text: /*
   * core.c  --  Voltage/Current Regulator framework.
   *
   * Copyright 2007, 2008 Wolfson Microelectronics PLC.
   * Copyright 2008 SlimLogic Ltd.
   *
   * Author: Liam Girdwood <lrg@slimlogic.co.uk>
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   *
   */
  
  #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.h>
  #include <linux/of.h>
  #include <linux/regmap.h>
  #include <linux/regulator/of_regulator.h>
  #include <linux/regulator/consumer.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"
  
  #define rdev_crit(rdev, fmt, ...)					\
  	pr_crit("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
  #define rdev_err(rdev, fmt, ...)					\
  	pr_err("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
  #define rdev_warn(rdev, fmt, ...)					\
  	pr_warn("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
  #define rdev_info(rdev, fmt, ...)					\
  	pr_info("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
  #define rdev_dbg(rdev, fmt, ...)					\
  	pr_debug("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
  
  static DEFINE_MUTEX(regulator_list_mutex);
  static LIST_HEAD(regulator_list);
  static LIST_HEAD(regulator_map_list);
  static LIST_HEAD(regulator_ena_gpio_list);
  static LIST_HEAD(regulator_supply_alias_list);
  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;
  	int gpio;
  	u32 enable_count;	/* a number of enabled shared GPIO */
  	u32 request_count;	/* a number of requested shared GPIO */
  	unsigned int ena_gpio_invert:1;
  };
  
  /*
   * 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_dev *rdev);
  static int _regulator_get_voltage(struct regulator_dev *rdev);
  static int _regulator_get_current_limit(struct regulator_dev *rdev);
  static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
  static void _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 struct regulator *create_regulator(struct regulator_dev *rdev,
  					  struct device *dev,
  					  const char *supply_name);
  
  static 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 "";
  }
  
  static bool have_full_constraints(void)
  {
  	return has_full_constraints || of_have_populated_dt();
  }
  
  /**
   * 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[32]; /* 32 is max size of property name */
  
  	dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);
  
  	snprintf(prop_name, 32, "%s-supply", supply);
  	regnode = of_parse_phandle(dev->of_node, prop_name, 0);
  
  	if (!regnode) {
  		dev_dbg(dev, "Looking up %s property in node %s failed",
  				prop_name, dev->of_node->full_name);
  		return NULL;
  	}
  	return regnode;
  }
  
  static int _regulator_can_change_status(struct regulator_dev *rdev)
  {
  	if (!rdev->constraints)
  		return 0;
  
  	if (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_STATUS)
  		return 1;
  	else
  		return 0;
  }
  
  /* Platform voltage constraint check */
  static int regulator_check_voltage(struct regulator_dev *rdev,
  				   int *min_uV, int *max_uV)
  {
  	BUG_ON(*min_uV > *max_uV);
  
  	if (!rdev->constraints) {
  		rdev_err(rdev, "no constraints\n");
  		return -ENODEV;
  	}
  	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
  		rdev_err(rdev, "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;
  }
  
  /* Make sure we select a voltage that suits the needs of all
   * regulator consumers
   */
  static int regulator_check_consumers(struct regulator_dev *rdev,
  				     int *min_uV, int *max_uV)
  {
  	struct regulator *regulator;
  
  	list_for_each_entry(regulator, &rdev->consumer_list, list) {
  		/*
  		 * Assume consumers that didn't say anything are OK
  		 * with anything in the constraint range.
  		 */
  		if (!regulator->min_uV && !regulator->max_uV)
  			continue;
  
  		if (*max_uV > regulator->max_uV)
  			*max_uV = regulator->max_uV;
  		if (*min_uV < regulator->min_uV)
  			*min_uV = regulator->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 (!rdev->constraints) {
  		rdev_err(rdev, "no constraints\n");
  		return -ENODEV;
  	}
  	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT)) {
  		rdev_err(rdev, "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, 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 (!rdev->constraints) {
  		rdev_err(rdev, "no constraints\n");
  		return -ENODEV;
  	}
  	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE)) {
  		rdev_err(rdev, "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;
  }
  
  /* dynamic regulator mode switching constraint check */
  static int regulator_check_drms(struct regulator_dev *rdev)
  {
  	if (!rdev->constraints) {
  		rdev_err(rdev, "no constraints\n");
  		return -ENODEV;
  	}
  	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) {
  		rdev_err(rdev, "operation not allowed\n");
  		return -EPERM;
  	}
  	return 0;
  }
  
  static ssize_t regulator_uV_show(struct device *dev,
  				struct device_attribute *attr, char *buf)
  {
  	struct regulator_dev *rdev = dev_get_drvdata(dev);
  	ssize_t ret;
  
  	mutex_lock(&rdev->mutex);
  	ret = sprintf(buf, "%d\n", _regulator_get_voltage(rdev));
  	mutex_unlock(&rdev->mutex);
  
  	return ret;
  }
  static DEVICE_ATTR(microvolts, 0444, regulator_uV_show, NULL);
  
  static ssize_t regulator_uA_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(microamps, 0444, regulator_uA_show, NULL);
  
  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 ssize_t regulator_print_opmode(char *buf, int mode)
  {
  	switch (mode) {
  	case REGULATOR_MODE_FAST:
  		return sprintf(buf, "fast\n");
  	case REGULATOR_MODE_NORMAL:
  		return sprintf(buf, "normal\n");
  	case REGULATOR_MODE_IDLE:
  		return sprintf(buf, "idle\n");
  	case REGULATOR_MODE_STANDBY:
  		return sprintf(buf, "standby\n");
  	}
  	return sprintf(buf, "unknown\n");
  }
  
  static ssize_t regulator_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(opmode, 0444, regulator_opmode_show, NULL);
  
  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 regulator_state_show(struct device *dev,
  				   struct device_attribute *attr, char *buf)
  {
  	struct regulator_dev *rdev = dev_get_drvdata(dev);
  	ssize_t ret;
  
  	mutex_lock(&rdev->mutex);
  	ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
  	mutex_unlock(&rdev->mutex);
  
  	return ret;
  }
  static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);
  
  static ssize_t regulator_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(status, 0444, regulator_status_show, NULL);
  
  static ssize_t regulator_min_uA_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(min_microamps, 0444, regulator_min_uA_show, NULL);
  
  static ssize_t regulator_max_uA_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(max_microamps, 0444, regulator_max_uA_show, NULL);
  
  static ssize_t regulator_min_uV_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(min_microvolts, 0444, regulator_min_uV_show, NULL);
  
  static ssize_t regulator_max_uV_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(max_microvolts, 0444, regulator_max_uV_show, NULL);
  
  static ssize_t regulator_total_uA_show(struct device *dev,
  				      struct device_attribute *attr, char *buf)
  {
  	struct regulator_dev *rdev = dev_get_drvdata(dev);
  	struct regulator *regulator;
  	int uA = 0;
  
  	mutex_lock(&rdev->mutex);
  	list_for_each_entry(regulator, &rdev->consumer_list, list)
  		uA += regulator->uA_load;
  	mutex_unlock(&rdev->mutex);
  	return sprintf(buf, "%d\n", uA);
  }
  static DEVICE_ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL);
  
