1 files changed, 515 insertions, 258 deletions

diff --git a/kernel/drivers/regulator/core.c b/kernel/drivers/regulator/core.c
index 8a28116b5..73b768335 100644
--- a/kernel/drivers/regulator/core.c
+++ b/kernel/drivers/regulator/core.c
@@ -51,7 +51,6 @@
 	pr_debug("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
 
 static DEFINE_MUTEX(regulator_list_mutex);
-static LIST_HEAD(regulator_list);
 static LIST_HEAD(regulator_map_list);
 static LIST_HEAD(regulator_ena_gpio_list);
 static LIST_HEAD(regulator_supply_alias_list);
@@ -59,6 +58,8 @@ static bool has_full_constraints;
 
 static struct dentry *debugfs_root;
 
+static struct class regulator_class;
+
 /*
  * struct regulator_map
  *
@@ -109,6 +110,12 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 static struct regulator *create_regulator(struct regulator_dev *rdev,
 					  struct device *dev,
 					  const char *supply_name);
+static void _regulator_put(struct regulator *regulator);
+
+static struct regulator_dev *dev_to_rdev(struct device *dev)
+{
+	return container_of(dev, struct regulator_dev, dev);
+}
 
 static const char *rdev_get_name(struct regulator_dev *rdev)
 {
@@ -126,6 +133,45 @@ static bool have_full_constraints(void)
 }
 
 /**
+ * regulator_lock_supply - lock a regulator and its supplies
+ * @rdev:         regulator source
+ */
+static void regulator_lock_supply(struct regulator_dev *rdev)
+{
+	struct regulator *supply;
+	int i = 0;
+
+	while (1) {
+		mutex_lock_nested(&rdev->mutex, i++);
+		supply = rdev->supply;
+
+		if (!rdev->supply)
+			return;
+
+		rdev = supply->rdev;
+	}
+}
+
+/**
+ * regulator_unlock_supply - unlock a regulator and its supplies
+ * @rdev:         regulator source
+ */
+static void regulator_unlock_supply(struct regulator_dev *rdev)
+{
+	struct regulator *supply;
+
+	while (1) {
+		mutex_unlock(&rdev->mutex);
+		supply = rdev->supply;
+
+		if (!rdev->supply)
+			return;
+
+		rdev = supply->rdev;
+	}
+}
+
+/**
  * of_get_regulator - get a regulator device node based on supply name
  * @dev: Device pointer for the consumer (of regulator) device
  * @supply: regulator supply name
@@ -174,7 +220,7 @@ static int regulator_check_voltage(struct regulator_dev *rdev,
 		return -ENODEV;
 	}
 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
-		rdev_err(rdev, "operation not allowed\n");
+		rdev_err(rdev, "voltage operation not allowed\n");
 		return -EPERM;
 	}
 
@@ -234,7 +280,7 @@ static int regulator_check_current_limit(struct regulator_dev *rdev,
 		return -ENODEV;
 	}
 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT)) {
-		rdev_err(rdev, "operation not allowed\n");
+		rdev_err(rdev, "current operation not allowed\n");
 		return -EPERM;
 	}
 
@@ -271,7 +317,7 @@ static int regulator_mode_constrain(struct regulator_dev *rdev, int *mode)
 		return -ENODEV;
 	}
 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE)) {
-		rdev_err(rdev, "operation not allowed\n");
+		rdev_err(rdev, "mode operation not allowed\n");
 		return -EPERM;
 	}
 
@@ -295,7 +341,7 @@ static int regulator_check_drms(struct regulator_dev *rdev)
 		return -ENODEV;
 	}
 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) {
-		rdev_err(rdev, "operation not allowed\n");
+		rdev_dbg(rdev, "drms operation not allowed\n");
 		return -EPERM;
 	}
 	return 0;
@@ -640,6 +686,8 @@ static int drms_uA_update(struct regulator_dev *rdev)
 	int current_uA = 0, output_uV, input_uV, err;
 	unsigned int mode;
 
+	lockdep_assert_held_once(&rdev->mutex);
+
 	/*
 	 * first check to see if we can set modes at all, otherwise just
 	 * tell the consumer everything is OK.
@@ -678,6 +726,8 @@ static int drms_uA_update(struct regulator_dev *rdev)
 	list_for_each_entry(sibling, &rdev->consumer_list, list)
 		current_uA += sibling->uA_load;
 
+	current_uA += rdev->constraints->system_load;
+
 	if (rdev->desc->ops->set_load) {
 		/* set the optimum mode for our new total regulator load */
 		err = rdev->desc->ops->set_load(rdev, current_uA);
@@ -758,6 +808,8 @@ static int suspend_set_state(struct regulator_dev *rdev,
 /* locks held by caller */
 static int suspend_prepare(struct regulator_dev *rdev, suspend_state_t state)
 {
+	lockdep_assert_held_once(&rdev->mutex);
+
 	if (!rdev->constraints)
 		return -EINVAL;
 
