net: dsa: mv88e6xxx: introduce invalid_port_mask in mv88e6xxx_info

With this it is possible to mark certain chip ports as invalid. This is
required for example for the MV88E6220 (which is in general a MV88E6250
with 7 ports) but the ports 2-4 are not routed to pins.

If a user configures an invalid port, an error is returned.
Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -2485,6 +2485,14 @@ static int mv88e6xxx_setup(struct dsa_switch *ds)
 
 	/* Setup Switch Port Registers */
 	for (i = 0; i < mv88e6xxx_num_ports(chip); i++) {
+		/* Prevent the use of an invalid port. */
+		if (mv88e6xxx_is_invalid_port(chip, i) &&
+		    !dsa_is_unused_port(ds, i)) {
+			dev_err(chip->dev, "port %d is invalid\n", i);
+			err = -EINVAL;
+			goto unlock;
+		}
+
 		if (dsa_is_unused_port(ds, i)) {
 			err = mv88e6xxx_port_set_state(chip, i,
 						       BR_STATE_DISABLED);
@@ -4286,6 +4294,7 @@ static const struct mv88e6xxx_info mv88e6xxx_table[] = {
 		 */
 		.num_ports = 7,
 		.num_internal_phys = 2,
+		.invalid_port_mask = BIT(2) | BIT(3) | BIT(4),
 		.max_vid = 4095,
 		.port_base_addr = 0x08,
 		.phy_base_addr = 0x00,

drivers/net/dsa/mv88e6xxx/chip.h

@@ -106,6 +106,11 @@ struct mv88e6xxx_info {
 	unsigned int g2_irqs;
 	bool pvt;
 
+	/* Mark certain ports as invalid. This is required for example for the
+	 * MV88E6220 (which is in general a MV88E6250 with 7 ports) but the
+	 * ports 2-4 are not routet to pins.
+	 */
+	unsigned int invalid_port_mask;
 	/* Multi-chip Addressing Mode.
 	 * Some chips respond to only 2 registers of its own SMI device address
 	 * when it is non-zero, and use indirect access to internal registers.
@@ -571,6 +576,11 @@ static inline unsigned int mv88e6xxx_num_gpio(struct mv88e6xxx_chip *chip)
 	return chip->info->num_gpio;
 }
 
+static inline bool mv88e6xxx_is_invalid_port(struct mv88e6xxx_chip *chip, int port)
+{
+	return (chip->info->invalid_port_mask & BIT(port)) != 0;
+}
+
 int mv88e6xxx_read(struct mv88e6xxx_chip *chip, int addr, int reg, u16 *val);
 int mv88e6xxx_write(struct mv88e6xxx_chip *chip, int addr, int reg, u16 val);
 int mv88e6xxx_update(struct mv88e6xxx_chip *chip, int addr, int reg,