net: dsa: mv88e6xxx: Allow PCS registers to be retrieved via ethtool

ethtool provides a generic mechanism for a driver to return the
registers of an ethernet device. DSA uses this to give the port
registers associated with an interfaces. Extend this to allow PCS
registers to also be returned, if the port has a PCS associated to it.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -1018,7 +1018,14 @@ static void mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds, int port,
 
 static int mv88e6xxx_get_regs_len(struct dsa_switch *ds, int port)
 {
-	return 32 * sizeof(u16);
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int len;
+
+	len = 32 * sizeof(u16);
+	if (chip->info->ops->serdes_get_regs_len)
+		len += chip->info->ops->serdes_get_regs_len(chip, port);
+
+	return len;
 }
 
 static void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,
@@ -1043,6 +1050,9 @@ static void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,
 			p[i] = reg;
 	}
 
+	if (chip->info->ops->serdes_get_regs)
+		chip->info->ops->serdes_get_regs(chip, port, &p[i]);
+
 	mv88e6xxx_reg_unlock(chip);
 }
 

drivers/net/dsa/mv88e6xxx/chip.h

@@ -517,6 +517,11 @@ struct mv88e6xxx_ops {
 	int (*serdes_get_stats)(struct mv88e6xxx_chip *chip,  int port,
 				uint64_t *data);
 
+	/* SERDES registers for ethtool */
+	int (*serdes_get_regs_len)(struct mv88e6xxx_chip *chip,  int port);
+	void (*serdes_get_regs)(struct mv88e6xxx_chip *chip, int port,
+				void *_p);
+
 	/* Address Translation Unit operations */
 	int (*atu_get_hash)(struct mv88e6xxx_chip *chip, u8 *hash);
 	int (*atu_set_hash)(struct mv88e6xxx_chip *chip, u8 hash);