core.c

Go to the documentation of this file.

/*
 * core.c  --  Voltage/Current Regulator framework.
 *
 * Copyright 2007, 2008 Wolfson Microelectronics PLC.
 * Copyright 2008 SlimLogic Ltd.
 *
 * Author: Liam Girdwood <[email protected]>
 *
 *  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"

#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 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
 *
 * 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_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 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)
        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 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 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 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;
    char buf[80] = "";
    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\n");
            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 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;

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

    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;
}

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;
}

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->desc->ops->enable_time)
        return rdev->desc->enable_time;
    return rdev->desc->ops->enable_time(rdev);
}

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;

    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 (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

    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;
}

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);
}

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);

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);
}

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;
}

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);

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_gpio) {
        gpio_set_value_cansleep(rdev->ena_gpio,
                    !rdev->ena_gpio_invert);
        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);
    }

    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;
}

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_gpio) {
        gpio_set_value_cansleep(rdev->ena_gpio,
                    rdev->ena_gpio_invert);
        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));

    _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;
            }
        }

        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;
}

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;

    /* force disable */
    if (rdev->desc->ops->disable) {
        /* ah well, who wants to live forever... */
        ret = rdev->desc->ops->disable(rdev);
        if (ret < 0) {
            rdev_err(rdev, "failed to force disable\n");
            return ret;
        }
        /* notify other consumers that power has been forced off */
        _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
            REGULATOR_EVENT_DISABLE, NULL);
    }

    return ret;
}

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);
            }
        }
    }
}

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);

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;

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

int regulator_enable_regmap(struct regulator_dev *rdev)
{
    return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
                  rdev->desc->enable_mask,
                  rdev->desc->enable_mask);
}
EXPORT_SYMBOL_GPL(regulator_enable_regmap);

int regulator_disable_regmap(struct regulator_dev *rdev)
{
    return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
                  rdev->desc->enable_mask, 0);
}
EXPORT_SYMBOL_GPL(regulator_disable_regmap);

static int _regulator_is_enabled(struct regulator_dev *rdev)
{
    /* A GPIO control always takes precedence */
    if (rdev->ena_gpio)
        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);
}

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);

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);

int regulator_list_voltage_linear(struct regulator_dev *rdev,
                  unsigned int selector)
{
    if (selector >= rdev->desc->n_voltages)
        return -EINVAL;

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

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);

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);

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;
    }

    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);

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);

int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel)
{
    sel <<= ffs(rdev->desc->vsel_mask) - 1;

    return regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
                  rdev->desc->vsel_mask, sel);
}
EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_regmap);

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);

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;

    /* 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);

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;
                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 &&
        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;
        }

        /* 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;
}

int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
{
    struct regulator_dev *rdev = regulator->rdev;
    int ret = 0;

    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;
    regulator->min_uV = min_uV;
    regulator->max_uV = max_uV;

    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_set_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);

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);

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 {
        return -EINVAL;
    }

    if (ret < 0)
        return ret;
    return ret - rdev->constraints->uV_offset;
}

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);

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;
}

int regulator_get_current_limit(struct regulator *regulator)
{
    return _regulator_get_current_limit(regulator->rdev);
}
EXPORT_SYMBOL_GPL(regulator_get_current_limit);

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;
}

unsigned int regulator_get_mode(struct regulator *regulator)
{
    return _regulator_get_mode(regulator->rdev);
}
EXPORT_SYMBOL_GPL(regulator_get_mode);

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);

int regulator_set_bypass_regmap(struct regulator_dev *rdev, bool enable)
{
    unsigned int val;

    if (enable)
        val = rdev->desc->bypass_mask;
    else
        val = 0;

    return regmap_update_bits(rdev->regmap, rdev->desc->bypass_reg,
                  rdev->desc->bypass_mask, val);
}
EXPORT_SYMBOL_GPL(regulator_set_bypass_regmap);

int regulator_get_bypass_regmap(struct regulator_dev *rdev, bool *enable)
{
    unsigned int val;
    int ret;

