regulator: devres: remove devm_regulator_unregister() function

This API hook isn't used anywhere and most-likely exists because of the
general principle of C APIs, where if an API function does an
allocation/registration, it must also have an equivalent
deallocation/deregistration counterpart.

For devm_ functions this isn't all that true (for all cases), as the idea
of these function is to provide an auto-cleanup logic on drivers/system
de-init.

Removing this also discourages any weird logic that could be created with
such an API function.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210625122324.327585-3-aardelean@deviqon.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/devres.c

@@ -205,35 +205,6 @@ struct regulator_dev *devm_regulator_register(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_regulator_register);
 
-static int devm_rdev_match(struct device *dev, void *res, void *data)
-{
-	struct regulator_dev **r = res;
-	if (!r || !*r) {
-		WARN_ON(!r || !*r);
-		return 0;
-	}
-	return *r == data;
-}
-
-/**
- * devm_regulator_unregister - Resource managed regulator_unregister()
- * @dev:  device to supply
- * @rdev: regulator to free
- *
- * Unregister a regulator registered with devm_regulator_register().
- * Normally this function will not need to be called and the resource
- * management code will ensure that the resource is freed.
- */
-void devm_regulator_unregister(struct device *dev, struct regulator_dev *rdev)
-{
-	int rc;
-
-	rc = devres_release(dev, devm_rdev_release, devm_rdev_match, rdev);
-	if (rc != 0)
-		WARN_ON(rc);
-}
-EXPORT_SYMBOL_GPL(devm_regulator_unregister);
-
 struct regulator_supply_alias_match {
 	struct device *dev;
 	const char *id;

include/linux/regulator/driver.h

@@ -645,7 +645,6 @@ devm_regulator_register(struct device *dev,
 			const struct regulator_desc *regulator_desc,
 			const struct regulator_config *config);
 void regulator_unregister(struct regulator_dev *rdev);
-void devm_regulator_unregister(struct device *dev, struct regulator_dev *rdev);
 
 int regulator_notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data);