net: phy: Add phy_ethtool_nway_reset

This function just calls into genphy_restart_aneg() to perform an
autonegotation restart.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -1441,3 +1441,14 @@ int phy_ethtool_set_link_ksettings(struct net_device *ndev,
 	return phy_ethtool_ksettings_set(phydev, cmd);
 }
 EXPORT_SYMBOL(phy_ethtool_set_link_ksettings);
+
+int phy_ethtool_nway_reset(struct net_device *ndev)
+{
+	struct phy_device *phydev = ndev->phydev;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return genphy_restart_aneg(phydev);
+}
+EXPORT_SYMBOL(phy_ethtool_nway_reset);

include/linux/phy.h

@@ -860,6 +860,7 @@ int phy_ethtool_get_link_ksettings(struct net_device *ndev,
 				   struct ethtool_link_ksettings *cmd);
 int phy_ethtool_set_link_ksettings(struct net_device *ndev,
 				   const struct ethtool_link_ksettings *cmd);
+int phy_ethtool_nway_reset(struct net_device *ndev);
 
 int __init mdio_bus_init(void);
 void mdio_bus_exit(void);