openfirmware: Add OF phylib support code

Add support for parsing the device tree for PHY devices on an MDIO bus.
Currently many of the PowerPC ethernet drivers are open coding a solution
for reading data out of the device tree to find the correct PHY device.
This patch implements a set of common routines to:

a) let MDIO bus drivers register phy_devices described in the tree, and
b) let MAC drivers find the correct phy_device via the tree.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
new file mode 100644
index 0000000..c9663c6
--- /dev/null
+++ b/include/linux/of_mdio.h
@@ -0,0 +1,22 @@
+/*
+ * OF helpers for the MDIO (Ethernet PHY) API
+ *
+ * Copyright (c) 2009 Secret Lab Technologies, Ltd.
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_OF_MDIO_H
+#define __LINUX_OF_MDIO_H
+
+#include <linux/phy.h>
+#include <linux/of.h>
+
+extern int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np);
+extern struct phy_device *of_phy_find_device(struct device_node *phy_np);
+extern struct phy_device *of_phy_connect(struct net_device *dev,
+					 struct device_node *phy_np,
+					 void (*hndlr)(struct net_device *),
+					 u32 flags, phy_interface_t iface);
+
+#endif /* __LINUX_OF_MDIO_H */