drivers/regulator/core.c

/*
 * 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 <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>

#include "dummy.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 bool has_full_constraints;
static bool board_wants_dummy_regulator;

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
 *
 * One for each consumer device.
 */
struct regulator {
	struct device *dev;
	struct list_head list;
	unsigned int always_on:1;
	unsigned int bypass:1;
	int uA_load;
	int min_uV;
	int max_uV;
	char *supply_name;
	struct device_attribute dev_attr;
	struct regulator_dev *rdev;
	struct dentry *debugfs;
};

static int _regulator_is_enabled(struct regulator_dev *rdev);
static int _regulator_disable(struct regulator_dev *rdev);
static int _regulator_enable(struct regulator_dev *rdev);
static int _regulator_get_enable_time(struct regulator_dev *rdev);
static int _regulator_get_disable_time(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 "";
}

/**
 * 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;
}

/* dynamic regulator control mode switching constraint check */
static int regulator_check_control(struct regulator_dev *rdev)
{
	if (!rdev->constraints) {
		rdev_err(rdev, "no constraints\n");
		return -ENODEV;
	}
	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CONTROL)) {
		rdev_err(rdev, "operation not allowed\n");
		return -EPERM;
	}
	return 0;
}

static ssize_t regulator_uV_set(struct device *dev,
	struct device_attribute *attr, const char *buf, size_t count)
{
	struct regulator_dev *rdev = dev_get_drvdata(dev);
	int ret;
	int min_uV;
	int max_uV = rdev->constraints->max_uV;
	char *p = (char *)buf;

	min_uV = memparse(p, &p);
	mutex_lock(&rdev->mutex);

	/* sanity check */
	if (!rdev->desc->ops->set_voltage &&
		!rdev->desc->ops->set_voltage_sel) {
		rdev_err(rdev, "The operation is not supported\n");
		goto out;
	}

	/* constraints check */
	ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
	if (ret < 0) {
		rdev_err(rdev, "Voltage is out of range min:max= %d:%d\n",
			rdev->constraints->min_uV, rdev->constraints->max_uV);
		goto out;
	}

	/* Consumer check */
	ret = regulator_check_consumers(rdev, &min_uV, &max_uV);
	if (ret < 0) {
		rdev_warn(rdev, "new voltage is out-range for some consumer\n");
		rdev_warn(rdev, "min: max = %d:%d\n", min_uV, max_uV);
	}

	rdev_info(rdev, "Setting voltage min:max = %d:%d\n", min_uV, max_uV);
	ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
	if (ret < 0)
		rdev_warn(rdev, "Can not set voltage %d:%d\n",  min_uV, max_uV);

out:
	mutex_unlock(&rdev->mutex);
	return count;
}

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, 0644, regulator_uV_show, regulator_uV_set);

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 regulator_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 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 ssize_t regulator_state_set(struct device *dev,
		   struct device_attribute *attr, const char *buf, size_t count)
{
	struct regulator_dev *rdev = dev_get_drvdata(dev);
	int ret;
	bool enabled;

	if ((*buf == 'E') || (*buf == 'e'))
		enabled = true;
	else if ((*buf == 'D') || (*buf == 'd'))
		enabled = false;
	else
		return -EINVAL;

	if ((_regulator_is_enabled(rdev) && enabled) ||
		(!_regulator_is_enabled(rdev) && !enabled))
		return count;

	mutex_lock(&rdev->mutex);
	if (enabled) {
		int delay = 0;
		if (!rdev->desc->ops->enable && !rdev->ena_pin) {
			rdev_warn(rdev, "Ops not supported\n");
			ret = -EINVAL;
			goto end;
		}
		ret = _regulator_get_enable_time(rdev);
		if (ret >= 0)
			delay = ret;

		if (rdev->ena_pin) {
			gpio_set_value_cansleep(rdev->ena_pin->gpio,
					!rdev->ena_pin->ena_gpio_invert);
			rdev->ena_gpio_state = 1;
		} else if (rdev->desc->ops->enable) {
			ret = rdev->desc->ops->enable(rdev);
			if (ret < 0) {
				rdev_warn(rdev, "enable() failed: %d\n", ret);
				goto end;
			}
		}