  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 regulator_suspend_mem_uV_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(suspend_mem_microvolts, 0444,
  		regulator_suspend_mem_uV_show, NULL);
  
  static ssize_t regulator_suspend_disk_uV_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(suspend_disk_microvolts, 0444,
  		regulator_suspend_disk_uV_show, NULL);
  
  static ssize_t regulator_suspend_standby_uV_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(suspend_standby_microvolts, 0444,
  		regulator_suspend_standby_uV_show, NULL);
  
  static ssize_t regulator_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(suspend_mem_mode, 0444,
  		regulator_suspend_mem_mode_show, NULL);
  
  static ssize_t regulator_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(suspend_disk_mode, 0444,
  		regulator_suspend_disk_mode_show, NULL);
  
  static ssize_t regulator_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(suspend_standby_mode, 0444,
  		regulator_suspend_standby_mode_show, NULL);
  
  static ssize_t regulator_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(suspend_mem_state, 0444,
  		regulator_suspend_mem_state_show, NULL);
  
  static ssize_t regulator_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(suspend_disk_state, 0444,
  		regulator_suspend_disk_state_show, NULL);
  
  static ssize_t regulator_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(suspend_standby_state, 0444,
  		regulator_suspend_standby_state_show, NULL);
  
  static ssize_t regulator_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(bypass, 0444,
  		   regulator_bypass_show, NULL);
  
  /*
   * These are the only attributes are present for all regulators.
   * Other attributes are a function of regulator functionality.
   */
  static struct attribute *regulator_dev_attrs[] = {
  	&dev_attr_name.attr,
  	&dev_attr_num_users.attr,
  	&dev_attr_type.attr,
  	NULL,
  };
  ATTRIBUTE_GROUPS(regulator_dev);
  
  static void regulator_dev_release(struct device *dev)
  {
  	struct regulator_dev *rdev = dev_get_drvdata(dev);
  	kfree(rdev);
  }
  
  static struct class regulator_class = {
  	.name = "regulator",
  	.dev_release = regulator_dev_release,
  	.dev_groups = regulator_dev_groups,
  };
  
  /* Calculate the new optimum regulator operating mode based on the new total
   * consumer load. All locks held by caller */
  static void drms_uA_update(struct regulator_dev *rdev)
  {
  	struct regulator *sibling;
  	int current_uA = 0, output_uV, input_uV, err;
  	unsigned int mode;
  
  	err = regulator_check_drms(rdev);
  	if (err < 0 || !rdev->desc->ops->get_optimum_mode ||
  	    (!rdev->desc->ops->get_voltage &&
  	     !rdev->desc->ops->get_voltage_sel) ||
  	    !rdev->desc->ops->set_mode)
  		return;
  
  	/* get output voltage */
  	output_uV = _regulator_get_voltage(rdev);
  	if (output_uV <= 0)
  		return;
  
  	/* 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)
  		return;
  
  	/* calc total requested load */
  	list_for_each_entry(sibling, &rdev->consumer_list, list)
  		current_uA += sibling->uA_load;
  
  	/* 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->desc->ops->set_mode(rdev, mode);
  }
  
  static int suspend_set_state(struct regulator_dev *rdev,
  	struct regulator_state *rstate)
  {
  	int ret = 0;
  
  	/* If we have no suspend mode configration don't set anything;
  	 * only warn if the driver implements set_suspend_voltage or
  	 * set_suspend_mode callback.
  	 */
  	if (!rstate->enabled && !rstate->disabled) {
  		if (rdev->desc->ops->set_suspend_voltage ||
  		    rdev->desc->ops->set_suspend_mode)
  			rdev_warn(rdev, "No configuration\n");
  		return 0;
  	}
  
  	if (rstate->enabled && rstate->disabled) {
  		rdev_err(rdev, "invalid configuration\n");
  		return -EINVAL;
  	}
  
  	if (rstate->enabled && rdev->desc->ops->set_suspend_enable)
  		ret = rdev->desc->ops->set_suspend_enable(rdev);
  	else if (rstate->disabled && 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\n");
  		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\n");
  			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\n");
  			return ret;
  		}
  	}
  	return ret;
  }
  
  /* locks held by caller */
  static int suspend_prepare(struct regulator_dev *rdev, suspend_state_t state)
  {
  	if (!rdev->constraints)
  		return -EINVAL;
  
  	switch (state) {
  	case PM_SUSPEND_STANDBY:
  		return suspend_set_state(rdev,
  			&rdev->constraints->state_standby);
  	case PM_SUSPEND_MEM:
  		return suspend_set_state(rdev,
  			&rdev->constraints->state_mem);
  	case PM_SUSPEND_MAX:
  		return suspend_set_state(rdev,
  			&rdev->constraints->state_disk);
  	default:
  		return -EINVAL;
  	}
  }
  
  static void print_constraints(struct regulator_dev *rdev)
  {
  	struct regulation_constraints *constraints = rdev->constraints;
  	char buf[160] = "";
  	int count = 0;
  	int ret;
  
  	if (constraints->min_uV && constraints->max_uV) {
  		if (constraints->min_uV == constraints->max_uV)
  			count += sprintf(buf + count, "%d mV ",
  					 constraints->min_uV / 1000);
  		else
  			count += sprintf(buf + count, "%d <--> %d mV ",
  					 constraints->min_uV / 1000,
  					 constraints->max_uV / 1000);
  	}
  
  	if (!constraints->min_uV ||
  	    constraints->min_uV != constraints->max_uV) {
  		ret = _regulator_get_voltage(rdev);
  		if (ret > 0)
  			count += sprintf(buf + count, "at %d mV ", ret / 1000);
  	}
  
  	if (constraints->uV_offset)
  		count += sprintf(buf, "%dmV offset ",
  				 constraints->uV_offset / 1000);
  
  	if (constraints->min_uA && constraints->max_uA) {
  		if (constraints->min_uA == constraints->max_uA)
  			count += sprintf(buf + count, "%d mA ",
  					 constraints->min_uA / 1000);
  		else
  			count += sprintf(buf + count, "%d <--> %d mA ",
  					 constraints->min_uA / 1000,
  					 constraints->max_uA / 1000);
  	}
  
  	if (!constraints->min_uA ||
  	    constraints->min_uA != constraints->max_uA) {
  		ret = _regulator_get_current_limit(rdev);
  		if (ret > 0)
  			count += sprintf(buf + count, "at %d mA ", ret / 1000);
  	}
  
  	if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
  		count += sprintf(buf + count, "fast ");
  	if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
  		count += sprintf(buf + count, "normal ");
  	if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
  		count += sprintf(buf + count, "idle ");
  	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
  		count += sprintf(buf + count, "standby");
  
  	if (!count)
  		sprintf(buf, "no parameters");
  
  	rdev_info(rdev, "%s\n", buf);
  
  	if ((constraints->min_uV != constraints->max_uV) &&
  	    !(constraints->valid_ops_mask & 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)
  {
  	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) {
  		ret = _regulator_do_set_voltage(rdev,
  						rdev->constraints->min_uV,
  						rdev->constraints->max_uV);
  		if (ret < 0) {
  			rdev_err(rdev, "failed to apply %duV constraint\n",
  				 rdev->constraints->min_uV);
  			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;
  		}
  
  		/* 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)
  {
  	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);
  
