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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 //
 // core.c  --  Voltage/Current Regulator framework.
 //
 // Copyright 2007, 2008 Wolfson Microelectronics PLC.
 // Copyright 2008 SlimLogic Ltd.
 //
 // Author: Liam Girdwood <lrg@slimlogic.co.uk>
 
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/async.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/suspend.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
 #include <linux/regmap.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/consumer.h>
 #include <linux/regulator/coupler.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/module.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/regulator.h>
 
 #include "dummy.h"
 #include "internal.h"
 
 static DEFINE_WW_CLASS(regulator_ww_class);
 static DEFINE_MUTEX(regulator_nesting_mutex);
 static DEFINE_MUTEX(regulator_list_mutex);
 static LIST_HEAD(regulator_map_list);
 static LIST_HEAD(regulator_ena_gpio_list);
 static LIST_HEAD(regulator_supply_alias_list);
 static LIST_HEAD(regulator_coupler_list);
 static bool has_full_constraints;
 
 static struct dentry *debugfs_root;
 
 /*
  * struct regulator_map
  *
  * Used to provide symbolic supply names to devices.
  */
 struct regulator_map {
     struct list_head list;
     const char *dev_name;   /* The dev_name() for the consumer */
     const char *supply;
     struct regulator_dev *regulator;
 };
 
 /*
  * struct regulator_enable_gpio
  *
  * Management for shared enable GPIO pin
  */
 struct regulator_enable_gpio {
     struct list_head list;
     struct gpio_desc *gpiod;
     u32 enable_count;   /* a number of enabled shared GPIO */
     u32 request_count;  /* a number of requested shared GPIO */
 };
 
 /*
  * struct regulator_supply_alias
  *
  * Used to map lookups for a supply onto an alternative device.
  */
 struct regulator_supply_alias {
     struct list_head list;
     struct device *src_dev;
     const char *src_supply;
     struct device *alias_dev;
     const char *alias_supply;
 };
 
 static int _regulator_is_enabled(struct regulator_dev *rdev);
 static int _regulator_disable(struct regulator *regulator);
 static int _regulator_get_error_flags(struct regulator_dev *rdev, unsigned int *flags);
 static int _regulator_get_current_limit(struct regulator_dev *rdev);
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
 static int _notifier_call_chain(struct regulator_dev *rdev,
                   unsigned long event, void *data);
 static int _regulator_do_set_voltage(struct regulator_dev *rdev,
                      int min_uV, int max_uV);
 static int regulator_balance_voltage(struct regulator_dev *rdev,
                      suspend_state_t state);
 static struct regulator *create_regulator(struct regulator_dev *rdev,
                       struct device *dev,
                       const char *supply_name);
 static void destroy_regulator(struct regulator *regulator);
 static void _regulator_put(struct regulator *regulator);
 
 const char *rdev_get_name(struct regulator_dev *rdev)
 {
     if (rdev->constraints && rdev->constraints->name)
         return rdev->constraints->name;
     else if (rdev->desc->name)
         return rdev->desc->name;
     else
         return "";
 }
 EXPORT_SYMBOL_GPL(rdev_get_name);
 
 static bool have_full_constraints(void)
 {
     return has_full_constraints || of_have_populated_dt();
 }
 
 static bool regulator_ops_is_valid(struct regulator_dev *rdev, int ops)
 {
     if (!rdev->constraints) {
         rdev_err(rdev, "no constraints\n");
         return false;
     }
 
     if (rdev->constraints->valid_ops_mask & ops)
         return true;
 
     return false;
 }
 
 /**
  * regulator_lock_nested - lock a single regulator
  * @rdev:       regulator source
  * @ww_ctx:     w/w mutex acquire context
  *
  * This function can be called many times by one task on
  * a single regulator and its mutex will be locked only
  * once. If a task, which is calling this function is other
  * than the one, which initially locked the mutex, it will
  * wait on mutex.
  */
 static inline int regulator_lock_nested(struct regulator_dev *rdev,
                     struct ww_acquire_ctx *ww_ctx)
 {
     bool lock = false;
     int ret = 0;
 
     mutex_lock(&regulator_nesting_mutex);
 
     if (!ww_mutex_trylock(&rdev->mutex, ww_ctx)) {
         if (rdev->mutex_owner == current)
             rdev->ref_cnt++;
         else
             lock = true;
 
         if (lock) {
             mutex_unlock(&regulator_nesting_mutex);
             ret = ww_mutex_lock(&rdev->mutex, ww_ctx);
             mutex_lock(&regulator_nesting_mutex);
         }
     } else {
         lock = true;
     }
 
     if (lock && ret != -EDEADLK) {
         rdev->ref_cnt++;
         rdev->mutex_owner = current;
     }
 
     mutex_unlock(&regulator_nesting_mutex);
 
     return ret;
 }
 
 /**
  * regulator_lock - lock a single regulator
  * @rdev:       regulator source
  *
  * This function can be called many times by one task on
  * a single regulator and its mutex will be locked only
  * once. If a task, which is calling this function is other
  * than the one, which initially locked the mutex, it will
  * wait on mutex.
  */
 static void regulator_lock(struct regulator_dev *rdev)
 {
     regulator_lock_nested(rdev, NULL);
 }
 
 /**
  * regulator_unlock - unlock a single regulator
  * @rdev:       regulator_source
  *
  * This function unlocks the mutex when the
  * reference counter reaches 0.
  */
 static void regulator_unlock(struct regulator_dev *rdev)
 {
     mutex_lock(&regulator_nesting_mutex);
 
     if (--rdev->ref_cnt == 0) {
         rdev->mutex_owner = NULL;
         ww_mutex_unlock(&rdev->mutex);
     }
 
     WARN_ON_ONCE(rdev->ref_cnt < 0);
 
     mutex_unlock(&regulator_nesting_mutex);
 }
 
 static bool regulator_supply_is_couple(struct regulator_dev *rdev)
 {
     struct regulator_dev *c_rdev;
     int i;
 
     for (i = 1; i < rdev->coupling_desc.n_coupled; i++) {
         c_rdev = rdev->coupling_desc.coupled_rdevs[i];
 
         if (rdev->supply->rdev == c_rdev)
             return true;
     }
 
     return false;
 }
 
 static void regulator_unlock_recursive(struct regulator_dev *rdev,
                        unsigned int n_coupled)
 {
     struct regulator_dev *c_rdev, *supply_rdev;
     int i, supply_n_coupled;
 
     for (i = n_coupled; i > 0; i--) {
         c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1];
 
         if (!c_rdev)
             continue;
 
         if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) {
             supply_rdev = c_rdev->supply->rdev;
             supply_n_coupled = supply_rdev->coupling_desc.n_coupled;
 
             regulator_unlock_recursive(supply_rdev,
                            supply_n_coupled);
         }
 
         regulator_unlock(c_rdev);
     }
 }
 
 static int regulator_lock_recursive(struct regulator_dev *rdev,
                     struct regulator_dev **new_contended_rdev,
                     struct regulator_dev **old_contended_rdev,
                     struct ww_acquire_ctx *ww_ctx)
 {
     struct regulator_dev *c_rdev;
     int i, err;
 
     for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {
         c_rdev = rdev->coupling_desc.coupled_rdevs[i];
 
         if (!c_rdev)
             continue;
 
         if (c_rdev != *old_contended_rdev) {
             err = regulator_lock_nested(c_rdev, ww_ctx);
             if (err) {
                 if (err == -EDEADLK) {
                     *new_contended_rdev = c_rdev;
                     goto err_unlock;
                 }
 
                 /* shouldn't happen */
                 WARN_ON_ONCE(err != -EALREADY);
             }
         } else {
             *old_contended_rdev = NULL;
         }
 
         if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) {
             err = regulator_lock_recursive(c_rdev->supply->rdev,
                                new_contended_rdev,
                                old_contended_rdev,
                                ww_ctx);
             if (err) {
                 regulator_unlock(c_rdev);
                 goto err_unlock;
             }
         }
     }
 
     return 0;
 
 err_unlock:
     regulator_unlock_recursive(rdev, i);
 
     return err;
 }
 
 /**
  * regulator_unlock_dependent - unlock regulator's suppliers and coupled
  *              regulators
  * @rdev:           regulator source
  * @ww_ctx:         w/w mutex acquire context
  *
  * Unlock all regulators related with rdev by coupling or supplying.
  */
 static void regulator_unlock_dependent(struct regulator_dev *rdev,
                        struct ww_acquire_ctx *ww_ctx)
 {
     regulator_unlock_recursive(rdev, rdev->coupling_desc.n_coupled);
     ww_acquire_fini(ww_ctx);
 }
 
 /**
  * regulator_lock_dependent - lock regulator's suppliers and coupled regulators
  * @rdev:           regulator source
  * @ww_ctx:         w/w mutex acquire context
  *
  * This function as a wrapper on regulator_lock_recursive(), which locks
  * all regulators related with rdev by coupling or supplying.
  */
 static void regulator_lock_dependent(struct regulator_dev *rdev,
                      struct ww_acquire_ctx *ww_ctx)
 {
     struct regulator_dev *new_contended_rdev = NULL;
     struct regulator_dev *old_contended_rdev = NULL;
     int err;
 
     mutex_lock(&regulator_list_mutex);
 
     ww_acquire_init(ww_ctx, &regulator_ww_class);
 
     do {
         if (new_contended_rdev) {
             ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
             old_contended_rdev = new_contended_rdev;
             old_contended_rdev->ref_cnt++;
         }
 
         err = regulator_lock_recursive(rdev,
                            &new_contended_rdev,
                            &old_contended_rdev,
                            ww_ctx);
 
         if (old_contended_rdev)
             regulator_unlock(old_contended_rdev);
 
     } while (err == -EDEADLK);
 
     ww_acquire_done(ww_ctx);
 
     mutex_unlock(&regulator_list_mutex);
 }
 
 /**
  * of_get_child_regulator - get a child regulator device node
  * based on supply name
  * @parent: Parent device node
  * @prop_name: Combination regulator supply name and "-supply"
  *
  * Traverse all child nodes.
  * Extract the child regulator device node corresponding to the supply name.
  * returns the device node corresponding to the regulator if found, else
  * returns NULL.
  */
 static struct device_node *of_get_child_regulator(struct device_node *parent,
                           const char *prop_name)
 {
     struct device_node *regnode = NULL;
     struct device_node *child = NULL;
 
     for_each_child_of_node(parent, child) {
         regnode = of_parse_phandle(child, prop_name, 0);
 
         if (!regnode) {
             regnode = of_get_child_regulator(child, prop_name);
             if (regnode)
                 goto err_node_put;
         } else {
             goto err_node_put;
         }
     }
     return NULL;
 
 err_node_put:
     of_node_put(child);
     return regnode;
 }
 
 /**
  * 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
  *
  * Extract the regulator device node corresponding to the supply name.
  * returns the device node corresponding to the regulator if found, else
  * returns NULL.
  */
 static struct device_node *of_get_regulator(struct device *dev, const char *supply)
 {
     struct device_node *regnode = NULL;
     char prop_name[64]; /* 64 is max size of property name */
 
     dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);
 
     snprintf(prop_name, 64, "%s-supply", supply);
     regnode = of_parse_phandle(dev->of_node, prop_name, 0);
 
     if (!regnode) {
         regnode = of_get_child_regulator(dev->of_node, prop_name);
         if (regnode)
             return regnode;
 
         dev_dbg(dev, "Looking up %s property in node %pOF failed\n",
                 prop_name, dev->of_node);
         return NULL;
     }
     return regnode;
 }
 
 /* Platform voltage constraint check */
 int regulator_check_voltage(struct regulator_dev *rdev,
                 int *min_uV, int *max_uV)
 {
     BUG_ON(*min_uV > *max_uV);
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
         rdev_err(rdev, "voltage operation not allowed\n");
         return -EPERM;
     }
 
     if (*max_uV > rdev->constraints->max_uV)
         *max_uV = rdev->constraints->max_uV;
     if (*min_uV < rdev->constraints->min_uV)
         *min_uV = rdev->constraints->min_uV;
 
     if (*min_uV > *max_uV) {
         rdev_err(rdev, "unsupportable voltage range: %d-%duV\n",
              *min_uV, *max_uV);
         return -EINVAL;
     }
 
     return 0;
 }
 
 /* return 0 if the state is valid */
 static int regulator_check_states(suspend_state_t state)
 {
     return (state > PM_SUSPEND_MAX || state == PM_SUSPEND_TO_IDLE);
 }
 
 /* Make sure we select a voltage that suits the needs of all
  * regulator consumers
  */
 int regulator_check_consumers(struct regulator_dev *rdev,
                   int *min_uV, int *max_uV,
                   suspend_state_t state)
 {
     struct regulator *regulator;
     struct regulator_voltage *voltage;
 
     list_for_each_entry(regulator, &rdev->consumer_list, list) {
         voltage = &regulator->voltage[state];
         /*
          * Assume consumers that didn't say anything are OK
          * with anything in the constraint range.
          */
         if (!voltage->min_uV && !voltage->max_uV)
             continue;
 
         if (*max_uV > voltage->max_uV)
             *max_uV = voltage->max_uV;
         if (*min_uV < voltage->min_uV)
             *min_uV = voltage->min_uV;
     }
 
     if (*min_uV > *max_uV) {
         rdev_err(rdev, "Restricting voltage, %u-%uuV\n",
             *min_uV, *max_uV);
         return -EINVAL;
     }
 
     return 0;
 }
 
 /* current constraint check */
 static int regulator_check_current_limit(struct regulator_dev *rdev,
                     int *min_uA, int *max_uA)
 {
     BUG_ON(*min_uA > *max_uA);
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_CURRENT)) {
         rdev_err(rdev, "current operation not allowed\n");
         return -EPERM;
     }
 
     if (*max_uA > rdev->constraints->max_uA)
         *max_uA = rdev->constraints->max_uA;
     if (*min_uA < rdev->constraints->min_uA)
         *min_uA = rdev->constraints->min_uA;
 
     if (*min_uA > *max_uA) {
         rdev_err(rdev, "unsupportable current range: %d-%duA\n",
              *min_uA, *max_uA);
         return -EINVAL;
     }
 
     return 0;
 }
 
 /* operating mode constraint check */
 static int regulator_mode_constrain(struct regulator_dev *rdev,
                     unsigned int *mode)
 {
     switch (*mode) {
     case REGULATOR_MODE_FAST:
     case REGULATOR_MODE_NORMAL:
     case REGULATOR_MODE_IDLE:
     case REGULATOR_MODE_STANDBY:
         break;
     default:
         rdev_err(rdev, "invalid mode %x specified\n", *mode);
         return -EINVAL;
     }
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_MODE)) {
         rdev_err(rdev, "mode operation not allowed\n");
         return -EPERM;
     }
 
     /* The modes are bitmasks, the most power hungry modes having
      * the lowest values. If the requested mode isn't supported
      * try higher modes.
      */
     while (*mode) {
         if (rdev->constraints->valid_modes_mask & *mode)
             return 0;
         *mode /= 2;
     }
 
     return -EINVAL;
 }
 
 static inline struct regulator_state *
 regulator_get_suspend_state(struct regulator_dev *rdev, suspend_state_t state)
 {
     if (rdev->constraints == NULL)
         return NULL;
 
     switch (state) {
     case PM_SUSPEND_STANDBY:
         return &rdev->constraints->state_standby;
     case PM_SUSPEND_MEM:
         return &rdev->constraints->state_mem;
     case PM_SUSPEND_MAX:
         return &rdev->constraints->state_disk;
     default:
         return NULL;
     }
 }
 
 static const struct regulator_state *
 regulator_get_suspend_state_check(struct regulator_dev *rdev, suspend_state_t state)
 {
     const struct regulator_state *rstate;
 
     rstate = regulator_get_suspend_state(rdev, state);
     if (rstate == NULL)
         return NULL;
 
     /* If we have no suspend mode configuration don't set anything;
      * only warn if the driver implements set_suspend_voltage or
      * set_suspend_mode callback.
      */
     if (rstate->enabled != ENABLE_IN_SUSPEND &&
         rstate->enabled != DISABLE_IN_SUSPEND) {
         if (rdev->desc->ops->set_suspend_voltage ||
             rdev->desc->ops->set_suspend_mode)
             rdev_warn(rdev, "No configuration\n");
         return NULL;
     }
 
     return rstate;
 }
 
 static ssize_t microvolts_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     int uV;
 
     regulator_lock(rdev);
     uV = regulator_get_voltage_rdev(rdev);
     regulator_unlock(rdev);
 
     if (uV < 0)
         return uV;
     return sprintf(buf, "%d\n", uV);
 }
 static DEVICE_ATTR_RO(microvolts);
 
 static ssize_t microamps_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return sprintf(buf, "%d\n", _regulator_get_current_limit(rdev));
 }
 static DEVICE_ATTR_RO(microamps);
 
 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
              char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return sprintf(buf, "%s\n", rdev_get_name(rdev));
 }
 static DEVICE_ATTR_RO(name);
 
 static const char *regulator_opmode_to_str(int mode)
 {
     switch (mode) {
     case REGULATOR_MODE_FAST:
         return "fast";
     case REGULATOR_MODE_NORMAL:
         return "normal";
     case REGULATOR_MODE_IDLE:
         return "idle";
     case REGULATOR_MODE_STANDBY:
         return "standby";
     }
     return "unknown";
 }
 
 static ssize_t regulator_print_opmode(char *buf, int mode)
 {
     return sprintf(buf, "%s\n", regulator_opmode_to_str(mode));
 }
 
 static ssize_t opmode_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_opmode(buf, _regulator_get_mode(rdev));
 }
 static DEVICE_ATTR_RO(opmode);
 
 static ssize_t regulator_print_state(char *buf, int state)
 {
     if (state > 0)
         return sprintf(buf, "enabled\n");
     else if (state == 0)
         return sprintf(buf, "disabled\n");
     else
         return sprintf(buf, "unknown\n");
 }
 
 static ssize_t state_show(struct device *dev,
               struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     ssize_t ret;
 
     regulator_lock(rdev);
     ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
     regulator_unlock(rdev);
 
     return ret;
 }
 static DEVICE_ATTR_RO(state);
 
 static ssize_t status_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     int status;
     char *label;
 
     status = rdev->desc->ops->get_status(rdev);
     if (status < 0)
         return status;
 
     switch (status) {
     case REGULATOR_STATUS_OFF:
         label = "off";
         break;
     case REGULATOR_STATUS_ON:
         label = "on";
         break;
     case REGULATOR_STATUS_ERROR:
         label = "error";
         break;
     case REGULATOR_STATUS_FAST:
         label = "fast";
         break;
     case REGULATOR_STATUS_NORMAL:
         label = "normal";
         break;
     case REGULATOR_STATUS_IDLE:
         label = "idle";
         break;
     case REGULATOR_STATUS_STANDBY:
         label = "standby";
         break;
     case REGULATOR_STATUS_BYPASS:
         label = "bypass";
         break;
     case REGULATOR_STATUS_UNDEFINED:
         label = "undefined";
         break;
     default:
         return -ERANGE;
     }
 
     return sprintf(buf, "%s\n", label);
 }
 static DEVICE_ATTR_RO(status);
 
 static ssize_t min_microamps_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     if (!rdev->constraints)
         return sprintf(buf, "constraint not defined\n");
 
     return sprintf(buf, "%d\n", rdev->constraints->min_uA);
 }
 static DEVICE_ATTR_RO(min_microamps);
 
 static ssize_t max_microamps_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     if (!rdev->constraints)
         return sprintf(buf, "constraint not defined\n");
 
     return sprintf(buf, "%d\n", rdev->constraints->max_uA);
 }
 static DEVICE_ATTR_RO(max_microamps);
 
 static ssize_t min_microvolts_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     if (!rdev->constraints)
         return sprintf(buf, "constraint not defined\n");
 
     return sprintf(buf, "%d\n", rdev->constraints->min_uV);
 }
 static DEVICE_ATTR_RO(min_microvolts);
 
 static ssize_t max_microvolts_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     if (!rdev->constraints)
         return sprintf(buf, "constraint not defined\n");
 
     return sprintf(buf, "%d\n", rdev->constraints->max_uV);
 }
 static DEVICE_ATTR_RO(max_microvolts);
 
 static ssize_t requested_microamps_show(struct device *dev,
                     struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     struct regulator *regulator;
     int uA = 0;
 
     regulator_lock(rdev);
     list_for_each_entry(regulator, &rdev->consumer_list, list) {
         if (regulator->enable_count)
             uA += regulator->uA_load;
     }
     regulator_unlock(rdev);
     return sprintf(buf, "%d\n", uA);
 }
 static DEVICE_ATTR_RO(requested_microamps);
 
 static ssize_t num_users_show(struct device *dev, struct device_attribute *attr,
                   char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     return sprintf(buf, "%d\n", rdev->use_count);
 }
 static DEVICE_ATTR_RO(num_users);
 
