net: dsa: microchip: lan9371/2: add 100BaseTX PHY support

On the LAN9371 and LAN9372, the 4th internal PHY is a 100BaseTX PHY
instead of a 100BaseT1 PHY. The 100BaseTX PHYs have a different base
register offset.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz_common.h

@@ -22,6 +22,7 @@
 /* all KSZ switches count ports from 1 */
 #define KSZ_PORT_1 0
 #define KSZ_PORT_2 1
+#define KSZ_PORT_4 3
 
 struct ksz_device;
 struct ksz_port;

drivers/net/dsa/microchip/lan937x_main.c

@@ -55,6 +55,10 @@ static int lan937x_vphy_ind_addr_wr(struct ksz_device *dev, int addr, int reg)
 	u16 addr_base = REG_PORT_T1_PHY_CTRL_BASE;
 	u16 temp;
 
+	if ((dev->info->chip_id == LAN9371_CHIP_ID ||
+	     dev->info->chip_id == LAN9372_CHIP_ID) && addr == KSZ_PORT_4)
+		addr_base = REG_PORT_TX_PHY_CTRL_BASE;
+
 	/* get register address based on the logical port */
 	temp = PORT_CTRL_ADDR(addr, (addr_base + (reg << 2)));
 

drivers/net/dsa/microchip/lan937x_reg.h

@@ -147,6 +147,7 @@
 
 /* 1 - Phy */
 #define REG_PORT_T1_PHY_CTRL_BASE	0x0100
+#define REG_PORT_TX_PHY_CTRL_BASE	0x0280
 
 /* 3 - xMII */
 #define PORT_SGMII_SEL			BIT(7)