		if (delay >= 1000) {
			mdelay(delay / 1000);
			udelay(delay % 1000);
		} else if (delay) {
			udelay(delay);
		}
	} else {
		int delay = 0;
		if (!rdev->desc->ops->disable && !rdev->ena_pin) {
			rdev_warn(rdev, "Ops not supported\n");
			ret = -EINVAL;
			goto end;
		}
		ret = _regulator_get_disable_time(rdev);
		if (ret >= 0)
			delay = ret;

		if (rdev->ena_pin) {
			gpio_set_value_cansleep(rdev->ena_pin->gpio,
					rdev->ena_pin->ena_gpio_invert);
			rdev->ena_gpio_state = 0;
		} else if (rdev->desc->ops->disable) {
			ret = rdev->desc->ops->disable(rdev);
			if (ret < 0) {
				rdev_warn(rdev, "disable() failed: %d\n", ret);
				goto end;
			}
		}

		if (delay >= 1000) {
			mdelay(delay / 1000);
			udelay(delay % 1000);
		} else if (delay) {
			udelay(delay);
		}
	}

end:
	mutex_unlock(&rdev->mutex);
	if (ret < 0)
		return ret;
	return count;
}
static DEVICE_ATTR(state, 0644, regulator_state_show, regulator_state_set);

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 regulator_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 ssize_t regulator_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 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 device_attribute regulator_dev_attrs[] = {
	__ATTR(name, 0444, regulator_name_show, NULL),
	__ATTR(num_users, 0444, regulator_num_users_show, NULL),
	__ATTR(type, 0444, regulator_type_show, NULL),
	__ATTR_NULL,
};

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_attrs = regulator_dev_attrs,
};

/* 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;
	unsigned int ramp_delay = 0;
	char buf[110] = "";
	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->min_uV && !constraints->max_uV) {
			constraints->min_uV = ret;
			constraints->max_uV = ret;
		}
	}

	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 (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)
		count += sprintf(buf + count, "with ramp delay %u uV/us ",
				ramp_delay);

	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;
		}
	}

	if (rdev->constraints->init_uV) {
		ret = _regulator_do_set_voltage(rdev,
						rdev->constraints->init_uV,
						rdev->constraints->init_uV);
		if (ret < 0) {
			rdev_err(rdev, "failed to set init %duV constraint\n",
				 rdev->constraints->init_uV);
			return ret;
		}

		rdev_info(rdev, "applied init %duV constraint\n",
				 rdev->constraints->init_uV);
	}

	/* 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->ignore_current_constraint_init)
		return 0;
	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 (rdev->constraints->sleep_mode) {
		if (!ops->set_sleep_mode) {
			rdev_err(rdev, "no set_sleep_mode operation\n");
			ret = -EINVAL;
			goto out;
		}

		ret = ops->set_sleep_mode(rdev, rdev->constraints->sleep_mode);
		if (ret < 0) {
			rdev_err(rdev, "failed to set sleep 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;
		}

		ret = _regulator_get_enable_time(rdev);
		if (ret > 0) {
			if (ret >= 1000) {
				mdelay(ret / 1000);
				udelay(ret % 1000);
			} else {
				udelay(ret);
			}
		}
	}

	if ((rdev->constraints->boot_off) && ops->disable) {
		ret = ops->disable(rdev);
		if (ret < 0) {
			rdev_err(rdev, "failed to disable\n");
			goto out;
		}

		ret = _regulator_get_disable_time(rdev);
		if (ret > 0) {
			if (ret >= 1000) {
				mdelay(ret / 1000);
				udelay(ret % 1000);
			} else {
				udelay(ret);
			}
		}
	}

	if (rdev->constraints->ramp_delay && 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);
	}

	if (rdev->constraints->max_uV &&
		(rdev->constraints->max_uV == rdev->constraints->min_uV)) {
		regulator->min_uV = rdev->constraints->min_uV;
		regulator->max_uV = rdev->constraints->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 int _regulator_get_disable_time(struct regulator_dev *rdev)
{
	if (rdev->constraints && rdev->constraints->disable_time)
		return rdev->constraints->disable_time;
	return rdev->desc->disable_time;
}

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;