 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
              char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     switch (rdev->desc->type) {
     case REGULATOR_VOLTAGE:
         return sprintf(buf, "voltage\n");
     case REGULATOR_CURRENT:
         return sprintf(buf, "current\n");
     }
     return sprintf(buf, "unknown\n");
 }
 static DEVICE_ATTR_RO(type);
 
 static ssize_t suspend_mem_microvolts_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return sprintf(buf, "%d\n", rdev->constraints->state_mem.uV);
 }
 static DEVICE_ATTR_RO(suspend_mem_microvolts);
 
 static ssize_t suspend_disk_microvolts_show(struct device *dev,
                         struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return sprintf(buf, "%d\n", rdev->constraints->state_disk.uV);
 }
 static DEVICE_ATTR_RO(suspend_disk_microvolts);
 
 static ssize_t suspend_standby_microvolts_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return sprintf(buf, "%d\n", rdev->constraints->state_standby.uV);
 }
 static DEVICE_ATTR_RO(suspend_standby_microvolts);
 
 static ssize_t suspend_mem_mode_show(struct device *dev,
                      struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_opmode(buf,
         rdev->constraints->state_mem.mode);
 }
 static DEVICE_ATTR_RO(suspend_mem_mode);
 
 static ssize_t suspend_disk_mode_show(struct device *dev,
                       struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_opmode(buf,
         rdev->constraints->state_disk.mode);
 }
 static DEVICE_ATTR_RO(suspend_disk_mode);
 
 static ssize_t suspend_standby_mode_show(struct device *dev,
                      struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_opmode(buf,
         rdev->constraints->state_standby.mode);
 }
 static DEVICE_ATTR_RO(suspend_standby_mode);
 
 static ssize_t suspend_mem_state_show(struct device *dev,
                       struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_state(buf,
             rdev->constraints->state_mem.enabled);
 }
 static DEVICE_ATTR_RO(suspend_mem_state);
 
 static ssize_t suspend_disk_state_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_state(buf,
             rdev->constraints->state_disk.enabled);
 }
 static DEVICE_ATTR_RO(suspend_disk_state);
 
 static ssize_t suspend_standby_state_show(struct device *dev,
                       struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
 
     return regulator_print_state(buf,
             rdev->constraints->state_standby.enabled);
 }
 static DEVICE_ATTR_RO(suspend_standby_state);
 
 static ssize_t bypass_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
     struct regulator_dev *rdev = dev_get_drvdata(dev);
     const char *report;
     bool bypass;
     int ret;
 
     ret = rdev->desc->ops->get_bypass(rdev, &bypass);
 
     if (ret != 0)
         report = "unknown";
     else if (bypass)
         report = "enabled";
     else
         report = "disabled";
 
     return sprintf(buf, "%s\n", report);
 }
 static DEVICE_ATTR_RO(bypass);
 
 #define REGULATOR_ERROR_ATTR(name, bit)                         \
     static ssize_t name##_show(struct device *dev, struct device_attribute *attr,   \
                    char *buf)                       \
     {                                       \
         int ret;                                \
         unsigned int flags;                         \
         struct regulator_dev *rdev = dev_get_drvdata(dev);          \
         ret = _regulator_get_error_flags(rdev, &flags);             \
         if (ret)                                \
             return ret;                         \
         return sysfs_emit(buf, "%d\n", !!(flags & (bit)));          \
     }                                       \
     static DEVICE_ATTR_RO(name)
 
 REGULATOR_ERROR_ATTR(under_voltage, REGULATOR_ERROR_UNDER_VOLTAGE);
 REGULATOR_ERROR_ATTR(over_current, REGULATOR_ERROR_OVER_CURRENT);
 REGULATOR_ERROR_ATTR(regulation_out, REGULATOR_ERROR_REGULATION_OUT);
 REGULATOR_ERROR_ATTR(fail, REGULATOR_ERROR_FAIL);
 REGULATOR_ERROR_ATTR(over_temp, REGULATOR_ERROR_OVER_TEMP);
 REGULATOR_ERROR_ATTR(under_voltage_warn, REGULATOR_ERROR_UNDER_VOLTAGE_WARN);
 REGULATOR_ERROR_ATTR(over_current_warn, REGULATOR_ERROR_OVER_CURRENT_WARN);
 REGULATOR_ERROR_ATTR(over_voltage_warn, REGULATOR_ERROR_OVER_VOLTAGE_WARN);
 REGULATOR_ERROR_ATTR(over_temp_warn, REGULATOR_ERROR_OVER_TEMP_WARN);
 
 /* Calculate the new optimum regulator operating mode based on the new total
  * consumer load. All locks held by caller
  */
 static int drms_uA_update(struct regulator_dev *rdev)
 {
     struct regulator *sibling;
     int current_uA = 0, output_uV, input_uV, err;
     unsigned int mode;
 
     /*
      * first check to see if we can set modes at all, otherwise just
      * tell the consumer everything is OK.
      */
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_DRMS)) {
         rdev_dbg(rdev, "DRMS operation not allowed\n");
         return 0;
     }
 
     if (!rdev->desc->ops->get_optimum_mode &&
         !rdev->desc->ops->set_load)
         return 0;
 
     if (!rdev->desc->ops->set_mode &&
         !rdev->desc->ops->set_load)
         return -EINVAL;
 
     /* calc total requested load */
     list_for_each_entry(sibling, &rdev->consumer_list, list) {
         if (sibling->enable_count)
             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);
         if (err < 0)
             rdev_err(rdev, "failed to set load %d: %pe\n",
                  current_uA, ERR_PTR(err));
     } else {
         /* get output voltage */
         output_uV = regulator_get_voltage_rdev(rdev);
         if (output_uV <= 0) {
             rdev_err(rdev, "invalid output voltage found\n");
             return -EINVAL;
         }
 
         /* get input voltage */
         input_uV = 0;
         if (rdev->supply)
             input_uV = regulator_get_voltage(rdev->supply);
         if (input_uV <= 0)
             input_uV = rdev->constraints->input_uV;
         if (input_uV <= 0) {
             rdev_err(rdev, "invalid input voltage found\n");
             return -EINVAL;
         }
 
         /* now get the optimum mode for our new total regulator load */
         mode = rdev->desc->ops->get_optimum_mode(rdev, input_uV,
                              output_uV, current_uA);
 
         /* check the new mode is allowed */
         err = regulator_mode_constrain(rdev, &mode);
         if (err < 0) {
             rdev_err(rdev, "failed to get optimum mode @ %d uA %d -> %d uV: %pe\n",
                  current_uA, input_uV, output_uV, ERR_PTR(err));
             return err;
         }
 
         err = rdev->desc->ops->set_mode(rdev, mode);
         if (err < 0)
             rdev_err(rdev, "failed to set optimum mode %x: %pe\n",
                  mode, ERR_PTR(err));
     }
 
     return err;
 }
 
 static int __suspend_set_state(struct regulator_dev *rdev,
                    const struct regulator_state *rstate)
 {
     int ret = 0;
 
     if (rstate->enabled == ENABLE_IN_SUSPEND &&
         rdev->desc->ops->set_suspend_enable)
         ret = rdev->desc->ops->set_suspend_enable(rdev);
     else if (rstate->enabled == DISABLE_IN_SUSPEND &&
         rdev->desc->ops->set_suspend_disable)
         ret = rdev->desc->ops->set_suspend_disable(rdev);
     else /* OK if set_suspend_enable or set_suspend_disable is NULL */
         ret = 0;
 
     if (ret < 0) {
         rdev_err(rdev, "failed to enabled/disable: %pe\n", ERR_PTR(ret));
         return ret;
     }
 
     if (rdev->desc->ops->set_suspend_voltage && rstate->uV > 0) {
         ret = rdev->desc->ops->set_suspend_voltage(rdev, rstate->uV);
         if (ret < 0) {
             rdev_err(rdev, "failed to set voltage: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     if (rdev->desc->ops->set_suspend_mode && rstate->mode > 0) {
         ret = rdev->desc->ops->set_suspend_mode(rdev, rstate->mode);
         if (ret < 0) {
             rdev_err(rdev, "failed to set mode: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     return ret;
 }
 
 static int suspend_set_initial_state(struct regulator_dev *rdev)
 {
     const struct regulator_state *rstate;
 
     rstate = regulator_get_suspend_state_check(rdev,
             rdev->constraints->initial_state);
     if (!rstate)
         return 0;
 
     return __suspend_set_state(rdev, rstate);
 }
 
 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 static void print_constraints_debug(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 += scnprintf(buf + count, len - count, "%d mV ",
                        constraints->min_uV / 1000);
         else
             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(rdev);
         if (ret > 0)
             count += scnprintf(buf + count, len - count,
                        "at %d mV ", ret / 1000);
     }
 
     if (constraints->uV_offset)
         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 += scnprintf(buf + count, len - count, "%d mA ",
                        constraints->min_uA / 1000);
         else
             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 += scnprintf(buf + count, len - count,
                        "at %d mA ", ret / 1000);
     }
 
     if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
         count += scnprintf(buf + count, len - count, "fast ");
     if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
         count += scnprintf(buf + count, len - count, "normal ");
     if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
         count += scnprintf(buf + count, len - count, "idle ");
     if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
         count += scnprintf(buf + count, len - count, "standby ");
 
     if (!count)
         count = scnprintf(buf, len, "no parameters");
     else
         --count;
 
     count += scnprintf(buf + count, len - count, ", %s",
         _regulator_is_enabled(rdev) ? "enabled" : "disabled");
 
     rdev_dbg(rdev, "%s\n", buf);
 }
 #else /* !DEBUG && !CONFIG_DYNAMIC_DEBUG */
 static inline void print_constraints_debug(struct regulator_dev *rdev) {}
 #endif /* !DEBUG && !CONFIG_DYNAMIC_DEBUG */
 
 static void print_constraints(struct regulator_dev *rdev)
 {
     struct regulation_constraints *constraints = rdev->constraints;
 
     print_constraints_debug(rdev);
 
     if ((constraints->min_uV != constraints->max_uV) &&
         !regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE))
         rdev_warn(rdev,
               "Voltage range but no REGULATOR_CHANGE_VOLTAGE\n");
 }
 
 static int machine_constraints_voltage(struct regulator_dev *rdev,
     struct regulation_constraints *constraints)
 {
     const struct regulator_ops *ops = rdev->desc->ops;
     int ret;
 
     /* do we need to apply the constraint voltage */
     if (rdev->constraints->apply_uV &&
         rdev->constraints->min_uV && rdev->constraints->max_uV) {
         int target_min, target_max;
         int current_uV = regulator_get_voltage_rdev(rdev);
 
         if (current_uV == -ENOTRECOVERABLE) {
             /* This regulator can't be read and must be initialized */
             rdev_info(rdev, "Setting %d-%duV\n",
                   rdev->constraints->min_uV,
                   rdev->constraints->max_uV);
             _regulator_do_set_voltage(rdev,
                           rdev->constraints->min_uV,
                           rdev->constraints->max_uV);
             current_uV = regulator_get_voltage_rdev(rdev);
         }
 
         if (current_uV < 0) {
             if (current_uV != -EPROBE_DEFER)
                 rdev_err(rdev,
                      "failed to get the current voltage: %pe\n",
                      ERR_PTR(current_uV));
             return current_uV;
         }
 
         /*
          * If we're below the minimum voltage move up to the
          * minimum voltage, if we're above the maximum voltage
          * then move down to the maximum.
          */
         target_min = current_uV;
         target_max = current_uV;
 
         if (current_uV < rdev->constraints->min_uV) {
             target_min = rdev->constraints->min_uV;
             target_max = rdev->constraints->min_uV;
         }
 
         if (current_uV > rdev->constraints->max_uV) {
             target_min = rdev->constraints->max_uV;
             target_max = rdev->constraints->max_uV;
         }
 
         if (target_min != current_uV || target_max != current_uV) {
             rdev_info(rdev, "Bringing %duV into %d-%duV\n",
                   current_uV, target_min, target_max);
             ret = _regulator_do_set_voltage(
                 rdev, target_min, target_max);
             if (ret < 0) {
                 rdev_err(rdev,
                     "failed to apply %d-%duV constraint: %pe\n",
                     target_min, target_max, ERR_PTR(ret));
                 return ret;
             }
         }
     }
 
     /* constrain machine-level voltage specs to fit
      * the actual range supported by this regulator.
      */
     if (ops->list_voltage && rdev->desc->n_voltages) {
         int count = rdev->desc->n_voltages;
         int i;
         int min_uV = INT_MAX;
         int max_uV = INT_MIN;
         int cmin = constraints->min_uV;
         int cmax = constraints->max_uV;
 
         /* it's safe to autoconfigure fixed-voltage supplies
          * and the constraints are used by list_voltage.
          */
         if (count == 1 && !cmin) {
             cmin = 1;
             cmax = INT_MAX;
             constraints->min_uV = cmin;
             constraints->max_uV = cmax;
         }
 
         /* voltage constraints are optional */
         if ((cmin == 0) && (cmax == 0))
             return 0;
 
         /* else require explicit machine-level constraints */
         if (cmin <= 0 || cmax <= 0 || cmax < cmin) {
             rdev_err(rdev, "invalid voltage constraints\n");
             return -EINVAL;
         }
 
         /* no need to loop voltages if range is continuous */
         if (rdev->desc->continuous_voltage_range)
             return 0;
 
         /* initial: [cmin..cmax] valid, [min_uV..max_uV] not */
         for (i = 0; i < count; i++) {
             int value;
 
             value = ops->list_voltage(rdev, i);
             if (value <= 0)
                 continue;
 
             /* maybe adjust [min_uV..max_uV] */
             if (value >= cmin && value < min_uV)
                 min_uV = value;
             if (value <= cmax && value > max_uV)
                 max_uV = value;
         }
 
         /* final: [min_uV..max_uV] valid iff constraints valid */
         if (max_uV < min_uV) {
             rdev_err(rdev,
                  "unsupportable voltage constraints %u-%uuV\n",
                  min_uV, max_uV);
             return -EINVAL;
         }
 
         /* use regulator's subset of machine constraints */
         if (constraints->min_uV < min_uV) {
             rdev_dbg(rdev, "override min_uV, %d -> %d\n",
                  constraints->min_uV, min_uV);
             constraints->min_uV = min_uV;
         }
         if (constraints->max_uV > max_uV) {
             rdev_dbg(rdev, "override max_uV, %d -> %d\n",
                  constraints->max_uV, max_uV);
             constraints->max_uV = max_uV;
         }
     }
 
     return 0;
 }
 
 static int machine_constraints_current(struct regulator_dev *rdev,
     struct regulation_constraints *constraints)
 {
     const struct regulator_ops *ops = rdev->desc->ops;
     int ret;
 
     if (!constraints->min_uA && !constraints->max_uA)
         return 0;
 
     if (constraints->min_uA > constraints->max_uA) {
         rdev_err(rdev, "Invalid current constraints\n");
         return -EINVAL;
     }
 
     if (!ops->set_current_limit || !ops->get_current_limit) {
         rdev_warn(rdev, "Operation of current configuration missing\n");
         return 0;
     }
 
     /* Set regulator current in constraints range */
     ret = ops->set_current_limit(rdev, constraints->min_uA,
             constraints->max_uA);
     if (ret < 0) {
         rdev_err(rdev, "Failed to set current constraint, %d\n", ret);
         return ret;
     }
 
     return 0;
 }
 
 static int _regulator_do_enable(struct regulator_dev *rdev);
 
 static int notif_set_limit(struct regulator_dev *rdev,
                int (*set)(struct regulator_dev *, int, int, bool),
                int limit, int severity)
 {
     bool enable;
 
     if (limit == REGULATOR_NOTIF_LIMIT_DISABLE) {
         enable = false;
         limit = 0;
     } else {
         enable = true;
     }
 
     if (limit == REGULATOR_NOTIF_LIMIT_ENABLE)
         limit = 0;
 
     return set(rdev, limit, severity, enable);
 }
 
 static int handle_notify_limits(struct regulator_dev *rdev,
             int (*set)(struct regulator_dev *, int, int, bool),
             struct notification_limit *limits)
 {
     int ret = 0;
 
     if (!set)
         return -EOPNOTSUPP;
 
     if (limits->prot)
         ret = notif_set_limit(rdev, set, limits->prot,
                       REGULATOR_SEVERITY_PROT);
     if (ret)
         return ret;
 
     if (limits->err)
         ret = notif_set_limit(rdev, set, limits->err,
                       REGULATOR_SEVERITY_ERR);
     if (ret)
         return ret;
 
     if (limits->warn)
         ret = notif_set_limit(rdev, set, limits->warn,
                       REGULATOR_SEVERITY_WARN);
 
     return ret;
 }
 /**
  * set_machine_constraints - sets regulator constraints
  * @rdev: regulator source
  *
  * Allows platform initialisation code to define and constrain
  * regulator circuits e.g. valid voltage/current ranges, etc.  NOTE:
  * Constraints *must* be set by platform code in order for some
  * regulator operations to proceed i.e. set_voltage, set_current_limit,
  * set_mode.
  */
 static int set_machine_constraints(struct regulator_dev *rdev)
 {
     int ret = 0;
     const struct regulator_ops *ops = rdev->desc->ops;
 
     ret = machine_constraints_voltage(rdev, rdev->constraints);
     if (ret != 0)
         return ret;
 
     ret = machine_constraints_current(rdev, rdev->constraints);
     if (ret != 0)
         return ret;
 
     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: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     /* do we need to setup our suspend state */
     if (rdev->constraints->initial_state) {
         ret = suspend_set_initial_state(rdev);
         if (ret < 0) {
             rdev_err(rdev, "failed to set suspend state: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     if (rdev->constraints->initial_mode) {
         if (!ops->set_mode) {
             rdev_err(rdev, "no set_mode operation\n");
             return -EINVAL;
         }
 
         ret = ops->set_mode(rdev, rdev->constraints->initial_mode);
         if (ret < 0) {
             rdev_err(rdev, "failed to set initial mode: %pe\n", ERR_PTR(ret));
             return ret;
         }
     } else if (rdev->constraints->system_load) {
         /*
          * We'll only apply the initial system load if an
          * initial mode wasn't specified.
          */
         drms_uA_update(rdev);
     }
 
     if ((rdev->constraints->ramp_delay || rdev->constraints->ramp_disable)
         && ops->set_ramp_delay) {
         ret = ops->set_ramp_delay(rdev, rdev->constraints->ramp_delay);
         if (ret < 0) {
             rdev_err(rdev, "failed to set ramp_delay: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     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: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     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: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     /*
      * Existing logic does not warn if over_current_protection is given as
      * a constraint but driver does not support that. I think we should
      * warn about this type of issues as it is possible someone changes
      * PMIC on board to another type - and the another PMIC's driver does
      * not support setting protection. Board composer may happily believe
      * the DT limits are respected - especially if the new PMIC HW also
      * supports protection but the driver does not. I won't change the logic
      * without hearing more experienced opinion on this though.
      *
      * If warning is seen as a good idea then we can merge handling the
      * over-curret protection and detection and get rid of this special
      * handling.
      */
     if (rdev->constraints->over_current_protection
         && ops->set_over_current_protection) {
         int lim = rdev->constraints->over_curr_limits.prot;
 
         ret = ops->set_over_current_protection(rdev, lim,
                                REGULATOR_SEVERITY_PROT,
                                true);
         if (ret < 0) {
             rdev_err(rdev, "failed to set over current protection: %pe\n",
                  ERR_PTR(ret));
             return ret;
         }
     }
 
     if (rdev->constraints->over_current_detection)
         ret = handle_notify_limits(rdev,
                        ops->set_over_current_protection,
                        &rdev->constraints->over_curr_limits);
     if (ret) {
         if (ret != -EOPNOTSUPP) {
             rdev_err(rdev, "failed to set over current limits: %pe\n",
                  ERR_PTR(ret));
             return ret;
         }
         rdev_warn(rdev,
               "IC does not support requested over-current limits\n");
     }
 
     if (rdev->constraints->over_voltage_detection)
         ret = handle_notify_limits(rdev,
                        ops->set_over_voltage_protection,
                        &rdev->constraints->over_voltage_limits);
     if (ret) {
         if (ret != -EOPNOTSUPP) {
             rdev_err(rdev, "failed to set over voltage limits %pe\n",
                  ERR_PTR(ret));
             return ret;
         }
         rdev_warn(rdev,
               "IC does not support requested over voltage limits\n");
     }
 
     if (rdev->constraints->under_voltage_detection)
         ret = handle_notify_limits(rdev,
                        ops->set_under_voltage_protection,
                        &rdev->constraints->under_voltage_limits);
     if (ret) {
         if (ret != -EOPNOTSUPP) {
             rdev_err(rdev, "failed to set under voltage limits %pe\n",
                  ERR_PTR(ret));
             return ret;
         }
         rdev_warn(rdev,
               "IC does not support requested under voltage limits\n");
     }
 
     if (rdev->constraints->over_temp_detection)
         ret = handle_notify_limits(rdev,
                        ops->set_thermal_protection,
                        &rdev->constraints->temp_limits);
     if (ret) {
         if (ret != -EOPNOTSUPP) {
             rdev_err(rdev, "failed to set temperature limits %pe\n",
                  ERR_PTR(ret));
             return ret;
         }
         rdev_warn(rdev,
               "IC does not support requested temperature limits\n");
     }
 
     if (rdev->constraints->active_discharge && ops->set_active_discharge) {
         bool ad_state = (rdev->constraints->active_discharge ==
                   REGULATOR_ACTIVE_DISCHARGE_ENABLE) ? true : false;
 
         ret = ops->set_active_discharge(rdev, ad_state);
         if (ret < 0) {
             rdev_err(rdev, "failed to set active discharge: %pe\n", ERR_PTR(ret));
             return ret;
         }
     }
 
     /*
      * If there is no mechanism for controlling the regulator then
      * flag it as always_on so we don't end up duplicating checks
      * for this so much.  Note that we could control the state of
      * a supply to control the output on a regulator that has no
      * direct control.
      */
     if (!rdev->ena_pin && !ops->enable) {
         if (rdev->supply_name && !rdev->supply)
             return -EPROBE_DEFER;
 
         if (rdev->supply)
             rdev->constraints->always_on =
                 rdev->supply->rdev->constraints->always_on;
         else
             rdev->constraints->always_on = true;
     }
 
     if (rdev->desc->off_on_delay)
         rdev->last_off = ktime_get();
 
