-platform.c
+++ b/arch/mips/cavium-octeon/octeon-platform.c
@@ -159,6 +159,36 @@ static int __init octeon_rng_device_init(void)
 }
 device_initcall(octeon_rng_device_init);
 
+/* Octeon SMI/MDIO interface.  */
+static int __init octeon_mdiobus_device_init(void)
+{
+	struct platform_device *pd;
+	int ret = 0;
+
+	if (octeon_is_simulation())
+		return 0; /* No mdio in the simulator. */
+
+	/* The bus number is the platform_device id.  */
+	pd = platform_device_alloc("mdio-octeon", 0);
+	if (!pd) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = platform_device_add(pd);
+	if (ret)
+		goto fail;
+
+	return ret;
+fail:
+	platform_device_put(pd);
+
+out:
+	return ret;
+
+}
+device_initcall(octeon_mdiobus_device_init);
+
 MODULE_AUTHOR("David Daney <ddaney@caviumnetworks.com>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Platform driver for Octeon SOC");