	/* 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;
		} 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,
					int exclusive)
{
	struct regulator_dev *rdev;
	struct regulator *regulator = ERR_PTR(-EPROBE_DEFER);
	const char *devname = NULL;
	int ret = 0;

	if (id == NULL) {
		pr_err("get() with no identifier\n");
		return regulator;
	}

	if (dev)
		devname = dev_name(dev);

	mutex_lock(&regulator_list_mutex);

	rdev = regulator_dev_lookup(dev, id, &ret);
	if (rdev)
		goto found;

	/*
	 * If we have return value from dev_lookup fail, we do not expect to
	 * succeed, so, set the regulator with appropriate error pointer.
	 */
	if (ret)
		regulator = ERR_PTR(ret);

	if (board_wants_dummy_regulator) {
		rdev = dummy_regulator_rdev;
		goto found;
	}

#ifdef CONFIG_REGULATOR_DUMMY
	if (!devname)
		devname = "deviceless";

	/* If the board didn't flag that it was fully constrained then
	 * substitute in a dummy regulator so consumers can continue.
	 */
	if (!has_full_constraints) {
		pr_warn("%s supply %s not found, using dummy regulator\n",
			devname, id);
		rdev = dummy_regulator_rdev;
		goto found;
	}
#endif

	goto out;

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);

	if (IS_ERR(regulator)) {
		ret = PTR_ERR(regulator);
		if(ret != -EPROBE_DEFER)
			pr_err("regulator_get() failed for (%s,%s), %d\n",
				(devname) ? devname : "NULL", id, ret);
	}

	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, 0);
}
EXPORT_SYMBOL_GPL(regulator_get);

static void devm_regulator_release(struct device *dev, void *res)
{
	regulator_put(*(struct regulator **)res);
}

/**
 * devm_regulator_get - Resource managed regulator_get()
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Managed regulator_get(). Regulators returned from this function are
 * automatically regulator_put() on driver detach. See regulator_get() for more
 * information.
 */
struct regulator *devm_regulator_get(struct device *dev, const char *id)
{
	struct regulator **ptr, *regulator;

	ptr = devres_alloc(devm_regulator_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	regulator = regulator_get(dev, id);
	if (!IS_ERR(regulator)) {
		*ptr = regulator;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return regulator;
}
EXPORT_SYMBOL_GPL(devm_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, 1);
}
EXPORT_SYMBOL_GPL(regulator_get_exclusive);

/* Locks 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);
	kfree(regulator->supply_name);
	list_del(&regulator->list);
	kfree(regulator);

	rdev->open_count--;
	rdev->exclusive = 0;

	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);

static int devm_regulator_match(struct device *dev, void *res, void *data)
{
	struct regulator **r = res;
	if (!r || !*r) {
		WARN_ON(!r || !*r);
		return 0;
	}
	return *r == data;
}

/**
 * devm_regulator_put - Resource managed regulator_put()
 * @regulator: regulator to free
 *
 * Deallocate a regulator allocated with devm_regulator_get(). Normally
 * this function will not need to be called and the resource management
 * code will ensure that the resource is freed.
 */
void devm_regulator_put(struct regulator *regulator)
{
	int rc;

	rc = devres_release(regulator->dev, devm_regulator_release,
			    devm_regulator_match, regulator);
	if (rc != 0)
		WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_regulator_put);

/* 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));
	_notifier_call_chain(rdev, REGULATOR_EVENT_PRE_ENABLE, NULL);

	if (rdev->ena_pin) {
		ret = regulator_ena_gpio_ctrl(rdev, true);
		if (ret < 0)
			return ret;
		rdev->ena_gpio_state = 1;
	} else if (rdev->desc->ops->enable) {
		ret = rdev->desc->ops->enable(rdev);
		if (ret < 0)
			return ret;
	} else {
		return -EINVAL;
	}

	/* Allow the regulator to ramp; it would be useful to extend
	 * this for bulk operations so that the regulators can ramp
	 * together.  */
	trace_regulator_enable_delay(rdev_get_name(rdev));

	if (delay >= 1000) {
		mdelay(delay / 1000);
		udelay(delay % 1000);
	} else if (delay) {
		udelay(delay);
	}

