phy/marvell: add 88e1121 interface mode support

This patch adds support for RGMII RX/TX delay configuration on marvell 88e1121
and derivatives.  With this patch, PHY_INTERFACE_MODE_RGMII_*ID modes are now
supported on these devices.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/marvell.c

@@ -69,6 +69,12 @@
 #define MII_M1111_COPPER		0
 #define MII_M1111_FIBER			1
 
+#define MII_88E1121_PHY_MSCR_PAGE	2
+#define MII_88E1121_PHY_MSCR_REG	21
+#define MII_88E1121_PHY_MSCR_RX_DELAY	BIT(5)
+#define MII_88E1121_PHY_MSCR_TX_DELAY	BIT(4)
+#define MII_88E1121_PHY_MSCR_DELAY_MASK	(~(0x3 << 4))
+
 #define MII_88E1121_PHY_LED_CTRL	16
 #define MII_88E1121_PHY_LED_PAGE	3
 #define MII_88E1121_PHY_LED_DEF		0x0030
@@ -180,7 +186,30 @@ static int marvell_config_aneg(struct phy_device *phydev)
 
 static int m88e1121_config_aneg(struct phy_device *phydev)
 {
-	int err, temp;
+	int err, oldpage, mscr;
+
+	oldpage = phy_read(phydev, MII_88E1121_PHY_PAGE);
+
+	err = phy_write(phydev, MII_88E1121_PHY_PAGE,
+			MII_88E1121_PHY_MSCR_PAGE);
+	if (err < 0)
+		return err;
+	mscr = phy_read(phydev, MII_88E1121_PHY_MSCR_REG) &
+		MII_88E1121_PHY_MSCR_DELAY_MASK;
+
+	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
+		mscr |= (MII_88E1121_PHY_MSCR_RX_DELAY |
+			 MII_88E1121_PHY_MSCR_TX_DELAY);
+	else if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID)
+		mscr |= MII_88E1121_PHY_MSCR_RX_DELAY;
+	else if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID)
+		mscr |= MII_88E1121_PHY_MSCR_TX_DELAY;
+
+	err = phy_write(phydev, MII_88E1121_PHY_MSCR_REG, mscr);
+	if (err < 0)
+		return err;
+
+	phy_write(phydev, MII_88E1121_PHY_PAGE, oldpage);
 
 	err = phy_write(phydev, MII_BMCR, BMCR_RESET);
 	if (err < 0)
@@ -191,11 +220,11 @@ static int m88e1121_config_aneg(struct phy_device *phydev)
 	if (err < 0)
 		return err;
 
-	temp = phy_read(phydev, MII_88E1121_PHY_PAGE);
+	oldpage = phy_read(phydev, MII_88E1121_PHY_PAGE);
 
 	phy_write(phydev, MII_88E1121_PHY_PAGE, MII_88E1121_PHY_LED_PAGE);
 	phy_write(phydev, MII_88E1121_PHY_LED_CTRL, MII_88E1121_PHY_LED_DEF);
-	phy_write(phydev, MII_88E1121_PHY_PAGE, temp);
+	phy_write(phydev, MII_88E1121_PHY_PAGE, oldpage);
 
 	err = genphy_config_aneg(phydev);