net: phy: marvell10g: add support for half duplex 100M and 10M

Add support for half-duplex 100M and 10M copper connections by parsing
the advertisment results rather than trying to decode the negotiated
speed from one of the PHYs "vendor" registers.  This allows us to
decode the duplex as well, which means we can support half-duplex mode
for the slower speeds.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/marvell10g.c

@@ -40,13 +40,6 @@ enum {
 	 */
 	MV_AN_CTRL1000		= 0x8000, /* 1000base-T control register */
 	MV_AN_STAT1000		= 0x8001, /* 1000base-T status register */
-
-	/* This register appears to reflect the copper status */
-	MV_AN_RESULT		= 0xa016,
-	MV_AN_RESULT_SPD_10	= BIT(12),
-	MV_AN_RESULT_SPD_100	= BIT(13),
-	MV_AN_RESULT_SPD_1000	= BIT(14),
-	MV_AN_RESULT_SPD_10000	= BIT(15),
 };
 
 static int mv3310_modify(struct phy_device *phydev, int devad, u16 reg,
@@ -160,12 +153,18 @@ static int mv3310_config_init(struct phy_device *phydev)
 		if (val & MDIO_PMA_EXTABLE_1000BKX)
 			__set_bit(ETHTOOL_LINK_MODE_1000baseKX_Full_BIT,
 				  supported);
-		if (val & MDIO_PMA_EXTABLE_100BTX)
+		if (val & MDIO_PMA_EXTABLE_100BTX) {
 			__set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
 				  supported);
-		if (val & MDIO_PMA_EXTABLE_10BT)
+			__set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
+				  supported);
+		}
+		if (val & MDIO_PMA_EXTABLE_10BT) {
 			__set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
 				  supported);
+			__set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
+				  supported);
+		}
 	}
 
 	if (!ethtool_convert_link_mode_to_legacy_u32(&mask, supported))
@@ -325,22 +324,8 @@ static int mv3310_read_status(struct phy_device *phydev)
 
 		phydev->lp_advertising |= mii_stat1000_to_ethtool_lpa_t(val);
 
-		if (phydev->autoneg == AUTONEG_ENABLE) {
-			val = phy_read_mmd(phydev, MDIO_MMD_AN, MV_AN_RESULT);
-			if (val < 0)
-				return val;
-
-			if (val & MV_AN_RESULT_SPD_10000)
-				phydev->speed = SPEED_10000;
-			else if (val & MV_AN_RESULT_SPD_1000)
-				phydev->speed = SPEED_1000;
-			else if (val & MV_AN_RESULT_SPD_100)
-				phydev->speed = SPEED_100;
-			else if (val & MV_AN_RESULT_SPD_10)
-				phydev->speed = SPEED_10;
-
-			phydev->duplex = DUPLEX_FULL;
-		}
+		if (phydev->autoneg == AUTONEG_ENABLE)
+			phy_resolve_aneg_linkmode(phydev);
 	}
 
 	if (phydev->autoneg != AUTONEG_ENABLE) {
@@ -382,7 +367,9 @@ static struct phy_driver mv3310_drivers[] = {
 		.phy_id_mask	= MARVELL_PHY_ID_MASK,
 		.name		= "mv88x3310",
 		.features	= SUPPORTED_10baseT_Full |
+				  SUPPORTED_10baseT_Half |
 				  SUPPORTED_100baseT_Full |
+				  SUPPORTED_100baseT_Half |
 				  SUPPORTED_1000baseT_Full |
 				  SUPPORTED_Autoneg |
 				  SUPPORTED_TP |