	_notifier_call_chain(rdev, REGULATOR_EVENT_POST_ENABLE, NULL);
	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 (rdev->supply &&
		(ret || rdev->constraints->disable_parent_after_enable)) {
		rdev_info(rdev, "Disabling parent\n");
		regulator_disable(rdev->supply);
	}
	return ret;
}
EXPORT_SYMBOL_GPL(regulator_enable);

static int _regulator_do_disable(struct regulator_dev *rdev)
{
	int ret, delay;

	ret = _regulator_get_disable_time(rdev);
	if (ret >= 0) {
		delay = ret;
	} else {
		rdev_warn(rdev, "disable_time() failed: %d\n", ret);
		delay = 0;
	}

	trace_regulator_disable(rdev_get_name(rdev));

	if (rdev->ena_pin) {
		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));

	if (delay >= 1000) {
		mdelay(delay / 1000);
		udelay(delay % 1000);
	} else if (delay) {
		udelay(delay);
	}

	_notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE,
			     NULL);
	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) {
		if (!rdev->constraints->disable_parent_after_enable)
			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 = schedule_delayed_work(&rdev->disable_work,
				    msecs_to_jiffies(ms));
	if (ret < 0)
		return ret;
	else
		return 0;
}
EXPORT_SYMBOL_GPL(regulator_disable_deferred);

/**
 * regulator_is_enabled_regmap - standard is_enabled() for regmap users
 *
 * @rdev: regulator to operate on
 *
 * Regulators that use regmap for their register I/O can set the
 * enable_reg and enable_mask fields in their descriptor and then use
 * this as their is_enabled operation, saving some code.
 */
int regulator_is_enabled_regmap(struct regulator_dev *rdev)
{
	unsigned int val;
	int ret;

	ret = regmap_read(rdev->regmap, rdev->desc->enable_reg, &val);
	if (ret != 0)
		return ret;

	if (rdev->desc->enable_is_inverted)
		return (val & rdev->desc->enable_mask) == 0;
	else
		return (val & rdev->desc->enable_mask) != 0;
}
EXPORT_SYMBOL_GPL(regulator_is_enabled_regmap);

/**
 * regulator_enable_regmap - standard enable() for regmap users
 *
 * @rdev: regulator to operate on
 *
 * Regulators that use regmap for their register I/O can set the
 * enable_reg and enable_mask fields in their descriptor and then use
 * this as their enable() operation, saving some code.
 */
int regulator_enable_regmap(struct regulator_dev *rdev)
{
	unsigned int val;

	if (rdev->desc->enable_is_inverted)
		val = 0;
	else
		val = rdev->desc->enable_mask;

	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
				  rdev->desc->enable_mask, val);
}
EXPORT_SYMBOL_GPL(regulator_enable_regmap);

/**
 * regulator_disable_regmap - standard disable() for regmap users
 *
 * @rdev: regulator to operate on
 *
 * Regulators that use regmap for their register I/O can set the
 * enable_reg and enable_mask fields in their descriptor and then use
 * this as their disable() operation, saving some code.
 */
int regulator_disable_regmap(struct regulator_dev *rdev)
{
	unsigned int val;

	if (rdev->desc->enable_is_inverted)
		val = rdev->desc->enable_mask;
	else
		val = 0;

	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
				  rdev->desc->enable_mask, val);
}
EXPORT_SYMBOL_GPL(regulator_disable_regmap);

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_linear - List voltages with simple calculation
 *
 * @rdev: Regulator device
 * @selector: Selector to convert into a voltage
 *
 * Regulators with a simple linear mapping between voltages and
 * selectors can set min_uV and uV_step in the regulator descriptor
 * and then use this function as their list_voltage() operation,
 */
int regulator_list_voltage_linear(struct regulator_dev *rdev,
				  unsigned int selector)
{
	if (selector >= rdev->desc->n_voltages)
		return -EINVAL;
	if (selector < rdev->desc->linear_min_sel)
		return 0;

	selector -= rdev->desc->linear_min_sel;

	return rdev->desc->min_uV + (rdev->desc->uV_step * selector);
}
EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);

/**
 * regulator_list_voltage_linear_range - List voltages for linear ranges
 *
 * @rdev: Regulator device
 * @selector: Selector to convert into a voltage
 *
 * Regulators with a series of simple linear mappings between voltages
 * and selectors can set linear_ranges in the regulator descriptor and
 * then use this function as their list_voltage() operation,
 */
int regulator_list_voltage_linear_range(struct regulator_dev *rdev,
					unsigned int selector)
{
	const struct regulator_linear_range *range;
	int i;

	if (!rdev->desc->n_linear_ranges) {
		BUG_ON(!rdev->desc->n_linear_ranges);
		return -EINVAL;
	}

