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>

3 files changed, 47 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index a6284964b711..2e58aa54484c 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/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);
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 731d3d9052d7..7c8c142e4eb8 100644
--- a/drivers/of/of_mdio.c
+++ b/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)
 {
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index d449018d0726..a70c9493d55a 100644
--- a/include/linux/of_mdio.h
+++ b/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)