power: supply: bq25890: Add get_voltage support to Vbus regulator

The chip is capable of reporting Vbus voltage, add .get_voltage
implementation to Vbus regulator to report current Vbus voltage.
This requires for the Vbus regulator to be registered always
instead of the current state where the regulator is registered
only in case USB PHY is not found.

Do not provide Vbus regulator enable/disable ops in case USB PHY
is present, as they would race with USB PHY notifier which is also
used to toggle OTG boost mode.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/bq25890_charger.c

@@ -1095,10 +1095,18 @@ static int bq25890_vbus_is_enabled(struct regulator_dev *rdev)
 	return bq25890_field_read(bq, F_OTG_CFG);
 }
 
+static int bq25890_vbus_get_voltage(struct regulator_dev *rdev)
+{
+	struct bq25890_device *bq = rdev_get_drvdata(rdev);
+
+	return bq25890_get_vbus_voltage(bq);
+}
+
 static const struct regulator_ops bq25890_vbus_ops = {
 	.enable = bq25890_vbus_enable,
 	.disable = bq25890_vbus_disable,
 	.is_enabled = bq25890_vbus_is_enabled,
+	.get_voltage = bq25890_vbus_get_voltage,
 };
 
 static const struct regulator_desc bq25890_vbus_desc = {
@@ -1107,8 +1115,6 @@ static const struct regulator_desc bq25890_vbus_desc = {
 	.type = REGULATOR_VOLTAGE,
 	.owner = THIS_MODULE,
 	.ops = &bq25890_vbus_ops,
-	.fixed_uV = 5000000,
-	.n_voltages = 1,
 };
 
 static int bq25890_register_regulator(struct bq25890_device *bq)
@@ -1120,9 +1126,6 @@ static int bq25890_register_regulator(struct bq25890_device *bq)
 	};
 	struct regulator_dev *reg;
 
-	if (!IS_ERR_OR_NULL(bq->usb_phy))
-		return 0;
-
 	if (pdata)
 		cfg.init_data = pdata->regulator_init_data;