	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
		range = &rdev->desc->linear_ranges[i];

		if (!(selector >= range->min_sel &&
		      selector <= range->max_sel))
			continue;

		selector -= range->min_sel;

		return range->min_uV + (range->uV_step * selector);
	}

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(regulator_list_voltage_linear_range);

/**
 * regulator_list_voltage_table - List voltages with table based mapping
 *
 * @rdev: Regulator device
 * @selector: Selector to convert into a voltage
 *
 * Regulators with table based mapping between voltages and
 * selectors can set volt_table in the regulator descriptor
 * and then use this function as their list_voltage() operation.
 */
int regulator_list_voltage_table(struct regulator_dev *rdev,
				 unsigned int selector)
{
	if (!rdev->desc->volt_table) {
		BUG_ON(!rdev->desc->volt_table);
		return -EINVAL;
	}

	if (selector >= rdev->desc->n_voltages)
		return -EINVAL;

	return rdev->desc->volt_table[selector];
}
EXPORT_SYMBOL_GPL(regulator_list_voltage_table);

/**
 * 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 (!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_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);

/**
 * regulator_get_voltage_sel_regmap - standard get_voltage_sel for regmap users
 *
 * @rdev: regulator to operate on
 *
 * Regulators that use regmap for their register I/O can set the
 * vsel_reg and vsel_mask fields in their descriptor and then use this
 * as their get_voltage_vsel operation, saving some code.
 */
int regulator_get_voltage_sel_regmap(struct regulator_dev *rdev)
{
	unsigned int val;
	int ret;

	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
	if (ret != 0)
		return ret;

	val &= rdev->desc->vsel_mask;
	val >>= ffs(rdev->desc->vsel_mask) - 1;

	return val;
}
EXPORT_SYMBOL_GPL(regulator_get_voltage_sel_regmap);

/**
 * regulator_set_voltage_sel_regmap - standard set_voltage_sel for regmap users
 *
 * @rdev: regulator to operate on
 * @sel: Selector to set
 *
 * Regulators that use regmap for their register I/O can set the
 * vsel_reg and vsel_mask fields in their descriptor and then use this
 * as their set_voltage_vsel operation, saving some code.
 */
int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel)
{
	int ret;

	sel <<= ffs(rdev->desc->vsel_mask) - 1;

	if (rdev->desc->vsel_persist) {
		sel &= rdev->desc->vsel_mask;
		sel |= ~rdev->desc->vsel_mask & rdev->desc->vsel_persist_val;
		ret = regmap_write(rdev->regmap, rdev->desc->vsel_reg, sel);
	} else {
		ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
					  rdev->desc->vsel_mask, sel);
	}
	if (ret)
		return ret;

	if (rdev->desc->apply_bit)
		ret = regmap_update_bits(rdev->regmap, rdev->desc->apply_reg,
					 rdev->desc->apply_bit,
					 rdev->desc->apply_bit);
	return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_regmap);

/**
 * regulator_map_voltage_iterate - map_voltage() based on list_voltage()
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers implementing set_voltage_sel() and list_voltage() can use
 * this as their map_voltage() operation.  It will find a suitable
 * voltage by calling list_voltage() until it gets something in bounds
 * for the requested voltages.
 */
int regulator_map_voltage_iterate(struct regulator_dev *rdev,
				  int min_uV, int max_uV)
{
	int best_val = INT_MAX;
	int selector = 0;
	int i, ret;

	/* Find the smallest voltage that falls within the specified
	 * range.
	 */
	for (i = 0; i < rdev->desc->n_voltages; i++) {
		ret = rdev->desc->ops->list_voltage(rdev, i);
		if (ret < 0)
			continue;

		if (ret < best_val && ret >= min_uV && ret <= max_uV) {
			best_val = ret;
			selector = i;
		}
	}

	if (best_val != INT_MAX)
		return selector;
	else
		return -EINVAL;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_iterate);

