of: mdio: export of_mdio_parse_addr

Export of_mdio_parse_addr() which allows parsing a given Ethernet PHY
node MDIO address, verify it is within the allowed range, and return
its value. This is going to be useful for the DSA code which needs to
deal with multiple layers of MDIO buses.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 1bd4305..0c064485 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -88,7 +88,7 @@
 	return 0;
 }
 
-static int of_mdio_parse_addr(struct device *dev, const struct device_node *np)
+int of_mdio_parse_addr(struct device *dev, const struct device_node *np)
 {
 	u32 addr;
 	int ret;
@@ -108,6 +108,7 @@
 
 	return addr;
 }
+EXPORT_SYMBOL(of_mdio_parse_addr);
 
 /**
  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index d449018..8f2237e 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -24,6 +24,7 @@
 				 phy_interface_t iface);
 
 extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
+extern int of_mdio_parse_addr(struct device *dev, const struct device_node *np);
 
 #else /* CONFIG_OF */
 static inline int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
@@ -60,6 +61,12 @@
 {
 	return NULL;
 }
+
+static inline int of_mdio_parse_addr(struct device *dev,
+				     const struct device_node *np)
+{
+	return -ENOSYS;
+}
 #endif /* CONFIG_OF */
 
 #if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)