     /* If the constraints say the regulator should be on at this point
      * and we have control then make sure it is enabled.
      */
     if (rdev->constraints->always_on || rdev->constraints->boot_on) {
         /* If we want to enable this regulator, make sure that we know
          * the supplying regulator.
          */
         if (rdev->supply_name && !rdev->supply)
             return -EPROBE_DEFER;
 
         if (rdev->supply) {
             ret = regulator_enable(rdev->supply);
             if (ret < 0) {
                 _regulator_put(rdev->supply);
                 rdev->supply = NULL;
                 return ret;
             }
         }
 
         ret = _regulator_do_enable(rdev);
         if (ret < 0 && ret != -EINVAL) {
             rdev_err(rdev, "failed to enable: %pe\n", ERR_PTR(ret));
             return ret;
         }
 
         if (rdev->constraints->always_on)
             rdev->use_count++;
     }
 
     print_constraints(rdev);
     return 0;
 }
 
 /**
  * set_supply - set regulator supply regulator
  * @rdev: regulator name
  * @supply_rdev: supply regulator name
  *
  * Called by platform initialisation code to set the supply regulator for this
  * regulator. This ensures that a regulators supply will also be enabled by the
  * core if it's child is enabled.
  */
 static int set_supply(struct regulator_dev *rdev,
               struct regulator_dev *supply_rdev)
 {
     int err;
 
     rdev_dbg(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;
         return err;
     }
     supply_rdev->open_count++;
 
     return 0;
 }
 
 /**
  * set_consumer_device_supply - Bind a regulator to a symbolic supply
  * @rdev:         regulator source
  * @consumer_dev_name: dev_name() string for device supply applies to
  * @supply:       symbolic name for supply
  *
  * Allows platform initialisation code to map physical regulator
  * sources to symbolic names for supplies for use by devices.  Devices
  * should use these symbolic names to request regulators, avoiding the
  * need to provide board-specific regulator names as platform data.
  */
 static int set_consumer_device_supply(struct regulator_dev *rdev,
                       const char *consumer_dev_name,
                       const char *supply)
 {
     struct regulator_map *node, *new_node;
     int has_dev;
 
     if (supply == NULL)
         return -EINVAL;
 
     if (consumer_dev_name != NULL)
         has_dev = 1;
     else
         has_dev = 0;
 
     new_node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
     if (new_node == NULL)
         return -ENOMEM;
 
     new_node->regulator = rdev;
     new_node->supply = supply;
 
     if (has_dev) {
         new_node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
         if (new_node->dev_name == NULL) {
             kfree(new_node);
             return -ENOMEM;
         }
     }
 
     mutex_lock(&regulator_list_mutex);
     list_for_each_entry(node, &regulator_map_list, list) {
         if (node->dev_name && consumer_dev_name) {
             if (strcmp(node->dev_name, consumer_dev_name) != 0)
                 continue;
         } else if (node->dev_name || consumer_dev_name) {
             continue;
         }
 
         if (strcmp(node->supply, supply) != 0)
             continue;
 
         pr_debug("%s: %s/%s is '%s' supply; fail %s/%s\n",
              consumer_dev_name,
              dev_name(&node->regulator->dev),
              node->regulator->desc->name,
              supply,
              dev_name(&rdev->dev), rdev_get_name(rdev));
         goto fail;
     }
 
     list_add(&new_node->list, &regulator_map_list);
     mutex_unlock(&regulator_list_mutex);
 
     return 0;
 
 fail:
     mutex_unlock(&regulator_list_mutex);
     kfree(new_node->dev_name);
     kfree(new_node);
     return -EBUSY;
 }
 
 static void unset_regulator_supplies(struct regulator_dev *rdev)
 {
     struct regulator_map *node, *n;
 
     list_for_each_entry_safe(node, n, &regulator_map_list, list) {
         if (rdev == node->regulator) {
             list_del(&node->list);
             kfree(node->dev_name);
             kfree(node);
         }
     }
 }
 
 #ifdef CONFIG_DEBUG_FS
 static ssize_t constraint_flags_read_file(struct file *file,
                       char __user *user_buf,
                       size_t count, loff_t *ppos)
 {
     const struct regulator *regulator = file->private_data;
     const struct regulation_constraints *c = regulator->rdev->constraints;
     char *buf;
     ssize_t ret;
 
     if (!c)
         return 0;
 
     buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
     if (!buf)
         return -ENOMEM;
 
     ret = snprintf(buf, PAGE_SIZE,
             "always_on: %u\n"
             "boot_on: %u\n"
             "apply_uV: %u\n"
             "ramp_disable: %u\n"
             "soft_start: %u\n"
             "pull_down: %u\n"
             "over_current_protection: %u\n",
             c->always_on,
             c->boot_on,
             c->apply_uV,
             c->ramp_disable,
             c->soft_start,
             c->pull_down,
             c->over_current_protection);
 
     ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
     kfree(buf);
 
     return ret;
 }
 
 #endif
 
 static const struct file_operations constraint_flags_fops = {
 #ifdef CONFIG_DEBUG_FS
     .open = simple_open,
     .read = constraint_flags_read_file,
     .llseek = default_llseek,
 #endif
 };
 
 #define REG_STR_SIZE    64
 
 static struct regulator *create_regulator(struct regulator_dev *rdev,
                       struct device *dev,
                       const char *supply_name)
 {
     struct regulator *regulator;
     int err = 0;
 
     if (dev) {
         char buf[REG_STR_SIZE];
         int size;
 
         size = snprintf(buf, REG_STR_SIZE, "%s-%s",
                 dev->kobj.name, supply_name);
         if (size >= REG_STR_SIZE)
             return NULL;
 
         supply_name = kstrdup(buf, GFP_KERNEL);
         if (supply_name == NULL)
             return NULL;
     } else {
         supply_name = kstrdup_const(supply_name, GFP_KERNEL);
         if (supply_name == NULL)
             return NULL;
     }
 
     regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
     if (regulator == NULL) {
         kfree(supply_name);
         return NULL;
     }
 
     regulator->rdev = rdev;
     regulator->supply_name = supply_name;
 
     regulator_lock(rdev);
     list_add(&regulator->list, &rdev->consumer_list);
     regulator_unlock(rdev);
 
     if (dev) {
         regulator->dev = dev;
 
         /* Add a link to the device sysfs entry */
         err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj,
                            supply_name);
         if (err) {
             rdev_dbg(rdev, "could not add device link %s: %pe\n",
                   dev->kobj.name, ERR_PTR(err));
             /* non-fatal */
         }
     }
 
     if (err != -EEXIST)
         regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs);
     if (!regulator->debugfs) {
         rdev_dbg(rdev, "Failed to create debugfs directory\n");
     } else {
         debugfs_create_u32("uA_load", 0444, regulator->debugfs,
                    &regulator->uA_load);
         debugfs_create_u32("min_uV", 0444, regulator->debugfs,
                    &regulator->voltage[PM_SUSPEND_ON].min_uV);
         debugfs_create_u32("max_uV", 0444, regulator->debugfs,
                    &regulator->voltage[PM_SUSPEND_ON].max_uV);
         debugfs_create_file("constraint_flags", 0444,
                     regulator->debugfs, regulator,
                     &constraint_flags_fops);
     }
 
     /*
      * Check now if the regulator is an always on regulator - if
      * it is then we don't need to do nearly so much work for
      * enable/disable calls.
      */
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS) &&
         _regulator_is_enabled(rdev))
         regulator->always_on = true;
 
     return regulator;
 }
 
 static int _regulator_get_enable_time(struct regulator_dev *rdev)
 {
     if (rdev->constraints && rdev->constraints->enable_time)
         return rdev->constraints->enable_time;
     if (rdev->desc->ops->enable_time)
         return rdev->desc->ops->enable_time(rdev);
     return rdev->desc->enable_time;
 }
 
 static struct regulator_supply_alias *regulator_find_supply_alias(
         struct device *dev, const char *supply)
 {
     struct regulator_supply_alias *map;
 
     list_for_each_entry(map, &regulator_supply_alias_list, list)
         if (map->src_dev == dev && strcmp(map->src_supply, supply) == 0)
             return map;
 
     return NULL;
 }
 
 static void regulator_supply_alias(struct device **dev, const char **supply)
 {
     struct regulator_supply_alias *map;
 
     map = regulator_find_supply_alias(*dev, *supply);
     if (map) {
         dev_dbg(*dev, "Mapping supply %s to %s,%s\n",
                 *supply, map->alias_supply,
                 dev_name(map->alias_dev));
         *dev = map->alias_dev;
         *supply = map->alias_supply;
     }
 }
 
 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.
  *
  * If successful, returns a struct regulator_dev that corresponds to the name
  * @supply and with the embedded struct device refcount incremented by one.
  * The refcount must be dropped by calling put_device().
  * On failure one of the following ERR-PTR-encoded values is returned:
  * -ENODEV if lookup fails permanently, -EPROBE_DEFER if lookup could succeed
  * in the future.
  */
 static struct regulator_dev *regulator_dev_lookup(struct device *dev,
                           const char *supply)
 {
     struct regulator_dev *r = NULL;
     struct device_node *node;
     struct regulator_map *map;
     const char *devname = NULL;
 
     regulator_supply_alias(&dev, &supply);
 
     /* first do a dt based lookup */
     if (dev && dev->of_node) {
         node = of_get_regulator(dev, supply);
         if (node) {
             r = of_find_regulator_by_node(node);
             if (r)
                 return r;
 
             /*
              * We have a node, but there is no device.
              * assume it has not registered yet.
              */
             return ERR_PTR(-EPROBE_DEFER);
         }
     }
 
     /* if not found, try doing it non-dt way */
     if (dev)
         devname = dev_name(dev);
 
     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 &&
             get_device(&map->regulator->dev)) {
             r = map->regulator;
             break;
         }
     }
     mutex_unlock(&regulator_list_mutex);
 
     if (r)
         return r;
 
     r = regulator_lookup_by_name(supply);
     if (r)
         return r;
 
     return ERR_PTR(-ENODEV);
 }
 
 static int regulator_resolve_supply(struct regulator_dev *rdev)
 {
     struct regulator_dev *r;
     struct device *dev = rdev->dev.parent;
     int ret = 0;
 
     /* No supply to resolve? */
     if (!rdev->supply_name)
         return 0;
 
     /* Supply already resolved? (fast-path without locking contention) */
     if (rdev->supply)
         return 0;
 
     r = regulator_dev_lookup(dev, rdev->supply_name);
     if (IS_ERR(r)) {
         ret = PTR_ERR(r);
 
         /* Did the lookup explicitly defer for us? */
         if (ret == -EPROBE_DEFER)
             goto out;
 
         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);
             ret = -EPROBE_DEFER;
             goto out;
         }
     }
 
     if (r == rdev) {
         dev_err(dev, "Supply for %s (%s) resolved to itself\n",
             rdev->desc->name, rdev->supply_name);
         if (!have_full_constraints()) {
             ret = -EINVAL;
             goto out;
         }
         r = dummy_regulator_rdev;
         get_device(&r->dev);
     }
 
     /*
      * If the supply's parent device is not the same as the
      * regulator's parent device, then ensure the parent device
      * is bound before we resolve the supply, in case the parent
      * device get probe deferred and unregisters the supply.
      */
     if (r->dev.parent && r->dev.parent != rdev->dev.parent) {
         if (!device_is_bound(r->dev.parent)) {
             put_device(&r->dev);
             ret = -EPROBE_DEFER;
             goto out;
         }
     }
 
     /* Recursively resolve the supply of the supply */
     ret = regulator_resolve_supply(r);
     if (ret < 0) {
         put_device(&r->dev);
         goto out;
     }
 
     /*
      * Recheck rdev->supply with rdev->mutex lock held to avoid a race
      * between rdev->supply null check and setting rdev->supply in
      * set_supply() from concurrent tasks.
      */
     regulator_lock(rdev);
 
     /* Supply just resolved by a concurrent task? */
     if (rdev->supply) {
         regulator_unlock(rdev);
         put_device(&r->dev);
         goto out;
     }
 
     ret = set_supply(rdev, r);
     if (ret < 0) {
         regulator_unlock(rdev);
         put_device(&r->dev);
         goto out;
     }
 
     regulator_unlock(rdev);
 
     /*
      * In set_machine_constraints() we may have turned this regulator on
      * but we couldn't propagate to the supply if it hadn't been resolved
      * yet.  Do it now.
      */
     if (rdev->use_count) {
         ret = regulator_enable(rdev->supply);
         if (ret < 0) {
             _regulator_put(rdev->supply);
             rdev->supply = NULL;
             goto out;
         }
     }
 
 out:
     return ret;
 }
 
 /* Internal regulator request function */
 struct regulator *_regulator_get(struct device *dev, const char *id,
                  enum regulator_get_type get_type)
 {
     struct regulator_dev *rdev;
     struct regulator *regulator;
     struct device_link *link;
     int ret;
 
     if (get_type >= MAX_GET_TYPE) {
         dev_err(dev, "invalid type %d in %s\n", get_type, __func__);
         return ERR_PTR(-EINVAL);
     }
 
     if (id == NULL) {
         pr_err("get() with no identifier\n");
         return ERR_PTR(-EINVAL);
     }
 
     rdev = regulator_dev_lookup(dev, id);
     if (IS_ERR(rdev)) {
         ret = PTR_ERR(rdev);
 
         /*
          * If regulator_dev_lookup() fails with error other
          * than -ENODEV our job here is done, we simply return it.
          */
         if (ret != -ENODEV)
             return ERR_PTR(ret);
 
         if (!have_full_constraints()) {
             dev_warn(dev,
                  "incomplete constraints, dummy supplies not allowed\n");
             return ERR_PTR(-ENODEV);
         }
 
         switch (get_type) {
         case NORMAL_GET:
             /*
              * Assume that a regulator is physically present and
              * enabled, even if it isn't hooked up, and just
              * provide a dummy.
              */
             dev_warn(dev, "supply %s not found, using dummy regulator\n", id);
             rdev = dummy_regulator_rdev;
             get_device(&rdev->dev);
             break;
 
         case EXCLUSIVE_GET:
             dev_warn(dev,
                  "dummy supplies not allowed for exclusive requests\n");
             fallthrough;
 
         default:
             return ERR_PTR(-ENODEV);
         }
     }
 
     if (rdev->exclusive) {
         regulator = ERR_PTR(-EPERM);
         put_device(&rdev->dev);
         return regulator;
     }
 
     if (get_type == EXCLUSIVE_GET && rdev->open_count) {
         regulator = ERR_PTR(-EBUSY);
         put_device(&rdev->dev);
         return regulator;
     }
 
     mutex_lock(&regulator_list_mutex);
     ret = (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled);
     mutex_unlock(&regulator_list_mutex);
 
     if (ret != 0) {
         regulator = ERR_PTR(-EPROBE_DEFER);
         put_device(&rdev->dev);
         return regulator;
     }
 
     ret = regulator_resolve_supply(rdev);
     if (ret < 0) {
         regulator = ERR_PTR(ret);
         put_device(&rdev->dev);
         return regulator;
     }
 
     if (!try_module_get(rdev->owner)) {
         regulator = ERR_PTR(-EPROBE_DEFER);
         put_device(&rdev->dev);
         return regulator;
     }
 
     regulator = create_regulator(rdev, dev, id);
     if (regulator == NULL) {
         regulator = ERR_PTR(-ENOMEM);
         module_put(rdev->owner);
         put_device(&rdev->dev);
         return regulator;
     }
 
     rdev->open_count++;
     if (get_type == EXCLUSIVE_GET) {
         rdev->exclusive = 1;
 
         ret = _regulator_is_enabled(rdev);
         if (ret > 0) {
             rdev->use_count = 1;
             regulator->enable_count = 1;
         } else {
             rdev->use_count = 0;
             regulator->enable_count = 0;
         }
     }
 
     link = device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
     if (!IS_ERR_OR_NULL(link))
         regulator->device_link = true;
 
     return regulator;
 }
 
 /**
  * regulator_get - lookup and obtain a reference to a regulator.
  * @dev: device for regulator "consumer"
  * @id: Supply name or regulator ID.
  *
  * Returns a struct regulator corresponding to the regulator producer,
  * or IS_ERR() condition containing errno.
  *
  * Use of supply names configured via set_consumer_device_supply() is
  * strongly encouraged.  It is recommended that the supply name used
  * should match the name used for the supply and/or the relevant
  * device pins in the datasheet.
  */
 struct regulator *regulator_get(struct device *dev, const char *id)
 {
     return _regulator_get(dev, id, NORMAL_GET);
 }
 EXPORT_SYMBOL_GPL(regulator_get);
 
 /**
  * regulator_get_exclusive - obtain exclusive access to a regulator.
  * @dev: device for regulator "consumer"
  * @id: Supply name or regulator ID.
  *
  * Returns a struct regulator corresponding to the regulator producer,
  * or IS_ERR() condition containing errno.  Other consumers will be
  * unable to obtain this regulator while this reference is held and the
  * use count for the regulator will be initialised to reflect the current
  * state of the regulator.
  *
  * This is intended for use by consumers which cannot tolerate shared
  * use of the regulator such as those which need to force the
  * regulator off for correct operation of the hardware they are
  * controlling.
  *
  * Use of supply names configured via set_consumer_device_supply() is
  * strongly encouraged.  It is recommended that the supply name used
  * should match the name used for the supply and/or the relevant
  * device pins in the datasheet.
  */
 struct regulator *regulator_get_exclusive(struct device *dev, const char *id)
 {
     return _regulator_get(dev, id, EXCLUSIVE_GET);
 }
 EXPORT_SYMBOL_GPL(regulator_get_exclusive);
 
 /**
  * regulator_get_optional - obtain optional access to a regulator.
  * @dev: device for regulator "consumer"
  * @id: Supply name or regulator ID.
  *
  * Returns a struct regulator corresponding to the regulator producer,
  * or IS_ERR() condition containing errno.
  *
  * This is intended for use by consumers for devices which can have
  * some supplies unconnected in normal use, such as some MMC devices.
  * It can allow the regulator core to provide stub supplies for other
  * supplies requested using normal regulator_get() calls without
  * disrupting the operation of drivers that can handle absent
  * supplies.
  *
  * Use of supply names configured via set_consumer_device_supply() is
  * strongly encouraged.  It is recommended that the supply name used
  * should match the name used for the supply and/or the relevant
  * device pins in the datasheet.
  */
 struct regulator *regulator_get_optional(struct device *dev, const char *id)
 {
     return _regulator_get(dev, id, OPTIONAL_GET);
 }
 EXPORT_SYMBOL_GPL(regulator_get_optional);
 
 static void destroy_regulator(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
 
     debugfs_remove_recursive(regulator->debugfs);
 
     if (regulator->dev) {
         if (regulator->device_link)
             device_link_remove(regulator->dev, &rdev->dev);
 
         /* remove any sysfs entries */
         sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
     }
 
     regulator_lock(rdev);
     list_del(&regulator->list);
 
     rdev->open_count--;
     rdev->exclusive = 0;
     regulator_unlock(rdev);
 
     kfree_const(regulator->supply_name);
     kfree(regulator);
 }
 
 /* regulator_list_mutex lock held by regulator_put() */
 static void _regulator_put(struct regulator *regulator)
 {
     struct regulator_dev *rdev;
 
     if (IS_ERR_OR_NULL(regulator))
         return;
 
     lockdep_assert_held_once(&regulator_list_mutex);
 
     /* Docs say you must disable before calling regulator_put() */
     WARN_ON(regulator->enable_count);
 
     rdev = regulator->rdev;
 
     destroy_regulator(regulator);
 
     module_put(rdev->owner);
     put_device(&rdev->dev);
 }
 
 /**
  * regulator_put - "free" the regulator source
  * @regulator: regulator source
  *
  * Note: drivers must ensure that all regulator_enable calls made on this
  * regulator source are balanced by regulator_disable calls prior to calling
  * this function.
  */
 void regulator_put(struct regulator *regulator)
 {
     mutex_lock(&regulator_list_mutex);
     _regulator_put(regulator);
     mutex_unlock(&regulator_list_mutex);
 }
 EXPORT_SYMBOL_GPL(regulator_put);
 
 /**
  * regulator_register_supply_alias - Provide device alias for supply lookup
  *
  * @dev: device that will be given as the regulator "consumer"
  * @id: Supply name or regulator ID
  * @alias_dev: device that should be used to lookup the supply
  * @alias_id: Supply name or regulator ID that should be used to lookup the
  * supply
  *
  * All lookups for id on dev will instead be conducted for alias_id on
  * alias_dev.
  */
 int regulator_register_supply_alias(struct device *dev, const char *id,
                     struct device *alias_dev,
                     const char *alias_id)
 {
     struct regulator_supply_alias *map;
 
     map = regulator_find_supply_alias(dev, id);
     if (map)
         return -EEXIST;
 
     map = kzalloc(sizeof(struct regulator_supply_alias), GFP_KERNEL);
     if (!map)
         return -ENOMEM;
 
     map->src_dev = dev;
     map->src_supply = id;
     map->alias_dev = alias_dev;
     map->alias_supply = alias_id;
 
     list_add(&map->list, &regulator_supply_alias_list);
 
     pr_info("Adding alias for supply %s,%s -> %s,%s\n",
         id, dev_name(dev), alias_id, dev_name(alias_dev));
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(regulator_register_supply_alias);
 
