usb: misc: usb3503: refactor code to prepare for usb3803 addition

Refactor code to simplify adding support for USB3803 and bypass mode.

Remove static usb3503_reset() and move it to usb3503_switch_mode(),
with the addition of the bypass mode we need to drive the various
control signals to the expected configuration, not just to
assert/release the reset.

In addition to that the usb3503_connect() needs to be called only
for HUB mode.

No functional changes expected nor intended because of this change.
Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20230313165039.255579-3-francesco@dolcini.itSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/usb3503.c

@@ -52,28 +52,11 @@ struct usb3503 {
 	bool	secondary_ref_clk;
 };
 
-static int usb3503_reset(struct usb3503 *hub, int state)
-{
-	if (!state && hub->connect)
-		gpiod_set_value_cansleep(hub->connect, 0);
-
-	if (hub->reset)
-		gpiod_set_value_cansleep(hub->reset, !state);
-
-	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
-	if (state)
-		usleep_range(4000, 10000);
-
-	return 0;
-}
-
 static int usb3503_connect(struct usb3503 *hub)
 {
 	struct device *dev = hub->dev;
 	int err;
 
-	usb3503_reset(hub, 1);
-
 	if (hub->regmap) {
 		/* SP_ILOCK: set connect_n, config_n for config */
 		err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
@@ -126,25 +109,36 @@ static int usb3503_connect(struct usb3503 *hub)
 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
 {
 	struct device *dev = hub->dev;
-	int err = 0;
+	int rst, conn;
 
 	switch (mode) {
 	case USB3503_MODE_HUB:
-		err = usb3503_connect(hub);
+		conn = 1;
+		rst = 0;
 		break;
-
 	case USB3503_MODE_STANDBY:
-		usb3503_reset(hub, 0);
+		conn = 0;
+		rst = 1;
 		dev_info(dev, "switched to STANDBY mode\n");
 		break;
-
 	default:
 		dev_err(dev, "unknown mode is requested\n");
-		err = -EINVAL;
-		break;
+		return -EINVAL;
 	}
 
-	return err;
+	if (!conn && hub->connect)
+		gpiod_set_value_cansleep(hub->connect, 0);
+
+	if (hub->reset)
+		gpiod_set_value_cansleep(hub->reset, rst);
+
+	if (conn) {
+		/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
+		usleep_range(4000, 10000);
+		return usb3503_connect(hub);
+	}
+
+	return 0;
 }
 
 static const struct regmap_config usb3503_regmap_config = {