Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livep...
[firefly-linux-kernel-4.4.55.git] / drivers / regulator / core.c
index 8a34f6acc801531ce8eb16882fed2b04ed4c874c..73b7683355cd015791114249defc26fdf2b644cf 100644 (file)
@@ -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
  *
@@ -131,6 +132,45 @@ static bool have_full_constraints(void)
        return has_full_constraints || of_have_populated_dt();
 }
 
+/**
+ * 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
@@ -180,7 +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;
        }
 
@@ -240,7 +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;
        }
 
@@ -277,7 +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;
        }
 
@@ -301,7 +341,7 @@ static int regulator_check_drms(struct regulator_dev *rdev)
                return -ENODEV;
        }
        if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) {
-               rdev_dbg(rdev, "operation not allowed\n");
+               rdev_dbg(rdev, "drms operation not allowed\n");
                return -EPERM;
        }
        return 0;
@@ -1325,6 +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)
@@ -1340,10 +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 {
@@ -1361,20 +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;
 }
@@ -1409,6 +1493,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 
                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);
@@ -1418,12 +1503,16 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 
        /* 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) && rdev->supply) {
@@ -1459,8 +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;
@@ -1472,7 +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";
@@ -1486,40 +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++;
@@ -1533,9 +1626,6 @@ found:
                        rdev->use_count = 0;
        }
 
-out:
-       mutex_unlock(&regulator_list_mutex);
-
        return regulator;
 }
 
@@ -1633,6 +1723,7 @@ static void _regulator_put(struct regulator *regulator)
 
        rdev->open_count--;
        rdev->exclusive = 0;
+       put_device(&rdev->dev);
        mutex_unlock(&rdev->mutex);
 
        kfree(regulator->supply_name);
@@ -2312,6 +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
@@ -2401,33 +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);
 
@@ -2562,6 +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)
@@ -2650,23 +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) {
@@ -2717,32 +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
@@ -2786,17 +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);
@@ -2949,7 +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;
        }
@@ -2972,11 +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;
 }
@@ -3810,8 +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);
@@ -3865,6 +4024,19 @@ void regulator_unregister(struct regulator_dev *rdev)
 }
 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
@@ -3874,30 +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
@@ -3907,33 +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);
 
@@ -4053,14 +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;
@@ -4110,33 +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;
-
-       seq_puts(s, " regulator                      use open bypass voltage current     min     max\n");
-       seq_puts(s, "-------------------------------------------------------------------------------\n");
+       struct regulator_dev *rdev = dev_to_rdev(dev);
+       struct seq_file *s = data;
 
-       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;
 }
@@ -4170,7 +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();