@@ -780,58 +832,63 @@ static void print_constraints(struct regulator_dev *rdev)
 {
 	struct regulation_constraints *constraints = rdev->constraints;
 	char buf[160] = "";
+	size_t len = sizeof(buf) - 1;
 	int count = 0;
 	int ret;
 
 	if (constraints->min_uV && constraints->max_uV) {
 		if (constraints->min_uV == constraints->max_uV)
-			count += sprintf(buf + count, "%d mV ",
-					 constraints->min_uV / 1000);
+			count += scnprintf(buf + count, len - count, "%d mV ",
+					   constraints->min_uV / 1000);
 		else
-			count += sprintf(buf + count, "%d <--> %d mV ",
-					 constraints->min_uV / 1000,
-					 constraints->max_uV / 1000);
+			count += scnprintf(buf + count, len - count,
+					   "%d <--> %d mV ",
+					   constraints->min_uV / 1000,
+					   constraints->max_uV / 1000);
 	}
 
 	if (!constraints->min_uV ||
 	    constraints->min_uV != constraints->max_uV) {
 		ret = _regulator_get_voltage(rdev);
 		if (ret > 0)
-			count += sprintf(buf + count, "at %d mV ", ret / 1000);
+			count += scnprintf(buf + count, len - count,
+					   "at %d mV ", ret / 1000);
 	}
 
 	if (constraints->uV_offset)
-		count += sprintf(buf, "%dmV offset ",
-				 constraints->uV_offset / 1000);
+		count += scnprintf(buf + count, len - count, "%dmV offset ",
+				   constraints->uV_offset / 1000);
 
 	if (constraints->min_uA && constraints->max_uA) {
 		if (constraints->min_uA == constraints->max_uA)
-			count += sprintf(buf + count, "%d mA ",
-					 constraints->min_uA / 1000);
+			count += scnprintf(buf + count, len - count, "%d mA ",
+					   constraints->min_uA / 1000);
 		else
-			count += sprintf(buf + count, "%d <--> %d mA ",
-					 constraints->min_uA / 1000,
-					 constraints->max_uA / 1000);
+			count += scnprintf(buf + count, len - count,
+					   "%d <--> %d mA ",
+					   constraints->min_uA / 1000,
+					   constraints->max_uA / 1000);
 	}
 
 	if (!constraints->min_uA ||
 	    constraints->min_uA != constraints->max_uA) {
 		ret = _regulator_get_current_limit(rdev);
 		if (ret > 0)
-			count += sprintf(buf + count, "at %d mA ", ret / 1000);
+			count += scnprintf(buf + count, len - count,
+					   "at %d mA ", ret / 1000);
 	}
 
 	if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
-		count += sprintf(buf + count, "fast ");
+		count += scnprintf(buf + count, len - count, "fast ");
 	if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
-		count += sprintf(buf + count, "normal ");
+		count += scnprintf(buf + count, len - count, "normal ");
 	if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
-		count += sprintf(buf + count, "idle ");
+		count += scnprintf(buf + count, len - count, "idle ");
 	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
-		count += sprintf(buf + count, "standby");
+		count += scnprintf(buf + count, len - count, "standby");
 
 	if (!count)
-		sprintf(buf, "no parameters");
+		scnprintf(buf, len, "no parameters");
 
 	rdev_dbg(rdev, "%s\n", buf);
 
@@ -1006,6 +1063,15 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 	if (ret != 0)
 		goto out;
 
+	if (rdev->constraints->ilim_uA && ops->set_input_current_limit) {
+		ret = ops->set_input_current_limit(rdev,
+						   rdev->constraints->ilim_uA);
+		if (ret < 0) {
+			rdev_err(rdev, "failed to set input limit\n");
+			goto out;
+		}
+	}
+
 	/* do we need to setup our suspend state */
 	if (rdev->constraints->initial_state) {
 		ret = suspend_prepare(rdev, rdev->constraints->initial_state);
@@ -1049,6 +1115,31 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 		}
 	}
 
+	if (rdev->constraints->pull_down && ops->set_pull_down) {
+		ret = ops->set_pull_down(rdev);
+		if (ret < 0) {
+			rdev_err(rdev, "failed to set pull down\n");
+			goto out;
+		}
+	}
+
+	if (rdev->constraints->soft_start && ops->set_soft_start) {
+		ret = ops->set_soft_start(rdev);
+		if (ret < 0) {
+			rdev_err(rdev, "failed to set soft start\n");
+			goto out;
+		}
+	}
+
+	if (rdev->constraints->over_current_protection
+		&& ops->set_over_current_protection) {
+		ret = ops->set_over_current_protection(rdev);
+		if (ret < 0) {
+			rdev_err(rdev, "failed to set over current protection\n");
+			goto out;
+		}
+	}
+
 	print_constraints(rdev);
 	return 0;
 out:
@@ -1073,6 +1164,9 @@ static int set_supply(struct regulator_dev *rdev,
 
 	rdev_info(rdev, "supplied by %s\n", rdev_get_name(supply_rdev));
 
+	if (!try_module_get(supply_rdev->owner))
+		return -ENODEV;
+
 	rdev->supply = create_regulator(supply_rdev, &rdev->dev, "SUPPLY");
 	if (rdev->supply == NULL) {
 		err = -ENOMEM;
@@ -1192,10 +1286,10 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 		if (regulator->supply_name == NULL)
 			goto overflow_err;
 
