net: dsa: mv88e6xxx: Add SERDES phydev_link_change for 6352

The 6352 family has one SERDES interface, which can be used by either
port 4 or port 5. Add interrupt support for the SERDES interface, and
report when the link status changes.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index e82983975754..bb69650ff772 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -185,6 +185,111 @@ int mv88e6352_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
 	return ARRAY_SIZE(mv88e6352_serdes_hw_stats);
 }
 
+static void mv88e6352_serdes_irq_link(struct mv88e6xxx_chip *chip, int port)
+{
+	struct dsa_switch *ds = chip->ds;
+	u16 status;
+	bool up;
+
+	mv88e6352_serdes_read(chip, MII_BMSR, &status);
+
+	/* Status must be read twice in order to give the current link
+	 * status. Otherwise the change in link status since the last
+	 * read of the register is returned.
+	 */
+	mv88e6352_serdes_read(chip, MII_BMSR, &status);
+
+	up = status & BMSR_LSTATUS;
+
+	dsa_port_phylink_mac_change(ds, port, up);
+}
+
+static irqreturn_t mv88e6352_serdes_thread_fn(int irq, void *dev_id)
+{
+	struct mv88e6xxx_port *port = dev_id;
+	struct mv88e6xxx_chip *chip = port->chip;
+	irqreturn_t ret = IRQ_NONE;
+	u16 status;
+	int err;
+
+	mutex_lock(&chip->reg_lock);
+
+	err = mv88e6352_serdes_read(chip, MV88E6352_SERDES_INT_STATUS, &status);
+	if (err)
+		goto out;
+
+	if (status & MV88E6352_SERDES_INT_LINK_CHANGE) {
+		ret = IRQ_HANDLED;
+		mv88e6352_serdes_irq_link(chip, port->port);
+	}
+out:
+	mutex_unlock(&chip->reg_lock);
+
+	return ret;
+}
+
+static int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip)
+{
+	return mv88e6352_serdes_write(chip, MV88E6352_SERDES_INT_ENABLE,
+				      MV88E6352_SERDES_INT_LINK_CHANGE);
+}
+
+static int mv88e6352_serdes_irq_disable(struct mv88e6xxx_chip *chip)
+{
+	return mv88e6352_serdes_write(chip, MV88E6352_SERDES_INT_ENABLE, 0);
+}
+
+int mv88e6352_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port)
+{
+	int err;
+
+	if (!mv88e6352_port_has_serdes(chip, port))
+		return 0;
+
+	chip->ports[port].serdes_irq = irq_find_mapping(chip->g2_irq.domain,
+							MV88E6352_SERDES_IRQ);
+	if (chip->ports[port].serdes_irq < 0) {
+		dev_err(chip->dev, "Unable to map SERDES irq: %d\n",
+			chip->ports[port].serdes_irq);
+		return chip->ports[port].serdes_irq;
+	}
+
+	/* Requesting the IRQ will trigger irq callbacks. So we cannot
+	 * hold the reg_lock.
+	 */
+	mutex_unlock(&chip->reg_lock);
+	err = request_threaded_irq(chip->ports[port].serdes_irq, NULL,
+				   mv88e6352_serdes_thread_fn,
+				   IRQF_ONESHOT, "mv88e6xxx-serdes",
+				   &chip->ports[port]);
+	mutex_lock(&chip->reg_lock);
+
+	if (err) {
+		dev_err(chip->dev, "Unable to request SERDES interrupt: %d\n",
+			err);
+		return err;
+	}
+
+	return mv88e6352_serdes_irq_enable(chip);
+}
+
+void mv88e6352_serdes_irq_free(struct mv88e6xxx_chip *chip, int port)
+{
+	if (!mv88e6352_port_has_serdes(chip, port))
+		return;
+
+	mv88e6352_serdes_irq_disable(chip);
+
+	/* Freeing the IRQ will trigger irq callbacks. So we cannot
+	 * hold the reg_lock.
+	 */
+	mutex_unlock(&chip->reg_lock);
+	free_irq(chip->ports[port].serdes_irq, &chip->ports[port]);
+	mutex_lock(&chip->reg_lock);
+
+	chip->ports[port].serdes_irq = 0;
+}
+
 /* Return the SERDES lane address a port is using. Only Ports 9 and 10
  * have SERDES lanes. Returns -ENODEV if a port does not have a lane.
  */