gianfar: use DT more consistently when selecting PHY connection type

Historically, gianfar only used phy-connection-type DT property when
connected to PHY in the rgmii-id mode. It ignored the property otherwise,
relying on the connection type auto-detection carried out by MAC and
providing that reconstructed mode to of_phy_connect(). It also did not
consider alternative phy-mode property at all.

Make the driver properly query DT node for PHY connection type first and
use an obtained value if it was specified there. Otherwise, if a particular
DT relies on connection type auto-detection, fall back to reconstructing
the value from MAC registers, as before.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.c

@@ -639,7 +639,6 @@ static phy_interface_t gfar_get_interface(struct net_device *dev)
 static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 {
 	const char *model;
-	const char *ctype;
 	const void *mac_addr;
 	int err = 0, i;
 	struct net_device *dev = NULL;
@@ -802,13 +801,15 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 				     FSL_GIANFAR_DEV_HAS_TIMER |
 				     FSL_GIANFAR_DEV_HAS_RX_FILER;
 
-	err = of_property_read_string(np, "phy-connection-type", &ctype);
-
-	/* We only care about rgmii-id.  The rest are autodetected */
-	if (err == 0 && !strcmp(ctype, "rgmii-id"))
-		priv->interface = PHY_INTERFACE_MODE_RGMII_ID;
+	/* Use PHY connection type from the DT node if one is specified there.
+	 * rgmii-id really needs to be specified. Other types can be
+	 * detected by hardware
+	 */
+	err = of_get_phy_mode(np);
+	if (err >= 0)
+		priv->interface = err;
 	else
-		priv->interface = PHY_INTERFACE_MODE_MII;
+		priv->interface = gfar_get_interface(dev);
 
 	if (of_find_property(np, "fsl,magic-packet", NULL))
 		priv->device_flags |= FSL_GIANFAR_DEV_HAS_MAGIC_PACKET;
@@ -1670,7 +1671,7 @@ static int init_phy(struct net_device *dev)
 {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
 	struct gfar_private *priv = netdev_priv(dev);
-	phy_interface_t interface;
+	phy_interface_t interface = priv->interface;
 	struct phy_device *phydev;
 	struct ethtool_eee edata;
 
@@ -1686,8 +1687,6 @@ static int init_phy(struct net_device *dev)
 	priv->oldspeed = 0;
 	priv->oldduplex = -1;
 
-	interface = gfar_get_interface(dev);
-
 	phydev = of_phy_connect(dev, priv->phy_node, &adjust_link, 0,
 				interface);
 	if (!phydev) {