net: dsa: mv88e6xxx: simplify .serdes_get_lane

Because the mapping between a SERDES interface and its lane is static,
we don't need to stick with negative error codes actually and we can
simply return 0 if there is no lane, just like the IRQ mapping.

This way we can keep a simple and intuitive API using unsigned lane
numbers while simplifying the implementations with single return
statements. Last but not least, fix the reverse chrismas tree in
mv88e6390x_serdes_get_lane.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 74 insertions, 122 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index b116bd7f6109..add0ec5188ec 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -444,7 +444,7 @@ struct mv88e6xxx_ops {
 	int (*serdes_power)(struct mv88e6xxx_chip *chip, int port, bool on);
 
 	/* SERDES lane mapping */
-	int (*serdes_get_lane)(struct mv88e6xxx_chip *chip, int port, u8 *lane);
+	u8 (*serdes_get_lane)(struct mv88e6xxx_chip *chip, int port);
 
 	/* SERDES interrupt handling */
 	unsigned int (*serdes_irq_mapping)(struct mv88e6xxx_chip *chip,
diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c
index 4f841335ea32..06e2bdf6fa82 100644
--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -431,11 +431,8 @@ static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 	if (cmode == chip->ports[port].cmode)
 		return 0;
 
-	err = mv88e6xxx_serdes_get_lane(chip, port, &lane);
-	if (err && err != -ENODEV)
-		return err;
-
-	if (err != -ENODEV) {
+	lane = mv88e6xxx_serdes_get_lane(chip, port);
+	if (lane) {
 		if (chip->ports[port].serdes_irq) {
 			err = mv88e6390_serdes_irq_disable(chip, port, lane);
 			if (err)
@@ -463,9 +460,9 @@ static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
 
 		chip->ports[port].cmode = cmode;
 
-		err = mv88e6xxx_serdes_get_lane(chip, port, &lane);
-		if (err)
-			return err;
+		lane = mv88e6xxx_serdes_get_lane(chip, port);
+		if (!lane)
+			return -ENODEV;
 
 		err = mv88e6390_serdes_power(chip, port, true);
 		if (err)
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 4fb1dca64ef1..ce6d97e5caf8 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -295,149 +295,119 @@ void mv88e6352_serdes_irq_free(struct mv88e6xxx_chip *chip, int port)
 	chip->ports[port].serdes_irq = 0;
 }
 
-int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane)
+u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
+	u8 lane = 0;
 
-	if (port != 5)
-		return -ENODEV;
-
-	if (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
-	    cmode == MV88E6XXX_PORT_STS_CMODE_SGMII ||
-	    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX) {
-		*lane = MV88E6341_PORT5_LANE;
-		return 0;
+	switch (port) {
+	case 5:
+		if (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
+		    cmode == MV88E6XXX_PORT_STS_CMODE_SGMII ||
+		    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			lane = MV88E6341_PORT5_LANE;
+		break;
 	}
 
-	return -ENODEV;
+	return lane;
 }
 
-int mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane)
+u8 mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
 	u8 cmode = chip->ports[port].cmode;
+	u8 lane = 0;
 
 	switch (port) {
 	case 9:
 		if (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode == MV88E6XXX_PORT_STS_CMODE_SGMII ||
-		    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX) {
-			*lane = MV88E6390_PORT9_LANE0;
-			return 0;
-		}
+		    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			lane = MV88E6390_PORT9_LANE0;
 		break;
 	case 10:
 		if (cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode == MV88E6XXX_PORT_STS_CMODE_SGMII ||
-		    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX) {
-			*lane = MV88E6390_PORT10_LANE0;
-			return 0;
-		}
-		break;
-	default:
+		    cmode == MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			lane = MV88E6390_PORT10_LANE0;
 		break;
 	}
 
-	return -ENODEV;
+	return lane;
 }
 
-int mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane)
+u8 mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 {
-	u8 cmode_port9, cmode_port10, cmode_port;
-
-	cmode_port9 = chip->ports[9].cmode;
-	cmode_port10 = chip->ports[10].cmode;
-	cmode_port = chip->ports[port].cmode;
+	u8 cmode_port = chip->ports[port].cmode;
+	u8 cmode_port10 = chip->ports[10].cmode;
+	u8 cmode_port9 = chip->ports[9].cmode;
+	u8 lane = 0;
 