 /**
  * regulator_unregister_supply_alias - Remove device alias
  *
  * @dev: device that will be given as the regulator "consumer"
  * @id: Supply name or regulator ID
  *
  * Remove a lookup alias if one exists for id on dev.
  */
 void regulator_unregister_supply_alias(struct device *dev, const char *id)
 {
     struct regulator_supply_alias *map;
 
     map = regulator_find_supply_alias(dev, id);
     if (map) {
         list_del(&map->list);
         kfree(map);
     }
 }
 EXPORT_SYMBOL_GPL(regulator_unregister_supply_alias);
 
 /**
  * regulator_bulk_register_supply_alias - register multiple aliases
  *
  * @dev: device that will be given as the regulator "consumer"
  * @id: List of supply names or regulator IDs
  * @alias_dev: device that should be used to lookup the supply
  * @alias_id: List of supply names or regulator IDs that should be used to
  * lookup the supply
  * @num_id: Number of aliases to register
  *
  * @return 0 on success, an errno on failure.
  *
  * This helper function allows drivers to register several supply
  * aliases in one operation.  If any of the aliases cannot be
  * registered any aliases that were registered will be removed
  * before returning to the caller.
  */
 int regulator_bulk_register_supply_alias(struct device *dev,
                      const char *const *id,
                      struct device *alias_dev,
                      const char *const *alias_id,
                      int num_id)
 {
     int i;
     int ret;
 
     for (i = 0; i < num_id; ++i) {
         ret = regulator_register_supply_alias(dev, id[i], alias_dev,
                               alias_id[i]);
         if (ret < 0)
             goto err;
     }
 
     return 0;
 
 err:
     dev_err(dev,
         "Failed to create supply alias %s,%s -> %s,%s\n",
         id[i], dev_name(dev), alias_id[i], dev_name(alias_dev));
 
     while (--i >= 0)
         regulator_unregister_supply_alias(dev, id[i]);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_register_supply_alias);
 
 /**
  * regulator_bulk_unregister_supply_alias - unregister multiple aliases
  *
  * @dev: device that will be given as the regulator "consumer"
  * @id: List of supply names or regulator IDs
  * @num_id: Number of aliases to unregister
  *
  * This helper function allows drivers to unregister several supply
  * aliases in one operation.
  */
 void regulator_bulk_unregister_supply_alias(struct device *dev,
                         const char *const *id,
                         int num_id)
 {
     int i;
 
     for (i = 0; i < num_id; ++i)
         regulator_unregister_supply_alias(dev, id[i]);
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_unregister_supply_alias);
 
 
 /* Manage enable GPIO list. Same GPIO pin can be shared among regulators */
 static int regulator_ena_gpio_request(struct regulator_dev *rdev,
                 const struct regulator_config *config)
 {
     struct regulator_enable_gpio *pin, *new_pin;
     struct gpio_desc *gpiod;
 
     gpiod = config->ena_gpiod;
     new_pin = kzalloc(sizeof(*new_pin), GFP_KERNEL);
 
     mutex_lock(&regulator_list_mutex);
 
     list_for_each_entry(pin, &regulator_ena_gpio_list, list) {
         if (pin->gpiod == gpiod) {
             rdev_dbg(rdev, "GPIO is already used\n");
             goto update_ena_gpio_to_rdev;
         }
     }
 
     if (new_pin == NULL) {
         mutex_unlock(&regulator_list_mutex);
         return -ENOMEM;
     }
 
     pin = new_pin;
     new_pin = NULL;
 
     pin->gpiod = gpiod;
     list_add(&pin->list, &regulator_ena_gpio_list);
 
 update_ena_gpio_to_rdev:
     pin->request_count++;
     rdev->ena_pin = pin;
 
     mutex_unlock(&regulator_list_mutex);
     kfree(new_pin);
 
     return 0;
 }
 
 static void regulator_ena_gpio_free(struct regulator_dev *rdev)
 {
     struct regulator_enable_gpio *pin, *n;
 
     if (!rdev->ena_pin)
         return;
 
     /* Free the GPIO only in case of no use */
     list_for_each_entry_safe(pin, n, &regulator_ena_gpio_list, list) {
         if (pin != rdev->ena_pin)
             continue;
 
         if (--pin->request_count)
             break;
 
         gpiod_put(pin->gpiod);
         list_del(&pin->list);
         kfree(pin);
         break;
     }
 
     rdev->ena_pin = NULL;
 }
 
 /**
  * regulator_ena_gpio_ctrl - balance enable_count of each GPIO and actual GPIO pin control
  * @rdev: regulator_dev structure
  * @enable: enable GPIO at initial use?
  *
  * GPIO is enabled in case of initial use. (enable_count is 0)
  * GPIO is disabled when it is not shared any more. (enable_count <= 1)
  */
 static int regulator_ena_gpio_ctrl(struct regulator_dev *rdev, bool enable)
 {
     struct regulator_enable_gpio *pin = rdev->ena_pin;
 
     if (!pin)
         return -EINVAL;
 
     if (enable) {
         /* Enable GPIO at initial use */
         if (pin->enable_count == 0)
             gpiod_set_value_cansleep(pin->gpiod, 1);
 
         pin->enable_count++;
     } else {
         if (pin->enable_count > 1) {
             pin->enable_count--;
             return 0;
         }
 
         /* Disable GPIO if not used */
         if (pin->enable_count <= 1) {
             gpiod_set_value_cansleep(pin->gpiod, 0);
             pin->enable_count = 0;
         }
     }
 
     return 0;
 }
 
 /**
  * _regulator_delay_helper - a delay helper function
  * @delay: time to delay in microseconds
  *
  * Delay for the requested amount of time as per the guidelines in:
  *
  *     Documentation/timers/timers-howto.rst
  *
  * The assumption here is that these regulator operations will never used in
  * atomic context and therefore sleeping functions can be used.
  */
 static void _regulator_delay_helper(unsigned int delay)
 {
     unsigned int ms = delay / 1000;
     unsigned int us = delay % 1000;
 
     if (ms > 0) {
         /*
          * For small enough values, handle super-millisecond
          * delays in the usleep_range() call below.
          */
         if (ms < 20)
             us += ms * 1000;
         else
             msleep(ms);
     }
 
     /*
      * Give the scheduler some room to coalesce with any other
      * wakeup sources. For delays shorter than 10 us, don't even
      * bother setting up high-resolution timers and just busy-
      * loop.
      */
     if (us >= 10)
         usleep_range(us, us + 100);
     else
         udelay(us);
 }
 
 /**
  * _regulator_check_status_enabled
  *
  * A helper function to check if the regulator status can be interpreted
  * as 'regulator is enabled'.
  * @rdev: the regulator device to check
  *
  * Return:
  * * 1          - if status shows regulator is in enabled state
  * * 0          - if not enabled state
  * * Error Value    - as received from ops->get_status()
  */
 static inline int _regulator_check_status_enabled(struct regulator_dev *rdev)
 {
     int ret = rdev->desc->ops->get_status(rdev);
 
     if (ret < 0) {
         rdev_info(rdev, "get_status returned error: %d\n", ret);
         return ret;
     }
 
     switch (ret) {
     case REGULATOR_STATUS_OFF:
     case REGULATOR_STATUS_ERROR:
     case REGULATOR_STATUS_UNDEFINED:
         return 0;
     default:
         return 1;
     }
 }
 
 static int _regulator_do_enable(struct regulator_dev *rdev)
 {
     int ret, delay;
 
     /* Query before enabling in case configuration dependent.  */
     ret = _regulator_get_enable_time(rdev);
     if (ret >= 0) {
         delay = ret;
     } else {
         rdev_warn(rdev, "enable_time() failed: %pe\n", ERR_PTR(ret));
         delay = 0;
     }
 
     trace_regulator_enable(rdev_get_name(rdev));
 
     if (rdev->desc->off_on_delay && rdev->last_off) {
         /* if needed, keep a distance of off_on_delay from last time
          * this regulator was disabled.
          */
         ktime_t end = ktime_add_us(rdev->last_off, rdev->desc->off_on_delay);
         s64 remaining = ktime_us_delta(end, ktime_get());
 
         if (remaining > 0)
             _regulator_delay_helper(remaining);
     }
 
     if (rdev->ena_pin) {
         if (!rdev->ena_gpio_state) {
             ret = regulator_ena_gpio_ctrl(rdev, true);
             if (ret < 0)
                 return ret;
             rdev->ena_gpio_state = 1;
         }
     } else if (rdev->desc->ops->enable) {
         ret = rdev->desc->ops->enable(rdev);
         if (ret < 0)
             return ret;
     } else {
         return -EINVAL;
     }
 
     /* Allow the regulator to ramp; it would be useful to extend
      * this for bulk operations so that the regulators can ramp
      * together.
      */
     trace_regulator_enable_delay(rdev_get_name(rdev));
 
     /* If poll_enabled_time is set, poll upto the delay calculated
      * above, delaying poll_enabled_time uS to check if the regulator
      * actually got enabled.
      * If the regulator isn't enabled after our delay helper has expired,
      * return -ETIMEDOUT.
      */
     if (rdev->desc->poll_enabled_time) {
         unsigned int time_remaining = delay;
 
         while (time_remaining > 0) {
             _regulator_delay_helper(rdev->desc->poll_enabled_time);
 
             if (rdev->desc->ops->get_status) {
                 ret = _regulator_check_status_enabled(rdev);
                 if (ret < 0)
                     return ret;
                 else if (ret)
                     break;
             } else if (rdev->desc->ops->is_enabled(rdev))
                 break;
 
             time_remaining -= rdev->desc->poll_enabled_time;
         }
 
         if (time_remaining <= 0) {
             rdev_err(rdev, "Enabled check timed out\n");
             return -ETIMEDOUT;
         }
     } else {
         _regulator_delay_helper(delay);
     }
 
     trace_regulator_enable_complete(rdev_get_name(rdev));
 
     return 0;
 }
 
 /**
  * _regulator_handle_consumer_enable - handle that a consumer enabled
  * @regulator: regulator source
  *
  * Some things on a regulator consumer (like the contribution towards total
  * load on the regulator) only have an effect when the consumer wants the
  * regulator enabled.  Explained in example with two consumers of the same
  * regulator:
  *   consumer A: set_load(100);       => total load = 0
  *   consumer A: regulator_enable();  => total load = 100
  *   consumer B: set_load(1000);      => total load = 100
  *   consumer B: regulator_enable();  => total load = 1100
  *   consumer A: regulator_disable(); => total_load = 1000
  *
  * This function (together with _regulator_handle_consumer_disable) is
  * responsible for keeping track of the refcount for a given regulator consumer
  * and applying / unapplying these things.
  *
  * Returns 0 upon no error; -error upon error.
  */
 static int _regulator_handle_consumer_enable(struct regulator *regulator)
 {
     int ret;
     struct regulator_dev *rdev = regulator->rdev;
 
     lockdep_assert_held_once(&rdev->mutex.base);
 
     regulator->enable_count++;
     if (regulator->uA_load && regulator->enable_count == 1) {
         ret = drms_uA_update(rdev);
         if (ret)
             regulator->enable_count--;
         return ret;
     }
 
     return 0;
 }
 
 /**
  * _regulator_handle_consumer_disable - handle that a consumer disabled
  * @regulator: regulator source
  *
  * The opposite of _regulator_handle_consumer_enable().
  *
  * Returns 0 upon no error; -error upon error.
  */
 static int _regulator_handle_consumer_disable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
 
     lockdep_assert_held_once(&rdev->mutex.base);
 
     if (!regulator->enable_count) {
         rdev_err(rdev, "Underflow of regulator enable count\n");
         return -EINVAL;
     }
 
     regulator->enable_count--;
     if (regulator->uA_load && regulator->enable_count == 0)
         return drms_uA_update(rdev);
 
     return 0;
 }
 
 /* locks held by regulator_enable() */
 static int _regulator_enable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int ret;
 
     lockdep_assert_held_once(&rdev->mutex.base);
 
     if (rdev->use_count == 0 && rdev->supply) {
         ret = _regulator_enable(rdev->supply);
         if (ret < 0)
             return ret;
     }
 
     /* balance only if there are regulators coupled */
     if (rdev->coupling_desc.n_coupled > 1) {
         ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
         if (ret < 0)
             goto err_disable_supply;
     }
 
     ret = _regulator_handle_consumer_enable(regulator);
     if (ret < 0)
         goto err_disable_supply;
 
     if (rdev->use_count == 0) {
         /*
          * The regulator may already be enabled if it's not switchable
          * or was left on
          */
         ret = _regulator_is_enabled(rdev);
         if (ret == -EINVAL || ret == 0) {
             if (!regulator_ops_is_valid(rdev,
                     REGULATOR_CHANGE_STATUS)) {
                 ret = -EPERM;
                 goto err_consumer_disable;
             }
 
             ret = _regulator_do_enable(rdev);
             if (ret < 0)
                 goto err_consumer_disable;
 
             _notifier_call_chain(rdev, REGULATOR_EVENT_ENABLE,
                          NULL);
         } else if (ret < 0) {
             rdev_err(rdev, "is_enabled() failed: %pe\n", ERR_PTR(ret));
             goto err_consumer_disable;
         }
         /* Fallthrough on positive return values - already enabled */
     }
 
     rdev->use_count++;
 
     return 0;
 
 err_consumer_disable:
     _regulator_handle_consumer_disable(regulator);
 
 err_disable_supply:
     if (rdev->use_count == 0 && rdev->supply)
         _regulator_disable(rdev->supply);
 
     return ret;
 }
 
 /**
  * regulator_enable - enable regulator output
  * @regulator: regulator source
  *
  * Request that the regulator be enabled with the regulator output at
  * the predefined voltage or current value.  Calls to regulator_enable()
  * must be balanced with calls to regulator_disable().
  *
  * NOTE: the output value can be set by other drivers, boot loader or may be
  * hardwired in the regulator.
  */
 int regulator_enable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     regulator_lock_dependent(rdev, &ww_ctx);
     ret = _regulator_enable(regulator);
     regulator_unlock_dependent(rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_enable);
 
 static int _regulator_do_disable(struct regulator_dev *rdev)
 {
     int ret;
 
     trace_regulator_disable(rdev_get_name(rdev));
 
     if (rdev->ena_pin) {
         if (rdev->ena_gpio_state) {
             ret = regulator_ena_gpio_ctrl(rdev, false);
             if (ret < 0)
                 return ret;
             rdev->ena_gpio_state = 0;
         }
 
     } else if (rdev->desc->ops->disable) {
         ret = rdev->desc->ops->disable(rdev);
         if (ret != 0)
             return ret;
     }
 
     if (rdev->desc->off_on_delay)
         rdev->last_off = ktime_get();
 
     trace_regulator_disable_complete(rdev_get_name(rdev));
 
     return 0;
 }
 
 /* locks held by regulator_disable() */
 static int _regulator_disable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int ret = 0;
 
     lockdep_assert_held_once(&rdev->mutex.base);
 
     if (WARN(rdev->use_count <= 0,
          "unbalanced disables for %s\n", rdev_get_name(rdev)))
         return -EIO;
 
     /* are we the last user and permitted to disable ? */
     if (rdev->use_count == 1 &&
         (rdev->constraints && !rdev->constraints->always_on)) {
 
         /* we are last user */
         if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) {
             ret = _notifier_call_chain(rdev,
                            REGULATOR_EVENT_PRE_DISABLE,
                            NULL);
             if (ret & NOTIFY_STOP_MASK)
                 return -EINVAL;
 
             ret = _regulator_do_disable(rdev);
             if (ret < 0) {
                 rdev_err(rdev, "failed to disable: %pe\n", ERR_PTR(ret));
                 _notifier_call_chain(rdev,
                         REGULATOR_EVENT_ABORT_DISABLE,
                         NULL);
                 return ret;
             }
             _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE,
                     NULL);
         }
 
         rdev->use_count = 0;
     } else if (rdev->use_count > 1) {
         rdev->use_count--;
     }
 
     if (ret == 0)
         ret = _regulator_handle_consumer_disable(regulator);
 
     if (ret == 0 && rdev->coupling_desc.n_coupled > 1)
         ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
 
     if (ret == 0 && rdev->use_count == 0 && rdev->supply)
         ret = _regulator_disable(rdev->supply);
 
     return ret;
 }
 
 /**
  * regulator_disable - disable regulator output
  * @regulator: regulator source
  *
  * Disable the regulator output voltage or current.  Calls to
  * regulator_enable() must be balanced with calls to
  * regulator_disable().
  *
  * NOTE: this will only disable the regulator output if no other consumer
  * devices have it enabled, the regulator device supports disabling and
  * machine constraints permit this operation.
  */
 int regulator_disable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     regulator_lock_dependent(rdev, &ww_ctx);
     ret = _regulator_disable(regulator);
     regulator_unlock_dependent(rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_disable);
 
 /* locks held by regulator_force_disable() */
 static int _regulator_force_disable(struct regulator_dev *rdev)
 {
     int ret = 0;
 
     lockdep_assert_held_once(&rdev->mutex.base);
 
     ret = _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
             REGULATOR_EVENT_PRE_DISABLE, NULL);
     if (ret & NOTIFY_STOP_MASK)
         return -EINVAL;
 
     ret = _regulator_do_disable(rdev);
     if (ret < 0) {
         rdev_err(rdev, "failed to force disable: %pe\n", ERR_PTR(ret));
         _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
                 REGULATOR_EVENT_ABORT_DISABLE, NULL);
         return ret;
     }
 
     _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
             REGULATOR_EVENT_DISABLE, NULL);
 
     return 0;
 }
 
 /**
  * regulator_force_disable - force disable regulator output
  * @regulator: regulator source
  *
  * Forcibly disable the regulator output voltage or current.
  * NOTE: this *will* disable the regulator output even if other consumer
  * devices have it enabled. This should be used for situations when device
  * damage will likely occur if the regulator is not disabled (e.g. over temp).
  */
 int regulator_force_disable(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     regulator_lock_dependent(rdev, &ww_ctx);
 
     ret = _regulator_force_disable(regulator->rdev);
 
     if (rdev->coupling_desc.n_coupled > 1)
         regulator_balance_voltage(rdev, PM_SUSPEND_ON);
 
     if (regulator->uA_load) {
         regulator->uA_load = 0;
         ret = drms_uA_update(rdev);
     }
 
     if (rdev->use_count != 0 && rdev->supply)
         _regulator_disable(rdev->supply);
 
     regulator_unlock_dependent(rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_force_disable);
 
 static void regulator_disable_work(struct work_struct *work)
 {
     struct regulator_dev *rdev = container_of(work, struct regulator_dev,
                           disable_work.work);
     struct ww_acquire_ctx ww_ctx;
     int count, i, ret;
     struct regulator *regulator;
     int total_count = 0;
 
     regulator_lock_dependent(rdev, &ww_ctx);
 
     /*
      * Workqueue functions queue the new work instance while the previous
      * work instance is being processed. Cancel the queued work instance
      * as the work instance under processing does the job of the queued
      * work instance.
      */
     cancel_delayed_work(&rdev->disable_work);
 
     list_for_each_entry(regulator, &rdev->consumer_list, list) {
         count = regulator->deferred_disables;
 
         if (!count)
             continue;
 
         total_count += count;
         regulator->deferred_disables = 0;
 
         for (i = 0; i < count; i++) {
             ret = _regulator_disable(regulator);
             if (ret != 0)
                 rdev_err(rdev, "Deferred disable failed: %pe\n",
                      ERR_PTR(ret));
         }
     }
     WARN_ON(!total_count);
 
     if (rdev->coupling_desc.n_coupled > 1)
         regulator_balance_voltage(rdev, PM_SUSPEND_ON);
 
     regulator_unlock_dependent(rdev, &ww_ctx);
 }
 
 /**
  * regulator_disable_deferred - disable regulator output with delay
  * @regulator: regulator source
  * @ms: milliseconds until the regulator is disabled
  *
  * Execute regulator_disable() on the regulator after a delay.  This
  * is intended for use with devices that require some time to quiesce.
  *
  * NOTE: this will only disable the regulator output if no other consumer
  * devices have it enabled, the regulator device supports disabling and
  * machine constraints permit this operation.
  */
 int regulator_disable_deferred(struct regulator *regulator, int ms)
 {
     struct regulator_dev *rdev = regulator->rdev;
 
     if (!ms)
         return regulator_disable(regulator);
 
     regulator_lock(rdev);
     regulator->deferred_disables++;
     mod_delayed_work(system_power_efficient_wq, &rdev->disable_work,
              msecs_to_jiffies(ms));
     regulator_unlock(rdev);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(regulator_disable_deferred);
 
 static int _regulator_is_enabled(struct regulator_dev *rdev)
 {
     /* A GPIO control always takes precedence */
     if (rdev->ena_pin)
         return rdev->ena_gpio_state;
 
     /* If we don't know then assume that the regulator is always on */
     if (!rdev->desc->ops->is_enabled)
         return 1;
 
     return rdev->desc->ops->is_enabled(rdev);
 }
 
 static int _regulator_list_voltage(struct regulator_dev *rdev,
                    unsigned selector, int lock)
 {
     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 (selector < rdev->desc->linear_min_sel)
             return 0;
         if (lock)
             regulator_lock(rdev);
         ret = ops->list_voltage(rdev, selector);
         if (lock)
             regulator_unlock(rdev);
     } else if (rdev->is_switch && rdev->supply) {
         ret = _regulator_list_voltage(rdev->supply->rdev,
                           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
  *
  * Returns positive if the regulator driver backing the source/client
  * has requested that the device be enabled, zero if it hasn't, else a
  * negative errno code.
  *
  * Note that the device backing this regulator handle can have multiple
  * users, so it might be enabled even if regulator_enable() was never
  * called for this particular source.
  */
 int regulator_is_enabled(struct regulator *regulator)
 {
     int ret;
 
     if (regulator->always_on)
         return 1;
 
     regulator_lock(regulator->rdev);
     ret = _regulator_is_enabled(regulator->rdev);
     regulator_unlock(regulator->rdev);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_is_enabled);
 
