net: phy: provide phy_resume/phy_suspend helpers

This adds helper functions to resume and suspend a given phy_device
by calling the corresponding driver callbacks if available.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 5a619f0..91f1717 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -679,6 +679,30 @@
 }
 EXPORT_SYMBOL(phy_detach);
 
+int phy_suspend(struct phy_device *phydev)
+{
+	struct phy_driver *phydrv = to_phy_driver(phydev->dev.driver);
+	struct ethtool_wolinfo wol;
+
+	/* If the device has WOL enabled, we cannot suspend the PHY */
+	wol.cmd = ETHTOOL_GWOL;
+	phy_ethtool_get_wol(phydev, &wol);
+	if (wol.wolopts)
+		return -EBUSY;
+
+	if (phydrv->suspend)
+		return phydrv->suspend(phydev);
+	return 0;
+}
+
+int phy_resume(struct phy_device *phydev)
+{
+	struct phy_driver *phydrv = to_phy_driver(phydev->dev.driver);
+
+	if (phydrv->resume)
+		return phydrv->resume(phydev);
+	return 0;
+}
 
 /* Generic PHY support and helper functions */
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 90a666e..73384ff 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -548,6 +548,8 @@
 struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);
 int phy_device_register(struct phy_device *phy);
 int phy_init_hw(struct phy_device *phydev);
+int phy_suspend(struct phy_device *phydev);
+int phy_resume(struct phy_device *phydev);
 struct phy_device * phy_attach(struct net_device *dev,
 		const char *bus_id, phy_interface_t interface);
 struct phy_device *phy_find_first(struct mii_bus *bus);