 	switch (port) {
 	case 2:
 		if (cmode_port9 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
-		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_2500BASEX) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT9_LANE1;
-				return 0;
-			}
-		}
+		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT9_LANE1;
 		break;
 	case 3:
 		if (cmode_port9 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
-		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT9_LANE2;
-				return 0;
-			}
-		}
+		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT9_LANE2;
 		break;
 	case 4:
 		if (cmode_port9 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
-		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT9_LANE3;
-				return 0;
-			}
-		}
+		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT9_LANE3;
 		break;
 	case 5:
 		if (cmode_port10 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
-		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_2500BASEX) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT10_LANE1;
-				return 0;
-			}
-		}
+		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_2500BASEX)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT10_LANE1;
 		break;
 	case 6:
 		if (cmode_port10 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
-		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT10_LANE2;
-				return 0;
-			}
-		}
+		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT10_LANE2;
 		break;
 	case 7:
 		if (cmode_port10 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
-		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX) {
-				*lane = MV88E6390_PORT10_LANE3;
-				return 0;
-			}
-		}
+		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			if (cmode_port == MV88E6XXX_PORT_STS_CMODE_1000BASEX)
+				lane = MV88E6390_PORT10_LANE3;
 		break;
 	case 9:
 		if (cmode_port9 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
 		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_XAUI ||
-		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			*lane = MV88E6390_PORT9_LANE0;
-			return 0;
-		}
+		    cmode_port9 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			lane = MV88E6390_PORT9_LANE0;
 		break;
 	case 10:
 		if (cmode_port10 == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_SGMII ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_2500BASEX ||
 		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_XAUI ||
-		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI) {
-			*lane = MV88E6390_PORT10_LANE0;
-			return 0;
-		}
-		break;
-	default:
+		    cmode_port10 == MV88E6XXX_PORT_STS_CMODE_RXAUI)
+			lane = MV88E6390_PORT10_LANE0;
 		break;
 	}
 
-	return -ENODEV;
+	return lane;
 }
 
 /* Set the power on/off for 10GBASE-R and 10GBASE-X4/X2 */
@@ -497,14 +467,10 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on)
 {
 	u8 cmode = chip->ports[port].cmode;
 	u8 lane;
-	int err;
 
-	err = mv88e6xxx_serdes_get_lane(chip, port, &lane);
-	if (err) {
-		if (err == -ENODEV)
-			err = 0;
-		return err;
-	}
+	lane = mv88e6xxx_serdes_get_lane(chip, port);
+	if (!lane)
+		return 0;
 
 	switch (cmode) {
 	case MV88E6XXX_PORT_STS_CMODE_SGMII:
@@ -657,8 +623,8 @@ static irqreturn_t mv88e6390_serdes_thread_fn(int irq, void *dev_id)
 
 	mv88e6xxx_reg_lock(chip);
 
-	err = mv88e6xxx_serdes_get_lane(chip, port->port, &lane);
-	if (err)
+	lane = mv88e6xxx_serdes_get_lane(chip, port->port);
+	if (!lane)
 		goto out;
 
 	switch (cmode) {
@@ -691,12 +657,9 @@ int mv88e6390_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port)
 	int err;
 	u8 lane;
 
-	err = mv88e6xxx_serdes_get_lane(chip, port, &lane);
-	if (err) {
-		if (err == -ENODEV)
-			err = 0;
-		return err;
-	}
+	lane = mv88e6xxx_serdes_get_lane(chip, port);
+	if (!lane)
+		return 0;
 
 	irq = mv88e6xxx_serdes_irq_mapping(chip, port);
 	if (!irq)
@@ -725,16 +688,11 @@ int mv88e6390_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port)
 
 void mv88e6390_serdes_irq_free(struct mv88e6xxx_chip *chip, int port)
 {
-	int err;
 	u8 lane;
 
-	err = mv88e6xxx_serdes_get_lane(chip, port, &lane);
-	if (err) {
-		if (err != -ENODEV)
-			dev_err(chip->dev, "Unable to free SERDES irq: %d\n",
-				err);
+	lane = mv88e6xxx_serdes_get_lane(chip, port);
+	if (!lane)
 		return;
-	}
 
 	mv88e6390_serdes_irq_disable(chip, port, lane);
 
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index cb8d287c9388..4718dcca6b3c 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -74,22 +74,9 @@
 #define MV88E6390_SGMII_PHY_STATUS_SPD_DPL_VALID BIT(11)
 #define MV88E6390_SGMII_PHY_STATUS_LINK		BIT(10)
 
-/* Put the SERDES lane address a port is using into *lane. If a port has
- * multiple lanes, should put the first lane the port is using. If a port does
- * not have a lane, return -ENODEV.
- */
-static inline int mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip,
-					    int port, u8 *lane)
-{
-	if (!chip->info->ops->serdes_get_lane)
-		return -EOPNOTSUPP;
-
-	return chip->info->ops->serdes_get_lane(chip, port, lane);
-}
-
-int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane);
-int mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane);
-int mv88e6390x_serdes_get_lane(struct mv88e6xxx_chip *chip, int port, u8 *lane);
+u8 mv88e6341_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,
 					  int port);
 unsigned int mv88e6390_serdes_irq_mapping(struct mv88e6xxx_chip *chip,
@@ -110,6 +97,16 @@ int mv88e6390_serdes_irq_disable(struct mv88e6xxx_chip *chip, int port,
 int mv88e6352_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port);
 void mv88e6352_serdes_irq_free(struct mv88e6xxx_chip *chip, int port);
 
+/* Return the (first) SERDES lane address a port is using, 0 otherwise. */
+static inline u8 mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip,
+					   int port)
+{
+	if (!chip->info->ops->serdes_get_lane)
+		return 0;
+
+	return chip->info->ops->serdes_get_lane(chip, port);
+}
+
 static inline unsigned int
 mv88e6xxx_serdes_irq_mapping(struct mv88e6xxx_chip *chip, int port)
 {