net: ethernet: mediatek: fix RMII mode and add REVMII supported by GMAC

The patch fixes up the incorrect setup of reduced MII (RMII) on GMAC
and adds the supplement for the setup of reverse MII (REVMII) on GMAC
, and rearranges the error handling for invalid PHY argument.
Signed-off-by: NSean Wang <sean.wang@mediatek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -245,12 +245,16 @@ static int mtk_phy_connect(struct mtk_mac *mac)
 	case PHY_INTERFACE_MODE_MII:
 		ge_mode = 1;
 		break;
-	case PHY_INTERFACE_MODE_RMII:
+	case PHY_INTERFACE_MODE_REVMII:
 		ge_mode = 2;
 		break;
+	case PHY_INTERFACE_MODE_RMII:
+		if (!mac->id)
+			goto err_phy;
+		ge_mode = 3;
+		break;
 	default:
-		dev_err(eth->dev, "invalid phy_mode\n");
-		return -1;
+		goto err_phy;
 	}
 
 	/* put the gmac into the right mode */
@@ -272,6 +276,11 @@ static int mtk_phy_connect(struct mtk_mac *mac)
 	of_node_put(np);
 
 	return 0;
+
+err_phy:
+	of_node_put(np);
+	dev_err(eth->dev, "invalid phy_mode\n");
+	return -EINVAL;
 }
 
 static int mtk_mdio_init(struct mtk_eth *eth)