net: phy: add generic ndo_do_ioctl handler phy_do_ioctl

A number of network drivers has the same glue code to use phy_mii_ioctl
as ndo_do_ioctl handler. So let's add such a generic ndo_do_ioctl
handler to phylib.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -432,6 +432,21 @@ int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd)
 }
 EXPORT_SYMBOL(phy_mii_ioctl);
 
+/**
+ * phy_do_ioctl - generic ndo_do_ioctl implementation
+ * @dev: the net_device struct
+ * @ifr: &struct ifreq for socket ioctl's
+ * @cmd: ioctl cmd to execute
+ */
+int phy_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	if (!netif_running(dev) || !dev->phydev)
+		return -ENODEV;
+
+	return phy_mii_ioctl(dev->phydev, ifr, cmd);
+}
+EXPORT_SYMBOL(phy_do_ioctl);
+
 void phy_queue_state_machine(struct phy_device *phydev, unsigned long jiffies)
 {
 	mod_delayed_work(system_power_efficient_wq, &phydev->state_queue,

include/linux/phy.h

@@ -1242,6 +1242,7 @@ void phy_ethtool_ksettings_get(struct phy_device *phydev,
 int phy_ethtool_ksettings_set(struct phy_device *phydev,
 			      const struct ethtool_link_ksettings *cmd);
 int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd);
+int phy_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
 void phy_request_interrupt(struct phy_device *phydev);
 void phy_free_interrupt(struct phy_device *phydev);
 void phy_print_status(struct phy_device *phydev);