net: dsa: mv88e6xxx: add helper to hardware reset

Add an helper to toggle the eventual GPIO connected to the reset pin.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -2356,6 +2356,19 @@ static void mv88e6xxx_port_bridge_leave(struct dsa_switch *ds, int port)
 	mutex_unlock(&chip->reg_lock);
 }
 
+static void mv88e6xxx_hardware_reset(struct mv88e6xxx_chip *chip)
+{
+	struct gpio_desc *gpiod = chip->reset;
+
+	/* If there is a GPIO connected to the reset pin, toggle it */
+	if (gpiod) {
+		gpiod_set_value_cansleep(gpiod, 1);
+		usleep_range(10000, 20000);
+		gpiod_set_value_cansleep(gpiod, 0);
+		usleep_range(10000, 20000);
+	}
+}
+
 static int mv88e6xxx_disable_ports(struct mv88e6xxx_chip *chip)
 {
 	int i, err;
@@ -2380,7 +2393,6 @@ static int mv88e6xxx_switch_reset(struct mv88e6xxx_chip *chip)
 {
 	bool ppu_active = mv88e6xxx_has(chip, MV88E6XXX_FLAG_PPU_ACTIVE);
 	u16 is_reset = (ppu_active ? 0x8800 : 0xc800);
-	struct gpio_desc *gpiod = chip->reset;
 	unsigned long timeout;
 	u16 reg;
 	int err;
@@ -2389,13 +2401,7 @@ static int mv88e6xxx_switch_reset(struct mv88e6xxx_chip *chip)
 	if (err)
 		return err;
 
-	/* If there is a gpio connected to the reset pin, toggle it */
-	if (gpiod) {
-		gpiod_set_value_cansleep(gpiod, 1);
-		usleep_range(10000, 20000);
-		gpiod_set_value_cansleep(gpiod, 0);
-		usleep_range(10000, 20000);
-	}
+	mv88e6xxx_hardware_reset(chip);
 
 	/* Reset the switch. Keep the PPU active if requested. The PPU
 	 * needs to be active to support indirect phy register access