net: dsa: microchip: lan937x: add phylink_mac_config support

This patch add support for phylink_mac_config dsa hook. It configures
the mac for MII/RMII modes. The RGMII mode will be added in the future
patches.
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz_common.c

@@ -221,6 +221,7 @@ static const struct ksz_dev_ops lan937x_dev_ops = {
 	.mirror_add = ksz9477_port_mirror_add,
 	.mirror_del = ksz9477_port_mirror_del,
 	.get_caps = lan937x_phylink_get_caps,
+	.phylink_mac_config = lan937x_phylink_mac_config,
 	.phylink_mac_link_up = lan937x_phylink_mac_link_up,
 	.fdb_dump = ksz9477_fdb_dump,
 	.fdb_add = ksz9477_fdb_add,
@@ -1341,6 +1342,16 @@ static int ksz_max_mtu(struct dsa_switch *ds, int port)
 	return dev->dev_ops->max_mtu(dev, port);
 }
 
+static void ksz_phylink_mac_config(struct dsa_switch *ds, int port,
+				   unsigned int mode,
+				   const struct phylink_link_state *state)
+{
+	struct ksz_device *dev = ds->priv;
+
+	if (dev->dev_ops->phylink_mac_config)
+		dev->dev_ops->phylink_mac_config(dev, port, mode, state);
+}
+
 static void ksz_phylink_mac_link_up(struct dsa_switch *ds, int port,
 				    unsigned int mode,
 				    phy_interface_t interface,
@@ -1428,6 +1439,7 @@ static const struct dsa_switch_ops ksz_switch_ops = {
 	.phy_read		= ksz_phy_read16,
 	.phy_write		= ksz_phy_write16,
 	.phylink_get_caps	= ksz_phylink_get_caps,
+	.phylink_mac_config	= ksz_phylink_mac_config,
 	.phylink_mac_link_up	= ksz_phylink_mac_link_up,
 	.phylink_mac_link_down	= ksz_mac_link_down,
 	.port_enable		= ksz_enable_port,

drivers/net/dsa/microchip/ksz_common.h

@@ -271,6 +271,9 @@ struct ksz_dev_ops {
 	int (*max_mtu)(struct ksz_device *dev, int port);
 	void (*freeze_mib)(struct ksz_device *dev, int port, bool freeze);
 	void (*port_init_cnt)(struct ksz_device *dev, int port);
+	void (*phylink_mac_config)(struct ksz_device *dev, int port,
+				   unsigned int mode,
+				   const struct phylink_link_state *state);
 	void (*phylink_mac_link_up)(struct ksz_device *dev, int port,
 				    unsigned int mode,
 				    phy_interface_t interface,

drivers/net/dsa/microchip/lan937x.h

@@ -21,4 +21,7 @@ void lan937x_phylink_mac_link_up(struct ksz_device *dev, int port,
 				 unsigned int mode, phy_interface_t interface,
 				 struct phy_device *phydev, int speed,
 				 int duplex, bool tx_pause, bool rx_pause);
+void lan937x_phylink_mac_config(struct ksz_device *dev, int port,
+				unsigned int mode,
+				const struct phylink_link_state *state);
 #endif

drivers/net/dsa/microchip/lan937x_main.c

@@ -312,6 +312,44 @@ int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu)
 	return 0;
 }
 
+static void lan937x_config_gbit(struct ksz_device *dev, bool gbit, u8 *data)
+{
+	if (gbit)
+		*data &= ~PORT_MII_NOT_1GBIT;
+	else
+		*data |= PORT_MII_NOT_1GBIT;
+}
+
+static void lan937x_mac_config(struct ksz_device *dev, int port,
+			       phy_interface_t interface)
+{
+	u8 data8;
+
+	ksz_pread8(dev, port, REG_PORT_XMII_CTRL_1, &data8);
+
+	/* clear MII selection & set it based on interface later */
+	data8 &= ~PORT_MII_SEL_M;
+
+	/* configure MAC based on interface */
+	switch (interface) {
+	case PHY_INTERFACE_MODE_MII:
+		lan937x_config_gbit(dev, false, &data8);
+		data8 |= PORT_MII_SEL;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		lan937x_config_gbit(dev, false, &data8);
+		data8 |= PORT_RMII_SEL;
+		break;
+	default:
+		dev_err(dev->dev, "Unsupported interface '%s' for port %d\n",
+			phy_modes(interface), port);
+		return;
+	}
+
+	/* Write the updated value */
+	ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_1, data8);
+}
+
 static void lan937x_config_interface(struct ksz_device *dev, int port,
 				     int speed, int duplex,
 				     bool tx_pause, bool rx_pause)
@@ -325,9 +363,9 @@ static void lan937x_config_interface(struct ksz_device *dev, int port,
 			PORT_MII_TX_FLOW_CTRL | PORT_MII_RX_FLOW_CTRL);
 
 	if (speed == SPEED_1000)
-		xmii_ctrl1 &= ~PORT_MII_NOT_1GBIT;
+		lan937x_config_gbit(dev, true, &xmii_ctrl1);
 	else
-		xmii_ctrl1 |= PORT_MII_NOT_1GBIT;
+		lan937x_config_gbit(dev, false, &xmii_ctrl1);
 
 	if (speed == SPEED_100)
 		xmii_ctrl0 |= PORT_MII_100MBIT;
@@ -370,6 +408,22 @@ void lan937x_phylink_mac_link_up(struct ksz_device *dev, int port,
 				 tx_pause, rx_pause);
 }
 
+void lan937x_phylink_mac_config(struct ksz_device *dev, int port,
+				unsigned int mode,
+				const struct phylink_link_state *state)
+{
+	/* Internal PHYs */
+	if (dev->info->internal_phy[port])
+		return;
+
+	if (phylink_autoneg_inband(mode)) {
+		dev_err(dev->dev, "In-band AN not supported!\n");
+		return;
+	}
+
+	lan937x_mac_config(dev, port, state->interface);
+}
+
 int lan937x_setup(struct dsa_switch *ds)
 {
 	struct ksz_device *dev = ds->priv;