net: dsa: mv88e6xxx: Add serdes interrupt support for MV88E6097

The MV88E6097 presents the serdes interrupts for ports 8 and 9 via the
Switch Global 2 registers. There is no additional layer of
enablinh/disabling the serdes interrupts like other mv88e6xxx switches.
Even though most of the serdes behaviour is the same as the MV88E6185
that chip does not provide interrupts for serdes events so unlike
earlier commits the functions added here are specific to the MV88E6097.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -3308,6 +3308,9 @@ static const struct mv88e6xxx_ops mv88e6097_ops = {
 	.serdes_power = mv88e6185_serdes_power,
 	.serdes_get_lane = mv88e6185_serdes_get_lane,
 	.serdes_pcs_get_state = mv88e6185_serdes_pcs_get_state,
+	.serdes_irq_mapping = mv88e6390_serdes_irq_mapping,
+	.serdes_irq_enable = mv88e6097_serdes_irq_enable,
+	.serdes_irq_status = mv88e6097_serdes_irq_status,
 	.pot_clear = mv88e6xxx_g2_pot_clear,
 	.reset = mv88e6352_g1_reset,
 	.rmu_disable = mv88e6085_g1_rmu_disable,

drivers/net/dsa/mv88e6xxx/serdes.c

@@ -490,6 +490,53 @@ int mv88e6185_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 	return 0;
 }
 
+int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+				bool enable)
+{
+	u8 cmode = chip->ports[port].cmode;
+
+	/* The serdes interrupts are enabled in the G2_INT_MASK register. We
+	 * need to return 0 to avoid returning -EOPNOTSUPP in
+	 * mv88e6xxx_serdes_irq_enable/mv88e6xxx_serdes_irq_disable
+	 */
+	switch (cmode) {
+	case MV88E6185_PORT_STS_CMODE_SERDES:
+	case MV88E6185_PORT_STS_CMODE_1000BASE_X:
+		return 0;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static void mv88e6097_serdes_irq_link(struct mv88e6xxx_chip *chip, int port)
+{
+	u16 status;
+	int err;
+
+	err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_STS, &status);
+	if (err) {
+		dev_err(chip->dev, "can't read port status: %d\n", err);
+		return;
+	}
+
+	dsa_port_phylink_mac_change(chip->ds, port, !!(status & MV88E6XXX_PORT_STS_LINK));
+}
+
+irqreturn_t mv88e6097_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
+					u8 lane)
+{
+	u8 cmode = chip->ports[port].cmode;
+
+	switch (cmode) {
+	case MV88E6185_PORT_STS_CMODE_SERDES:
+	case MV88E6185_PORT_STS_CMODE_1000BASE_X:
+		mv88e6097_serdes_irq_link(chip, port);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
 u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;

drivers/net/dsa/mv88e6xxx/serdes.h

@@ -110,10 +110,14 @@ int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 			   bool on);
 int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 			   bool on);
+int mv88e6097_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
+				bool enable);
 int mv88e6352_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
 				bool enable);
 int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port, u8 lane,
 				bool enable);
+irqreturn_t mv88e6097_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
+					u8 lane);
 irqreturn_t mv88e6352_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
 					u8 lane);
 irqreturn_t mv88e6390_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,