 /**
  * regulator_count_voltages - count regulator_list_voltage() selectors
  * @regulator: regulator source
  *
  * Returns number of selectors, or negative errno.  Selectors are
  * numbered starting at zero, and typically correspond to bitfields
  * in hardware registers.
  */
 int regulator_count_voltages(struct regulator *regulator)
 {
     struct regulator_dev    *rdev = regulator->rdev;
 
     if (rdev->desc->n_voltages)
         return rdev->desc->n_voltages;
 
     if (!rdev->is_switch || !rdev->supply)
         return -EINVAL;
 
     return regulator_count_voltages(rdev->supply);
 }
 EXPORT_SYMBOL_GPL(regulator_count_voltages);
 
 /**
  * regulator_list_voltage - enumerate supported voltages
  * @regulator: regulator source
  * @selector: identify voltage to list
  * Context: can sleep
  *
  * Returns a voltage that can be passed to @regulator_set_voltage(),
  * zero if this selector code can't be used on this system, or a
  * negative errno.
  */
 int regulator_list_voltage(struct regulator *regulator, unsigned selector)
 {
     return _regulator_list_voltage(regulator->rdev, selector, 1);
 }
 EXPORT_SYMBOL_GPL(regulator_list_voltage);
 
 /**
  * regulator_get_regmap - get the regulator's register map
  * @regulator: regulator source
  *
  * Returns the register map for the given regulator, or an ERR_PTR value
  * if the regulator doesn't use regmap.
  */
 struct regmap *regulator_get_regmap(struct regulator *regulator)
 {
     struct regmap *map = regulator->rdev->regmap;
 
     return map ? map : ERR_PTR(-EOPNOTSUPP);
 }
 
 /**
  * regulator_get_hardware_vsel_register - get the HW voltage selector register
  * @regulator: regulator source
  * @vsel_reg: voltage selector register, output parameter
  * @vsel_mask: mask for voltage selector bitfield, output parameter
  *
  * Returns the hardware register offset and bitmask used for setting the
  * regulator voltage. This might be useful when configuring voltage-scaling
  * hardware or firmware that can make I2C requests behind the kernel's back,
  * for example.
  *
  * On success, the output parameters @vsel_reg and @vsel_mask are filled in
  * and 0 is returned, otherwise a negative errno is returned.
  */
 int regulator_get_hardware_vsel_register(struct regulator *regulator,
                      unsigned *vsel_reg,
                      unsigned *vsel_mask)
 {
     struct regulator_dev *rdev = regulator->rdev;
     const struct regulator_ops *ops = rdev->desc->ops;
 
     if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
         return -EOPNOTSUPP;
 
     *vsel_reg = rdev->desc->vsel_reg;
     *vsel_mask = rdev->desc->vsel_mask;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(regulator_get_hardware_vsel_register);
 
 /**
  * regulator_list_hardware_vsel - get the HW-specific register value for a selector
  * @regulator: regulator source
  * @selector: identify voltage to list
  *
  * Converts the selector to a hardware-specific voltage selector that can be
  * directly written to the regulator registers. The address of the voltage
  * register can be determined by calling @regulator_get_hardware_vsel_register.
  *
  * On error a negative errno is returned.
  */
 int regulator_list_hardware_vsel(struct regulator *regulator,
                  unsigned selector)
 {
     struct regulator_dev *rdev = regulator->rdev;
     const struct regulator_ops *ops = rdev->desc->ops;
 
     if (selector >= rdev->desc->n_voltages)
         return -EINVAL;
     if (selector < rdev->desc->linear_min_sel)
         return 0;
     if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
         return -EOPNOTSUPP;
 
     return selector;
 }
 EXPORT_SYMBOL_GPL(regulator_list_hardware_vsel);
 
 /**
  * regulator_get_linear_step - return the voltage step size between VSEL values
  * @regulator: regulator source
  *
  * Returns the voltage step size between VSEL values for linear
  * regulators, or return 0 if the regulator isn't a linear regulator.
  */
 unsigned int regulator_get_linear_step(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
 
     return rdev->desc->uV_step;
 }
 EXPORT_SYMBOL_GPL(regulator_get_linear_step);
 
 /**
  * regulator_is_supported_voltage - check if a voltage range can be supported
  *
  * @regulator: Regulator to check.
  * @min_uV: Minimum required voltage in uV.
  * @max_uV: Maximum required voltage in uV.
  *
  * Returns a boolean.
  */
 int regulator_is_supported_voltage(struct regulator *regulator,
                    int min_uV, int max_uV)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int i, voltages, ret;
 
     /* If we can't change voltage check the current voltage */
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
         ret = regulator_get_voltage(regulator);
         if (ret >= 0)
             return min_uV <= ret && ret <= max_uV;
         else
             return ret;
     }
 
     /* Any voltage within constrains range is fine? */
     if (rdev->desc->continuous_voltage_range)
         return min_uV >= rdev->constraints->min_uV &&
                 max_uV <= rdev->constraints->max_uV;
 
     ret = regulator_count_voltages(regulator);
     if (ret < 0)
         return 0;
     voltages = ret;
 
     for (i = 0; i < voltages; i++) {
         ret = regulator_list_voltage(regulator, i);
 
         if (ret >= min_uV && ret <= max_uV)
             return 1;
     }
 
     return 0;
 }
 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);
 
     if (desc->ops->list_voltage ==
         regulator_list_voltage_pickable_linear_range)
         return regulator_map_voltage_pickable_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)
 {
     struct pre_voltage_change_data data;
     int ret;
 
     data.old_uV = regulator_get_voltage_rdev(rdev);
     data.min_uV = min_uV;
     data.max_uV = max_uV;
     ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,
                    &data);
     if (ret & NOTIFY_STOP_MASK)
         return -EINVAL;
 
     ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV, selector);
     if (ret >= 0)
         return ret;
 
     _notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE,
                  (void *)data.old_uV);
 
     return ret;
 }
 
 static int _regulator_call_set_voltage_sel(struct regulator_dev *rdev,
                        int uV, unsigned selector)
 {
     struct pre_voltage_change_data data;
     int ret;
 
     data.old_uV = regulator_get_voltage_rdev(rdev);
     data.min_uV = uV;
     data.max_uV = uV;
     ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,
                    &data);
     if (ret & NOTIFY_STOP_MASK)
         return -EINVAL;
 
     ret = rdev->desc->ops->set_voltage_sel(rdev, selector);
     if (ret >= 0)
         return ret;
 
     _notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE,
                  (void *)data.old_uV);
 
     return ret;
 }
 
 static int _regulator_set_voltage_sel_step(struct regulator_dev *rdev,
                        int uV, int new_selector)
 {
     const struct regulator_ops *ops = rdev->desc->ops;
     int diff, old_sel, curr_sel, ret;
 
     /* Stepping is only needed if the regulator is enabled. */
     if (!_regulator_is_enabled(rdev))
         goto final_set;
 
     if (!ops->get_voltage_sel)
         return -EINVAL;
 
     old_sel = ops->get_voltage_sel(rdev);
     if (old_sel < 0)
         return old_sel;
 
     diff = new_selector - old_sel;
     if (diff == 0)
         return 0; /* No change needed. */
 
     if (diff > 0) {
         /* Stepping up. */
         for (curr_sel = old_sel + rdev->desc->vsel_step;
              curr_sel < new_selector;
              curr_sel += rdev->desc->vsel_step) {
             /*
              * Call the callback directly instead of using
              * _regulator_call_set_voltage_sel() as we don't
              * want to notify anyone yet. Same in the branch
              * below.
              */
             ret = ops->set_voltage_sel(rdev, curr_sel);
             if (ret)
                 goto try_revert;
         }
     } else {
         /* Stepping down. */
         for (curr_sel = old_sel - rdev->desc->vsel_step;
              curr_sel > new_selector;
              curr_sel -= rdev->desc->vsel_step) {
             ret = ops->set_voltage_sel(rdev, curr_sel);
             if (ret)
                 goto try_revert;
         }
     }
 
 final_set:
     /* The final selector will trigger the notifiers. */
     return _regulator_call_set_voltage_sel(rdev, uV, new_selector);
 
 try_revert:
     /*
      * At least try to return to the previous voltage if setting a new
      * one failed.
      */
     (void)ops->set_voltage_sel(rdev, old_sel);
     return ret;
 }
 
 static int _regulator_set_voltage_time(struct regulator_dev *rdev,
                        int old_uV, int new_uV)
 {
     unsigned int ramp_delay = 0;
 
     if (rdev->constraints->ramp_delay)
         ramp_delay = rdev->constraints->ramp_delay;
     else if (rdev->desc->ramp_delay)
         ramp_delay = rdev->desc->ramp_delay;
     else if (rdev->constraints->settling_time)
         return rdev->constraints->settling_time;
     else if (rdev->constraints->settling_time_up &&
          (new_uV > old_uV))
         return rdev->constraints->settling_time_up;
     else if (rdev->constraints->settling_time_down &&
          (new_uV < old_uV))
         return rdev->constraints->settling_time_down;
 
     if (ramp_delay == 0) {
         rdev_dbg(rdev, "ramp_delay not set\n");
         return 0;
     }
 
     return DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay);
 }
 
 static int _regulator_do_set_voltage(struct regulator_dev *rdev,
                      int min_uV, int max_uV)
 {
     int ret;
     int delay = 0;
     int best_val = 0;
     unsigned int selector;
     int old_selector = -1;
     const struct regulator_ops *ops = rdev->desc->ops;
     int old_uV = regulator_get_voltage_rdev(rdev);
 
     trace_regulator_set_voltage(rdev_get_name(rdev), min_uV, max_uV);
 
     min_uV += rdev->constraints->uV_offset;
     max_uV += rdev->constraints->uV_offset;
 
     /*
      * If we can't obtain the old selector there is not enough
      * info to call set_voltage_time_sel().
      */
     if (_regulator_is_enabled(rdev) &&
         ops->set_voltage_time_sel && ops->get_voltage_sel) {
         old_selector = ops->get_voltage_sel(rdev);
         if (old_selector < 0)
             return old_selector;
     }
 
     if (ops->set_voltage) {
         ret = _regulator_call_set_voltage(rdev, min_uV, max_uV,
                           &selector);
 
         if (ret >= 0) {
             if (ops->list_voltage)
                 best_val = ops->list_voltage(rdev,
                                  selector);
             else
                 best_val = regulator_get_voltage_rdev(rdev);
         }
 
     } else if (ops->set_voltage_sel) {
         ret = regulator_map_voltage(rdev, min_uV, max_uV);
         if (ret >= 0) {
             best_val = ops->list_voltage(rdev, ret);
             if (min_uV <= best_val && max_uV >= best_val) {
                 selector = ret;
                 if (old_selector == selector)
                     ret = 0;
                 else if (rdev->desc->vsel_step)
                     ret = _regulator_set_voltage_sel_step(
                         rdev, best_val, selector);
                 else
                     ret = _regulator_call_set_voltage_sel(
                         rdev, best_val, selector);
             } else {
                 ret = -EINVAL;
             }
         }
     } else {
         ret = -EINVAL;
     }
 
     if (ret)
         goto out;
 
     if (ops->set_voltage_time_sel) {
         /*
          * Call set_voltage_time_sel if successfully obtained
          * old_selector
          */
         if (old_selector >= 0 && old_selector != selector)
             delay = ops->set_voltage_time_sel(rdev, old_selector,
                               selector);
     } else {
         if (old_uV != best_val) {
             if (ops->set_voltage_time)
                 delay = ops->set_voltage_time(rdev, old_uV,
                                   best_val);
             else
                 delay = _regulator_set_voltage_time(rdev,
                                     old_uV,
                                     best_val);
         }
     }
 
     if (delay < 0) {
         rdev_warn(rdev, "failed to get delay: %pe\n", ERR_PTR(delay));
         delay = 0;
     }
 
     /* Insert any necessary delays */
     _regulator_delay_helper(delay);
 
     if (best_val >= 0) {
         unsigned long data = best_val;
 
         _notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE,
                      (void *)data);
     }
 
 out:
     trace_regulator_set_voltage_complete(rdev_get_name(rdev), best_val);
 
     return ret;
 }
 
 static int _regulator_do_set_suspend_voltage(struct regulator_dev *rdev,
                   int min_uV, int max_uV, suspend_state_t state)
 {
     struct regulator_state *rstate;
     int uV, sel;
 
     rstate = regulator_get_suspend_state(rdev, state);
     if (rstate == NULL)
         return -EINVAL;
 
     if (min_uV < rstate->min_uV)
         min_uV = rstate->min_uV;
     if (max_uV > rstate->max_uV)
         max_uV = rstate->max_uV;
 
     sel = regulator_map_voltage(rdev, min_uV, max_uV);
     if (sel < 0)
         return sel;
 
     uV = rdev->desc->ops->list_voltage(rdev, sel);
     if (uV >= min_uV && uV <= max_uV)
         rstate->uV = uV;
 
     return 0;
 }
 
 static int regulator_set_voltage_unlocked(struct regulator *regulator,
                       int min_uV, int max_uV,
                       suspend_state_t state)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct regulator_voltage *voltage = &regulator->voltage[state];
     int ret = 0;
     int old_min_uV, old_max_uV;
     int current_uV;
 
     /* If we're setting the same range as last time the change
      * should be a noop (some cpufreq implementations use the same
      * voltage for multiple frequencies, for example).
      */
     if (voltage->min_uV == min_uV && voltage->max_uV == max_uV)
         goto out;
 
     /* If we're trying to set a range that overlaps the current voltage,
      * return successfully even though the regulator does not support
      * changing the voltage.
      */
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
         current_uV = regulator_get_voltage_rdev(rdev);
         if (min_uV <= current_uV && current_uV <= max_uV) {
             voltage->min_uV = min_uV;
             voltage->max_uV = max_uV;
             goto out;
         }
     }
 
     /* sanity check */
     if (!rdev->desc->ops->set_voltage &&
         !rdev->desc->ops->set_voltage_sel) {
         ret = -EINVAL;
         goto out;
     }
 
     /* constraints check */
     ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
     if (ret < 0)
         goto out;
 
     /* restore original values in case of error */
     old_min_uV = voltage->min_uV;
     old_max_uV = voltage->max_uV;
     voltage->min_uV = min_uV;
     voltage->max_uV = max_uV;
 
     /* for not coupled regulators this will just set the voltage */
     ret = regulator_balance_voltage(rdev, state);
     if (ret < 0) {
         voltage->min_uV = old_min_uV;
         voltage->max_uV = old_max_uV;
     }
 
 out:
     return ret;
 }
 
 int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,
                    int max_uV, suspend_state_t state)
 {
     int best_supply_uV = 0;
     int supply_change_uV = 0;
     int ret;
 
     if (rdev->supply &&
         regulator_ops_is_valid(rdev->supply->rdev,
                    REGULATOR_CHANGE_VOLTAGE) &&
         (rdev->desc->min_dropout_uV || !(rdev->desc->ops->get_voltage ||
                        rdev->desc->ops->get_voltage_sel))) {
         int current_supply_uV;
         int selector;
 
         selector = regulator_map_voltage(rdev, min_uV, max_uV);
         if (selector < 0) {
             ret = selector;
             goto out;
         }
 
         best_supply_uV = _regulator_list_voltage(rdev, selector, 0);
         if (best_supply_uV < 0) {
             ret = best_supply_uV;
             goto out;
         }
 
         best_supply_uV += rdev->desc->min_dropout_uV;
 
         current_supply_uV = regulator_get_voltage_rdev(rdev->supply->rdev);
         if (current_supply_uV < 0) {
             ret = current_supply_uV;
             goto out;
         }
 
         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, state);
         if (ret) {
             dev_err(&rdev->dev, "Failed to increase supply voltage: %pe\n",
                 ERR_PTR(ret));
             goto out;
         }
     }
 
     if (state == PM_SUSPEND_ON)
         ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
     else
         ret = _regulator_do_set_suspend_voltage(rdev, min_uV,
                             max_uV, state);
     if (ret < 0)
         goto out;
 
     if (supply_change_uV < 0) {
         ret = regulator_set_voltage_unlocked(rdev->supply,
                 best_supply_uV, INT_MAX, state);
         if (ret)
             dev_warn(&rdev->dev, "Failed to decrease supply voltage: %pe\n",
                  ERR_PTR(ret));
         /* No need to fail here */
         ret = 0;
     }
 
 out:
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage_rdev);
 
 static int regulator_limit_voltage_step(struct regulator_dev *rdev,
                     int *current_uV, int *min_uV)
 {
     struct regulation_constraints *constraints = rdev->constraints;
 
     /* Limit voltage change only if necessary */
     if (!constraints->max_uV_step || !_regulator_is_enabled(rdev))
         return 1;
 
     if (*current_uV < 0) {
         *current_uV = regulator_get_voltage_rdev(rdev);
 
         if (*current_uV < 0)
             return *current_uV;
     }
 
     if (abs(*current_uV - *min_uV) <= constraints->max_uV_step)
         return 1;
 
     /* Clamp target voltage within the given step */
     if (*current_uV < *min_uV)
         *min_uV = min(*current_uV + constraints->max_uV_step,
                   *min_uV);
     else
         *min_uV = max(*current_uV - constraints->max_uV_step,
                   *min_uV);
 
     return 0;
 }
 
 static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
                      int *current_uV,
                      int *min_uV, int *max_uV,
                      suspend_state_t state,
                      int n_coupled)
 {
     struct coupling_desc *c_desc = &rdev->coupling_desc;
     struct regulator_dev **c_rdevs = c_desc->coupled_rdevs;
     struct regulation_constraints *constraints = rdev->constraints;
     int desired_min_uV = 0, desired_max_uV = INT_MAX;
     int max_current_uV = 0, min_current_uV = INT_MAX;
     int highest_min_uV = 0, target_uV, possible_uV;
     int i, ret, max_spread;
     bool done;
 
     *current_uV = -1;
 
     /*
      * If there are no coupled regulators, simply set the voltage
      * demanded by consumers.
      */
     if (n_coupled == 1) {
         /*
          * If consumers don't provide any demands, set voltage
          * to min_uV
          */
         desired_min_uV = constraints->min_uV;
         desired_max_uV = constraints->max_uV;
 
         ret = regulator_check_consumers(rdev,
                         &desired_min_uV,
                         &desired_max_uV, state);
         if (ret < 0)
             return ret;
 
         possible_uV = desired_min_uV;
         done = true;
 
         goto finish;
     }
 
     /* Find highest min desired voltage */
     for (i = 0; i < n_coupled; i++) {
         int tmp_min = 0;
         int tmp_max = INT_MAX;
 
         lockdep_assert_held_once(&c_rdevs[i]->mutex.base);
 
         ret = regulator_check_consumers(c_rdevs[i],
                         &tmp_min,
                         &tmp_max, state);
         if (ret < 0)
             return ret;
 
         ret = regulator_check_voltage(c_rdevs[i], &tmp_min, &tmp_max);
         if (ret < 0)
             return ret;
 
         highest_min_uV = max(highest_min_uV, tmp_min);
 
         if (i == 0) {
             desired_min_uV = tmp_min;
             desired_max_uV = tmp_max;
         }
     }
 
     max_spread = constraints->max_spread[0];
 
     /*
      * Let target_uV be equal to the desired one if possible.
      * If not, set it to minimum voltage, allowed by other coupled
      * regulators.
      */
     target_uV = max(desired_min_uV, highest_min_uV - max_spread);
 
     /*
      * Find min and max voltages, which currently aren't violating
      * max_spread.
      */
     for (i = 1; i < n_coupled; i++) {
         int tmp_act;
 
         if (!_regulator_is_enabled(c_rdevs[i]))
             continue;
 
         tmp_act = regulator_get_voltage_rdev(c_rdevs[i]);
         if (tmp_act < 0)
             return tmp_act;
 
         min_current_uV = min(tmp_act, min_current_uV);
         max_current_uV = max(tmp_act, max_current_uV);
     }
 
     /* There aren't any other regulators enabled */
     if (max_current_uV == 0) {
         possible_uV = target_uV;
     } else {
         /*
          * Correct target voltage, so as it currently isn't
          * violating max_spread
          */
         possible_uV = max(target_uV, max_current_uV - max_spread);
         possible_uV = min(possible_uV, min_current_uV + max_spread);
     }
 
     if (possible_uV > desired_max_uV)
         return -EINVAL;
 
     done = (possible_uV == target_uV);
     desired_min_uV = possible_uV;
 
 finish:
     /* Apply max_uV_step constraint if necessary */
     if (state == PM_SUSPEND_ON) {
         ret = regulator_limit_voltage_step(rdev, current_uV,
                            &desired_min_uV);
         if (ret < 0)
             return ret;
 
         if (ret == 0)
             done = false;
     }
 
     /* Set current_uV if wasn't done earlier in the code and if necessary */
     if (n_coupled > 1 && *current_uV == -1) {
 
         if (_regulator_is_enabled(rdev)) {
             ret = regulator_get_voltage_rdev(rdev);
             if (ret < 0)
                 return ret;
 