  /**
   * set_machine_constraints - sets regulator constraints
   * @rdev: regulator source
   * @constraints: constraints to apply
   *
   * 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,
  	const struct regulation_constraints *constraints)
  {
  	int ret = 0;
  	struct regulator_ops *ops = rdev->desc->ops;
  
  	if (constraints)
  		rdev->constraints = kmemdup(constraints, sizeof(*constraints),
  					    GFP_KERNEL);
  	else
  		rdev->constraints = kzalloc(sizeof(*constraints),
  					    GFP_KERNEL);
  	if (!rdev->constraints)
  		return -ENOMEM;
  
  	ret = machine_constraints_voltage(rdev, rdev->constraints);
  	if (ret != 0)
  		goto out;
  
  	ret = machine_constraints_current(rdev, rdev->constraints);
  	if (ret != 0)
  		goto out;
  
  	/* do we need to setup our suspend state */
  	if (rdev->constraints->initial_state) {
  		ret = suspend_prepare(rdev, rdev->constraints->initial_state);
  		if (ret < 0) {
  			rdev_err(rdev, "failed to set suspend state\n");
  			goto out;
  		}
  	}
  
  	if (rdev->constraints->initial_mode) {
  		if (!ops->set_mode) {
  			rdev_err(rdev, "no set_mode operation\n");
  			ret = -EINVAL;
  			goto out;
  		}
  
  		ret = ops->set_mode(rdev, rdev->constraints->initial_mode);
  		if (ret < 0) {
  			rdev_err(rdev, "failed to set initial mode: %d\n", ret);
  			goto out;
  		}
  	}
  
  	/* 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) {
  		ret = _regulator_do_enable(rdev);
  		if (ret < 0 && ret != -EINVAL) {
  			rdev_err(rdev, "failed to enable\n");
  			goto out;
  		}
  	}
  
  	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\n");
  			goto out;
  		}
  	}
  
  	print_constraints(rdev);
  	return 0;
  out:
  	kfree(rdev->constraints);
  	rdev->constraints = NULL;
  	return ret;
  }
  
  /**
   * 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_info(rdev, "supplied by %s\n", rdev_get_name(supply_rdev));
  
  	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;
  	int has_dev;
  
  	if (supply == NULL)
  		return -EINVAL;
  
  	if (consumer_dev_name != NULL)
  		has_dev = 1;
  	else
  		has_dev = 0;
  
  	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));
  		return -EBUSY;
  	}
  
  	node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
  	if (node == NULL)
  		return -ENOMEM;
  
  	node->regulator = rdev;
  	node->supply = supply;
  
  	if (has_dev) {
  		node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
  		if (node->dev_name == NULL) {
  			kfree(node);
  			return -ENOMEM;
  		}
  	}
  
  	list_add(&node->list, &regulator_map_list);
  	return 0;
  }
  
  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);
  		}
  	}
  }
  
  #define REG_STR_SIZE	64
  
  static struct regulator *create_regulator(struct regulator_dev *rdev,
  					  struct device *dev,
  					  const char *supply_name)
  {
  	struct regulator *regulator;
  	char buf[REG_STR_SIZE];
  	int err, size;
  
  	regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
  	if (regulator == NULL)
  		return NULL;
  
  	mutex_lock(&rdev->mutex);
  	regulator->rdev = rdev;
  	list_add(&regulator->list, &rdev->consumer_list);
  
  	if (dev) {
  		regulator->dev = dev;
  
  		/* Add a link to the device sysfs entry */
  		size = scnprintf(buf, REG_STR_SIZE, "%s-%s",
  				 dev->kobj.name, supply_name);
  		if (size >= REG_STR_SIZE)
  			goto overflow_err;
  
  		regulator->supply_name = kstrdup(buf, GFP_KERNEL);
  		if (regulator->supply_name == NULL)
  			goto overflow_err;
  
  		err = sysfs_create_link(&rdev->dev.kobj, &dev->kobj,
  					buf);
  		if (err) {
  			rdev_warn(rdev, "could not add device link %s err %d\n",
  				  dev->kobj.name, err);
  			/* non-fatal */
  		}
  	} else {
  		regulator->supply_name = kstrdup(supply_name, GFP_KERNEL);
  		if (regulator->supply_name == NULL)
  			goto overflow_err;
  	}
  
  	regulator->debugfs = debugfs_create_dir(regulator->supply_name,
  						rdev->debugfs);
  	if (!regulator->debugfs) {
  		rdev_warn(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->min_uV);
  		debugfs_create_u32("max_uV", 0444, regulator->debugfs,
  				   &regulator->max_uV);
  	}
  
  	/*
  	 * 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_can_change_status(rdev) &&
  	    _regulator_is_enabled(rdev))
  		regulator->always_on = true;
  
  	mutex_unlock(&rdev->mutex);
  	return regulator;
  overflow_err:
  	list_del(&regulator->list);
  	kfree(regulator);
  	mutex_unlock(&rdev->mutex);
  	return NULL;
  }
  
  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->enable_time;
  	return rdev->desc->ops->enable_time(rdev);
  }
  
  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 struct regulator_dev *regulator_dev_lookup(struct device *dev,
  						  const char *supply,
  						  int *ret)
  {
  	struct regulator_dev *r;
  	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) {
  			list_for_each_entry(r, &regulator_list, list)
  				if (r->dev.parent &&
  					node == r->dev.of_node)
  					return r;
  			*ret = -EPROBE_DEFER;
  			return NULL;
  		} else {
  			/*
  			 * If we couldn't even get the node then it's
  			 * not just that the device didn't register
  			 * yet, there's no node and we'll never
  			 * succeed.
  			 */
  			*ret = -ENODEV;
  		}
  	}
  
  	/* if not found, try doing it non-dt way */
  	if (dev)
  		devname = dev_name(dev);
  
  	list_for_each_entry(r, &regulator_list, list)
  		if (strcmp(rdev_get_name(r), supply) == 0)
  			return r;
  
  	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)
  			return map->regulator;
  	}
  
  
  	return NULL;
  }
  
  /* Internal regulator request function */
  static struct regulator *_regulator_get(struct device *dev, const char *id,
  					bool exclusive, bool allow_dummy)
  {
  	struct regulator_dev *rdev;
  	struct regulator *regulator = ERR_PTR(-EPROBE_DEFER);
  	const char *devname = NULL;
  	int ret;
  
  	if (id == NULL) {
  		pr_err("get() with no identifier\n");
  		return ERR_PTR(-EINVAL);
  	}
  
  	if (dev)
  		devname = dev_name(dev);
  
  	if (have_full_constraints())
  		ret = -ENODEV;
  	else
  		ret = -EPROBE_DEFER;
  
  	mutex_lock(&regulator_list_mutex);
  
  	rdev = regulator_dev_lookup(dev, id, &ret);
  	if (rdev)
  		goto found;
  
  	regulator = ERR_PTR(ret);
  
  	/*
  	 * If we have return value from dev_lookup fail, we do not expect to
  	 * succeed, so, quit with appropriate error value
  	 */
  	if (ret && ret != -ENODEV) {
  		goto out;
  	}
  
  	if (!devname)
  		devname = "deviceless";
  
