net: lan743x: add generic implementation for phy interface selection

Add logic to read the Phy interface from MAC_CR register for LAN743x
driver.

Checks for the LAN7430/31 or pci11x1x devices and the adapter
interface is updated accordingly. For LAN7431, adapter interface is set
based on Bit 19 of MAC_CR register as MII or RGMII which removes the
forced RGMII/GMII configurations in lan743x_phy_open().
Signed-off-by: Pavithra Sathyanarayanan <Pavithra.Sathyanarayanan@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/microchip/lan743x_main.c

@@ -1469,6 +1469,24 @@ static void lan743x_phy_close(struct lan743x_adapter *adapter)
 	netdev->phydev = NULL;
 }
 
+static void lan743x_phy_interface_select(struct lan743x_adapter *adapter)
+{
+	u32 id_rev;
+	u32 data;
+
+	data = lan743x_csr_read(adapter, MAC_CR);
+	id_rev = adapter->csr.id_rev & ID_REV_ID_MASK_;
+
+	if (adapter->is_pci11x1x && adapter->is_sgmii_en)
+		adapter->phy_interface = PHY_INTERFACE_MODE_SGMII;
+	else if (id_rev == ID_REV_ID_LAN7430_)
+		adapter->phy_interface = PHY_INTERFACE_MODE_GMII;
+	else if ((id_rev == ID_REV_ID_LAN7431_) && (data & MAC_CR_MII_EN_))
+		adapter->phy_interface = PHY_INTERFACE_MODE_MII;
+	else
+		adapter->phy_interface = PHY_INTERFACE_MODE_RGMII;
+}
+
 static int lan743x_phy_open(struct lan743x_adapter *adapter)
 {
 	struct net_device *netdev = adapter->netdev;
@@ -1486,14 +1504,11 @@ static int lan743x_phy_open(struct lan743x_adapter *adapter)
 		if (!phydev)
 			goto return_error;
 
-		if (adapter->is_pci11x1x)
-			ret = phy_connect_direct(netdev, phydev,
-						 lan743x_phy_link_status_change,
-						 PHY_INTERFACE_MODE_RGMII);
-		else
-			ret = phy_connect_direct(netdev, phydev,
-						 lan743x_phy_link_status_change,
-						 PHY_INTERFACE_MODE_GMII);
+		lan743x_phy_interface_select(adapter);
+
+		ret = phy_connect_direct(netdev, phydev,
+					 lan743x_phy_link_status_change,
+					 adapter->phy_interface);
 		if (ret)
 			goto return_error;
 	}

drivers/net/ethernet/microchip/lan743x_main.h

@@ -1042,6 +1042,7 @@ struct lan743x_adapter {
 #define LAN743X_ADAPTER_FLAG_OTP		BIT(0)
 	u32			flags;
 	u32			hw_cfg;
+	phy_interface_t		phy_interface;
 };
 
 #define LAN743X_COMPONENT_FLAG_RX(channel)  BIT(20 + (channel))