phy: tegra: xusb: track whether the USB2 VBUS supply is enabled

- Remember if this port turned its VBUS regulator on
- Switching to host mode twice no longer enables it a second time, and
  switching to none no longer disables a regulator it never enabled
- Fixes the unbalanced regulator warnings on USB-C role changes

drivers/phy/tegra/xusb-tegra210.c

@@ -2167,7 +2167,10 @@ static int tegra210_usb2_phy_set_mode(struct phy *phy, enum phy_mode mode,
 		if (submode == USB_ROLE_HOST) {
 			tegra210_xusb_padctl_id_override(padctl, true);
 
-			err = regulator_enable(port->supply);
+			if (!port->supply_enabled) {
+				err = regulator_enable(port->supply);
+				port->supply_enabled = !err;
+			}
 		} else if (submode == USB_ROLE_DEVICE) {
 			tegra210_xusb_padctl_vbus_override(padctl, true);
 		} else if (submode == USB_ROLE_NONE) {
@@ -2176,8 +2179,10 @@ static int tegra210_usb2_phy_set_mode(struct phy *phy, enum phy_mode mode,
 			 * USB_ROLE_NONE from USB_ROLE_DEVICE, regulator is not
 			 * be enabled.
 			 */
-			if (regulator_is_enabled(port->supply))
+			if (port->supply_enabled) {
 				regulator_disable(port->supply);
+				port->supply_enabled = false;
+			}
 
 			tegra210_xusb_padctl_id_override(padctl, false);
 			tegra210_xusb_padctl_vbus_override(padctl, false);

drivers/phy/tegra/xusb.h

@@ -314,6 +314,7 @@ struct tegra_xusb_usb2_port {
 	struct tegra_xusb_port base;
 
 	struct regulator *supply;
+	bool supply_enabled;
 	enum usb_dr_mode mode;
 	bool internal;
 	int usb3_port_fake;