  	/*
  	 * Assume that a regulator is physically present and enabled
  	 * even if it isn't hooked up and just provide a dummy.
  	 */
  	if (have_full_constraints() && allow_dummy) {
  		pr_warn("%s supply %s not found, using dummy regulator\n",
  			devname, id);
  
  		rdev = dummy_regulator_rdev;
  		goto found;
  	} else {
  		dev_warn(dev, "dummy supplies not allowed\n");
  	}
  
  	mutex_unlock(&regulator_list_mutex);
  	return regulator;
  
  found:
  	if (rdev->exclusive) {
  		regulator = ERR_PTR(-EPERM);
  		goto out;
  	}
  
  	if (exclusive && rdev->open_count) {
  		regulator = ERR_PTR(-EBUSY);
  		goto out;
  	}
  
  	if (!try_module_get(rdev->owner))
  		goto out;
  
  	regulator = create_regulator(rdev, dev, id);
  	if (regulator == NULL) {
  		regulator = ERR_PTR(-ENOMEM);
  		module_put(rdev->owner);
  		goto out;
  	}
  
  	rdev->open_count++;
  	if (exclusive) {
  		rdev->exclusive = 1;
  
  		ret = _regulator_is_enabled(rdev);
  		if (ret > 0)
  			rdev->use_count = 1;
  		else
  			rdev->use_count = 0;
  	}
  
  out:
  	mutex_unlock(&regulator_list_mutex);
  
  	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 regulator_set_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, false, true);
  }
  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 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 regulator_set_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, true, false);
  }
  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.  Other consumers will be
   * unable to obtain 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 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 regulator_set_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, false, false);
  }
  EXPORT_SYMBOL_GPL(regulator_get_optional);
  
  /* regulator_list_mutex lock held by regulator_put() */
  static void _regulator_put(struct regulator *regulator)
  {
  	struct regulator_dev *rdev;
  
  	if (regulator == NULL || IS_ERR(regulator))
  		return;
  
  	rdev = regulator->rdev;
  
  	debugfs_remove_recursive(regulator->debugfs);
  
  	/* remove any sysfs entries */
  	if (regulator->dev)
  		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
  	mutex_lock(&rdev->mutex);
  	kfree(regulator->supply_name);
  	list_del(&regulator->list);
  	kfree(regulator);
  
  	rdev->open_count--;
  	rdev->exclusive = 0;
  	mutex_unlock(&rdev->mutex);
  
  	module_put(rdev->owner);
  }
  
  /**
   * 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 **id,
  					 struct device *alias_dev,
  					 const char **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 **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;
  	int ret;
  
  	list_for_each_entry(pin, &regulator_ena_gpio_list, list) {
  		if (pin->gpio == config->ena_gpio) {
  			rdev_dbg(rdev, "GPIO %d is already used\n",
  				config->ena_gpio);
  			goto update_ena_gpio_to_rdev;
  		}
  	}
  
  	ret = gpio_request_one(config->ena_gpio,
  				GPIOF_DIR_OUT | config->ena_gpio_flags,
  				rdev_get_name(rdev));
  	if (ret)
  		return ret;
  
  	pin = kzalloc(sizeof(struct regulator_enable_gpio), GFP_KERNEL);
  	if (pin == NULL) {
  		gpio_free(config->ena_gpio);
  		return -ENOMEM;
  	}
  
  	pin->gpio = config->ena_gpio;
  	pin->ena_gpio_invert = config->ena_gpio_invert;
  	list_add(&pin->list, &regulator_ena_gpio_list);
  
  update_ena_gpio_to_rdev:
  	pin->request_count++;
  	rdev->ena_pin = 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->gpio == rdev->ena_pin->gpio) {
  			if (pin->request_count <= 1) {
  				pin->request_count = 0;
  				gpio_free(pin->gpio);
  				list_del(&pin->list);
  				kfree(pin);
  			} else {
  				pin->request_count--;
  			}
  		}
  	}
  }
  
  /**
   * 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)
  			gpio_set_value_cansleep(pin->gpio,
  						!pin->ena_gpio_invert);
  
  		pin->enable_count++;
  	} else {
  		if (pin->enable_count > 1) {
  			pin->enable_count--;
  			return 0;
  		}
  
  		/* Disable GPIO if not used */
  		if (pin->enable_count <= 1) {
  			gpio_set_value_cansleep(pin->gpio,
  						pin->ena_gpio_invert);
  			pin->enable_count = 0;
  		}
  	}
  
  	return 0;
  }
  
  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: %d\n", ret);
  		delay = 0;
  	}
  
  	trace_regulator_enable(rdev_get_name(rdev));
  
  	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));
  
  	/*
  	 * Delay for the requested amount of time as per the guidelines in:
  	 *
  	 *     Documentation/timers/timers-howto.txt
  	 *
  	 * The assumption here is that regulators will never be enabled in
  	 * atomic context and therefore sleeping functions can be used.
  	 */
  	if (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);
  	}
  
  	trace_regulator_enable_complete(rdev_get_name(rdev));
  
  	return 0;
  }
  
  /* locks held by regulator_enable() */
  static int _regulator_enable(struct regulator_dev *rdev)
  {
  	int ret;
  
  	/* check voltage and requested load before enabling */
  	if (rdev->constraints &&
  	    (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
  		drms_uA_update(rdev);
  
  	if (rdev->use_count == 0) {
  		/* The regulator may on if it's not switchable or left on */
  		ret = _regulator_is_enabled(rdev);
  		if (ret == -EINVAL || ret == 0) {
  			if (!_regulator_can_change_status(rdev))
  				return -EPERM;
  
  			ret = _regulator_do_enable(rdev);
  			if (ret < 0)
  				return ret;
  
  		} else if (ret < 0) {
  			rdev_err(rdev, "is_enabled() failed: %d\n", ret);
  			return ret;
  		}
  		/* Fallthrough on positive return values - already enabled */
  	}
  
  	rdev->use_count++;
  
  	return 0;
  }
  
  /**
   * 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;
  	int ret = 0;
  
  	if (regulator->always_on)
  		return 0;
  
  	if (rdev->supply) {
  		ret = regulator_enable(rdev->supply);
  		if (ret != 0)
  			return ret;
  	}
  
  	mutex_lock(&rdev->mutex);
  	ret = _regulator_enable(rdev);
  	mutex_unlock(&rdev->mutex);
  
  	if (ret != 0 && rdev->supply)
  		regulator_disable(rdev->supply);
  
  	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;
  	}
  
  	trace_regulator_disable_complete(rdev_get_name(rdev));
  
  	return 0;
  }
  
  /* locks held by regulator_disable() */
  static int _regulator_disable(struct regulator_dev *rdev)
  {
  	int ret = 0;
  
  	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_can_change_status(rdev)) {
  			ret = _regulator_do_disable(rdev);
  			if (ret < 0) {
  				rdev_err(rdev, "failed to disable\n");
  				return ret;
  			}
  			_notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE,
  					NULL);
  		}
  
  		rdev->use_count = 0;
  	} else if (rdev->use_count > 1) {
  
  		if (rdev->constraints &&
  			(rdev->constraints->valid_ops_mask &
  			REGULATOR_CHANGE_DRMS))
  			drms_uA_update(rdev);
  
  		rdev->use_count--;
  	}
  
  	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;
  	int ret = 0;
  
  	if (regulator->always_on)
  		return 0;
  
  	mutex_lock(&rdev->mutex);
  	ret = _regulator_disable(rdev);
  	mutex_unlock(&rdev->mutex);
  
  	if (ret == 0 && rdev->supply)
  		regulator_disable(rdev->supply);
  