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

    *enable = val & rdev->desc->bypass_mask;

    return 0;
}
EXPORT_SYMBOL_GPL(regulator_get_bypass_regmap);

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);

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);

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);
}

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);

int devm_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 = devm_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:
    for (i = 0; i < num_consumers && consumers[i].consumer; i++)
        devm_regulator_put(consumers[i].consumer);

    return ret;
}
EXPORT_SYMBOL_GPL(devm_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);
}

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:
    pr_err("Failed to enable %s: %d\n", consumers[i].supply, ret);
    while (--i >= 0)
        regulator_disable(consumers[i].consumer);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_enable);

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);

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);

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);

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);

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)) {
        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 (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);
}

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 = gpio_request_one(config->ena_gpio,
                       GPIOF_DIR_OUT | config->ena_gpio_flags,
                       rdev_get_name(rdev));
        if (ret != 0) {
            rdev_err(rdev, "Failed to request enable GPIO%d: %d\n",
                 config->ena_gpio, ret);
            goto wash;
        }

        rdev->ena_gpio = config->ena_gpio;
        rdev->ena_gpio_invert = config->ena_gpio_invert;

        if (config->ena_gpio_flags & GPIOF_OUT_INIT_HIGH)
            rdev->ena_gpio_state = 1;

        if (rdev->ena_gpio_invert)
            rdev->ena_gpio_state = !rdev->ena_gpio_state;
    }

    /* 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 (!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 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);
    if (rdev->ena_gpio)
        gpio_free(rdev->ena_gpio);
    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);

void regulator_unregister(struct regulator_dev *rdev)
{
    if (rdev == NULL)
        return;

    if (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);
    if (rdev->ena_gpio)
        gpio_free(rdev->ena_gpio);
    device_unregister(&rdev->dev);
    mutex_unlock(&regulator_list_mutex);
}
EXPORT_SYMBOL_GPL(regulator_unregister);

int regulator_suspend_prepare(suspend_state_t state)
{
    struct regulator_dev *rdev;
    int ret = 0;

    /* ON is handled by regulator active state */
    if (state == PM_SUSPEND_ON)
        return -EINVAL;

    mutex_lock(&regulator_list_mutex);
    list_for_each_entry(rdev, &regulator_list, list) {

        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);

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) {
        struct regulator_ops *ops = rdev->desc->ops;

        mutex_lock(&rdev->mutex);
        if ((rdev->use_count > 0  || rdev->constraints->always_on) &&
                ops->enable) {
            error = ops->enable(rdev);
            if (error)
                ret = error;
        } else {
            if (!has_full_constraints)
                goto unlock;
            if (!ops->disable)
                goto unlock;
            if (!_regulator_is_enabled(rdev))
                goto unlock;

            error = ops->disable(rdev);
            if (error)
                ret = error;
        }
unlock:
        mutex_unlock(&rdev->mutex);
    }
    mutex_unlock(&regulator_list_mutex);
    return ret;
}
EXPORT_SYMBOL_GPL(regulator_suspend_finish);

void regulator_has_full_constraints(void)
{
    has_full_constraints = 1;
}
EXPORT_SYMBOL_GPL(regulator_has_full_constraints);

void regulator_use_dummy_regulator(void)
{
    board_wants_dummy_regulator = true;
}
EXPORT_SYMBOL_GPL(regulator_use_dummy_regulator);

void *rdev_get_drvdata(struct regulator_dev *rdev)
{
    return rdev->reg_data;
}
EXPORT_SYMBOL_GPL(rdev_get_drvdata);

void *regulator_get_drvdata(struct regulator *regulator)
{
    return regulator->rdev->reg_data;
}
EXPORT_SYMBOL_GPL(regulator_get_drvdata);

void regulator_set_drvdata(struct regulator *regulator, void *data)
{
    regulator->rdev->reg_data = data;
}
EXPORT_SYMBOL_GPL(regulator_set_drvdata);

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 (!ops->disable || (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 (has_full_constraints) {
            /* We log since this may kill the system if it
             * goes wrong. */
            rdev_info(rdev, "disabling\n");
            ret = ops->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);