             *current_uV = ret;
         } else {
             *current_uV = desired_min_uV;
         }
     }
 
     *min_uV = desired_min_uV;
     *max_uV = desired_max_uV;
 
     return done;
 }
 
 int regulator_do_balance_voltage(struct regulator_dev *rdev,
                  suspend_state_t state, bool skip_coupled)
 {
     struct regulator_dev **c_rdevs;
     struct regulator_dev *best_rdev;
     struct coupling_desc *c_desc = &rdev->coupling_desc;
     int i, ret, n_coupled, best_min_uV, best_max_uV, best_c_rdev;
     unsigned int delta, best_delta;
     unsigned long c_rdev_done = 0;
     bool best_c_rdev_done;
 
     c_rdevs = c_desc->coupled_rdevs;
     n_coupled = skip_coupled ? 1 : c_desc->n_coupled;
 
     /*
      * Find the best possible voltage change on each loop. Leave the loop
      * if there isn't any possible change.
      */
     do {
         best_c_rdev_done = false;
         best_delta = 0;
         best_min_uV = 0;
         best_max_uV = 0;
         best_c_rdev = 0;
         best_rdev = NULL;
 
         /*
          * Find highest difference between optimal voltage
          * and current voltage.
          */
         for (i = 0; i < n_coupled; i++) {
             /*
              * optimal_uV is the best voltage that can be set for
              * i-th regulator at the moment without violating
              * max_spread constraint in order to balance
              * the coupled voltages.
              */
             int optimal_uV = 0, optimal_max_uV = 0, current_uV = 0;
 
             if (test_bit(i, &c_rdev_done))
                 continue;
 
             ret = regulator_get_optimal_voltage(c_rdevs[i],
                                 &current_uV,
                                 &optimal_uV,
                                 &optimal_max_uV,
                                 state, n_coupled);
             if (ret < 0)
                 goto out;
 
             delta = abs(optimal_uV - current_uV);
 
             if (delta && best_delta <= delta) {
                 best_c_rdev_done = ret;
                 best_delta = delta;
                 best_rdev = c_rdevs[i];
                 best_min_uV = optimal_uV;
                 best_max_uV = optimal_max_uV;
                 best_c_rdev = i;
             }
         }
 
         /* Nothing to change, return successfully */
         if (!best_rdev) {
             ret = 0;
             goto out;
         }
 
         ret = regulator_set_voltage_rdev(best_rdev, best_min_uV,
                          best_max_uV, state);
 
         if (ret < 0)
             goto out;
 
         if (best_c_rdev_done)
             set_bit(best_c_rdev, &c_rdev_done);
 
     } while (n_coupled > 1);
 
 out:
     return ret;
 }
 
 static int regulator_balance_voltage(struct regulator_dev *rdev,
                      suspend_state_t state)
 {
     struct coupling_desc *c_desc = &rdev->coupling_desc;
     struct regulator_coupler *coupler = c_desc->coupler;
     bool skip_coupled = false;
 
     /*
      * If system is in a state other than PM_SUSPEND_ON, don't check
      * other coupled regulators.
      */
     if (state != PM_SUSPEND_ON)
         skip_coupled = true;
 
     if (c_desc->n_resolved < c_desc->n_coupled) {
         rdev_err(rdev, "Not all coupled regulators registered\n");
         return -EPERM;
     }
 
     /* Invoke custom balancer for customized couplers */
     if (coupler && coupler->balance_voltage)
         return coupler->balance_voltage(coupler, rdev, state);
 
     return regulator_do_balance_voltage(rdev, state, skip_coupled);
 }
 
 /**
  * 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)
 {
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     regulator_lock_dependent(regulator->rdev, &ww_ctx);
 
     ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV,
                          PM_SUSPEND_ON);
 
     regulator_unlock_dependent(regulator->rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage);
 
 static inline int regulator_suspend_toggle(struct regulator_dev *rdev,
                        suspend_state_t state, bool en)
 {
     struct regulator_state *rstate;
 
     rstate = regulator_get_suspend_state(rdev, state);
     if (rstate == NULL)
         return -EINVAL;
 
     if (!rstate->changeable)
         return -EPERM;
 
     rstate->enabled = (en) ? ENABLE_IN_SUSPEND : DISABLE_IN_SUSPEND;
 
     return 0;
 }
 
 int regulator_suspend_enable(struct regulator_dev *rdev,
                     suspend_state_t state)
 {
     return regulator_suspend_toggle(rdev, state, true);
 }
 EXPORT_SYMBOL_GPL(regulator_suspend_enable);
 
 int regulator_suspend_disable(struct regulator_dev *rdev,
                      suspend_state_t state)
 {
     struct regulator *regulator;
     struct regulator_voltage *voltage;
 
     /*
      * if any consumer wants this regulator device keeping on in
      * suspend states, don't set it as disabled.
      */
     list_for_each_entry(regulator, &rdev->consumer_list, list) {
         voltage = &regulator->voltage[state];
         if (voltage->min_uV || voltage->max_uV)
             return 0;
     }
 
     return regulator_suspend_toggle(rdev, state, false);
 }
 EXPORT_SYMBOL_GPL(regulator_suspend_disable);
 
 static int _regulator_set_suspend_voltage(struct regulator *regulator,
                       int min_uV, int max_uV,
                       suspend_state_t state)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct regulator_state *rstate;
 
     rstate = regulator_get_suspend_state(rdev, state);
     if (rstate == NULL)
         return -EINVAL;
 
     if (rstate->min_uV == rstate->max_uV) {
         rdev_err(rdev, "The suspend voltage can't be changed!\n");
         return -EPERM;
     }
 
     return regulator_set_voltage_unlocked(regulator, min_uV, max_uV, state);
 }
 
 int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV,
                   int max_uV, suspend_state_t state)
 {
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     /* PM_SUSPEND_ON is handled by regulator_set_voltage() */
     if (regulator_check_states(state) || state == PM_SUSPEND_ON)
         return -EINVAL;
 
     regulator_lock_dependent(regulator->rdev, &ww_ctx);
 
     ret = _regulator_set_suspend_voltage(regulator, min_uV,
                          max_uV, state);
 
     regulator_unlock_dependent(regulator->rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_suspend_voltage);
 
 /**
  * regulator_set_voltage_time - get raise/fall time
  * @regulator: regulator source
  * @old_uV: starting voltage in microvolts
  * @new_uV: target voltage in microvolts
  *
  * Provided with the starting and ending voltage, this function attempts to
  * calculate the time in microseconds required to rise or fall to this new
  * voltage.
  */
 int regulator_set_voltage_time(struct regulator *regulator,
                    int old_uV, int new_uV)
 {
     struct regulator_dev *rdev = regulator->rdev;
     const struct regulator_ops *ops = rdev->desc->ops;
     int old_sel = -1;
     int new_sel = -1;
     int voltage;
     int i;
 
     if (ops->set_voltage_time)
         return ops->set_voltage_time(rdev, old_uV, new_uV);
     else if (!ops->set_voltage_time_sel)
         return _regulator_set_voltage_time(rdev, old_uV, new_uV);
 
     /* Currently requires operations to do this */
     if (!ops->list_voltage || !rdev->desc->n_voltages)
         return -EINVAL;
 
     for (i = 0; i < rdev->desc->n_voltages; i++) {
         /* We only look for exact voltage matches here */
         if (i < rdev->desc->linear_min_sel)
             continue;
 
         if (old_sel >= 0 && new_sel >= 0)
             break;
 
         voltage = regulator_list_voltage(regulator, i);
         if (voltage < 0)
             return -EINVAL;
         if (voltage == 0)
             continue;
         if (voltage == old_uV)
             old_sel = i;
         if (voltage == new_uV)
             new_sel = i;
     }
 
     if (old_sel < 0 || new_sel < 0)
         return -EINVAL;
 
     return ops->set_voltage_time_sel(rdev, old_sel, new_sel);
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage_time);
 
 /**
  * regulator_set_voltage_time_sel - get raise/fall time
  * @rdev: regulator source device
  * @old_selector: selector for starting voltage
  * @new_selector: selector for target voltage
  *
  * Provided with the starting and target voltage selectors, this function
  * returns time in microseconds required to rise or fall to this new voltage
  *
  * Drivers providing ramp_delay in regulation_constraints can use this as their
  * set_voltage_time_sel() operation.
  */
 int regulator_set_voltage_time_sel(struct regulator_dev *rdev,
                    unsigned int old_selector,
                    unsigned int new_selector)
 {
     int old_volt, new_volt;
 
     /* sanity check */
     if (!rdev->desc->ops->list_voltage)
         return -EINVAL;
 
     old_volt = rdev->desc->ops->list_voltage(rdev, old_selector);
     new_volt = rdev->desc->ops->list_voltage(rdev, new_selector);
 
     if (rdev->desc->ops->set_voltage_time)
         return rdev->desc->ops->set_voltage_time(rdev, old_volt,
                              new_volt);
     else
         return _regulator_set_voltage_time(rdev, old_volt, new_volt);
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage_time_sel);
 
 int regulator_sync_voltage_rdev(struct regulator_dev *rdev)
 {
     int ret;
 
     regulator_lock(rdev);
 
     if (!rdev->desc->ops->set_voltage &&
         !rdev->desc->ops->set_voltage_sel) {
         ret = -EINVAL;
         goto out;
     }
 
     /* balance only, if regulator is coupled */
     if (rdev->coupling_desc.n_coupled > 1)
         ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
     else
         ret = -EOPNOTSUPP;
 
 out:
     regulator_unlock(rdev);
     return ret;
 }
 
 /**
  * regulator_sync_voltage - re-apply last regulator output voltage
  * @regulator: regulator source
  *
  * Re-apply the last configured voltage.  This is intended to be used
  * where some external control source the consumer is cooperating with
  * has caused the configured voltage to change.
  */
 int regulator_sync_voltage(struct regulator *regulator)
 {
     struct regulator_dev *rdev = regulator->rdev;
     struct regulator_voltage *voltage = &regulator->voltage[PM_SUSPEND_ON];
     int ret, min_uV, max_uV;
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE))
         return 0;
 
     regulator_lock(rdev);
 
     if (!rdev->desc->ops->set_voltage &&
         !rdev->desc->ops->set_voltage_sel) {
         ret = -EINVAL;
         goto out;
     }
 
     /* This is only going to work if we've had a voltage configured. */
     if (!voltage->min_uV && !voltage->max_uV) {
         ret = -EINVAL;
         goto out;
     }
 
     min_uV = voltage->min_uV;
     max_uV = voltage->max_uV;
 
     /* This should be a paranoia check... */
     ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
     if (ret < 0)
         goto out;
 
     ret = regulator_check_consumers(rdev, &min_uV, &max_uV, 0);
     if (ret < 0)
         goto out;
 
     /* balance only, if regulator is coupled */
     if (rdev->coupling_desc.n_coupled > 1)
         ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
     else
         ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
 
 out:
     regulator_unlock(rdev);
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_sync_voltage);
 
 int regulator_get_voltage_rdev(struct regulator_dev *rdev)
 {
     int sel, ret;
     bool bypassed;
 
     if (rdev->desc->ops->get_bypass) {
         ret = rdev->desc->ops->get_bypass(rdev, &bypassed);
         if (ret < 0)
             return ret;
         if (bypassed) {
             /* if bypassed the regulator must have a supply */
             if (!rdev->supply) {
                 rdev_err(rdev,
                      "bypassed regulator has no supply!\n");
                 return -EPROBE_DEFER;
             }
 
             return regulator_get_voltage_rdev(rdev->supply->rdev);
         }
     }
 
     if (rdev->desc->ops->get_voltage_sel) {
         sel = rdev->desc->ops->get_voltage_sel(rdev);
         if (sel < 0)
             return sel;
         ret = rdev->desc->ops->list_voltage(rdev, sel);
     } else if (rdev->desc->ops->get_voltage) {
         ret = rdev->desc->ops->get_voltage(rdev);
     } else if (rdev->desc->ops->list_voltage) {
         ret = rdev->desc->ops->list_voltage(rdev, 0);
     } 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(rdev->supply->rdev);
     } else if (rdev->supply_name) {
         return -EPROBE_DEFER;
     } else {
         return -EINVAL;
     }
 
     if (ret < 0)
         return ret;
     return ret - rdev->constraints->uV_offset;
 }
 EXPORT_SYMBOL_GPL(regulator_get_voltage_rdev);
 
 /**
  * regulator_get_voltage - get regulator output voltage
  * @regulator: regulator source
  *
  * This returns the current regulator voltage in uV.
  *
  * NOTE: If the regulator is disabled it will return the voltage value. This
  * function should not be used to determine regulator state.
  */
 int regulator_get_voltage(struct regulator *regulator)
 {
     struct ww_acquire_ctx ww_ctx;
     int ret;
 
     regulator_lock_dependent(regulator->rdev, &ww_ctx);
     ret = regulator_get_voltage_rdev(regulator->rdev);
     regulator_unlock_dependent(regulator->rdev, &ww_ctx);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_get_voltage);
 
 /**
  * regulator_set_current_limit - set regulator output current limit
  * @regulator: regulator source
  * @min_uA: Minimum supported current in uA
  * @max_uA: Maximum supported current in uA
  *
  * Sets current sink to the desired output current. This can be set during
  * any regulator state. IOW, regulator can be disabled or enabled.
  *
  * If the regulator is enabled then the current will change to the new value
  * immediately otherwise if the regulator is disabled the regulator will
  * output at the new current when enabled.
  *
  * NOTE: Regulator system constraints must be set for this regulator before
  * calling this function otherwise this call will fail.
  */
 int regulator_set_current_limit(struct regulator *regulator,
                    int min_uA, int max_uA)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int ret;
 
     regulator_lock(rdev);
 
     /* sanity check */
     if (!rdev->desc->ops->set_current_limit) {
         ret = -EINVAL;
         goto out;
     }
 
     /* constraints check */
     ret = regulator_check_current_limit(rdev, &min_uA, &max_uA);
     if (ret < 0)
         goto out;
 
     ret = rdev->desc->ops->set_current_limit(rdev, min_uA, max_uA);
 out:
     regulator_unlock(rdev);
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_current_limit);
 
 static int _regulator_get_current_limit_unlocked(struct regulator_dev *rdev)
 {
     /* sanity check */
     if (!rdev->desc->ops->get_current_limit)
         return -EINVAL;
 
     return rdev->desc->ops->get_current_limit(rdev);
 }
 
 static int _regulator_get_current_limit(struct regulator_dev *rdev)
 {
     int ret;
 
     regulator_lock(rdev);
     ret = _regulator_get_current_limit_unlocked(rdev);
     regulator_unlock(rdev);
 
     return ret;
 }
 
 /**
  * regulator_get_current_limit - get regulator output current
  * @regulator: regulator source
  *
  * This returns the current supplied by the specified current sink in uA.
  *
  * NOTE: If the regulator is disabled it will return the current value. This
  * function should not be used to determine regulator state.
  */
 int regulator_get_current_limit(struct regulator *regulator)
 {
     return _regulator_get_current_limit(regulator->rdev);
 }
 EXPORT_SYMBOL_GPL(regulator_get_current_limit);
 
 /**
  * regulator_set_mode - set regulator operating mode
  * @regulator: regulator source
  * @mode: operating mode - one of the REGULATOR_MODE constants
  *
  * Set regulator operating mode to increase regulator efficiency or improve
  * regulation performance.
  *
  * NOTE: Regulator system constraints must be set for this regulator before
  * calling this function otherwise this call will fail.
  */
 int regulator_set_mode(struct regulator *regulator, unsigned int mode)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int ret;
     int regulator_curr_mode;
 
     regulator_lock(rdev);
 
     /* sanity check */
     if (!rdev->desc->ops->set_mode) {
         ret = -EINVAL;
         goto out;
     }
 
     /* return if the same mode is requested */
     if (rdev->desc->ops->get_mode) {
         regulator_curr_mode = rdev->desc->ops->get_mode(rdev);
         if (regulator_curr_mode == mode) {
             ret = 0;
             goto out;
         }
     }
 
     /* constraints check */
     ret = regulator_mode_constrain(rdev, &mode);
     if (ret < 0)
         goto out;
 
     ret = rdev->desc->ops->set_mode(rdev, mode);
 out:
     regulator_unlock(rdev);
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_mode);
 
 static unsigned int _regulator_get_mode_unlocked(struct regulator_dev *rdev)
 {
     /* sanity check */
     if (!rdev->desc->ops->get_mode)
         return -EINVAL;
 
     return rdev->desc->ops->get_mode(rdev);
 }
 
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
 {
     int ret;
 
     regulator_lock(rdev);
     ret = _regulator_get_mode_unlocked(rdev);
     regulator_unlock(rdev);
 
     return ret;
 }
 
 /**
  * regulator_get_mode - get regulator operating mode
  * @regulator: regulator source
  *
  * Get the current regulator operating mode.
  */
 unsigned int regulator_get_mode(struct regulator *regulator)
 {
     return _regulator_get_mode(regulator->rdev);
 }
 EXPORT_SYMBOL_GPL(regulator_get_mode);
 
 static int rdev_get_cached_err_flags(struct regulator_dev *rdev)
 {
     int ret = 0;
 
     if (rdev->use_cached_err) {
         spin_lock(&rdev->err_lock);
         ret = rdev->cached_err;
         spin_unlock(&rdev->err_lock);
     }
     return ret;
 }
 
 static int _regulator_get_error_flags(struct regulator_dev *rdev,
                     unsigned int *flags)
 {
     int cached_flags, ret = 0;
 
     regulator_lock(rdev);
 
     cached_flags = rdev_get_cached_err_flags(rdev);
 
     if (rdev->desc->ops->get_error_flags)
         ret = rdev->desc->ops->get_error_flags(rdev, flags);
     else if (!rdev->use_cached_err)
         ret = -EINVAL;
 
     *flags |= cached_flags;
 
     regulator_unlock(rdev);
 
     return ret;
 }
 
 /**
  * regulator_get_error_flags - get regulator error information
  * @regulator: regulator source
  * @flags: pointer to store error flags
  *
  * Get the current regulator error information.
  */
 int regulator_get_error_flags(struct regulator *regulator,
                 unsigned int *flags)
 {
     return _regulator_get_error_flags(regulator->rdev, flags);
 }
 EXPORT_SYMBOL_GPL(regulator_get_error_flags);
 
 /**
  * regulator_set_load - set regulator load
  * @regulator: regulator source
  * @uA_load: load current
  *
  * Notifies the regulator core of a new device load. This is then used by
  * DRMS (if enabled by constraints) to set the most efficient regulator
  * operating mode for the new regulator loading.
  *
  * Consumer devices notify their supply regulator of the maximum power
  * they will require (can be taken from device datasheet in the power
  * consumption tables) when they change operational status and hence power
  * state. Examples of operational state changes that can affect power
  * consumption are :-
  *
  *    o Device is opened / closed.
  *    o Device I/O is about to begin or has just finished.
  *    o Device is idling in between work.
  *
  * This information is also exported via sysfs to userspace.
  *
  * DRMS will sum the total requested load on the regulator and change
  * to the most efficient operating mode if platform constraints allow.
  *
  * NOTE: when a regulator consumer requests to have a regulator
  * disabled then any load that consumer requested no longer counts
  * toward the total requested load.  If the regulator is re-enabled
  * then the previously requested load will start counting again.
  *
  * If a regulator is an always-on regulator then an individual consumer's
  * load will still be removed if that consumer is fully disabled.
  *
  * On error a negative errno is returned.
  */
 int regulator_set_load(struct regulator *regulator, int uA_load)
 {
     struct regulator_dev *rdev = regulator->rdev;
     int old_uA_load;
     int ret = 0;
 
     regulator_lock(rdev);
     old_uA_load = regulator->uA_load;
     regulator->uA_load = uA_load;
     if (regulator->enable_count && old_uA_load != uA_load) {
         ret = drms_uA_update(rdev);
         if (ret < 0)
             regulator->uA_load = old_uA_load;
     }
     regulator_unlock(rdev);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_load);
 
 /**
  * regulator_allow_bypass - allow the regulator to go into bypass mode
  *
  * @regulator: Regulator to configure
  * @enable: enable or disable bypass mode
  *
  * Allow the regulator to go into bypass mode if all other consumers
  * for the regulator also enable bypass mode and the machine
  * constraints allow this.  Bypass mode means that the regulator is
  * simply passing the input directly to the output with no regulation.
  */
 int regulator_allow_bypass(struct regulator *regulator, bool enable)
 {
     struct regulator_dev *rdev = regulator->rdev;
     const char *name = rdev_get_name(rdev);
     int ret = 0;
 
     if (!rdev->desc->ops->set_bypass)
         return 0;
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_BYPASS))
         return 0;
 
     regulator_lock(rdev);
 
     if (enable && !regulator->bypass) {
         rdev->bypass_count++;
 
         if (rdev->bypass_count == rdev->open_count) {
             trace_regulator_bypass_enable(name);
 
             ret = rdev->desc->ops->set_bypass(rdev, enable);
             if (ret != 0)
                 rdev->bypass_count--;
             else
                 trace_regulator_bypass_enable_complete(name);
         }
 
     } else if (!enable && regulator->bypass) {
         rdev->bypass_count--;
 
         if (rdev->bypass_count != rdev->open_count) {
             trace_regulator_bypass_disable(name);
 
             ret = rdev->desc->ops->set_bypass(rdev, enable);
             if (ret != 0)
                 rdev->bypass_count++;
             else
                 trace_regulator_bypass_disable_complete(name);
         }
     }
 
     if (ret == 0)
         regulator->bypass = enable;
 
     regulator_unlock(rdev);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_allow_bypass);
 
