diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 53d4fc70dbd0..462e6e679ce1 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1326,8 +1326,8 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 		regulator->dev = dev;
 
 		/* Add a link to the device sysfs entry */
-		size = scnprintf(buf, REG_STR_SIZE, "%s-%s",
-				 dev->kobj.name, supply_name);
+		size = snprintf(buf, REG_STR_SIZE, "%s-%s",
+				dev->kobj.name, supply_name);
 		if (size >= REG_STR_SIZE)
 			goto overflow_err;
 
@@ -1343,7 +1343,7 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 			/* non-fatal */
 		}
 	} else {
-		regulator->supply_name = kstrdup(supply_name, GFP_KERNEL);
+		regulator->supply_name = kstrdup_const(supply_name, GFP_KERNEL);
 		if (regulator->supply_name == NULL)
 			goto overflow_err;
 	}
@@ -1451,8 +1451,6 @@ static struct regulator_dev *regulator_lookup_by_name(const char *name)
  * regulator_dev_lookup - lookup a regulator device.
  * @dev: device for regulator "consumer".
  * @supply: Supply name or regulator ID.
- * @ret: 0 on success, -ENODEV if lookup fails permanently, -EPROBE_DEFER if
- * lookup could succeed in the future.
  *
  * If successful, returns a struct regulator_dev that corresponds to the name
  * @supply and with the embedded struct device refcount incremented by one.
@@ -1534,14 +1532,6 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 	if (IS_ERR(r)) {
 		ret = PTR_ERR(r);
 
-		if (ret == -ENODEV) {
-			/*
-			 * No supply was specified for this regulator and
-			 * there will never be one.
-			 */
-			return 0;
-		}
-
 		/* Did the lookup explicitly defer for us? */
 		if (ret == -EPROBE_DEFER)
 			return ret;
@@ -1799,7 +1789,7 @@ static void _regulator_put(struct regulator *regulator)
 	put_device(&rdev->dev);
 	mutex_unlock(&rdev->mutex);
 
-	kfree(regulator->supply_name);
+	kfree_const(regulator->supply_name);
 	kfree(regulator);
 
 	module_put(rdev->owner);
@@ -2486,7 +2476,7 @@ static int _regulator_list_voltage(struct regulator *regulator,
 		ret = ops->list_voltage(rdev, selector);
 		if (lock)
 			mutex_unlock(&rdev->mutex);
-	} else if (rdev->supply) {
+	} else if (rdev->is_switch && rdev->supply) {
 		ret = _regulator_list_voltage(rdev->supply, selector, lock);
 	} else {
 		return -EINVAL;
@@ -2544,7 +2534,7 @@ int regulator_count_voltages(struct regulator *regulator)
 	if (rdev->desc->n_voltages)
 		return rdev->desc->n_voltages;
 
-	if (!rdev->supply)
+	if (!rdev->is_switch || !rdev->supply)
 		return -EINVAL;
 
 	return regulator_count_voltages(rdev->supply);
@@ -2941,8 +2931,10 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
 	if (ret < 0)
 		goto out2;
 
-	if (rdev->supply && (rdev->desc->min_dropout_uV ||
-				!rdev->desc->ops->get_voltage)) {
+	if (rdev->supply &&
+	    regulator_ops_is_valid(rdev->supply->rdev,
+				   REGULATOR_CHANGE_VOLTAGE) &&
+	    (rdev->desc->min_dropout_uV || !rdev->desc->ops->get_voltage)) {
 		int current_supply_uV;
 		int selector;
 
@@ -4099,6 +4091,11 @@ regulator_register(const struct regulator_desc *regulator_desc,
 		mutex_unlock(&regulator_list_mutex);
 	}
 
+	if (!rdev->desc->ops->get_voltage &&
+	    !rdev->desc->ops->list_voltage &&
+	    !rdev->desc->fixed_uV)
+		rdev->is_switch = true;
+
 	ret = device_register(&rdev->dev);
 	if (ret != 0) {
 		put_device(&rdev->dev);
diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index 1dd575b28564..66a8ea0c8386 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -29,7 +29,7 @@ struct regulator {
 	int uA_load;
 	int min_uV;
 	int max_uV;
-	char *supply_name;
+	const char *supply_name;
 	struct device_attribute dev_attr;
 	struct regulator_dev *rdev;
 	struct dentry *debugfs;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index dac8e7b16bc6..4cb1c9be6073 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -429,6 +429,8 @@ struct regulator_dev {
 	struct regulator_enable_gpio *ena_pin;
 	unsigned int ena_gpio_state:1;
 
+	unsigned int is_switch:1;
+
 	/* time when this regulator was disabled last time */
 	unsigned long last_off_jiffy;
 };