  	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;
  
  	ret = _regulator_do_disable(rdev);
  	if (ret < 0) {
  		rdev_err(rdev, "failed to force disable\n");
  		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;
  	int ret;
  
  	mutex_lock(&rdev->mutex);
  	regulator->uA_load = 0;
  	ret = _regulator_force_disable(regulator->rdev);
  	mutex_unlock(&rdev->mutex);
  
  	if (rdev->supply)
  		while (rdev->open_count--)
  			regulator_disable(rdev->supply);
  
  	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);
  	int count, i, ret;
  
  	mutex_lock(&rdev->mutex);
  
  	BUG_ON(!rdev->deferred_disables);
  
  	count = rdev->deferred_disables;
  	rdev->deferred_disables = 0;
  
  	for (i = 0; i < count; i++) {
  		ret = _regulator_disable(rdev);
  		if (ret != 0)
  			rdev_err(rdev, "Deferred disable failed: %d\n", ret);
  	}
  
  	mutex_unlock(&rdev->mutex);
  
  	if (rdev->supply) {
  		for (i = 0; i < count; i++) {
  			ret = regulator_disable(rdev->supply);
  			if (ret != 0) {
  				rdev_err(rdev,
  					 "Supply disable failed: %d\n", ret);
  			}
  		}
  	}
  }
  
  /**
   * regulator_disable_deferred - disable regulator output with delay
   * @regulator: regulator source
   * @ms: miliseconds 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;
  	int ret;
  
  	if (regulator->always_on)
  		return 0;
  
  	if (!ms)
  		return regulator_disable(regulator);
  
  	mutex_lock(&rdev->mutex);
  	rdev->deferred_disables++;
  	mutex_unlock(&rdev->mutex);
  
  	ret = queue_delayed_work(system_power_efficient_wq,
  				 &rdev->disable_work,
  				 msecs_to_jiffies(ms));
  	if (ret < 0)
  		return ret;
  	else
  		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);
  }
  
  /**
   * 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;
  
  	mutex_lock(&regulator->rdev->mutex);
  	ret = _regulator_is_enabled(regulator->rdev);
  	mutex_unlock(&regulator->rdev->mutex);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_is_enabled);
  
  /**
   * regulator_can_change_voltage - check if regulator can change voltage
   * @regulator: regulator source
   *
   * Returns positive if the regulator driver backing the source/client
   * can change its voltage, false otherwise. Usefull for detecting fixed
   * or dummy regulators and disabling voltage change logic in the client
   * driver.
   */
  int regulator_can_change_voltage(struct regulator *regulator)
  {
  	struct regulator_dev	*rdev = regulator->rdev;
  
  	if (rdev->constraints &&
  	    (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
  		if (rdev->desc->n_voltages - rdev->desc->linear_min_sel > 1)
  			return 1;
  
  		if (rdev->desc->continuous_voltage_range &&
  		    rdev->constraints->min_uV && rdev->constraints->max_uV &&
  		    rdev->constraints->min_uV != rdev->constraints->max_uV)
  			return 1;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(regulator_can_change_voltage);
  
  /**
   * 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;
  
  	return rdev->desc->n_voltages ? : -EINVAL;
  }
  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)
  {
  	struct regulator_dev	*rdev = regulator->rdev;
  	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 || selector >= rdev->desc->n_voltages)
  		return -EINVAL;
  
  	mutex_lock(&rdev->mutex);
  	ret = ops->list_voltage(rdev, selector);
  	mutex_unlock(&rdev->mutex);
  
  	if (ret > 0) {
  		if (ret < rdev->constraints->min_uV)
  			ret = 0;
  		else if (ret > rdev->constraints->max_uV)
  			ret = 0;
  	}
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_list_voltage);
  
  /**
   * 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 or a negative error code.
   */
  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 (!(rdev->constraints->valid_ops_mask & 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 ret;
  	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_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;
  
  	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) &&
  	    rdev->desc->ops->set_voltage_time_sel &&
  	    rdev->desc->ops->get_voltage_sel) {
  		old_selector = rdev->desc->ops->get_voltage_sel(rdev);
  		if (old_selector < 0)
  			return old_selector;
  	}
  
  	if (rdev->desc->ops->set_voltage) {
  		ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV,
  						   &selector);
  
  		if (ret >= 0) {
  			if (rdev->desc->ops->list_voltage)
  				best_val = rdev->desc->ops->list_voltage(rdev,
  									 selector);
  			else
  				best_val = _regulator_get_voltage(rdev);
  		}
  
  	} else if (rdev->desc->ops->set_voltage_sel) {
  		if (rdev->desc->ops->map_voltage) {
  			ret = rdev->desc->ops->map_voltage(rdev, min_uV,
  							   max_uV);
  		} else {
  			if (rdev->desc->ops->list_voltage ==
  			    regulator_list_voltage_linear)
  				ret = regulator_map_voltage_linear(rdev,
  								min_uV, max_uV);
  			else
  				ret = regulator_map_voltage_iterate(rdev,
  								min_uV, max_uV);
  		}
  
  		if (ret >= 0) {
  			best_val = rdev->desc->ops->list_voltage(rdev, ret);
  			if (min_uV <= best_val && max_uV >= best_val) {
  				selector = ret;
  				if (old_selector == selector)
  					ret = 0;
  				else
  					ret = rdev->desc->ops->set_voltage_sel(
  								rdev, ret);
  			} else {
  				ret = -EINVAL;
  			}
  		}
  	} else {
  		ret = -EINVAL;
  	}
  
  	/* Call set_voltage_time_sel if successfully obtained old_selector */
  	if (ret == 0 && !rdev->constraints->ramp_disable && old_selector >= 0
  		&& old_selector != selector) {
  
  		delay = rdev->desc->ops->set_voltage_time_sel(rdev,
  						old_selector, selector);
  		if (delay < 0) {
  			rdev_warn(rdev, "set_voltage_time_sel() failed: %d\n",
  				  delay);
  			delay = 0;
  		}
  
  		/* Insert any necessary delays */
  		if (delay >= 1000) {
  			mdelay(delay / 1000);
  			udelay(delay % 1000);
  		} else if (delay) {
  			udelay(delay);
  		}
  	}
  
  	if (ret == 0 && best_val >= 0) {
  		unsigned long data = best_val;
  
  		_notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE,
  				     (void *)data);
  	}
  
  	trace_regulator_set_voltage_complete(rdev_get_name(rdev), best_val);
  
  	return ret;
  }
  
  /**
   * regulator_set_voltage - set regulator output voltage
   * @regulator: regulator source
   * @min_uV: Minimum required voltage in uV
   * @max_uV: Maximum acceptable voltage in uV
   *
   * Sets a voltage regulator to the desired output voltage. This can be set
   * during any regulator state. IOW, regulator can be disabled or enabled.
   *
   * If the regulator is enabled then the voltage will change to the new value
   * immediately otherwise if the regulator is disabled the regulator will
   * output at the new voltage when enabled.
   *
   * NOTE: If the regulator is shared between several devices then the lowest
   * request voltage that meets the system constraints will be used.
   * Regulator system constraints must be set for this regulator before
   * calling this function otherwise this call will fail.
   */
  int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
  {
  	struct regulator_dev *rdev = regulator->rdev;
  	int ret = 0;
  	int old_min_uV, old_max_uV;
  
  	mutex_lock(&rdev->mutex);
  
