net: dsa: microchip: lan9371/2: update MAC capabilities for port 4

Set proper MAC capabilities for port 4 on LAN9371 and LAN9372 switches with
integrated 100BaseTX PHY. And introduce the is_lan937x_tx_phy() function to
reuse it where applicable.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz_common.h

@@ -638,6 +638,12 @@ static inline int is_lan937x(struct ksz_device *dev)
 		dev->chip_id == LAN9374_CHIP_ID;
 }
 
+static inline bool is_lan937x_tx_phy(struct ksz_device *dev, int port)
+{
+	return (dev->chip_id == LAN9371_CHIP_ID ||
+		dev->chip_id == LAN9372_CHIP_ID) && port == KSZ_PORT_4;
+}
+
 /* STP State Defines */
 #define PORT_TX_ENABLE			BIT(2)
 #define PORT_RX_ENABLE			BIT(1)

drivers/net/dsa/microchip/lan937x_main.c

@@ -55,8 +55,7 @@ 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)
+	if (is_lan937x_tx_phy(dev, addr))
 		addr_base = REG_PORT_TX_PHY_CTRL_BASE;
 
 	/* get register address based on the logical port */
@@ -324,6 +323,9 @@ void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
 		/* MII/RMII/RGMII ports */
 		config->mac_capabilities |= MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
 					    MAC_100HD | MAC_10 | MAC_1000FD;
+	} else if (is_lan937x_tx_phy(dev, port)) {
+		config->mac_capabilities |= MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+					    MAC_100HD | MAC_10;
 	}
 }