/**
 * regulator_map_voltage_ascend - map_voltage() for ascendant voltage list
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers that have ascendant voltage list can use this as their
 * map_voltage() operation.
 */
int regulator_map_voltage_ascend(struct regulator_dev *rdev,
				 int min_uV, int max_uV)
{
	int i, ret;

	for (i = 0; i < rdev->desc->n_voltages; i++) {
		ret = rdev->desc->ops->list_voltage(rdev, i);
		if (ret < 0)
			continue;

		if (ret > max_uV)
			break;

		if (ret >= min_uV && ret <= max_uV)
			return i;
	}

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_ascend);

/**
 * regulator_map_voltage_linear - map_voltage() for simple linear mappings
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers providing min_uV and uV_step in their regulator_desc can
 * use this as their map_voltage() operation.
 */
int regulator_map_voltage_linear(struct regulator_dev *rdev,
				 int min_uV, int max_uV)
{
	int ret, voltage;

	/* Allow uV_step to be 0 for fixed voltage */
	if (rdev->desc->n_voltages == 1 && rdev->desc->uV_step == 0) {
		if (min_uV <= rdev->desc->min_uV && rdev->desc->min_uV <= max_uV)
			return 0;
		else
			return -EINVAL;
	}

	if (!rdev->desc->uV_step) {
		BUG_ON(!rdev->desc->uV_step);
		return -EINVAL;
	}

	if (min_uV < rdev->desc->min_uV)
		min_uV = rdev->desc->min_uV;

	ret = DIV_ROUND_UP(min_uV - rdev->desc->min_uV, rdev->desc->uV_step);
	if (ret < 0)
		return ret;

	ret += rdev->desc->linear_min_sel;

	/* Map back into a voltage to verify we're still in bounds */
	voltage = rdev->desc->ops->list_voltage(rdev, ret);
	if (voltage < min_uV || voltage > max_uV)
		return -EINVAL;

	return ret;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_linear);

/**
 * regulator_map_voltage_linear - map_voltage() for multiple linear ranges
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers providing linear_ranges in their descriptor can use this as
 * their map_voltage() callback.
 */
int regulator_map_voltage_linear_range(struct regulator_dev *rdev,
				       int min_uV, int max_uV)
{
	const struct regulator_linear_range *range;
	int ret = -EINVAL;
	int voltage, i;

	if (!rdev->desc->n_linear_ranges) {
		BUG_ON(!rdev->desc->n_linear_ranges);
		return -EINVAL;
	}

	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
		range = &rdev->desc->linear_ranges[i];

		if (!(min_uV <= range->max_uV && max_uV >= range->min_uV))
			continue;

		if (min_uV <= range->min_uV)
			min_uV = range->min_uV;

		ret = DIV_ROUND_UP(min_uV - range->min_uV, range->uV_step);
		if (ret < 0)
			return ret;

		ret += range->min_sel;

		break;
	}

	if (i == rdev->desc->n_linear_ranges)
		return -EINVAL;

	/* Map back into a voltage to verify we're still in bounds */
	voltage = rdev->desc->ops->list_voltage(rdev, ret);
	if (voltage < min_uV || voltage > max_uV)
		return -EINVAL;

	return ret;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range);

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;
	bool tried_change = false;

	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) {
		if (_regulator_is_enabled(rdev)) {
			_notifier_call_chain(rdev,
			REGULATOR_EVENT_OUT_PRECHANGE, (void *)((long)min_uV));
			tried_change = true;
		}

		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 {
					if (_regulator_is_enabled(rdev)) {
						_notifier_call_chain(rdev,
						REGULATOR_EVENT_OUT_PRECHANGE,
						(void *)((long)best_val));
						tried_change = true;
					}
					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 && _regulator_is_enabled(rdev) && old_selector >= 0 &&
	    old_selector != selector && rdev->desc->ops->set_voltage_time_sel) {

		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;
		}
		if (rdev->constraints && rdev->constraints->ramp_delay_scale)
			delay = DIV_ROUND_UP(delay *
				    rdev->constraints->ramp_delay_scale, 100);

		/* 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);
	}

	if (tried_change) {
		long val = ret == 0 ? best_val : -1;
		_notifier_call_chain(rdev, REGULATOR_EVENT_OUT_POSTCHANGE,
				     (void *)val);
	}

	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;

#ifdef CONFIG_REGULATOR_DUMMY
	if (!strcmp(rdev->desc->name, "dummy")) {
		rdev_info(rdev,
			"regulator is dummy, skipping voltage change...\n");
		return ret;
	}
#endif

	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)) {