net: dsa: mv88e6xxx: implement mv88e6352_serdes_get_lane

Even though 88E6352 has no dedicated lane for SERDES interfaces, it
uses a similar code as the other .serdes_get_lane implementations to
check the port's CMODE and ensure that SERDES operations are doable.

For consistency, implement mv88e6352_serdes_get_lane for the 88E6352
and similar switches which simply returns an unused 0xff lane address.
Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -3093,6 +3093,7 @@ static const struct mv88e6xxx_ops mv88e6172_ops = {
 	.rmu_disable = mv88e6352_g1_rmu_disable,
 	.vtu_getnext = mv88e6352_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
+	.serdes_get_lane = mv88e6352_serdes_get_lane,
 	.serdes_power = mv88e6352_serdes_power,
 	.gpio_ops = &mv88e6352_gpio_ops,
 	.phylink_validate = mv88e6352_phylink_validate,
@@ -3178,6 +3179,7 @@ static const struct mv88e6xxx_ops mv88e6176_ops = {
 	.rmu_disable = mv88e6352_g1_rmu_disable,
 	.vtu_getnext = mv88e6352_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
+	.serdes_get_lane = mv88e6352_serdes_get_lane,
 	.serdes_power = mv88e6352_serdes_power,
 	.serdes_irq_mapping = mv88e6352_serdes_irq_mapping,
 	.serdes_irq_setup = mv88e6352_serdes_irq_setup,
@@ -3407,6 +3409,7 @@ static const struct mv88e6xxx_ops mv88e6240_ops = {
 	.rmu_disable = mv88e6352_g1_rmu_disable,
 	.vtu_getnext = mv88e6352_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
+	.serdes_get_lane = mv88e6352_serdes_get_lane,
 	.serdes_power = mv88e6352_serdes_power,
 	.serdes_irq_mapping = mv88e6352_serdes_irq_mapping,
 	.serdes_irq_setup = mv88e6352_serdes_irq_setup,
@@ -3767,6 +3770,7 @@ static const struct mv88e6xxx_ops mv88e6352_ops = {
 	.rmu_disable = mv88e6352_g1_rmu_disable,
 	.vtu_getnext = mv88e6352_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
+	.serdes_get_lane = mv88e6352_serdes_get_lane,
 	.serdes_power = mv88e6352_serdes_power,
 	.serdes_irq_mapping = mv88e6352_serdes_irq_mapping,
 	.serdes_irq_setup = mv88e6352_serdes_irq_setup,

drivers/net/dsa/mv88e6xxx/serdes.c

@@ -69,13 +69,22 @@ static int mv88e6352_serdes_power_set(struct mv88e6xxx_chip *chip, bool on)
 	return err;
 }
 
-static bool mv88e6352_port_has_serdes(struct mv88e6xxx_chip *chip, int port)
+u8 mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
+	u8 lane = 0;
 
 	if ((cmode == MV88E6XXX_PORT_STS_CMODE_100BASEX) ||
 	    (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX) ||
 	    (cmode == MV88E6XXX_PORT_STS_CMODE_SGMII))
+		lane = 0xff; /* Unused */
+
+	return lane;
+}
+
+static bool mv88e6352_port_has_serdes(struct mv88e6xxx_chip *chip, int port)
+{
+	if (mv88e6xxx_serdes_get_lane(chip, port))
 		return true;
 
 	return false;

drivers/net/dsa/mv88e6xxx/serdes.h

@@ -75,6 +75,7 @@
 #define MV88E6390_SGMII_PHY_STATUS_LINK		BIT(10)
 
 u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
+u8 mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
 u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
 u8 mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
 unsigned int mv88e6352_serdes_irq_mapping(struct mv88e6xxx_chip *chip,