net: dsa: mv88e6xxx: add PHYLINK support

Add rudimentary phylink support to mv88e6xxx. This allows the driver
using user ports with fixed links to keep operating normally. User ports
with normal PHYs are not affected since the switch automatically manages
their link parameters. User facing ports which use a SFP/SFF with a
non-fixed link mode might require a call to phylink_mac_change() to
operate properly.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
[Andrew: fixed link setting after adding link polling]
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[florian: expand commit message]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -31,6 +31,7 @@
 #include <linux/netdevice.h>
 #include <linux/gpio/consumer.h>
 #include <linux/phy.h>
+#include <linux/phylink.h>
 #include <net/dsa.h>
 
 #include "chip.h"
@@ -580,6 +581,83 @@ static void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,
 		dev_err(ds->dev, "p%d: failed to configure MAC\n", port);
 }
 
+static void mv88e6xxx_validate(struct dsa_switch *ds, int port,
+			       unsigned long *supported,
+			       struct phylink_link_state *state)
+{
+}
+
+static int mv88e6xxx_link_state(struct dsa_switch *ds, int port,
+				struct phylink_link_state *state)
+{
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int err;
+
+	mutex_lock(&chip->reg_lock);
+	err = mv88e6xxx_port_link_state(chip, port, state);
+	mutex_unlock(&chip->reg_lock);
+
+	return err;
+}
+
+static void mv88e6xxx_mac_config(struct dsa_switch *ds, int port,
+				 unsigned int mode,
+				 const struct phylink_link_state *state)
+{
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int speed, duplex, link, err;
+
+	if (mode == MLO_AN_PHY)
+		return;
+
+	if (mode == MLO_AN_FIXED) {
+		link = LINK_FORCED_UP;
+		speed = state->speed;
+		duplex = state->duplex;
+	} else {
+		speed = SPEED_UNFORCED;
+		duplex = DUPLEX_UNFORCED;
+		link = LINK_UNFORCED;
+	}
+
+	mutex_lock(&chip->reg_lock);
+	err = mv88e6xxx_port_setup_mac(chip, port, link, speed, duplex,
+				       state->interface);
+	mutex_unlock(&chip->reg_lock);
+
+	if (err && err != -EOPNOTSUPP)
+		dev_err(ds->dev, "p%d: failed to configure MAC\n", port);
+}
+
+static void mv88e6xxx_mac_link_force(struct dsa_switch *ds, int port, int link)
+{
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int err;
+
+	mutex_lock(&chip->reg_lock);
+	err = chip->info->ops->port_set_link(chip, port, link);
+	mutex_unlock(&chip->reg_lock);
+
+	if (err)
+		dev_err(chip->dev, "p%d: failed to force MAC link\n", port);
+}
+
+static void mv88e6xxx_mac_link_down(struct dsa_switch *ds, int port,
+				    unsigned int mode,
+				    phy_interface_t interface)
+{
+	if (mode == MLO_AN_FIXED)
+		mv88e6xxx_mac_link_force(ds, port, LINK_FORCED_DOWN);
+}
+
+static void mv88e6xxx_mac_link_up(struct dsa_switch *ds, int port,
+				  unsigned int mode, phy_interface_t interface,
+				  struct phy_device *phydev)
+{
+	if (mode == MLO_AN_FIXED)
+		mv88e6xxx_mac_link_force(ds, port, LINK_FORCED_UP);
+}
+
 static int mv88e6xxx_stats_snapshot(struct mv88e6xxx_chip *chip, int port)
 {
 	if (!chip->info->ops->stats_snapshot)
@@ -4169,6 +4247,11 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 	.get_tag_protocol	= mv88e6xxx_get_tag_protocol,
 	.setup			= mv88e6xxx_setup,
 	.adjust_link		= mv88e6xxx_adjust_link,
+	.phylink_validate	= mv88e6xxx_validate,
+	.phylink_mac_link_state	= mv88e6xxx_link_state,
+	.phylink_mac_config	= mv88e6xxx_mac_config,
+	.phylink_mac_link_down	= mv88e6xxx_mac_link_down,
+	.phylink_mac_link_up	= mv88e6xxx_mac_link_up,
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
 	.get_sset_count		= mv88e6xxx_get_sset_count,

drivers/net/dsa/mv88e6xxx/port.c

@@ -15,6 +15,7 @@
 #include <linux/bitfield.h>
 #include <linux/if_bridge.h>
 #include <linux/phy.h>
+#include <linux/phylink.h>
 
 #include "chip.h"
 #include "port.h"
@@ -378,6 +379,44 @@ int mv88e6xxx_port_get_cmode(struct mv88e6xxx_chip *chip, int port, u8 *cmode)
 	return 0;
 }
 
+int mv88e6xxx_port_link_state(struct mv88e6xxx_chip *chip, int port,
+			      struct phylink_link_state *state)
+{
+	int err;
+	u16 reg;
+
+	err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_STS, &reg);
+	if (err)
+		return err;
+
+	switch (reg & MV88E6XXX_PORT_STS_SPEED_MASK) {
+	case MV88E6XXX_PORT_STS_SPEED_10:
+		state->speed = SPEED_10;
+		break;
+	case MV88E6XXX_PORT_STS_SPEED_100:
+		state->speed = SPEED_100;
+		break;
+	case MV88E6XXX_PORT_STS_SPEED_1000:
+		state->speed = SPEED_1000;
+		break;
+	case MV88E6XXX_PORT_STS_SPEED_10000:
+		if ((reg &MV88E6XXX_PORT_STS_CMODE_MASK) ==
+		    MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			state->speed = SPEED_2500;
+		else
+			state->speed = SPEED_10000;
+		break;
+	}
+
+	state->duplex = reg & MV88E6XXX_PORT_STS_DUPLEX ?
+			DUPLEX_FULL : DUPLEX_HALF;
+	state->link = !!(reg & MV88E6XXX_PORT_STS_LINK);
+	state->an_enabled = 1;
+	state->an_complete = state->link;
+
+	return 0;
+}
+
 /* Offset 0x02: Jamming Control
  *
  * Do not limit the period of time that this port can be paused for by

drivers/net/dsa/mv88e6xxx/port.h

@@ -29,6 +29,7 @@
 #define MV88E6XXX_PORT_STS_SPEED_10		0x0000
 #define MV88E6XXX_PORT_STS_SPEED_100		0x0100
 #define MV88E6XXX_PORT_STS_SPEED_1000		0x0200
+#define MV88E6XXX_PORT_STS_SPEED_10000		0x0300
 #define MV88E6352_PORT_STS_EEE			0x0040
 #define MV88E6165_PORT_STS_AM_DIS		0x0040
 #define MV88E6185_PORT_STS_MGMII		0x0040
@@ -295,6 +296,8 @@ int mv88e6390_port_pause_limit(struct mv88e6xxx_chip *chip, int port, u8 in,
 int mv88e6390x_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 			      phy_interface_t mode);
 int mv88e6xxx_port_get_cmode(struct mv88e6xxx_chip *chip, int port, u8 *cmode);
+int mv88e6xxx_port_link_state(struct mv88e6xxx_chip *chip, int port,
+			      struct phylink_link_state *state);
 int mv88e6xxx_port_set_map_da(struct mv88e6xxx_chip *chip, int port);
 int mv88e6095_port_set_upstream_port(struct mv88e6xxx_chip *chip, int port,
 				     int upstream_port);