-		err = sysfs_create_link(&rdev->dev.kobj, &dev->kobj,
+		err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj,
 					buf);
 		if (err) {
-			rdev_warn(rdev, "could not add device link %s err %d\n",
+			rdev_dbg(rdev, "could not add device link %s err %d\n",
 				  dev->kobj.name, err);
 			/* non-fatal */
 		}
@@ -1208,7 +1302,7 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 	regulator->debugfs = debugfs_create_dir(regulator->supply_name,
 						rdev->debugfs);
 	if (!regulator->debugfs) {
-		rdev_warn(rdev, "Failed to create debugfs directory\n");
+		rdev_dbg(rdev, "Failed to create debugfs directory\n");
 	} else {
 		debugfs_create_u32("uA_load", 0444, regulator->debugfs,
 				   &regulator->uA_load);
@@ -1271,6 +1365,47 @@ static void regulator_supply_alias(struct device **dev, const char **supply)
 	}
 }
 
+static int of_node_match(struct device *dev, const void *data)
+{
+	return dev->of_node == data;
+}
+
+static struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
+{
+	struct device *dev;
+
+	dev = class_find_device(&regulator_class, NULL, np, of_node_match);
+
+	return dev ? dev_to_rdev(dev) : NULL;
+}
+
+static int regulator_match(struct device *dev, const void *data)
+{
+	struct regulator_dev *r = dev_to_rdev(dev);
+
+	return strcmp(rdev_get_name(r), data) == 0;
+}
+
+static struct regulator_dev *regulator_lookup_by_name(const char *name)
+{
+	struct device *dev;
+
+	dev = class_find_device(&regulator_class, NULL, name, regulator_match);
+
+	return dev ? dev_to_rdev(dev) : NULL;
+}
+
+/**
+ * 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,
+ * or NULL on failure. The refcount must be dropped by calling put_device().
+ */
 static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 						  const char *supply,
 						  int *ret)
@@ -1286,10 +1421,9 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 	if (dev && dev->of_node) {
 		node = of_get_regulator(dev, supply);
 		if (node) {
-			list_for_each_entry(r, &regulator_list, list)
-				if (r->dev.parent &&
-					node == r->dev.of_node)
-					return r;
+			r = of_find_regulator_by_node(node);
+			if (r)
+				return r;
 			*ret = -EPROBE_DEFER;
 			return NULL;
 		} else {
@@ -1307,20 +1441,24 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 	if (dev)
 		devname = dev_name(dev);
 
-	list_for_each_entry(r, &regulator_list, list)
-		if (strcmp(rdev_get_name(r), supply) == 0)
-			return r;
+	r = regulator_lookup_by_name(supply);
+	if (r)
+		return r;
 
+	mutex_lock(&regulator_list_mutex);
 	list_for_each_entry(map, &regulator_map_list, list) {
 		/* If the mapping has a device set up it must match */
 		if (map->dev_name &&
 		    (!devname || strcmp(map->dev_name, devname)))
 			continue;
 
-		if (strcmp(map->supply, supply) == 0)
+		if (strcmp(map->supply, supply) == 0 &&
+		    get_device(&map->regulator->dev)) {
+			mutex_unlock(&regulator_list_mutex);
 			return map->regulator;
+		}
 	}
-
+	mutex_unlock(&regulator_list_mutex);
 
 	return NULL;
 }
@@ -1340,34 +1478,49 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 		return 0;
 
 	r = regulator_dev_lookup(dev, rdev->supply_name, &ret);
-	if (ret == -ENODEV) {
-		/*
-		 * No supply was specified for this regulator and
-		 * there will never be one.
-		 */
-		return 0;
-	}
-
 	if (!r) {
-		dev_err(dev, "Failed to resolve %s-supply for %s\n",
-			rdev->supply_name, rdev->desc->name);
-		return -EPROBE_DEFER;
+		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;
+
+		if (have_full_constraints()) {
+			r = dummy_regulator_rdev;
+			get_device(&r->dev);
+		} else {
+			dev_err(dev, "Failed to resolve %s-supply for %s\n",
+				rdev->supply_name, rdev->desc->name);
+			return -EPROBE_DEFER;
+		}
 	}
 
 	/* Recursively resolve the supply of the supply */
 	ret = regulator_resolve_supply(r);
-	if (ret < 0)
+	if (ret < 0) {
+		put_device(&r->dev);
 		return ret;
+	}
 
 	ret = set_supply(rdev, r);
-	if (ret < 0)
+	if (ret < 0) {
+		put_device(&r->dev);
 		return ret;
+	}
 
 	/* Cascade always-on state to supply */
-	if (_regulator_is_enabled(rdev)) {
+	if (_regulator_is_enabled(rdev) && rdev->supply) {
 		ret = regulator_enable(rdev->supply);
-		if (ret < 0)
+		if (ret < 0) {
+			_regulator_put(rdev->supply);
 			return ret;
+		}
 	}
 
 	return 0;
@@ -1395,8 +1548,6 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
 	else
 		ret = -EPROBE_DEFER;
 