  	/* 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 (regulator->min_uV == min_uV && regulator->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 = regulator->min_uV;
  	old_max_uV = regulator->max_uV;
  	regulator->min_uV = min_uV;
  	regulator->max_uV = max_uV;
  
  	ret = regulator_check_consumers(rdev, &min_uV, &max_uV);
  	if (ret < 0)
  		goto out2;
  
  	ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
  	if (ret < 0)
  		goto out2;
  	
  out:
  	mutex_unlock(&rdev->mutex);
  	return ret;
  out2:
  	regulator->min_uV = old_min_uV;
  	regulator->max_uV = old_max_uV;
  	mutex_unlock(&rdev->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_set_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;
  	struct regulator_ops	*ops = rdev->desc->ops;
  	int old_sel = -1;
  	int new_sel = -1;
  	int voltage;
  	int i;
  
  	/* Currently requires operations to do this */
  	if (!ops->list_voltage || !ops->set_voltage_time_sel
  	    || !rdev->desc->n_voltages)
  		return -EINVAL;
  
  	for (i = 0; i < rdev->desc->n_voltages; i++) {
  		/* We only look for exact voltage matches here */
  		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)
  {
  	unsigned int ramp_delay = 0;
  	int old_volt, new_volt;
  
  	if (rdev->constraints->ramp_delay)
  		ramp_delay = rdev->constraints->ramp_delay;
  	else if (rdev->desc->ramp_delay)
  		ramp_delay = rdev->desc->ramp_delay;
  
  	if (ramp_delay == 0) {
  		rdev_warn(rdev, "ramp_delay not set\n");
  		return 0;
  	}
  
  	/* 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);
  
  	return DIV_ROUND_UP(abs(new_volt - old_volt), ramp_delay);
  }
  EXPORT_SYMBOL_GPL(regulator_set_voltage_time_sel);
  
  /**
   * 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;
  	int ret, min_uV, max_uV;
  
  	mutex_lock(&rdev->mutex);
  
  	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 (!regulator->min_uV && !regulator->max_uV) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	min_uV = regulator->min_uV;
  	max_uV = regulator->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);
  	if (ret < 0)
  		goto out;
  
  	ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
  
  out:
  	mutex_unlock(&rdev->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_sync_voltage);
  
  static int _regulator_get_voltage(struct regulator_dev *rdev)
  {
  	int sel, ret;
  
  	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 {
  		return -EINVAL;
  	}
  
  	if (ret < 0)
  		return ret;
  	return ret - rdev->constraints->uV_offset;
  }
  
  /**
   * 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)
  {
  	int ret;
  
  	mutex_lock(&regulator->rdev->mutex);
  
  	ret = _regulator_get_voltage(regulator->rdev);
  
  	mutex_unlock(&regulator->rdev->mutex);
  
  	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;
  
  	mutex_lock(&rdev->mutex);
  
  	/* 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:
  	mutex_unlock(&rdev->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_set_current_limit);
  
  static int _regulator_get_current_limit(struct regulator_dev *rdev)
  {
  	int ret;
  
  	mutex_lock(&rdev->mutex);
  
  	/* sanity check */
  	if (!rdev->desc->ops->get_current_limit) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ret = rdev->desc->ops->get_current_limit(rdev);
  out:
  	mutex_unlock(&rdev->mutex);
  	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;
  
  	mutex_lock(&rdev->mutex);
  
  	/* 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:
  	mutex_unlock(&rdev->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_set_mode);
  
  static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
  {
  	int ret;
  
  	mutex_lock(&rdev->mutex);
  
  	/* sanity check */
  	if (!rdev->desc->ops->get_mode) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ret = rdev->desc->ops->get_mode(rdev);
  out:
  	mutex_unlock(&rdev->mutex);
  	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);
  
  /**
   * regulator_set_optimum_mode - set regulator optimum operating mode
   * @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.
   *
   * Returns the new regulator mode or error.
   */
  int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
  {
  	struct regulator_dev *rdev = regulator->rdev;
  	struct regulator *consumer;
  	int ret, output_uV, input_uV = 0, total_uA_load = 0;
  	unsigned int mode;
  
  	if (rdev->supply)
  		input_uV = regulator_get_voltage(rdev->supply);
  
  	mutex_lock(&rdev->mutex);
  
  	/*
  	 * first check to see if we can set modes at all, otherwise just
  	 * tell the consumer everything is OK.
  	 */
  	regulator->uA_load = uA_load;
  	ret = regulator_check_drms(rdev);
  	if (ret < 0) {
  		ret = 0;
  		goto out;
  	}
  
  	if (!rdev->desc->ops->get_optimum_mode)
  		goto out;
  
  	/*
  	 * we can actually do this so any errors are indicators of
  	 * potential real failure.
  	 */
  	ret = -EINVAL;
  
  	if (!rdev->desc->ops->set_mode)
  		goto out;
  
  	/* get output voltage */
  	output_uV = _regulator_get_voltage(rdev);
  	if (output_uV <= 0) {
  		rdev_err(rdev, "invalid output voltage found\n");
  		goto out;
  	}
  
  	/* No supply? Use constraint voltage */
  	if (input_uV <= 0)
  		input_uV = rdev->constraints->input_uV;
  	if (input_uV <= 0) {
  		rdev_err(rdev, "invalid input voltage found\n");
  		goto out;
  	}
  
  	/* calc total requested load for this regulator */
  	list_for_each_entry(consumer, &rdev->consumer_list, list)
  		total_uA_load += consumer->uA_load;
  
  	mode = rdev->desc->ops->get_optimum_mode(rdev,
  						 input_uV, output_uV,
  						 total_uA_load);
  	ret = regulator_mode_constrain(rdev, &mode);
  	if (ret < 0) {
  		rdev_err(rdev, "failed to get optimum mode @ %d uA %d -> %d uV\n",
  			 total_uA_load, input_uV, output_uV);
  		goto out;
  	}
  
  	ret = rdev->desc->ops->set_mode(rdev, mode);
  	if (ret < 0) {
  		rdev_err(rdev, "failed to set optimum mode %x\n", mode);
  		goto out;
  	}
  	ret = mode;
  out:
  	mutex_unlock(&rdev->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_set_optimum_mode);
  
  /**
   * 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;
  	int ret = 0;
  
  	if (!rdev->desc->ops->set_bypass)
  		return 0;
  
  	if (rdev->constraints &&
  	    !(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_BYPASS))
  		return 0;
  
  	mutex_lock(&rdev->mutex);
  
  	if (enable && !regulator->bypass) {
  		rdev->bypass_count++;
  
  		if (rdev->bypass_count == rdev->open_count) {
  			ret = rdev->desc->ops->set_bypass(rdev, enable);
  			if (ret != 0)
  				rdev->bypass_count--;
  		}
  
  	} else if (!enable && regulator->bypass) {
  		rdev->bypass_count--;
  
  		if (rdev->bypass_count != rdev->open_count) {
  			ret = rdev->desc->ops->set_bypass(rdev, enable);
  			if (ret != 0)
  				rdev->bypass_count++;
  		}
  	}
  
  	if (ret == 0)
  		regulator->bypass = enable;
  
  	mutex_unlock(&rdev->mutex);
  
