net: of_mdio: add of_mdiobus_link_phydev()

Add a function to walk the list of subnodes of a mdio bus and look for
a node that matches the phy's address with its 'reg' property. If found,
set the of_node pointer for the phy. This allows auto-probed pyh
devices to be augmented by information passed in via DT.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio_bus.c

@@ -300,6 +300,12 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 	if (IS_ERR(phydev) || phydev == NULL)
 		return phydev;
 
+	/*
+	 * For DT, see if the auto-probed phy has a correspoding child
+	 * in the bus node, and set the of_node pointer in this case.
+	 */
+	of_mdiobus_link_phydev(bus, phydev);
+
 	err = phy_device_register(phydev);
 	if (err) {
 		phy_device_free(phydev);

drivers/of/of_mdio.c

@@ -183,6 +183,39 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 }
 EXPORT_SYMBOL(of_mdiobus_register);
 
+/**
+ * of_mdiobus_link_phydev - Find a device node for a phy
+ * @mdio: pointer to mii_bus structure
+ * @phydev: phydev for which the of_node pointer should be set
+ *
+ * Walk the list of subnodes of a mdio bus and look for a node that matches the
+ * phy's address with its 'reg' property. If found, set the of_node pointer for
+ * the phy. This allows auto-probed pyh devices to be supplied with information
+ * passed in via DT.
+ */
+void of_mdiobus_link_phydev(struct mii_bus *mdio,
+			    struct phy_device *phydev)
+{
+	struct device *dev = &phydev->dev;
+	struct device_node *child;
+
+	if (dev->of_node || !mdio->dev.of_node)
+		return;
+
+	for_each_available_child_of_node(mdio->dev.of_node, child) {
+		int addr;
+
+		addr = of_mdio_parse_addr(&mdio->dev, child);
+		if (addr < 0)
+			continue;
+
+		if (addr == phydev->addr) {
+			dev->of_node = child;
+			return;
+		}
+	}
+}
+
 /* Helper function for of_phy_find_device */
 static int of_phy_match(struct device *dev, void *phy_np)
 {

include/linux/of_mdio.h

@@ -25,6 +25,9 @@ struct phy_device *of_phy_attach(struct net_device *dev,
 
 extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
 
+extern void of_mdiobus_link_phydev(struct mii_bus *mdio,
+				   struct phy_device *phydev);
+
 #else /* CONFIG_OF */
 static inline int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 {
@@ -60,6 +63,11 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np)
 {
 	return NULL;
 }
+
+static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
+					  struct phy_device *phydev)
+{
+}
 #endif /* CONFIG_OF */
 
 #if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)