net: phy: Allow pre-declaration of MDIO devices

Allow board support code to collect pre-declarations for MDIO devices by
registering them with mdiobus_register_board_info(). SPI and I2C buses
have a similar feature, we were missing this for MDIO devices, but this
is particularly useful for e.g: MDIO-connected switches which need to
provide their port layout (often board-specific) to a MDIO Ethernet
switch driver.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index fc3aaaa..e24f289 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -34,6 +34,17 @@ static void mdio_device_release(struct device *dev)
 	kfree(to_mdio_device(dev));
 }
 
+int mdio_device_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct mdio_device *mdiodev = to_mdio_device(dev);
+	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
+
+	if (mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY)
+		return 0;
+
+	return strcmp(mdiodev->modalias, drv->name) == 0;
+}
+
 struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr)
 {
 	struct mdio_device *mdiodev;