-	mutex_lock(&regulator_list_mutex);
-
 	rdev = regulator_dev_lookup(dev, id, &ret);
 	if (rdev)
 		goto found;
@@ -1408,7 +1559,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
 	 * succeed, so, quit with appropriate error value
 	 */
 	if (ret && ret != -ENODEV)
-		goto out;
+		return regulator;
 
 	if (!devname)
 		devname = "deviceless";
@@ -1422,40 +1573,46 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
 			devname, id);
 
 		rdev = dummy_regulator_rdev;
+		get_device(&rdev->dev);
 		goto found;
 	/* Don't log an error when called from regulator_get_optional() */
 	} else if (!have_full_constraints() || exclusive) {
 		dev_warn(dev, "dummy supplies not allowed\n");
 	}
 
-	mutex_unlock(&regulator_list_mutex);
 	return regulator;
 
 found:
 	if (rdev->exclusive) {
 		regulator = ERR_PTR(-EPERM);
-		goto out;
+		put_device(&rdev->dev);
+		return regulator;
 	}
 
 	if (exclusive && rdev->open_count) {
 		regulator = ERR_PTR(-EBUSY);
-		goto out;
+		put_device(&rdev->dev);
+		return regulator;
 	}
 
 	ret = regulator_resolve_supply(rdev);
 	if (ret < 0) {
 		regulator = ERR_PTR(ret);
-		goto out;
+		put_device(&rdev->dev);
+		return regulator;
 	}
 
-	if (!try_module_get(rdev->owner))
-		goto out;
+	if (!try_module_get(rdev->owner)) {
+		put_device(&rdev->dev);
+		return regulator;
+	}
 
 	regulator = create_regulator(rdev, dev, id);
 	if (regulator == NULL) {
 		regulator = ERR_PTR(-ENOMEM);
+		put_device(&rdev->dev);
 		module_put(rdev->owner);
-		goto out;
+		return regulator;
 	}
 
 	rdev->open_count++;
@@ -1469,9 +1626,6 @@ found:
 			rdev->use_count = 0;
 	}
 
-out:
-	mutex_unlock(&regulator_list_mutex);
-
 	return regulator;
 }
 
@@ -1552,9 +1706,11 @@ static void _regulator_put(struct regulator *regulator)
 {
 	struct regulator_dev *rdev;
 
-	if (regulator == NULL || IS_ERR(regulator))
+	if (IS_ERR_OR_NULL(regulator))
 		return;
 
+	lockdep_assert_held_once(&regulator_list_mutex);
+
 	rdev = regulator->rdev;
 
 	debugfs_remove_recursive(regulator->debugfs);
@@ -1563,14 +1719,16 @@ static void _regulator_put(struct regulator *regulator)
 	if (regulator->dev)
 		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
 	mutex_lock(&rdev->mutex);
-	kfree(regulator->supply_name);
 	list_del(&regulator->list);
-	kfree(regulator);
 
 	rdev->open_count--;
 	rdev->exclusive = 0;
+	put_device(&rdev->dev);
 	mutex_unlock(&rdev->mutex);
 
+	kfree(regulator->supply_name);
+	kfree(regulator);
+
 	module_put(rdev->owner);
 }
 
@@ -1933,6 +2091,8 @@ static int _regulator_enable(struct regulator_dev *rdev)
 {
 	int ret;
 
+	lockdep_assert_held_once(&rdev->mutex);
+
 	/* check voltage and requested load before enabling */
 	if (rdev->constraints &&
 	    (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
@@ -2033,6 +2193,8 @@ static int _regulator_disable(struct regulator_dev *rdev)
 {
 	int ret = 0;
 
+	lockdep_assert_held_once(&rdev->mutex);
+
 	if (WARN(rdev->use_count <= 0,
 		 "unbalanced disables for %s\n", rdev_get_name(rdev)))
 		return -EIO;
@@ -2111,6 +2273,8 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
 {
 	int ret = 0;
 
+	lockdep_assert_held_once(&rdev->mutex);
+
 	ret = _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
 			REGULATOR_EVENT_PRE_DISABLE, NULL);
 	if (ret & NOTIFY_STOP_MASK)
@@ -2239,6 +2403,40 @@ static int _regulator_is_enabled(struct regulator_dev *rdev)
 	return rdev->desc->ops->is_enabled(rdev);
 }
 