 /**
  * regulator_register_notifier - register regulator event notifier
  * @regulator: regulator source
  * @nb: notifier block
  *
  * Register notifier block to receive regulator events.
  */
 int regulator_register_notifier(struct regulator *regulator,
                   struct notifier_block *nb)
 {
     return blocking_notifier_chain_register(&regulator->rdev->notifier,
                         nb);
 }
 EXPORT_SYMBOL_GPL(regulator_register_notifier);
 
 /**
  * regulator_unregister_notifier - unregister regulator event notifier
  * @regulator: regulator source
  * @nb: notifier block
  *
  * Unregister regulator event notifier block.
  */
 int regulator_unregister_notifier(struct regulator *regulator,
                 struct notifier_block *nb)
 {
     return blocking_notifier_chain_unregister(&regulator->rdev->notifier,
                           nb);
 }
 EXPORT_SYMBOL_GPL(regulator_unregister_notifier);
 
 /* notify regulator consumers and downstream regulator consumers.
  * Note mutex must be held by caller.
  */
 static int _notifier_call_chain(struct regulator_dev *rdev,
                   unsigned long event, void *data)
 {
     /* call rdev chain first */
     return blocking_notifier_call_chain(&rdev->notifier, event, data);
 }
 
 /**
  * regulator_bulk_get - get multiple regulator consumers
  *
  * @dev:           Device to supply
  * @num_consumers: Number of consumers to register
  * @consumers:     Configuration of consumers; clients are stored here.
  *
  * @return 0 on success, an errno on failure.
  *
  * This helper function allows drivers to get several regulator
  * consumers in one operation.  If any of the regulators cannot be
  * acquired then any regulators that were allocated will be freed
  * before returning to the caller.
  */
 int regulator_bulk_get(struct device *dev, int num_consumers,
                struct regulator_bulk_data *consumers)
 {
     int i;
     int ret;
 
     for (i = 0; i < num_consumers; i++)
         consumers[i].consumer = NULL;
 
     for (i = 0; i < num_consumers; i++) {
         consumers[i].consumer = regulator_get(dev,
                               consumers[i].supply);
         if (IS_ERR(consumers[i].consumer)) {
             ret = dev_err_probe(dev, PTR_ERR(consumers[i].consumer),
                         "Failed to get supply '%s'",
                         consumers[i].supply);
             consumers[i].consumer = NULL;
             goto err;
         }
 
         if (consumers[i].init_load_uA > 0) {
             ret = regulator_set_load(consumers[i].consumer,
                          consumers[i].init_load_uA);
             if (ret) {
                 i++;
                 goto err;
             }
         }
     }
 
     return 0;
 
 err:
     while (--i >= 0)
         regulator_put(consumers[i].consumer);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_get);
 
 static void regulator_bulk_enable_async(void *data, async_cookie_t cookie)
 {
     struct regulator_bulk_data *bulk = data;
 
     bulk->ret = regulator_enable(bulk->consumer);
 }
 
 /**
  * regulator_bulk_enable - enable multiple regulator consumers
  *
  * @num_consumers: Number of consumers
  * @consumers:     Consumer data; clients are stored here.
  * @return         0 on success, an errno on failure
  *
  * This convenience API allows consumers to enable multiple regulator
  * clients in a single API call.  If any consumers cannot be enabled
  * then any others that were enabled will be disabled again prior to
  * return.
  */
 int regulator_bulk_enable(int num_consumers,
               struct regulator_bulk_data *consumers)
 {
     ASYNC_DOMAIN_EXCLUSIVE(async_domain);
     int i;
     int ret = 0;
 
     for (i = 0; i < num_consumers; i++) {
         async_schedule_domain(regulator_bulk_enable_async,
                       &consumers[i], &async_domain);
     }
 
     async_synchronize_full_domain(&async_domain);
 
     /* If any consumer failed we need to unwind any that succeeded */
     for (i = 0; i < num_consumers; i++) {
         if (consumers[i].ret != 0) {
             ret = consumers[i].ret;
             goto err;
         }
     }
 
     return 0;
 
 err:
     for (i = 0; i < num_consumers; i++) {
         if (consumers[i].ret < 0)
             pr_err("Failed to enable %s: %pe\n", consumers[i].supply,
                    ERR_PTR(consumers[i].ret));
         else
             regulator_disable(consumers[i].consumer);
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_enable);
 
 /**
  * regulator_bulk_disable - disable multiple regulator consumers
  *
  * @num_consumers: Number of consumers
  * @consumers:     Consumer data; clients are stored here.
  * @return         0 on success, an errno on failure
  *
  * This convenience API allows consumers to disable multiple regulator
  * clients in a single API call.  If any consumers cannot be disabled
  * then any others that were disabled will be enabled again prior to
  * return.
  */
 int regulator_bulk_disable(int num_consumers,
                struct regulator_bulk_data *consumers)
 {
     int i;
     int ret, r;
 
     for (i = num_consumers - 1; i >= 0; --i) {
         ret = regulator_disable(consumers[i].consumer);
         if (ret != 0)
             goto err;
     }
 
     return 0;
 
 err:
     pr_err("Failed to disable %s: %pe\n", consumers[i].supply, ERR_PTR(ret));
     for (++i; i < num_consumers; ++i) {
         r = regulator_enable(consumers[i].consumer);
         if (r != 0)
             pr_err("Failed to re-enable %s: %pe\n",
                    consumers[i].supply, ERR_PTR(r));
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_disable);
 
 /**
  * regulator_bulk_force_disable - force disable multiple regulator consumers
  *
  * @num_consumers: Number of consumers
  * @consumers:     Consumer data; clients are stored here.
  * @return         0 on success, an errno on failure
  *
  * This convenience API allows consumers to forcibly disable multiple regulator
  * clients in a single API call.
  * NOTE: This should be used for situations when device damage will
  * likely occur if the regulators are not disabled (e.g. over temp).
  * Although regulator_force_disable function call for some consumers can
  * return error numbers, the function is called for all consumers.
  */
 int regulator_bulk_force_disable(int num_consumers,
                struct regulator_bulk_data *consumers)
 {
     int i;
     int ret = 0;
 
     for (i = 0; i < num_consumers; i++) {
         consumers[i].ret =
                 regulator_force_disable(consumers[i].consumer);
 
         /* Store first error for reporting */
         if (consumers[i].ret && !ret)
             ret = consumers[i].ret;
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_force_disable);
 
 /**
  * regulator_bulk_free - free multiple regulator consumers
  *
  * @num_consumers: Number of consumers
  * @consumers:     Consumer data; clients are stored here.
  *
  * This convenience API allows consumers to free multiple regulator
  * clients in a single API call.
  */
 void regulator_bulk_free(int num_consumers,
              struct regulator_bulk_data *consumers)
 {
     int i;
 
     for (i = 0; i < num_consumers; i++) {
         regulator_put(consumers[i].consumer);
         consumers[i].consumer = NULL;
     }
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_free);
 
 /**
  * regulator_notifier_call_chain - call regulator event notifier
  * @rdev: regulator source
  * @event: notifier block
  * @data: callback-specific data.
  *
  * Called by regulator drivers to notify clients a regulator event has
  * occurred.
  */
 int regulator_notifier_call_chain(struct regulator_dev *rdev,
                   unsigned long event, void *data)
 {
     _notifier_call_chain(rdev, event, data);
     return NOTIFY_DONE;
 
 }
 EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);
 
 /**
  * regulator_mode_to_status - convert a regulator mode into a status
  *
  * @mode: Mode to convert
  *
  * Convert a regulator mode into a status.
  */
 int regulator_mode_to_status(unsigned int mode)
 {
     switch (mode) {
     case REGULATOR_MODE_FAST:
         return REGULATOR_STATUS_FAST;
     case REGULATOR_MODE_NORMAL:
         return REGULATOR_STATUS_NORMAL;
     case REGULATOR_MODE_IDLE:
         return REGULATOR_STATUS_IDLE;
     case REGULATOR_MODE_STANDBY:
         return REGULATOR_STATUS_STANDBY;
     default:
         return REGULATOR_STATUS_UNDEFINED;
     }
 }
 EXPORT_SYMBOL_GPL(regulator_mode_to_status);
 
 static struct attribute *regulator_dev_attrs[] = {
     &dev_attr_name.attr,
     &dev_attr_num_users.attr,
     &dev_attr_type.attr,
     &dev_attr_microvolts.attr,
     &dev_attr_microamps.attr,
     &dev_attr_opmode.attr,
     &dev_attr_state.attr,
     &dev_attr_status.attr,
     &dev_attr_bypass.attr,
     &dev_attr_requested_microamps.attr,
     &dev_attr_min_microvolts.attr,
     &dev_attr_max_microvolts.attr,
     &dev_attr_min_microamps.attr,
     &dev_attr_max_microamps.attr,
     &dev_attr_under_voltage.attr,
     &dev_attr_over_current.attr,
     &dev_attr_regulation_out.attr,
     &dev_attr_fail.attr,
     &dev_attr_over_temp.attr,
     &dev_attr_under_voltage_warn.attr,
     &dev_attr_over_current_warn.attr,
     &dev_attr_over_voltage_warn.attr,
     &dev_attr_over_temp_warn.attr,
     &dev_attr_suspend_standby_state.attr,
     &dev_attr_suspend_mem_state.attr,
     &dev_attr_suspend_disk_state.attr,
     &dev_attr_suspend_standby_microvolts.attr,
     &dev_attr_suspend_mem_microvolts.attr,
     &dev_attr_suspend_disk_microvolts.attr,
     &dev_attr_suspend_standby_mode.attr,
     &dev_attr_suspend_mem_mode.attr,
     &dev_attr_suspend_disk_mode.attr,
     NULL
 };
 
 /*
  * To avoid cluttering sysfs (and memory) with useless state, only
  * create attributes that can be meaningfully displayed.
  */
 static umode_t regulator_attr_is_visible(struct kobject *kobj,
                      struct attribute *attr, int idx)
 {
     struct device *dev = kobj_to_dev(kobj);
     struct regulator_dev *rdev = dev_to_rdev(dev);
     const struct regulator_ops *ops = rdev->desc->ops;
     umode_t mode = attr->mode;
 
     /* these three are always present */
     if (attr == &dev_attr_name.attr ||
         attr == &dev_attr_num_users.attr ||
         attr == &dev_attr_type.attr)
         return mode;
 
     /* some attributes need specific methods to be displayed */
     if (attr == &dev_attr_microvolts.attr) {
         if ((ops->get_voltage && ops->get_voltage(rdev) >= 0) ||
             (ops->get_voltage_sel && ops->get_voltage_sel(rdev) >= 0) ||
             (ops->list_voltage && ops->list_voltage(rdev, 0) >= 0) ||
             (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1))
             return mode;
         return 0;
     }
 
     if (attr == &dev_attr_microamps.attr)
         return ops->get_current_limit ? mode : 0;
 
     if (attr == &dev_attr_opmode.attr)
         return ops->get_mode ? mode : 0;
 
     if (attr == &dev_attr_state.attr)
         return (rdev->ena_pin || ops->is_enabled) ? mode : 0;
 
     if (attr == &dev_attr_status.attr)
         return ops->get_status ? mode : 0;
 
     if (attr == &dev_attr_bypass.attr)
         return ops->get_bypass ? mode : 0;
 
     if (attr == &dev_attr_under_voltage.attr ||
         attr == &dev_attr_over_current.attr ||
         attr == &dev_attr_regulation_out.attr ||
         attr == &dev_attr_fail.attr ||
         attr == &dev_attr_over_temp.attr ||
         attr == &dev_attr_under_voltage_warn.attr ||
         attr == &dev_attr_over_current_warn.attr ||
         attr == &dev_attr_over_voltage_warn.attr ||
         attr == &dev_attr_over_temp_warn.attr)
         return ops->get_error_flags ? mode : 0;
 
     /* constraints need specific supporting methods */
     if (attr == &dev_attr_min_microvolts.attr ||
         attr == &dev_attr_max_microvolts.attr)
         return (ops->set_voltage || ops->set_voltage_sel) ? mode : 0;
 
     if (attr == &dev_attr_min_microamps.attr ||
         attr == &dev_attr_max_microamps.attr)
         return ops->set_current_limit ? mode : 0;
 
     if (attr == &dev_attr_suspend_standby_state.attr ||
         attr == &dev_attr_suspend_mem_state.attr ||
         attr == &dev_attr_suspend_disk_state.attr)
         return mode;
 
     if (attr == &dev_attr_suspend_standby_microvolts.attr ||
         attr == &dev_attr_suspend_mem_microvolts.attr ||
         attr == &dev_attr_suspend_disk_microvolts.attr)
         return ops->set_suspend_voltage ? mode : 0;
 
     if (attr == &dev_attr_suspend_standby_mode.attr ||
         attr == &dev_attr_suspend_mem_mode.attr ||
         attr == &dev_attr_suspend_disk_mode.attr)
         return ops->set_suspend_mode ? mode : 0;
 
     return mode;
 }
 
 static const struct attribute_group regulator_dev_group = {
     .attrs = regulator_dev_attrs,
     .is_visible = regulator_attr_is_visible,
 };
 
 static const struct attribute_group *regulator_dev_groups[] = {
     &regulator_dev_group,
     NULL
 };
 
 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);
 }
 
 static void rdev_init_debugfs(struct regulator_dev *rdev)
 {
     struct device *parent = rdev->dev.parent;
     const char *rname = rdev_get_name(rdev);
     char name[NAME_MAX];
 
     /* Avoid duplicate debugfs directory names */
     if (parent && rname == rdev->desc->name) {
         snprintf(name, sizeof(name), "%s-%s", dev_name(parent),
              rname);
         rname = name;
     }
 
     rdev->debugfs = debugfs_create_dir(rname, debugfs_root);
     if (!rdev->debugfs) {
         rdev_warn(rdev, "Failed to create debugfs directory\n");
         return;
     }
 
     debugfs_create_u32("use_count", 0444, rdev->debugfs,
                &rdev->use_count);
     debugfs_create_u32("open_count", 0444, rdev->debugfs,
                &rdev->open_count);
     debugfs_create_u32("bypass_count", 0444, rdev->debugfs,
                &rdev->bypass_count);
 }
 
 static int regulator_register_resolve_supply(struct device *dev, void *data)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
 
     if (regulator_resolve_supply(rdev))
         rdev_dbg(rdev, "unable to resolve supply\n");
 
     return 0;
 }
 
 int regulator_coupler_register(struct regulator_coupler *coupler)
 {
     mutex_lock(&regulator_list_mutex);
     list_add_tail(&coupler->list, &regulator_coupler_list);
     mutex_unlock(&regulator_list_mutex);
 
     return 0;
 }
 
 static struct regulator_coupler *
 regulator_find_coupler(struct regulator_dev *rdev)
 {
     struct regulator_coupler *coupler;
     int err;
 
     /*
      * Note that regulators are appended to the list and the generic
      * coupler is registered first, hence it will be attached at last
      * if nobody cared.
      */
     list_for_each_entry_reverse(coupler, &regulator_coupler_list, list) {
         err = coupler->attach_regulator(coupler, rdev);
         if (!err) {
             if (!coupler->balance_voltage &&
                 rdev->coupling_desc.n_coupled > 2)
                 goto err_unsupported;
 
             return coupler;
         }
 
         if (err < 0)
             return ERR_PTR(err);
 
         if (err == 1)
             continue;
 
         break;
     }
 
     return ERR_PTR(-EINVAL);
 
 err_unsupported:
     if (coupler->detach_regulator)
         coupler->detach_regulator(coupler, rdev);
 
     rdev_err(rdev,
         "Voltage balancing for multiple regulator couples is unimplemented\n");
 
     return ERR_PTR(-EPERM);
 }
 
 static void regulator_resolve_coupling(struct regulator_dev *rdev)
 {
     struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
     struct coupling_desc *c_desc = &rdev->coupling_desc;
     int n_coupled = c_desc->n_coupled;
     struct regulator_dev *c_rdev;
     int i;
 
     for (i = 1; i < n_coupled; i++) {
         /* already resolved */
         if (c_desc->coupled_rdevs[i])
             continue;
 
         c_rdev = of_parse_coupled_regulator(rdev, i - 1);
 
         if (!c_rdev)
             continue;
 
         if (c_rdev->coupling_desc.coupler != coupler) {
             rdev_err(rdev, "coupler mismatch with %s\n",
                  rdev_get_name(c_rdev));
             return;
         }
 
         c_desc->coupled_rdevs[i] = c_rdev;
         c_desc->n_resolved++;
 
         regulator_resolve_coupling(c_rdev);
     }
 }
 
 static void regulator_remove_coupling(struct regulator_dev *rdev)
 {
     struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
     struct coupling_desc *__c_desc, *c_desc = &rdev->coupling_desc;
     struct regulator_dev *__c_rdev, *c_rdev;
     unsigned int __n_coupled, n_coupled;
     int i, k;
     int err;
 
     n_coupled = c_desc->n_coupled;
 
     for (i = 1; i < n_coupled; i++) {
         c_rdev = c_desc->coupled_rdevs[i];
 
         if (!c_rdev)
             continue;
 
         regulator_lock(c_rdev);
 
         __c_desc = &c_rdev->coupling_desc;
         __n_coupled = __c_desc->n_coupled;
 
         for (k = 1; k < __n_coupled; k++) {
             __c_rdev = __c_desc->coupled_rdevs[k];
 
             if (__c_rdev == rdev) {
                 __c_desc->coupled_rdevs[k] = NULL;
                 __c_desc->n_resolved--;
                 break;
             }
         }
 
         regulator_unlock(c_rdev);
 
         c_desc->coupled_rdevs[i] = NULL;
         c_desc->n_resolved--;
     }
 
     if (coupler && coupler->detach_regulator) {
         err = coupler->detach_regulator(coupler, rdev);
         if (err)
             rdev_err(rdev, "failed to detach from coupler: %pe\n",
                  ERR_PTR(err));
     }
 
     kfree(rdev->coupling_desc.coupled_rdevs);
     rdev->coupling_desc.coupled_rdevs = NULL;
 }
 
 static int regulator_init_coupling(struct regulator_dev *rdev)
 {
     struct regulator_dev **coupled;
     int err, n_phandles;
 
     if (!IS_ENABLED(CONFIG_OF))
         n_phandles = 0;
     else
         n_phandles = of_get_n_coupled(rdev);
 
     coupled = kcalloc(n_phandles + 1, sizeof(*coupled), GFP_KERNEL);
     if (!coupled)
         return -ENOMEM;
 
     rdev->coupling_desc.coupled_rdevs = coupled;
 
     /*
      * Every regulator should always have coupling descriptor filled with
      * at least pointer to itself.
      */
     rdev->coupling_desc.coupled_rdevs[0] = rdev;
     rdev->coupling_desc.n_coupled = n_phandles + 1;
     rdev->coupling_desc.n_resolved++;
 
     /* regulator isn't coupled */
     if (n_phandles == 0)
         return 0;
 
     if (!of_check_coupling_data(rdev))
         return -EPERM;
 
     mutex_lock(&regulator_list_mutex);
     rdev->coupling_desc.coupler = regulator_find_coupler(rdev);
     mutex_unlock(&regulator_list_mutex);
 
     if (IS_ERR(rdev->coupling_desc.coupler)) {
         err = PTR_ERR(rdev->coupling_desc.coupler);
         rdev_err(rdev, "failed to get coupler: %pe\n", ERR_PTR(err));
         return err;
     }
 
     return 0;
 }
 
 static int generic_coupler_attach(struct regulator_coupler *coupler,
                   struct regulator_dev *rdev)
 {
     if (rdev->coupling_desc.n_coupled > 2) {
         rdev_err(rdev,
              "Voltage balancing for multiple regulator couples is unimplemented\n");
         return -EPERM;
     }
 
     if (!rdev->constraints->always_on) {
         rdev_err(rdev,
              "Coupling of a non always-on regulator is unimplemented\n");
         return -ENOTSUPP;
     }
 
     return 0;
 }
 
 static struct regulator_coupler generic_regulator_coupler = {
     .attach_regulator = generic_coupler_attach,
 };
 
 /**
  * regulator_register - register regulator
  * @regulator_desc: regulator to register
  * @cfg: runtime configuration for regulator
  *
  * Called by regulator drivers to register a regulator.
  * Returns a valid pointer to struct regulator_dev on success
  * or an ERR_PTR() on error.
  */
 struct regulator_dev *
 regulator_register(const struct regulator_desc *regulator_desc,
            const struct regulator_config *cfg)
 {
     const struct regulator_init_data *init_data;
     struct regulator_config *config = NULL;
     static atomic_t regulator_no = ATOMIC_INIT(-1);
     struct regulator_dev *rdev;
     bool dangling_cfg_gpiod = false;
     bool dangling_of_gpiod = false;
     struct device *dev;
     int ret, i;
 
     if (cfg == NULL)
         return ERR_PTR(-EINVAL);
     if (cfg->ena_gpiod)
         dangling_cfg_gpiod = true;
     if (regulator_desc == NULL) {
         ret = -EINVAL;
         goto rinse;
     }
 
     dev = cfg->dev;
     WARN_ON(!dev);
 
     if (regulator_desc->name == NULL || regulator_desc->ops == NULL) {
         ret = -EINVAL;
         goto rinse;
     }
 
     if (regulator_desc->type != REGULATOR_VOLTAGE &&
         regulator_desc->type != REGULATOR_CURRENT) {
         ret = -EINVAL;
         goto rinse;
     }
 
