power: supply: bq25890: Add support for registering the Vbus boost converter as a regulator

The bq25890_charger code supports enabling/disabling the boost converter
based on usb-phy notifications. But the usb-phy framework is not used on
all boards/platforms. At support for registering the Vbus boost converter
as a standard regulator when there is no usb-phy on the board.

Also add support for providing regulator_init_data through platform_data
for use on boards where device-tree is not used and the platform code must
thus provide the regulator_init_data.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/bq25890_charger.c

@@ -8,7 +8,9 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/power_supply.h>
+#include <linux/power/bq25890_charger.h>
 #include <linux/regmap.h>
+#include <linux/regulator/driver.h>
 #include <linux/types.h>
 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
@@ -876,6 +878,45 @@ static int bq25890_usb_notifier(struct notifier_block *nb, unsigned long val,
 	return NOTIFY_OK;
 }
 
+#ifdef CONFIG_REGULATOR
+static int bq25890_vbus_enable(struct regulator_dev *rdev)
+{
+	struct bq25890_device *bq = rdev_get_drvdata(rdev);
+
+	return bq25890_set_otg_cfg(bq, 1);
+}
+
+static int bq25890_vbus_disable(struct regulator_dev *rdev)
+{
+	struct bq25890_device *bq = rdev_get_drvdata(rdev);
+
+	return bq25890_set_otg_cfg(bq, 0);
+}
+
+static int bq25890_vbus_is_enabled(struct regulator_dev *rdev)
+{
+	struct bq25890_device *bq = rdev_get_drvdata(rdev);
+
+	return bq25890_field_read(bq, F_OTG_CFG);
+}
+
+static const struct regulator_ops bq25890_vbus_ops = {
+	.enable = bq25890_vbus_enable,
+	.disable = bq25890_vbus_disable,
+	.is_enabled = bq25890_vbus_is_enabled,
+};
+
+static const struct regulator_desc bq25890_vbus_desc = {
+	.name = "usb_otg_vbus",
+	.of_match = "usb-otg-vbus",
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+	.ops = &bq25890_vbus_ops,
+	.fixed_uV = 5000000,
+	.n_voltages = 1,
+};
+#endif
+
 static int bq25890_get_chip_version(struct bq25890_device *bq)
 {
 	int id, rev;
@@ -1075,6 +1116,22 @@ static int bq25890_probe(struct i2c_client *client,
 		bq->usb_nb.notifier_call = bq25890_usb_notifier;
 		usb_register_notifier(bq->usb_phy, &bq->usb_nb);
 	}
+#ifdef CONFIG_REGULATOR
+	else {
+		struct bq25890_platform_data *pdata = dev_get_platdata(dev);
+		struct regulator_config cfg = { };
+		struct regulator_dev *reg;
+
+		cfg.dev = dev;
+		cfg.driver_data = bq;
+		if (pdata)
+			cfg.init_data = pdata->regulator_init_data;
+
+		reg = devm_regulator_register(dev, &bq25890_vbus_desc, &cfg);
+		if (IS_ERR(reg))
+			return dev_err_probe(dev, PTR_ERR(reg), "registering regulator");
+	}
+#endif
 
 	ret = bq25890_power_supply_init(bq);
 	if (ret < 0) {
@@ -1113,6 +1170,28 @@ static int bq25890_remove(struct i2c_client *client)
 	return 0;
 }
 
+static void bq25890_shutdown(struct i2c_client *client)
+{
+	struct bq25890_device *bq = i2c_get_clientdata(client);
+
+	/*
+	 * TODO this if + return should probably be removed, but that would
+	 * introduce a function change for boards using the usb-phy framework.
+	 * This needs to be tested on such a board before making this change.
+	 */
+	if (!IS_ERR_OR_NULL(bq->usb_phy))
+		return;
+
+	/*
+	 * Turn off the 5v Boost regulator which outputs Vbus to the device's
+	 * Micro-USB or Type-C USB port. Leaving this on drains power and
+	 * this avoids the PMIC on some device-models seeing this as Vbus
+	 * getting inserted after shutdown, causing the device to immediately
+	 * power-up again.
+	 */
+	bq25890_set_otg_cfg(bq, 0);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int bq25890_suspend(struct device *dev)
 {
@@ -1192,6 +1271,7 @@ static struct i2c_driver bq25890_driver = {
 	},
 	.probe = bq25890_probe,
 	.remove = bq25890_remove,
+	.shutdown = bq25890_shutdown,
 	.id_table = bq25890_i2c_ids,
 };
 module_i2c_driver(bq25890_driver);

include/linux/power/bq25890_charger.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Platform data for the TI bq25890 battery charger driver.
+ */
+
+#ifndef _BQ25890_CHARGER_H_
+#define _BQ25890_CHARGER_H_
+
+struct regulator_init_data;
+
+struct bq25890_platform_data {
+	const struct regulator_init_data *regulator_init_data;
+};
+
+#endif