drivers: net: xgene: Enable MDIO driver

BugLink: https://launchpad.net/bugs/1632739

This patch enables MDIO driver by,

- Selecting MDIO_XGENE
- Changed open and close to use phy_start and phy_stop
- Changed to use mac_ops->tx(rx)_enable and tx(rx)_disable
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Fushen Chen <fchen@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 47c62b6d yakkety)
Signed-off-by: Craig Magina <craig.magina@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

drivers/net/ethernet/apm/xgene/Kconfig

@@ -3,6 +3,7 @@ config NET_XGENE
 	depends on HAS_DMA
 	depends on ARCH_XGENE || COMPILE_TEST
 	select PHYLIB
+	select MDIO_XGENE
 	help
 	  This is the Ethernet driver for the on-chip ethernet interface on the
 	  APM X-Gene SoC.

drivers/net/ethernet/apm/xgene/xgene_enet_hw.c

@@ -794,13 +794,13 @@ static void xgene_enet_adjust_link(struct net_device *ndev)
 		if (pdata->phy_speed != phydev->speed) {
 			pdata->phy_speed = phydev->speed;
 			mac_ops->set_speed(pdata);
-			xgene_gmac_rx_enable(pdata);
-			xgene_gmac_tx_enable(pdata);
+			mac_ops->rx_enable(pdata);
+			mac_ops->tx_enable(pdata);
 			phy_print_status(phydev);
 		}
 	} else {
-		xgene_gmac_rx_disable(pdata);
-		xgene_gmac_tx_disable(pdata);
+		mac_ops->rx_disable(pdata);
+		mac_ops->tx_disable(pdata);
 		pdata->phy_speed = SPEED_UNKNOWN;
 		phy_print_status(phydev);
 	}

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -739,9 +739,9 @@ static int xgene_enet_open(struct net_device *ndev)
 	if (ret)
 		return ret;
 
-	if (pdata->phy_mode == PHY_INTERFACE_MODE_RGMII)
+	if (pdata->phy_dev) {
 		phy_start(pdata->phy_dev);
-	else {
+	} else {
 		schedule_delayed_work(&pdata->link_work, PHY_POLL_LINK_OFF);
 		netif_carrier_off(ndev);
 	}