+static int _regulator_list_voltage(struct regulator *regulator,
+				    unsigned selector, int lock)
+{
+	struct regulator_dev *rdev = regulator->rdev;
+	const struct regulator_ops *ops = rdev->desc->ops;
+	int ret;
+
+	if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1 && !selector)
+		return rdev->desc->fixed_uV;
+
+	if (ops->list_voltage) {
+		if (selector >= rdev->desc->n_voltages)
+			return -EINVAL;
+		if (lock)
+			mutex_lock(&rdev->mutex);
+		ret = ops->list_voltage(rdev, selector);
+		if (lock)
+			mutex_unlock(&rdev->mutex);
+	} else if (rdev->supply) {
+		ret = _regulator_list_voltage(rdev->supply, selector, lock);
+	} else {
+		return -EINVAL;
+	}
+
+	if (ret > 0) {
+		if (ret < rdev->constraints->min_uV)
+			ret = 0;
+		else if (ret > rdev->constraints->max_uV)
+			ret = 0;
+	}
+
+	return ret;
+}
+
 /**
  * regulator_is_enabled - is the regulator output enabled
  * @regulator: regulator source
@@ -2328,33 +2526,7 @@ EXPORT_SYMBOL_GPL(regulator_count_voltages);
  */
 int regulator_list_voltage(struct regulator *regulator, unsigned selector)
 {
-	struct regulator_dev *rdev = regulator->rdev;
-	const struct regulator_ops *ops = rdev->desc->ops;
-	int ret;
-
-	if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1 && !selector)
-		return rdev->desc->fixed_uV;
-
-	if (ops->list_voltage) {
-		if (selector >= rdev->desc->n_voltages)
-			return -EINVAL;
-		mutex_lock(&rdev->mutex);
-		ret = ops->list_voltage(rdev, selector);
-		mutex_unlock(&rdev->mutex);
-	} else if (rdev->supply) {
-		ret = regulator_list_voltage(rdev->supply, selector);
-	} else {
-		return -EINVAL;
-	}
-
-	if (ret > 0) {
-		if (ret < rdev->constraints->min_uV)
-			ret = 0;
-		else if (ret > rdev->constraints->max_uV)
-			ret = 0;
-	}
-
-	return ret;
+	return _regulator_list_voltage(regulator, selector, 1);
 }
 EXPORT_SYMBOL_GPL(regulator_list_voltage);
 
@@ -2489,6 +2661,23 @@ int regulator_is_supported_voltage(struct regulator *regulator,
 }
 EXPORT_SYMBOL_GPL(regulator_is_supported_voltage);
 
+static int regulator_map_voltage(struct regulator_dev *rdev, int min_uV,
+				 int max_uV)
+{
+	const struct regulator_desc *desc = rdev->desc;
+
+	if (desc->ops->map_voltage)
+		return desc->ops->map_voltage(rdev, min_uV, max_uV);
+
+	if (desc->ops->list_voltage == regulator_list_voltage_linear)
+		return regulator_map_voltage_linear(rdev, min_uV, max_uV);
+
+	if (desc->ops->list_voltage == regulator_list_voltage_linear_range)
+		return regulator_map_voltage_linear_range(rdev, min_uV, max_uV);
+
+	return regulator_map_voltage_iterate(rdev, min_uV, max_uV);
+}
+
 static int _regulator_call_set_voltage(struct regulator_dev *rdev,
 				       int min_uV, int max_uV,
 				       unsigned *selector)
@@ -2577,23 +2766,7 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 		}
 
 	} else if (rdev->desc->ops->set_voltage_sel) {
-		if (rdev->desc->ops->map_voltage) {
-			ret = rdev->desc->ops->map_voltage(rdev, min_uV,
-							   max_uV);
-		} else {
-			if (rdev->desc->ops->list_voltage ==
-			    regulator_list_voltage_linear)
-				ret = regulator_map_voltage_linear(rdev,
-								min_uV, max_uV);
-			else if (rdev->desc->ops->list_voltage ==
-				 regulator_list_voltage_linear_range)
-				ret = regulator_map_voltage_linear_range(rdev,
-								min_uV, max_uV);
-			else
-				ret = regulator_map_voltage_iterate(rdev,
-								min_uV, max_uV);
-		}
-
+		ret = regulator_map_voltage(rdev, min_uV, max_uV);
 		if (ret >= 0) {
 			best_val = rdev->desc->ops->list_voltage(rdev, ret);
 			if (min_uV <= best_val && max_uV >= best_val) {
@@ -2644,32 +2817,15 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 	return ret;
 }
 
-/**
- * regulator_set_voltage - set regulator output voltage
- * @regulator: regulator source
- * @min_uV: Minimum required voltage in uV
- * @max_uV: Maximum acceptable voltage in uV
- *
- * Sets a voltage regulator to the desired output voltage. This can be set
- * during any regulator state. IOW, regulator can be disabled or enabled.
- *
- * If the regulator is enabled then the voltage will change to the new value
- * immediately otherwise if the regulator is disabled the regulator will
- * output at the new voltage when enabled.
- *
- * NOTE: If the regulator is shared between several devices then the lowest
- * request voltage that meets the system constraints will be used.
- * Regulator system constraints must be set for this regulator before
- * calling this function otherwise this call will fail.
- */
-int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
+static int regulator_set_voltage_unlocked(struct regulator *regulator,
+					  int min_uV, int max_uV)
 {
 	struct regulator_dev *rdev = regulator->rdev;
 	int ret = 0;
 	int old_min_uV, old_max_uV;
 	int current_uV;
-
-	mutex_lock(&rdev->mutex);
+	int best_supply_uV = 0;
+	int supply_change_uV = 0;
 
 	/* If we're setting the same range as last time the change
 	 * should be a noop (some cpufreq implementations use the same
@@ -2679,7 +2835,7 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
 		goto out;
 
 	/* If we're trying to set a range that overlaps the current voltage,
-	 * return succesfully even though the regulator does not support
+	 * return successfully even though the regulator does not support
 	 * changing the voltage.
 	 */
 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
@@ -2713,17 +2869,95 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
 	if (ret < 0)
 		goto out2;
 