  	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 void _notifier_call_chain(struct regulator_dev *rdev,
  				  unsigned long event, void *data)
  {
  	/* call rdev chain first */
  	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 = PTR_ERR(consumers[i].consumer);
  			dev_err(dev, "Failed to get supply '%s': %d\n",
  				consumers[i].supply, ret);
  			consumers[i].consumer = NULL;
  			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++) {
  		if (consumers[i].consumer->always_on)
  			consumers[i].ret = 0;
  		else
  			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: %d\n", consumers[i].supply,
  			       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: %d\n", consumers[i].supply, ret);
  	for (++i; i < num_consumers; ++i) {
  		r = regulator_enable(consumers[i].consumer);
  		if (r != 0)
  			pr_err("Failed to reename %s: %d\n",
  			       consumers[i].supply, 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;
  
  	for (i = 0; i < num_consumers; i++)
  		consumers[i].ret =
  			    regulator_force_disable(consumers[i].consumer);
  
  	for (i = 0; i < num_consumers; i++) {
  		if (consumers[i].ret != 0) {
  			ret = consumers[i].ret;
  			goto out;
  		}
  	}
  
  	return 0;
  out:
  	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. We also notify regulator clients downstream.
   * Note lock must be held by caller.
   */
  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);
  
  /*
   * To avoid cluttering sysfs (and memory) with useless state, only
   * create attributes that can be meaningfully displayed.
   */
  static int add_regulator_attributes(struct regulator_dev *rdev)
  {
  	struct device		*dev = &rdev->dev;
  	struct regulator_ops	*ops = rdev->desc->ops;
  	int			status = 0;
  
  	/* some attributes need specific methods to be displayed */
  	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))) {
  		status = device_create_file(dev, &dev_attr_microvolts);
  		if (status < 0)
  			return status;
  	}
  	if (ops->get_current_limit) {
  		status = device_create_file(dev, &dev_attr_microamps);
  		if (status < 0)
  			return status;
  	}
  	if (ops->get_mode) {
  		status = device_create_file(dev, &dev_attr_opmode);
  		if (status < 0)
  			return status;
  	}
  	if (rdev->ena_pin || ops->is_enabled) {
  		status = device_create_file(dev, &dev_attr_state);
  		if (status < 0)
  			return status;
  	}
  	if (ops->get_status) {
  		status = device_create_file(dev, &dev_attr_status);
  		if (status < 0)
  			return status;
  	}
  	if (ops->get_bypass) {
  		status = device_create_file(dev, &dev_attr_bypass);
  		if (status < 0)
  			return status;
  	}
  
  	/* some attributes are type-specific */
  	if (rdev->desc->type == REGULATOR_CURRENT) {
  		status = device_create_file(dev, &dev_attr_requested_microamps);
  		if (status < 0)
  			return status;
  	}
  
  	/* all the other attributes exist to support constraints;
  	 * don't show them if there are no constraints, or if the
  	 * relevant supporting methods are missing.
  	 */
  	if (!rdev->constraints)
  		return status;
  
  	/* constraints need specific supporting methods */
  	if (ops->set_voltage || ops->set_voltage_sel) {
  		status = device_create_file(dev, &dev_attr_min_microvolts);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev, &dev_attr_max_microvolts);
  		if (status < 0)
  			return status;
  	}
  	if (ops->set_current_limit) {
  		status = device_create_file(dev, &dev_attr_min_microamps);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev, &dev_attr_max_microamps);
  		if (status < 0)
  			return status;
  	}
  
  	status = device_create_file(dev, &dev_attr_suspend_standby_state);
  	if (status < 0)
  		return status;
  	status = device_create_file(dev, &dev_attr_suspend_mem_state);
  	if (status < 0)
  		return status;
  	status = device_create_file(dev, &dev_attr_suspend_disk_state);
  	if (status < 0)
  		return status;
  
  	if (ops->set_suspend_voltage) {
  		status = device_create_file(dev,
  				&dev_attr_suspend_standby_microvolts);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev,
  				&dev_attr_suspend_mem_microvolts);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev,
  				&dev_attr_suspend_disk_microvolts);
  		if (status < 0)
  			return status;
  	}
  
  	if (ops->set_suspend_mode) {
  		status = device_create_file(dev,
  				&dev_attr_suspend_standby_mode);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev,
  				&dev_attr_suspend_mem_mode);
  		if (status < 0)
  			return status;
  		status = device_create_file(dev,
  				&dev_attr_suspend_disk_mode);
  		if (status < 0)
  			return status;
  	}
  
  	return status;
  }
  
  static void rdev_init_debugfs(struct regulator_dev *rdev)
  {
  	rdev->debugfs = debugfs_create_dir(rdev_get_name(rdev), 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);
  }
  
  /**
   * regulator_register - register regulator
   * @regulator_desc: regulator to register
   * @config: 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 *config)
  {
  	const struct regulation_constraints *constraints = NULL;
  	const struct regulator_init_data *init_data;
  	static atomic_t regulator_no = ATOMIC_INIT(0);
  	struct regulator_dev *rdev;
  	struct device *dev;
  	int ret, i;
  	const char *supply = NULL;
  
  	if (regulator_desc == NULL || config == NULL)
  		return ERR_PTR(-EINVAL);
  
  	dev = config->dev;
  	WARN_ON(!dev);
  
  	if (regulator_desc->name == NULL || regulator_desc->ops == NULL)
  		return ERR_PTR(-EINVAL);
  
  	if (regulator_desc->type != REGULATOR_VOLTAGE &&
  	    regulator_desc->type != REGULATOR_CURRENT)
  		return ERR_PTR(-EINVAL);
  
  	/* 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) {
  		return ERR_PTR(-EINVAL);
  	}
  	if (regulator_desc->ops->set_voltage_sel &&
  	    !regulator_desc->ops->list_voltage) {
  		return ERR_PTR(-EINVAL);
  	}
  
  	init_data = config->init_data;
  
  	rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);
  	if (rdev == NULL)
  		return ERR_PTR(-ENOMEM);
  
  	mutex_lock(&regulator_list_mutex);
  
  	mutex_init(&rdev->mutex);
  	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;
  	}
  
  	/* register with sysfs */
  	rdev->dev.class = &regulator_class;
  	rdev->dev.of_node = config->of_node;
  	rdev->dev.parent = dev;
  	dev_set_name(&rdev->dev, "regulator.%d",
  		     atomic_inc_return(&regulator_no) - 1);
  	ret = device_register(&rdev->dev);
  	if (ret != 0) {
  		put_device(&rdev->dev);
  		goto clean;
  	}
  
  	dev_set_drvdata(&rdev->dev, rdev);
  
  	if (config->ena_gpio && gpio_is_valid(config->ena_gpio)) {
  		ret = regulator_ena_gpio_request(rdev, config);
  		if (ret != 0) {
  			rdev_err(rdev, "Failed to request enable GPIO%d: %d\n",
  				 config->ena_gpio, ret);
  			goto wash;
  		}
  	}
  
  	/* set regulator constraints */
  	if (init_data)
  		constraints = &init_data->constraints;
  
  	ret = set_machine_constraints(rdev, constraints);
  	if (ret < 0)
  		goto scrub;
  
