net: bcmgenet: Add support for PHY-based Wake-on-LAN

If available, interrogate the PHY to find out whether we can use it for
Wake-on-LAN. This can be a more power efficient way of implementing
that feature, especially when the MAC is powered off in low power
states.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c

@@ -42,6 +42,12 @@ void bcmgenet_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 	struct device *kdev = &priv->pdev->dev;
 
+	if (dev->phydev) {
+		phy_ethtool_get_wol(dev->phydev, wol);
+		if (wol->supported)
+			return;
+	}
+
 	if (!device_can_wakeup(kdev)) {
 		wol->supported = 0;
 		wol->wolopts = 0;
@@ -63,6 +69,14 @@ int bcmgenet_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 {
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 	struct device *kdev = &priv->pdev->dev;
+	int ret;
+
+	/* Try Wake-on-LAN from the PHY first */
+	if (dev->phydev) {
+		ret = phy_ethtool_set_wol(dev->phydev, wol);
+		if (ret != -EOPNOTSUPP)
+			return ret;
+	}
 
 	if (!device_can_wakeup(kdev))
 		return -ENOTSUPP;