+	if (rdev->supply && (rdev->desc->min_dropout_uV ||
+				!rdev->desc->ops->get_voltage)) {
+		int current_supply_uV;
+		int selector;
+
+		selector = regulator_map_voltage(rdev, min_uV, max_uV);
+		if (selector < 0) {
+			ret = selector;
+			goto out2;
+		}
+
+		best_supply_uV = _regulator_list_voltage(regulator, selector, 0);
+		if (best_supply_uV < 0) {
+			ret = best_supply_uV;
+			goto out2;
+		}
+
+		best_supply_uV += rdev->desc->min_dropout_uV;
+
+		current_supply_uV = _regulator_get_voltage(rdev->supply->rdev);
+		if (current_supply_uV < 0) {
+			ret = current_supply_uV;
+			goto out2;
+		}
+
+		supply_change_uV = best_supply_uV - current_supply_uV;
+	}
+
+	if (supply_change_uV > 0) {
+		ret = regulator_set_voltage_unlocked(rdev->supply,
+				best_supply_uV, INT_MAX);
+		if (ret) {
+			dev_err(&rdev->dev, "Failed to increase supply voltage: %d\n",
+					ret);
+			goto out2;
+		}
+	}
+
 	ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
 	if (ret < 0)
 		goto out2;
 
+	if (supply_change_uV < 0) {
+		ret = regulator_set_voltage_unlocked(rdev->supply,
+				best_supply_uV, INT_MAX);
+		if (ret)
+			dev_warn(&rdev->dev, "Failed to decrease supply voltage: %d\n",
+					ret);
+		/* No need to fail here */
+		ret = 0;
+	}
+
 out:
-	mutex_unlock(&rdev->mutex);
 	return ret;
 out2:
 	regulator->min_uV = old_min_uV;
 	regulator->max_uV = old_max_uV;
-	mutex_unlock(&rdev->mutex);
+
+	return ret;
+}
+
+/**
+ * regulator_set_voltage - set regulator output voltage
+ * @regulator: regulator source
+ * @min_uV: Minimum required voltage in uV
+ * @max_uV: Maximum acceptable voltage in uV
+ *
+ * Sets a voltage regulator to the desired output voltage. This can be set
+ * during any regulator state. IOW, regulator can be disabled or enabled.
+ *
+ * If the regulator is enabled then the voltage will change to the new value
+ * immediately otherwise if the regulator is disabled the regulator will
+ * output at the new voltage when enabled.
+ *
+ * NOTE: If the regulator is shared between several devices then the lowest
+ * request voltage that meets the system constraints will be used.
+ * Regulator system constraints must be set for this regulator before
+ * calling this function otherwise this call will fail.
+ */
+int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
+{
+	int ret = 0;
+
+	regulator_lock_supply(regulator->rdev);
+
+	ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV);
+
+	regulator_unlock_supply(regulator->rdev);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage);
@@ -2876,7 +3110,7 @@ static int _regulator_get_voltage(struct regulator_dev *rdev)
 	} else if (rdev->desc->fixed_uV && (rdev->desc->n_voltages == 1)) {
 		ret = rdev->desc->fixed_uV;
 	} else if (rdev->supply) {
-		ret = regulator_get_voltage(rdev->supply);
+		ret = _regulator_get_voltage(rdev->supply->rdev);
 	} else {
 		return -EINVAL;
 	}
@@ -2899,11 +3133,11 @@ int regulator_get_voltage(struct regulator *regulator)
 {
 	int ret;
 
-	mutex_lock(&regulator->rdev->mutex);
+	regulator_lock_supply(regulator->rdev);
 
 	ret = _regulator_get_voltage(regulator->rdev);
 
-	mutex_unlock(&regulator->rdev->mutex);
+	regulator_unlock_supply(regulator->rdev);
 
 	return ret;
 }
@@ -3407,6 +3641,8 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free);
 int regulator_notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data)
 {
+	lockdep_assert_held_once(&rdev->mutex);
+
 	_notifier_call_chain(rdev, event, data);
 	return NOTIFY_DONE;
 
@@ -3551,6 +3787,9 @@ static const struct attribute_group *regulator_dev_groups[] = {
 static void regulator_dev_release(struct device *dev)
 {
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
+
+	kfree(rdev->constraints);
+	of_node_put(rdev->dev.of_node);
 	kfree(rdev);
 }
 
@@ -3732,8 +3971,6 @@ regulator_register(const struct regulator_desc *regulator_desc,
 		}
 	}
 
-	list_add(&rdev->list, &regulator_list);
-
 	rdev_init_debugfs(rdev);
 out:
 	mutex_unlock(&regulator_list_mutex);
@@ -3781,14 +4018,25 @@ void regulator_unregister(struct regulator_dev *rdev)
 	WARN_ON(rdev->open_count);
 	unset_regulator_supplies(rdev);
 	list_del(&rdev->list);
-	kfree(rdev->constraints);
+	mutex_unlock(&regulator_list_mutex);
 	regulator_ena_gpio_free(rdev);
-	of_node_put(rdev->dev.of_node);
 	device_unregister(&rdev->dev);
-	mutex_unlock(&regulator_list_mutex);
 }
 EXPORT_SYMBOL_GPL(regulator_unregister);
 