     /* Only one of each should be implemented */
     WARN_ON(regulator_desc->ops->get_voltage &&
         regulator_desc->ops->get_voltage_sel);
     WARN_ON(regulator_desc->ops->set_voltage &&
         regulator_desc->ops->set_voltage_sel);
 
     /* If we're using selectors we must implement list_voltage. */
     if (regulator_desc->ops->get_voltage_sel &&
         !regulator_desc->ops->list_voltage) {
         ret = -EINVAL;
         goto rinse;
     }
     if (regulator_desc->ops->set_voltage_sel &&
         !regulator_desc->ops->list_voltage) {
         ret = -EINVAL;
         goto rinse;
     }
 
     rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);
     if (rdev == NULL) {
         ret = -ENOMEM;
         goto rinse;
     }
     device_initialize(&rdev->dev);
     spin_lock_init(&rdev->err_lock);
 
     /*
      * Duplicate the config so the driver could override it after
      * parsing init data.
      */
     config = kmemdup(cfg, sizeof(*cfg), GFP_KERNEL);
     if (config == NULL) {
         ret = -ENOMEM;
         goto clean;
     }
 
     init_data = regulator_of_get_init_data(dev, regulator_desc, config,
                            &rdev->dev.of_node);
 
     /*
      * Sometimes not all resources are probed already so we need to take
      * that into account. This happens most the time if the ena_gpiod comes
      * from a gpio extender or something else.
      */
     if (PTR_ERR(init_data) == -EPROBE_DEFER) {
         ret = -EPROBE_DEFER;
         goto clean;
     }
 
     /*
      * We need to keep track of any GPIO descriptor coming from the
      * device tree until we have handled it over to the core. If the
      * config that was passed in to this function DOES NOT contain
      * a descriptor, and the config after this call DOES contain
      * a descriptor, we definitely got one from parsing the device
      * tree.
      */
     if (!cfg->ena_gpiod && config->ena_gpiod)
         dangling_of_gpiod = true;
     if (!init_data) {
         init_data = config->init_data;
         rdev->dev.of_node = of_node_get(config->of_node);
     }
 
     ww_mutex_init(&rdev->mutex, &regulator_ww_class);
     rdev->reg_data = config->driver_data;
     rdev->owner = regulator_desc->owner;
     rdev->desc = regulator_desc;
     if (config->regmap)
         rdev->regmap = config->regmap;
     else if (dev_get_regmap(dev, NULL))
         rdev->regmap = dev_get_regmap(dev, NULL);
     else if (dev->parent)
         rdev->regmap = dev_get_regmap(dev->parent, NULL);
     INIT_LIST_HEAD(&rdev->consumer_list);
     INIT_LIST_HEAD(&rdev->list);
     BLOCKING_INIT_NOTIFIER_HEAD(&rdev->notifier);
     INIT_DELAYED_WORK(&rdev->disable_work, regulator_disable_work);
 
     /* preform any regulator specific init */
     if (init_data && init_data->regulator_init) {
         ret = init_data->regulator_init(rdev->reg_data);
         if (ret < 0)
             goto clean;
     }
 
     if (config->ena_gpiod) {
         ret = regulator_ena_gpio_request(rdev, config);
         if (ret != 0) {
             rdev_err(rdev, "Failed to request enable GPIO: %pe\n",
                  ERR_PTR(ret));
             goto clean;
         }
         /* The regulator core took over the GPIO descriptor */
         dangling_cfg_gpiod = false;
         dangling_of_gpiod = false;
     }
 
     /* register with sysfs */
     rdev->dev.class = &regulator_class;
     rdev->dev.parent = dev;
     dev_set_name(&rdev->dev, "regulator.%lu",
             (unsigned long) atomic_inc_return(&regulator_no));
     dev_set_drvdata(&rdev->dev, rdev);
 
     /* set regulator constraints */
     if (init_data)
         rdev->constraints = kmemdup(&init_data->constraints,
                         sizeof(*rdev->constraints),
                         GFP_KERNEL);
     else
         rdev->constraints = kzalloc(sizeof(*rdev->constraints),
                         GFP_KERNEL);
     if (!rdev->constraints) {
         ret = -ENOMEM;
         goto wash;
     }
 
     if (init_data && init_data->supply_regulator)
         rdev->supply_name = init_data->supply_regulator;
     else if (regulator_desc->supply_name)
         rdev->supply_name = regulator_desc->supply_name;
 
     ret = set_machine_constraints(rdev);
     if (ret == -EPROBE_DEFER) {
         /* Regulator might be in bypass mode and so needs its supply
          * to set the constraints
          */
         /* FIXME: this currently triggers a chicken-and-egg problem
          * when creating -SUPPLY symlink in sysfs to a regulator
          * that is just being created
          */
         rdev_dbg(rdev, "will resolve supply early: %s\n",
              rdev->supply_name);
         ret = regulator_resolve_supply(rdev);
         if (!ret)
             ret = set_machine_constraints(rdev);
         else
             rdev_dbg(rdev, "unable to resolve supply early: %pe\n",
                  ERR_PTR(ret));
     }
     if (ret < 0)
         goto wash;
 
     ret = regulator_init_coupling(rdev);
     if (ret < 0)
         goto wash;
 
     /* add consumers devices */
     if (init_data) {
         for (i = 0; i < init_data->num_consumer_supplies; i++) {
             ret = set_consumer_device_supply(rdev,
                 init_data->consumer_supplies[i].dev_name,
                 init_data->consumer_supplies[i].supply);
             if (ret < 0) {
                 dev_err(dev, "Failed to set supply %s\n",
                     init_data->consumer_supplies[i].supply);
                 goto unset_supplies;
             }
         }
     }
 
     if (!rdev->desc->ops->get_voltage &&
         !rdev->desc->ops->list_voltage &&
         !rdev->desc->fixed_uV)
         rdev->is_switch = true;
 
     ret = device_add(&rdev->dev);
     if (ret != 0)
         goto unset_supplies;
 
     rdev_init_debugfs(rdev);
 
     /* try to resolve regulators coupling since a new one was registered */
     mutex_lock(&regulator_list_mutex);
     regulator_resolve_coupling(rdev);
     mutex_unlock(&regulator_list_mutex);
 
     /* try to resolve regulators supply since a new one was registered */
     class_for_each_device(&regulator_class, NULL, NULL,
                   regulator_register_resolve_supply);
     kfree(config);
     return rdev;
 
 unset_supplies:
     mutex_lock(&regulator_list_mutex);
     unset_regulator_supplies(rdev);
     regulator_remove_coupling(rdev);
     mutex_unlock(&regulator_list_mutex);
 wash:
     kfree(rdev->coupling_desc.coupled_rdevs);
     mutex_lock(&regulator_list_mutex);
     regulator_ena_gpio_free(rdev);
     mutex_unlock(&regulator_list_mutex);
 clean:
     if (dangling_of_gpiod)
         gpiod_put(config->ena_gpiod);
     kfree(config);
     put_device(&rdev->dev);
 rinse:
     if (dangling_cfg_gpiod)
         gpiod_put(cfg->ena_gpiod);
     return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(regulator_register);
 
 /**
  * regulator_unregister - unregister regulator
  * @rdev: regulator to unregister
  *
  * Called by regulator drivers to unregister a regulator.
  */
 void regulator_unregister(struct regulator_dev *rdev)
 {
     if (rdev == NULL)
         return;
 
     if (rdev->supply) {
         while (rdev->use_count--)
             regulator_disable(rdev->supply);
         regulator_put(rdev->supply);
     }
 
     flush_work(&rdev->disable_work.work);
 
     mutex_lock(&regulator_list_mutex);
 
     debugfs_remove_recursive(rdev->debugfs);
     WARN_ON(rdev->open_count);
     regulator_remove_coupling(rdev);
     unset_regulator_supplies(rdev);
     list_del(&rdev->list);
     regulator_ena_gpio_free(rdev);
     device_unregister(&rdev->dev);
 
     mutex_unlock(&regulator_list_mutex);
 }
 EXPORT_SYMBOL_GPL(regulator_unregister);
 
 #ifdef CONFIG_SUSPEND
 /**
  * regulator_suspend - prepare regulators for system wide suspend
  * @dev: ``&struct device`` pointer that is passed to _regulator_suspend()
  *
  * Configure each regulator with it's suspend operating parameters for state.
  */
 static int regulator_suspend(struct device *dev)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
     suspend_state_t state = pm_suspend_target_state;
     int ret;
     const struct regulator_state *rstate;
 
     rstate = regulator_get_suspend_state_check(rdev, state);
     if (!rstate)
         return 0;
 
     regulator_lock(rdev);
     ret = __suspend_set_state(rdev, rstate);
     regulator_unlock(rdev);
 
     return ret;
 }
 
 static int regulator_resume(struct device *dev)
 {
     suspend_state_t state = pm_suspend_target_state;
     struct regulator_dev *rdev = dev_to_rdev(dev);
     struct regulator_state *rstate;
     int ret = 0;
 
     rstate = regulator_get_suspend_state(rdev, state);
     if (rstate == NULL)
         return 0;
 
     /* Avoid grabbing the lock if we don't need to */
     if (!rdev->desc->ops->resume)
         return 0;
 
     regulator_lock(rdev);
 
     if (rstate->enabled == ENABLE_IN_SUSPEND ||
         rstate->enabled == DISABLE_IN_SUSPEND)
         ret = rdev->desc->ops->resume(rdev);
 
     regulator_unlock(rdev);
 
     return ret;
 }
 #else /* !CONFIG_SUSPEND */
 
 #define regulator_suspend   NULL
 #define regulator_resume    NULL
 
 #endif /* !CONFIG_SUSPEND */
 
 #ifdef CONFIG_PM
 static const struct dev_pm_ops __maybe_unused regulator_pm_ops = {
     .suspend    = regulator_suspend,
     .resume     = regulator_resume,
 };
 #endif
 
 struct class regulator_class = {
     .name = "regulator",
     .dev_release = regulator_dev_release,
     .dev_groups = regulator_dev_groups,
 #ifdef CONFIG_PM
     .pm = &regulator_pm_ops,
 #endif
 };
 /**
  * regulator_has_full_constraints - the system has fully specified constraints
  *
  * Calling this function will cause the regulator API to disable all
  * regulators which have a zero use count and don't have an always_on
  * constraint in a late_initcall.
  *
  * The intention is that this will become the default behaviour in a
  * future kernel release so users are encouraged to use this facility
  * now.
  */
 void regulator_has_full_constraints(void)
 {
     has_full_constraints = 1;
 }
 EXPORT_SYMBOL_GPL(regulator_has_full_constraints);
 
 /**
  * rdev_get_drvdata - get rdev regulator driver data
  * @rdev: regulator
  *
  * Get rdev regulator driver private data. This call can be used in the
  * regulator driver context.
  */
 void *rdev_get_drvdata(struct regulator_dev *rdev)
 {
     return rdev->reg_data;
 }
 EXPORT_SYMBOL_GPL(rdev_get_drvdata);
 
 /**
  * regulator_get_drvdata - get regulator driver data
  * @regulator: regulator
  *
  * Get regulator driver private data. This call can be used in the consumer
  * driver context when non API regulator specific functions need to be called.
  */
 void *regulator_get_drvdata(struct regulator *regulator)
 {
     return regulator->rdev->reg_data;
 }
 EXPORT_SYMBOL_GPL(regulator_get_drvdata);
 
 /**
  * regulator_set_drvdata - set regulator driver data
  * @regulator: regulator
  * @data: data
  */
 void regulator_set_drvdata(struct regulator *regulator, void *data)
 {
     regulator->rdev->reg_data = data;
 }
 EXPORT_SYMBOL_GPL(regulator_set_drvdata);
 
 /**
  * rdev_get_id - get regulator ID
  * @rdev: regulator
  */
 int rdev_get_id(struct regulator_dev *rdev)
 {
     return rdev->desc->id;
 }
 EXPORT_SYMBOL_GPL(rdev_get_id);
 
 struct device *rdev_get_dev(struct regulator_dev *rdev)
 {
     return &rdev->dev;
 }
 EXPORT_SYMBOL_GPL(rdev_get_dev);
 
 struct regmap *rdev_get_regmap(struct regulator_dev *rdev)
 {
     return rdev->regmap;
 }
 EXPORT_SYMBOL_GPL(rdev_get_regmap);
 
 void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data)
 {
     return reg_init_data->driver_data;
 }
 EXPORT_SYMBOL_GPL(regulator_get_init_drvdata);
 
 #ifdef CONFIG_DEBUG_FS
 static int supply_map_show(struct seq_file *sf, void *data)
 {
     struct regulator_map *map;
 
     list_for_each_entry(map, &regulator_map_list, list) {
         seq_printf(sf, "%s -> %s.%s\n",
                 rdev_get_name(map->regulator), map->dev_name,
                 map->supply);
     }
 
     return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(supply_map);
 
 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 regulation_constraints *c;
     struct regulator *consumer;
     struct summary_data summary_data;
     unsigned int opmode;
 
     if (!rdev)
         return;
 
     opmode = _regulator_get_mode_unlocked(rdev);
     seq_printf(s, "%*s%-*s %3d %4d %6d %7s ",
            level * 3 + 1, "",
            30 - level * 3, rdev_get_name(rdev),
            rdev->use_count, rdev->open_count, rdev->bypass_count,
            regulator_opmode_to_str(opmode));
 
     seq_printf(s, "%5dmV ", regulator_get_voltage_rdev(rdev) / 1000);
     seq_printf(s, "%5dmA ",
            _regulator_get_current_limit_unlocked(rdev) / 1000);
 
     c = rdev->constraints;
     if (c) {
         switch (rdev->desc->type) {
         case REGULATOR_VOLTAGE:
             seq_printf(s, "%5dmV %5dmV ",
                    c->min_uV / 1000, c->max_uV / 1000);
             break;
         case REGULATOR_CURRENT:
             seq_printf(s, "%5dmA %5dmA ",
                    c->min_uA / 1000, c->max_uA / 1000);
             break;
         }
     }
 
     seq_puts(s, "\n");
 
     list_for_each_entry(consumer, &rdev->consumer_list, list) {
         if (consumer->dev && consumer->dev->class == &regulator_class)
             continue;
 
         seq_printf(s, "%*s%-*s ",
                (level + 1) * 3 + 1, "",
                30 - (level + 1) * 3,
                consumer->supply_name ? consumer->supply_name :
                consumer->dev ? dev_name(consumer->dev) : "deviceless");
 
         switch (rdev->desc->type) {
         case REGULATOR_VOLTAGE:
             seq_printf(s, "%3d %33dmA%c%5dmV %5dmV",
                    consumer->enable_count,
                    consumer->uA_load / 1000,
                    consumer->uA_load && !consumer->enable_count ?
                    '*' : ' ',
                    consumer->voltage[PM_SUSPEND_ON].min_uV / 1000,
                    consumer->voltage[PM_SUSPEND_ON].max_uV / 1000);
             break;
         case REGULATOR_CURRENT:
             break;
         }
 
         seq_puts(s, "\n");
     }
 
     summary_data.s = s;
     summary_data.level = level;
     summary_data.parent = rdev;
 
     class_for_each_device(&regulator_class, NULL, &summary_data,
                   regulator_summary_show_children);
 }
 
 struct summary_lock_data {
     struct ww_acquire_ctx *ww_ctx;
     struct regulator_dev **new_contended_rdev;
     struct regulator_dev **old_contended_rdev;
 };
 
 static int regulator_summary_lock_one(struct device *dev, void *data)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
     struct summary_lock_data *lock_data = data;
     int ret = 0;
 
     if (rdev != *lock_data->old_contended_rdev) {
         ret = regulator_lock_nested(rdev, lock_data->ww_ctx);
 
         if (ret == -EDEADLK)
             *lock_data->new_contended_rdev = rdev;
         else
             WARN_ON_ONCE(ret);
     } else {
         *lock_data->old_contended_rdev = NULL;
     }
 
     return ret;
 }
 
 static int regulator_summary_unlock_one(struct device *dev, void *data)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
     struct summary_lock_data *lock_data = data;
 
     if (lock_data) {
         if (rdev == *lock_data->new_contended_rdev)
             return -EDEADLK;
     }
 
     regulator_unlock(rdev);
 
     return 0;
 }
 
 static int regulator_summary_lock_all(struct ww_acquire_ctx *ww_ctx,
                       struct regulator_dev **new_contended_rdev,
                       struct regulator_dev **old_contended_rdev)
 {
     struct summary_lock_data lock_data;
     int ret;
 
     lock_data.ww_ctx = ww_ctx;
     lock_data.new_contended_rdev = new_contended_rdev;
     lock_data.old_contended_rdev = old_contended_rdev;
 
     ret = class_for_each_device(&regulator_class, NULL, &lock_data,
                     regulator_summary_lock_one);
     if (ret)
         class_for_each_device(&regulator_class, NULL, &lock_data,
                       regulator_summary_unlock_one);
 
     return ret;
 }
 
 static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx)
 {
     struct regulator_dev *new_contended_rdev = NULL;
     struct regulator_dev *old_contended_rdev = NULL;
     int err;
 
     mutex_lock(&regulator_list_mutex);
 
     ww_acquire_init(ww_ctx, &regulator_ww_class);
 
     do {
         if (new_contended_rdev) {
             ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
             old_contended_rdev = new_contended_rdev;
             old_contended_rdev->ref_cnt++;
         }
 
         err = regulator_summary_lock_all(ww_ctx,
                          &new_contended_rdev,
                          &old_contended_rdev);
 
         if (old_contended_rdev)
             regulator_unlock(old_contended_rdev);
 
     } while (err == -EDEADLK);
 
     ww_acquire_done(ww_ctx);
 }
 
 static void regulator_summary_unlock(struct ww_acquire_ctx *ww_ctx)
 {
     class_for_each_device(&regulator_class, NULL, NULL,
                   regulator_summary_unlock_one);
     ww_acquire_fini(ww_ctx);
 
     mutex_unlock(&regulator_list_mutex);
 }
 
 static int regulator_summary_show_roots(struct device *dev, void *data)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
     struct seq_file *s = data;
 
     if (!rdev->supply)
         regulator_summary_show_subtree(s, rdev, 0);
 
     return 0;
 }
 
 static int regulator_summary_show(struct seq_file *s, void *data)
 {
     struct ww_acquire_ctx ww_ctx;
 
     seq_puts(s, " regulator                      use open bypass  opmode voltage current     min     max\n");
     seq_puts(s, "---------------------------------------------------------------------------------------\n");
 
     regulator_summary_lock(&ww_ctx);
 
     class_for_each_device(&regulator_class, NULL, s,
                   regulator_summary_show_roots);
 
     regulator_summary_unlock(&ww_ctx);
 
     return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(regulator_summary);
 #endif /* CONFIG_DEBUG_FS */
 
 static int __init regulator_init(void)
 {
     int ret;
 
     ret = class_register(&regulator_class);
 
     debugfs_root = debugfs_create_dir("regulator", NULL);
     if (!debugfs_root)
         pr_warn("regulator: Failed to create debugfs directory\n");
 
 #ifdef CONFIG_DEBUG_FS
     debugfs_create_file("supply_map", 0444, debugfs_root, NULL,
                 &supply_map_fops);
 
     debugfs_create_file("regulator_summary", 0444, debugfs_root,
                 NULL, &regulator_summary_fops);
 #endif
     regulator_dummy_init();
 
     regulator_coupler_register(&generic_regulator_coupler);
 
     return ret;
 }
 
 /* init early to allow our consumers to complete system booting */
 core_initcall(regulator_init);
 
 static int regulator_late_cleanup(struct device *dev, void *data)
 {
     struct regulator_dev *rdev = dev_to_rdev(dev);
     struct regulation_constraints *c = rdev->constraints;
     int ret;
 
     if (c && c->always_on)
         return 0;
 
     if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS))
         return 0;
 
     regulator_lock(rdev);
 
     if (rdev->use_count)
         goto unlock;
 
     /* If reading the status failed, assume that it's off. */
     if (_regulator_is_enabled(rdev) <= 0)
         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: %pe\n", ERR_PTR(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:
     regulator_unlock(rdev);
 
     return 0;
 }
 
 static void regulator_init_complete_work_function(struct work_struct *work)
 {
     /*
      * Regulators may had failed to resolve their input supplies
      * when were registered, either because the input supply was
      * not registered yet or because its parent device was not
      * bound yet. So attempt to resolve the input supplies for
      * pending regulators before trying to disable unused ones.
      */
     class_for_each_device(&regulator_class, NULL, NULL,
                   regulator_register_resolve_supply);
 
     /* 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.
      */
     class_for_each_device(&regulator_class, NULL, NULL,
                   regulator_late_cleanup);
 }
 
 static DECLARE_DELAYED_WORK(regulator_init_complete_work,
                 regulator_init_complete_work_function);
 
 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
      * with DT to provide them just assume that a DT enabled
      * system has full constraints.
      */
     if (of_have_populated_dt())
         has_full_constraints = true;
 
     /*
      * We punt completion for an arbitrary amount of time since
      * systems like distros will load many drivers from userspace
      * so consumers might not always be ready yet, this is
      * particularly an issue with laptops where this might bounce
      * the display off then on.  Ideally we'd get a notification
      * from userspace when this happens but we don't so just wait
      * a bit and hope we waited long enough.  It'd be better if
      * we'd only do this on systems that need it, and a kernel
      * command line option might be useful.
      */
     schedule_delayed_work(&regulator_init_complete_work,
                   msecs_to_jiffies(30000));
 
     return 0;
 }
 late_initcall_sync(regulator_init_complete);