net: phy: marvell: fix detection of PHY on Topaz switches

commit 1fe976d308acb6374c899a4ee8025a0a016e453e upstream.

Since commit fee2d546414d ("net: phy: marvell: mv88e6390 temperature
sensor reading"), Linux reports the temperature of Topaz hwmon as
constant -75°C.

This is because switches from the Topaz family (88E6141 / 88E6341) have
the address of the temperature sensor register different from Peridot.

This address is instead compatible with 88E1510 PHYs, as was used for
Topaz before the above mentioned commit.

Create a new mapping table between switch family and PHY ID for families
which don't have a model number. And define PHY IDs for Topaz and Peridot
families.

Create a new PHY ID and a new PHY driver for Topaz's internal PHY.
The only difference from Peridot's PHY driver is the HWMON probing
method.

Prior this change Topaz's internal PHY is detected by kernel as:

  PHY [...] driver [Marvell 88E6390] (irq=63)

And afterwards as:

  PHY [...] driver [Marvell 88E6341 Family] (irq=63)

Signed-off-by: Pali Rohár <pali@kernel.org>
BugLink: https://github.com/globalscaletechnologies/linux/issues/1
Fixes: fee2d546414d ("net: phy: marvell: mv88e6390 temperature sensor reading")
Reviewed-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 17 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index e04b7fa068af..67c0ad3b8079 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2634,10 +2634,17 @@ unlock:
 	return err;
 }
 
+/* prod_id for switch families which do not have a PHY model number */
+static const u16 family_prod_id_table[] = {
+	[MV88E6XXX_FAMILY_6341] = MV88E6XXX_PORT_SWITCH_ID_PROD_6341,
+	[MV88E6XXX_FAMILY_6390] = MV88E6XXX_PORT_SWITCH_ID_PROD_6390,
+};
+
 static int mv88e6xxx_mdio_read(struct mii_bus *bus, int phy, int reg)
 {
 	struct mv88e6xxx_mdio_bus *mdio_bus = bus->priv;
 	struct mv88e6xxx_chip *chip = mdio_bus->chip;
+	u16 prod_id;
 	u16 val;
 	int err;
 
@@ -2648,23 +2655,12 @@ static int mv88e6xxx_mdio_read(struct mii_bus *bus, int phy, int reg)
 	err = chip->info->ops->phy_read(chip, bus, phy, reg, &val);
 	mutex_unlock(&chip->reg_lock);
 
-	if (reg == MII_PHYSID2) {
-		/* Some internal PHYs don't have a model number. */
-		if (chip->info->family != MV88E6XXX_FAMILY_6165)
-			/* Then there is the 6165 family. It gets is
-			 * PHYs correct. But it can also have two
-			 * SERDES interfaces in the PHY address
-			 * space. And these don't have a model
-			 * number. But they are not PHYs, so we don't
-			 * want to give them something a PHY driver
-			 * will recognise.
-			 *
-			 * Use the mv88e6390 family model number
-			 * instead, for anything which really could be
-			 * a PHY,
-			 */
-			if (!(val & 0x3f0))
-				val |= MV88E6XXX_PORT_SWITCH_ID_PROD_6390 >> 4;
+	/* Some internal PHYs don't have a model number. */
+	if (reg == MII_PHYSID2 && !(val & 0x3f0) &&
+	    chip->info->family < ARRAY_SIZE(family_prod_id_table)) {
+		prod_id = family_prod_id_table[chip->info->family];
+		if (prod_id)
+			val |= prod_id >> 4;
 	}
 
 	return err ? err : val;