+static int _regulator_suspend_prepare(struct device *dev, void *data)
+{
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+	const suspend_state_t *state = data;
+	int ret;
+
+	mutex_lock(&rdev->mutex);
+	ret = suspend_prepare(rdev, *state);
+	mutex_unlock(&rdev->mutex);
+
+	return ret;
+}
+
 /**
  * regulator_suspend_prepare - prepare regulators for system wide suspend
  * @state: system suspend state
@@ -3798,30 +4046,45 @@ EXPORT_SYMBOL_GPL(regulator_unregister);
  */
 int regulator_suspend_prepare(suspend_state_t state)
 {
-	struct regulator_dev *rdev;
-	int ret = 0;
-
 	/* ON is handled by regulator active state */
 	if (state == PM_SUSPEND_ON)
 		return -EINVAL;
 
-	mutex_lock(&regulator_list_mutex);
-	list_for_each_entry(rdev, &regulator_list, list) {
+	return class_for_each_device(&regulator_class, NULL, &state,
+				     _regulator_suspend_prepare);
+}
+EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
 
-		mutex_lock(&rdev->mutex);
-		ret = suspend_prepare(rdev, state);
-		mutex_unlock(&rdev->mutex);
+static int _regulator_suspend_finish(struct device *dev, void *data)
+{
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+	int ret;
 
-		if (ret < 0) {
-			rdev_err(rdev, "failed to prepare\n");
-			goto out;
+	mutex_lock(&rdev->mutex);
+	if (rdev->use_count > 0  || rdev->constraints->always_on) {
+		if (!_regulator_is_enabled(rdev)) {
+			ret = _regulator_do_enable(rdev);
+			if (ret)
+				dev_err(dev,
+					"Failed to resume regulator %d\n",
+					ret);
 		}
+	} else {
+		if (!have_full_constraints())
+			goto unlock;
+		if (!_regulator_is_enabled(rdev))
+			goto unlock;
+
+		ret = _regulator_do_disable(rdev);
+		if (ret)
+			dev_err(dev, "Failed to suspend regulator %d\n", ret);
 	}
-out:
-	mutex_unlock(&regulator_list_mutex);
-	return ret;
+unlock:
+	mutex_unlock(&rdev->mutex);
+
+	/* Keep processing regulators in spite of any errors */
+	return 0;
 }
-EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
 
 /**
  * regulator_suspend_finish - resume regulators from system wide suspend
@@ -3831,33 +4094,8 @@ EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
  */
 int regulator_suspend_finish(void)
 {
-	struct regulator_dev *rdev;
-	int ret = 0, error;
-
-	mutex_lock(&regulator_list_mutex);
-	list_for_each_entry(rdev, &regulator_list, list) {
-		mutex_lock(&rdev->mutex);
-		if (rdev->use_count > 0  || rdev->constraints->always_on) {
-			if (!_regulator_is_enabled(rdev)) {
-				error = _regulator_do_enable(rdev);
-				if (error)
-					ret = error;
-			}
-		} else {
-			if (!have_full_constraints())
-				goto unlock;
-			if (!_regulator_is_enabled(rdev))
-				goto unlock;
-
-			error = _regulator_do_disable(rdev);
-			if (error)
-				ret = error;
-		}
-unlock:
-		mutex_unlock(&rdev->mutex);
-	}
-	mutex_unlock(&regulator_list_mutex);
-	return ret;
+	return class_for_each_device(&regulator_class, NULL, NULL,
+				     _regulator_suspend_finish);
 }
 EXPORT_SYMBOL_GPL(regulator_suspend_finish);
 
@@ -3977,14 +4215,35 @@ static const struct file_operations supply_map_fops = {
 };
 
 #ifdef CONFIG_DEBUG_FS
+struct summary_data {
+	struct seq_file *s;
+	struct regulator_dev *parent;
+	int level;
+};
+
+static void regulator_summary_show_subtree(struct seq_file *s,
+					   struct regulator_dev *rdev,
+					   int level);
+
+static int regulator_summary_show_children(struct device *dev, void *data)
+{
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+	struct summary_data *summary_data = data;
+
+	if (rdev->supply && rdev->supply->rdev == summary_data->parent)
+		regulator_summary_show_subtree(summary_data->s, rdev,
+					       summary_data->level + 1);
+
+	return 0;
+}
+
 static void regulator_summary_show_subtree(struct seq_file *s,
 					   struct regulator_dev *rdev,
 					   int level)
 {
-	struct list_head *list = s->private;
-	struct regulator_dev *child;
 	struct regulation_constraints *c;
 	struct regulator *consumer;
+	struct summary_data summary_data;
 
 	if (!rdev)
 		return;
@@ -4034,33 +4293,32 @@ static void regulator_summary_show_subtree(struct seq_file *s,
 		seq_puts(s, "\n");
 	}
 
-	list_for_each_entry(child, list, list) {
-		/* handle only non-root regulators supplied by current rdev */
-		if (!child->supply || child->supply->rdev != rdev)
-			continue;
+	summary_data.s = s;
+	summary_data.level = level;
+	summary_data.parent = rdev;
 
-		regulator_summary_show_subtree(s, child, level + 1);
-	}
+	class_for_each_device(&regulator_class, NULL, &summary_data,
+			      regulator_summary_show_children);
 }
 
-static int regulator_summary_show(struct seq_file *s, void *data)
+static int regulator_summary_show_roots(struct device *dev, void *data)
 {
-	struct list_head *list = s->private;
-	struct regulator_dev *rdev;
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+	struct seq_file *s = data;
 
