Use devm_kzalloc(), devm_kasprintf(), and devm_power_supply_register()
to let the driver core handle resource cleanup. This allows removing
the mfi_fc_disconnect() function and the error labels in probe.

Also take the opportunity to shrink the private struct and move the
variables in probe as devm doesn't need them in the struct.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/usb/misc/apple-mfi-fastcharge.c | 61 ++++++-------------------
 1 file changed, 13 insertions(+), 48 deletions(-)

diff --git a/drivers/usb/misc/apple-mfi-fastcharge.c b/drivers/usb/misc/apple-mfi-fastcharge.c
index af266e19f2fd..c1064f672d6d 100644
--- a/drivers/usb/misc/apple-mfi-fastcharge.c
+++ b/drivers/usb/misc/apple-mfi-fastcharge.c
@@ -43,8 +43,6 @@ MODULE_DEVICE_TABLE(usb, mfi_fc_id_table);
 /* Driver-local specific stuff */
 struct mfi_device {
 	struct usb_device *udev;
-	struct power_supply *battery;
-	struct power_supply_desc battery_desc;
 	int charge_type;
 };
 
@@ -177,67 +175,34 @@ static bool mfi_fc_match(struct usb_device *udev)
 static int mfi_fc_probe(struct usb_device *udev)
 {
 	struct power_supply_config battery_cfg = {};
-	struct mfi_device *mfi = NULL;
-	char *battery_name;
-	int err;
-
-	if (!mfi_fc_match(udev))
-		return -ENODEV;
+	struct power_supply_desc battery_desc;
+	struct power_supply *battery;
+	struct mfi_device *mfi;
 
-	mfi = kzalloc_obj(struct mfi_device);
+	mfi = devm_kzalloc(&udev->dev, sizeof(*mfi), GFP_KERNEL);
 	if (!mfi)
 		return -ENOMEM;
 
-	battery_name = kasprintf(GFP_KERNEL, "apple_mfi_fastcharge_%d-%d",
-				 udev->bus->busnum, udev->devnum);
-	if (!battery_name) {
-		err = -ENOMEM;
-		goto err_free_mfi;
-	}
-
-	mfi->battery_desc = apple_mfi_fc_desc;
-	mfi->battery_desc.name = battery_name;
+	battery_desc = apple_mfi_fc_desc;
+	battery_desc.name = devm_kasprintf(&udev->dev, GFP_KERNEL,
+						"apple_mfi_fastcharge_%d-%d",
+						udev->bus->busnum,
+						udev->devnum);
+	if (!battery_desc.name)
+		return -ENOMEM;
 
 	battery_cfg.drv_data = mfi;
 
 	mfi->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
-	mfi->battery = power_supply_register(&udev->dev,
-						&mfi->battery_desc,
-						&battery_cfg);
-	if (IS_ERR(mfi->battery)) {
-		dev_err(&udev->dev, "Can't register battery\n");
-		err = PTR_ERR(mfi->battery);
-		goto err_free_name;
-	}
-
 	mfi->udev = udev;
-	dev_set_drvdata(&udev->dev, mfi);
-
-	return 0;
-
-err_free_name:
-	kfree(battery_name);
-err_free_mfi:
-	kfree(mfi);
-	return err;
-}
-
-static void mfi_fc_disconnect(struct usb_device *udev)
-{
-	struct mfi_device *mfi;
 
-	mfi = dev_get_drvdata(&udev->dev);
-	if (mfi->battery)
-		power_supply_unregister(mfi->battery);
-	kfree(mfi->battery_desc.name);
-	dev_set_drvdata(&udev->dev, NULL);
-	kfree(mfi);
+	battery = devm_power_supply_register(&udev->dev, &battery_desc, &battery_cfg);
+	return PTR_ERR_OR_ZERO(battery);
 }
 
 static struct usb_device_driver mfi_fc_driver = {
 	.name =		"apple-mfi-fastcharge",
 	.probe =	mfi_fc_probe,
-	.disconnect =	mfi_fc_disconnect,
 	.id_table =	mfi_fc_id_table,
 	.match =	mfi_fc_match,
 	.generic_subclass = 1,
-- 
2.54.0