  	/* add attributes supported by this regulator */
  	ret = add_regulator_attributes(rdev);
  	if (ret < 0)
  		goto scrub;
  
  	if (init_data && init_data->supply_regulator)
  		supply = init_data->supply_regulator;
  	else if (regulator_desc->supply_name)
  		supply = regulator_desc->supply_name;
  
  	if (supply) {
  		struct regulator_dev *r;
  
  		r = regulator_dev_lookup(dev, supply, &ret);
  
  		if (ret == -ENODEV) {
  			/*
  			 * No supply was specified for this regulator and
  			 * there will never be one.
  			 */
  			ret = 0;
  			goto add_dev;
  		} else if (!r) {
  			dev_err(dev, "Failed to find supply %s\n", supply);
  			ret = -EPROBE_DEFER;
  			goto scrub;
  		}
  
  		ret = set_supply(rdev, r);
  		if (ret < 0)
  			goto scrub;
  
  		/* Enable supply if rail is enabled */
  		if (_regulator_is_enabled(rdev)) {
  			ret = regulator_enable(rdev->supply);
  			if (ret < 0)
  				goto scrub;
  		}
  	}
  
  add_dev:
  	/* 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;
  			}
  		}
  	}
  
  	list_add(&rdev->list, &regulator_list);
  
  	rdev_init_debugfs(rdev);
  out:
  	mutex_unlock(&regulator_list_mutex);
  	return rdev;
  
  unset_supplies:
  	unset_regulator_supplies(rdev);
  
  scrub:
  	if (rdev->supply)
  		_regulator_put(rdev->supply);
  	regulator_ena_gpio_free(rdev);
  	kfree(rdev->constraints);
  wash:
  	device_unregister(&rdev->dev);
  	/* device core frees rdev */
  	rdev = ERR_PTR(ret);
  	goto out;
  
  clean:
  	kfree(rdev);
  	rdev = ERR_PTR(ret);
  	goto out;
  }
  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);
  	}
  	mutex_lock(&regulator_list_mutex);
  	debugfs_remove_recursive(rdev->debugfs);
  	flush_work(&rdev->disable_work.work);
  	WARN_ON(rdev->open_count);
  	unset_regulator_supplies(rdev);
  	list_del(&rdev->list);
  	kfree(rdev->constraints);
  	regulator_ena_gpio_free(rdev);
  	device_unregister(&rdev->dev);
  	mutex_unlock(&regulator_list_mutex);
  }
  EXPORT_SYMBOL_GPL(regulator_unregister);
  
  /**
   * regulator_suspend_prepare - prepare regulators for system wide suspend
   * @state: system suspend state
   *
   * Configure each regulator with it's suspend operating parameters for state.
   * This will usually be called by machine suspend code prior to supending.
   */
  int regulator_suspend_prepare(suspend_state_t state)
  {
  	struct regulator_dev *rdev;
  	int ret = 0;
  
  	/* ON is handled by regulator active state */
  	if (state == PM_SUSPEND_ON)
  		return -EINVAL;
  
  	mutex_lock(&regulator_list_mutex);
  	list_for_each_entry(rdev, &regulator_list, list) {
  
  		mutex_lock(&rdev->mutex);
  		ret = suspend_prepare(rdev, state);
  		mutex_unlock(&rdev->mutex);
  
  		if (ret < 0) {
  			rdev_err(rdev, "failed to prepare\n");
  			goto out;
  		}
  	}
  out:
  	mutex_unlock(&regulator_list_mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
  
  /**
   * regulator_suspend_finish - resume regulators from system wide suspend
   *
   * Turn on regulators that might be turned off by regulator_suspend_prepare
   * and that should be turned on according to the regulators properties.
   */
  int regulator_suspend_finish(void)
  {
  	struct regulator_dev *rdev;
  	int ret = 0, error;
  
  	mutex_lock(&regulator_list_mutex);
  	list_for_each_entry(rdev, &regulator_list, list) {
  		mutex_lock(&rdev->mutex);
  		if (rdev->use_count > 0  || rdev->constraints->always_on) {
  			if (!_regulator_is_enabled(rdev)) {
  				error = _regulator_do_enable(rdev);
  				if (error)
  					ret = error;
  			}
  		} else {
  			if (!have_full_constraints())
  				goto unlock;
  			if (!_regulator_is_enabled(rdev))
  				goto unlock;
  
  			error = _regulator_do_disable(rdev);
  			if (error)
  				ret = error;
  		}
  unlock:
  		mutex_unlock(&rdev->mutex);
  	}
  	mutex_unlock(&regulator_list_mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(regulator_suspend_finish);
  
  /**
   * 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);
  
  /**
   * regulator_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);
  
  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 ssize_t supply_map_read_file(struct file *file, char __user *user_buf,
  				    size_t count, loff_t *ppos)
  {
  	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  	ssize_t len, ret = 0;
  	struct regulator_map *map;
  
  	if (!buf)
  		return -ENOMEM;
  
  	list_for_each_entry(map, &regulator_map_list, list) {
  		len = snprintf(buf + ret, PAGE_SIZE - ret,
  			       "%s -> %s.%s\n",
  			       rdev_get_name(map->regulator), map->dev_name,
  			       map->supply);
  		if (len >= 0)
  			ret += len;
  		if (ret > PAGE_SIZE) {
  			ret = PAGE_SIZE;
  			break;
  		}
  	}
  
  	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
  
  	kfree(buf);
  
  	return ret;
  }
  #endif
  
  static const struct file_operations supply_map_fops = {
  #ifdef CONFIG_DEBUG_FS
  	.read = supply_map_read_file,
  	.llseek = default_llseek,
  #endif
  };
  
  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");
  
  	debugfs_create_file("supply_map", 0444, debugfs_root, NULL,
  			    &supply_map_fops);
  
  	regulator_dummy_init();
  
  	return ret;
  }
  
  /* init early to allow our consumers to complete system booting */
  core_initcall(regulator_init);
  
  static int __init regulator_init_complete(void)
  {
  	struct regulator_dev *rdev;
  	struct regulator_ops *ops;
  	struct regulation_constraints *c;
  	int enabled, ret;
  
  	/*
  	 * 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;
  
  	mutex_lock(&regulator_list_mutex);
  
  	/* If we have a full configuration then disable any regulators
  	 * which are not in use or always_on.  This will become the
  	 * default behaviour in the future.
  	 */
  	list_for_each_entry(rdev, &regulator_list, list) {
  		ops = rdev->desc->ops;
  		c = rdev->constraints;
  
  		if (c && c->always_on)
  			continue;
  
  		mutex_lock(&rdev->mutex);
  
  		if (rdev->use_count)
  			goto unlock;
  
  		/* If we can't read the status assume it's on. */
  		if (ops->is_enabled)
  			enabled = ops->is_enabled(rdev);
  		else
  			enabled = 1;
  
  		if (!enabled)
  			goto unlock;
  
  		if (have_full_constraints()) {
  			/* We log since this may kill the system if it
  			 * goes wrong. */
  			rdev_info(rdev, "disabling\n");
  			ret = _regulator_do_disable(rdev);
  			if (ret != 0) {
  				rdev_err(rdev, "couldn't disable: %d\n", ret);
  			}
  		} else {
  			/* The intention is that in future we will
  			 * assume that full constraints are provided
  			 * so warn even if we aren't going to do
  			 * anything here.
  			 */
  			rdev_warn(rdev, "incomplete constraints, leaving on\n");
  		}
  
  unlock:
  		mutex_unlock(&rdev->mutex);
  	}
  
  	mutex_unlock(&regulator_list_mutex);
  
  	return 0;
  }
  late_initcall(regulator_init_complete);
  