-	seq_puts(s, " regulator                      use open bypass voltage current     min     max\n");
-	seq_puts(s, "-------------------------------------------------------------------------------\n");
-
-	mutex_lock(&regulator_list_mutex);
+	if (!rdev->supply)
+		regulator_summary_show_subtree(s, rdev, 0);
 
-	list_for_each_entry(rdev, list, list) {
-		if (rdev->supply)
-			continue;
+	return 0;
+}
 
-		regulator_summary_show_subtree(s, rdev, 0);
-	}
+static int regulator_summary_show(struct seq_file *s, void *data)
+{
+	seq_puts(s, " regulator                      use open bypass voltage current     min     max\n");
+	seq_puts(s, "-------------------------------------------------------------------------------\n");
 
-	mutex_unlock(&regulator_list_mutex);
+	class_for_each_device(&regulator_class, NULL, s,
+			      regulator_summary_show_roots);
 
 	return 0;
 }
@@ -4094,7 +4352,7 @@ static int __init regulator_init(void)
 			    &supply_map_fops);
 
 	debugfs_create_file("regulator_summary", 0444, debugfs_root,
-			    &regulator_list, &regulator_summary_fops);
+			    NULL, &regulator_summary_fops);
 
 	regulator_dummy_init();
 
@@ -4104,13 +4362,57 @@ static int __init regulator_init(void)
 /* init early to allow our consumers to complete system booting */
 core_initcall(regulator_init);
 
-static int __init regulator_init_complete(void)
+static int __init regulator_late_cleanup(struct device *dev, void *data)
 {
-	struct regulator_dev *rdev;
-	const struct regulator_ops *ops;
-	struct regulation_constraints *c;
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+	const struct regulator_ops *ops = rdev->desc->ops;
+	struct regulation_constraints *c = rdev->constraints;
 	int enabled, ret;
 
+	if (c && c->always_on)
+		return 0;
+
+	if (c && !(c->valid_ops_mask & REGULATOR_CHANGE_STATUS))
+		return 0;
+
+	mutex_lock(&rdev->mutex);
+
+	if (rdev->use_count)
+		goto unlock;
+
+	/* If we can't read the status assume it's on. */
+	if (ops->is_enabled)
+		enabled = ops->is_enabled(rdev);
+	else
+		enabled = 1;
+
+	if (!enabled)
+		goto unlock;
+
+	if (have_full_constraints()) {
+		/* We log since this may kill the system if it goes
+		 * wrong. */
+		rdev_info(rdev, "disabling\n");
+		ret = _regulator_do_disable(rdev);
+		if (ret != 0)
+			rdev_err(rdev, "couldn't disable: %d\n", ret);
+	} else {
+		/* The intention is that in future we will
+		 * assume that full constraints are provided
+		 * so warn even if we aren't going to do
+		 * anything here.
+		 */
+		rdev_warn(rdev, "incomplete constraints, leaving on\n");
+	}
+
+unlock:
+	mutex_unlock(&rdev->mutex);
+
+	return 0;
+}
+
+static int __init regulator_init_complete(void)
+{
 	/*
 	 * Since DT doesn't provide an idiomatic mechanism for
 	 * enabling full constraints and since it's much more natural
@@ -4120,58 +4422,13 @@ static int __init regulator_init_complete(void)
 	if (of_have_populated_dt())
 		has_full_constraints = true;
 
-	mutex_lock(&regulator_list_mutex);
-
 	/* If we have a full configuration then disable any regulators
 	 * we have permission to change the status for and which are
 	 * not in use or always_on.  This is effectively the default
 	 * for DT and ACPI as they have full constraints.
 	 */
-	list_for_each_entry(rdev, &regulator_list, list) {
-		ops = rdev->desc->ops;
-		c = rdev->constraints;
-
-		if (c && c->always_on)
-			continue;
-
-		if (c && !(c->valid_ops_mask & REGULATOR_CHANGE_STATUS))
-			continue;
-
-		mutex_lock(&rdev->mutex);
-
-		if (rdev->use_count)
-			goto unlock;
-
-		/* If we can't read the status assume it's on. */
-		if (ops->is_enabled)
-			enabled = ops->is_enabled(rdev);
-		else
-			enabled = 1;
-
-		if (!enabled)
-			goto unlock;
-
-		if (have_full_constraints()) {
-			/* We log since this may kill the system if it
-			 * goes wrong. */
-			rdev_info(rdev, "disabling\n");
-			ret = _regulator_do_disable(rdev);
-			if (ret != 0)
-				rdev_err(rdev, "couldn't disable: %d\n", ret);
-		} else {
-			/* The intention is that in future we will
-			 * assume that full constraints are provided
-			 * so warn even if we aren't going to do
-			 * anything here.
-			 */
-			rdev_warn(rdev, "incomplete constraints, leaving on\n");
-		}
-
-unlock:
-		mutex_unlock(&rdev->mutex);
-	}
-
-	mutex_unlock(&regulator_list_mutex);
+	class_for_each_device(&regulator_class, NULL, NULL,
+			      regulator_late_cleanup);
 
 	return 0;
 }