net: dsa: mv88e6xxx: Add support to enabling pause

The 6185 can enable/disable 802.3z pause be setting the MyPause bit in
the port status register. Add an op to support this.

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

drivers/net/dsa/mv88e6xxx/chip.c

@@ -524,7 +524,7 @@ int mv88e6xxx_update(struct mv88e6xxx_chip *chip, int addr, int reg, u16 update)
 }
 
 static int mv88e6xxx_port_setup_mac(struct mv88e6xxx_chip *chip, int port,
-				    int link, int speed, int duplex,
+				    int link, int speed, int duplex, int pause,
 				    phy_interface_t mode)
 {
 	int err;
@@ -543,6 +543,12 @@ static int mv88e6xxx_port_setup_mac(struct mv88e6xxx_chip *chip, int port,
 			goto restore_link;
 	}
 
+	if (chip->info->ops->port_set_pause) {
+		err = chip->info->ops->port_set_pause(chip, port, pause);
+		if (err)
+			goto restore_link;
+	}
+
 	if (chip->info->ops->port_set_duplex) {
 		err = chip->info->ops->port_set_duplex(chip, port, duplex);
 		if (err && err != -EOPNOTSUPP)
@@ -584,7 +590,8 @@ static void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,
 
 	mutex_lock(&chip->reg_lock);
 	err = mv88e6xxx_port_setup_mac(chip, port, phydev->link, phydev->speed,
-				       phydev->duplex, phydev->interface);
+				       phydev->duplex, phydev->pause,
+				       phydev->interface);
 	mutex_unlock(&chip->reg_lock);
 
 	if (err && err != -EOPNOTSUPP)
@@ -615,7 +622,7 @@ static void mv88e6xxx_mac_config(struct dsa_switch *ds, int port,
 				 const struct phylink_link_state *state)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
-	int speed, duplex, link, err;
+	int speed, duplex, link, pause, err;
 
 	if (mode == MLO_AN_PHY)
 		return;
@@ -629,9 +636,10 @@ static void mv88e6xxx_mac_config(struct dsa_switch *ds, int port,
 		duplex = DUPLEX_UNFORCED;
 		link = LINK_UNFORCED;
 	}
+	pause = !!phylink_test(state->advertising, Pause);
 
 	mutex_lock(&chip->reg_lock);
-	err = mv88e6xxx_port_setup_mac(chip, port, link, speed, duplex,
+	err = mv88e6xxx_port_setup_mac(chip, port, link, speed, duplex, pause,
 				       state->interface);
 	mutex_unlock(&chip->reg_lock);
 
@@ -2087,10 +2095,12 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port)
 	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
 		err = mv88e6xxx_port_setup_mac(chip, port, LINK_FORCED_UP,
 					       SPEED_MAX, DUPLEX_FULL,
+					       PAUSE_OFF,
 					       PHY_INTERFACE_MODE_NA);
 	else
 		err = mv88e6xxx_port_setup_mac(chip, port, LINK_UNFORCED,
 					       SPEED_UNFORCED, DUPLEX_UNFORCED,
+					       PAUSE_ON,
 					       PHY_INTERFACE_MODE_NA);
 	if (err)
 		return err;
@@ -2729,6 +2739,7 @@ static const struct mv88e6xxx_ops mv88e6131_ops = {
 	.port_set_jumbo_size = mv88e6165_port_set_jumbo_size,
 	.port_egress_rate_limiting = mv88e6097_port_egress_rate_limiting,
 	.port_pause_limit = mv88e6097_port_pause_limit,
+	.port_set_pause = mv88e6185_port_set_pause,
 	.stats_snapshot = mv88e6xxx_g1_stats_snapshot,
 	.stats_set_histogram = mv88e6095_g1_stats_set_histogram,
 	.stats_get_sset_count = mv88e6095_stats_get_sset_count,
@@ -3021,6 +3032,7 @@ static const struct mv88e6xxx_ops mv88e6185_ops = {
 	.port_set_egress_floods = mv88e6185_port_set_egress_floods,
 	.port_egress_rate_limiting = mv88e6095_port_egress_rate_limiting,
 	.port_set_upstream_port = mv88e6095_port_set_upstream_port,
+	.port_set_pause = mv88e6185_port_set_pause,
 	.stats_snapshot = mv88e6xxx_g1_stats_snapshot,
 	.stats_set_histogram = mv88e6095_g1_stats_set_histogram,
 	.stats_get_sset_count = mv88e6095_stats_get_sset_count,

drivers/net/dsa/mv88e6xxx/chip.h

@@ -351,6 +351,13 @@ struct mv88e6xxx_ops {
 	 */
 	int (*port_set_duplex)(struct mv88e6xxx_chip *chip, int port, int dup);
 
+#define PAUSE_ON		1
+#define PAUSE_OFF		0
+
+	/* Enable/disable sending Pause */
+	int (*port_set_pause)(struct mv88e6xxx_chip *chip, int port,
+			      int pause);
+
 #define SPEED_MAX		INT_MAX
 #define SPEED_UNFORCED		-2
 

drivers/net/dsa/mv88e6xxx/port.c

@@ -36,6 +36,29 @@ int mv88e6xxx_port_write(struct mv88e6xxx_chip *chip, int port, int reg,
 	return mv88e6xxx_write(chip, addr, reg, val);
 }
 
+/* Offset 0x00: MAC (or PCS or Physical) Status Register
+ *
+ * For most devices, this is read only. However the 6185 has the MyPause
+ * bit read/write.
+ */
+int mv88e6185_port_set_pause(struct mv88e6xxx_chip *chip, int port,
+			     int pause)
+{
+	u16 reg;
+	int err;
+
+	err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_STS, &reg);
+	if (err)
+		return err;
+
+	if (pause)
+		reg |= MV88E6XXX_PORT_STS_MY_PAUSE;
+	else
+		reg &= ~MV88E6XXX_PORT_STS_MY_PAUSE;
+
+	return mv88e6xxx_port_write(chip, port, MV88E6XXX_PORT_STS, reg);
+}
+
 /* Offset 0x01: MAC (or PCS or Physical) Control Register
  *
  * Link, Duplex and Flow Control have one force bit, one value bit.

drivers/net/dsa/mv88e6xxx/port.h

@@ -242,6 +242,8 @@ int mv88e6xxx_port_read(struct mv88e6xxx_chip *chip, int port, int reg,
 int mv88e6xxx_port_write(struct mv88e6xxx_chip *chip, int port, int reg,
 			 u16 val);
 
+int mv88e6185_port_set_pause(struct mv88e6xxx_chip *chip, int port,
+			     int pause);
 int mv88e6352_port_set_rgmii_delay(struct mv88e6xxx_chip *chip, int port,
 				   phy_interface_t mode);
 int mv88e6390_port_set_rgmii_delay(struct mv88e6xxx_chip *chip, int port,