xref: /device/soc/rockchip/common/sdk_linux/drivers/regulator/core.c

// SPDX-License-Identifier: GPL-2.0-or-later
//
// core.c  --  Voltage/Current Regulator framework.
//
// Copyright 2007, 2008 Wolfson Microelectronics PLC.
// Copyright 2008 SlimLogic Ltd.
//
// Author: Liam Girdwood <lrg@slimlogic.co.uk>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/async.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/suspend.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/coupler.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/module.h>

#define CREATE_TRACE_POINTS
#include <trace/events/regulator.h>

#include "dummy.h"
#include "internal.h"

#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__)

#define CORE_FILE_PROPERTY_A 0200
#define CORE_FILE_PROPERTY_B 0444
#define CORE_TWO 2
#define CORE_THREE 3
#define CORE_TWENTY 20
#define CORE_THIRTY 30
#define CORE_SIXTYFOUR 64
#define CORE_ONETHOUSAND 1000
#define CORE_THIRTYTHOUSAND 30000

static DEFINE_WW_CLASS(regulator_ww_class);
static DEFINE_MUTEX(regulator_nesting_mutex);
static DEFINE_MUTEX(regulator_list_mutex);
static LIST_HEAD(regulator_map_list);
static LIST_HEAD(regulator_ena_gpio_list);
static LIST_HEAD(regulator_supply_alias_list);
static LIST_HEAD(regulator_coupler_list);
static LIST_HEAD(regulator_debug_list);
static bool has_full_constraints;

static struct dentry *debugfs_root;

/*
 * struct regulator_map
 *
 * Used to provide symbolic supply names to devices.
 */
struct regulator_map {
    struct list_head list;
    const char *dev_name; /* The dev_name() for the consumer */
    const char *supply;
    struct regulator_dev *regulator;
};

/*
 * struct regulator_enable_gpio
 *
 * Management for shared enable GPIO pin
 */
struct regulator_enable_gpio {
    struct list_head list;
    struct gpio_desc *gpiod;
    u32 enable_count;  /* a number of enabled shared GPIO */
    u32 request_count; /* a number of requested shared GPIO */
};

/*
 * struct regulator_supply_alias
 *
 * Used to map lookups for a supply onto an alternative device.
 */
struct regulator_supply_alias {
    struct list_head list;
    struct device *src_dev;
    const char *src_supply;
    struct device *alias_dev;
    const char *alias_supply;
};

struct regulator_limit_volt {
    struct list_head list;
    struct regulator *reg;
};

static int _regulator_is_enabled(struct regulator_dev *rdev);
static int _regulator_disable(struct regulator *regulator);
static int _regulator_get_current_limit(struct regulator_dev *rdev);
static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
static int _notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data);
static int _regulator_do_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV);
static int regulator_balance_voltage(struct regulator_dev *rdev, suspend_state_t state);
static struct regulator *create_regulator(struct regulator_dev *rdev, struct device *dev, const char *supply_name);
static void destroy_regulator(struct regulator *regulator);
static void _regulator_put(struct regulator *regulator);

const char *rdev_get_name(struct regulator_dev *rdev)
{
    if (rdev->constraints && rdev->constraints->name) {
        return rdev->constraints->name;
    } else if (rdev->desc->name) {
        return rdev->desc->name;
    } else {
        return "";
    }
}

static bool have_full_constraints(void)
{
    return has_full_constraints || of_have_populated_dt();
}

static bool regulator_ops_is_valid(struct regulator_dev *rdev, int ops)
{
    if (!rdev->constraints) {
        rdev_err(rdev, "no constraints\n");
        return false;
    }

    if (rdev->constraints->valid_ops_mask & ops) {
        return true;
    }

    return false;
}

/**
 * regulator_lock_nested - lock a single regulator
 * @rdev:        regulator source
 * @ww_ctx:        w/w mutex acquire context
 *
 * This function can be called many times by one task on
 * a single regulator and its mutex will be locked only
 * once. If a task, which is calling this function is other
 * than the one, which initially locked the mutex, it will
 * wait on mutex.
 */
static inline int regulator_lock_nested(struct regulator_dev *rdev, struct ww_acquire_ctx *ww_ctx)
{
    bool lock = false;
    int ret = 0;

    mutex_lock(&regulator_nesting_mutex);

    if (ww_ctx || !ww_mutex_trylock(&rdev->mutex)) {
        if (rdev->mutex_owner == current) {
            rdev->ref_cnt++;
        } else {
            lock = true;
        }

        if (lock) {
            mutex_unlock(&regulator_nesting_mutex);
            ret = ww_mutex_lock(&rdev->mutex, ww_ctx);
            mutex_lock(&regulator_nesting_mutex);
        }
    } else {
        lock = true;
    }

    if (lock && ret != -EDEADLK) {
        rdev->ref_cnt++;
        rdev->mutex_owner = current;
    }

    mutex_unlock(&regulator_nesting_mutex);

    return ret;
}

/**
 * regulator_lock - lock a single regulator
 * @rdev:        regulator source
 *
 * This function can be called many times by one task on
 * a single regulator and its mutex will be locked only
 * once. If a task, which is calling this function is other
 * than the one, which initially locked the mutex, it will
 * wait on mutex.
 */
static void regulator_lock(struct regulator_dev *rdev)
{
    regulator_lock_nested(rdev, NULL);
}

/**
 * regulator_unlock - unlock a single regulator
 * @rdev:        regulator_source
 *
 * This function unlocks the mutex when the
 * reference counter reaches 0.
 */
static void regulator_unlock(struct regulator_dev *rdev)
{
    mutex_lock(&regulator_nesting_mutex);

    if (--rdev->ref_cnt == 0) {
        rdev->mutex_owner = NULL;
        ww_mutex_unlock(&rdev->mutex);
    }

    WARN_ON_ONCE(rdev->ref_cnt < 0);

    mutex_unlock(&regulator_nesting_mutex);
}

static bool regulator_supply_is_couple(struct regulator_dev *rdev)
{
    struct regulator_dev *c_rdev;
    int i;

    for (i = 1; i < rdev->coupling_desc.n_coupled; i++) {
        c_rdev = rdev->coupling_desc.coupled_rdevs[i];

        if (rdev->supply->rdev == c_rdev) {
            return true;
        }
    }

    return false;
}

static void regulator_unlock_recursive(struct regulator_dev *rdev, unsigned int n_coupled)
{
    struct regulator_dev *c_rdev, *supply_rdev;
    int i, supply_n_coupled;

    for (i = n_coupled; i > 0; i--) {
        c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1];

        if (!c_rdev) {
            continue;
        }

        if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) {
            supply_rdev = c_rdev->supply->rdev;
            supply_n_coupled = supply_rdev->coupling_desc.n_coupled;

            regulator_unlock_recursive(supply_rdev, supply_n_coupled);
        }

        regulator_unlock(c_rdev);
    }
}

static int regulator_lock_recursive(struct regulator_dev *rdev, struct regulator_dev **new_contended_rdev,
                                    struct regulator_dev **old_contended_rdev, struct ww_acquire_ctx *ww_ctx)
{
    struct regulator_dev *c_rdev;
    int i, err;

    for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {
        c_rdev = rdev->coupling_desc.coupled_rdevs[i];

        if (!c_rdev) {
            continue;
        }

        if (c_rdev != *old_contended_rdev) {
            err = regulator_lock_nested(c_rdev, ww_ctx);
            if (err) {
                if (err == -EDEADLK) {
                    *new_contended_rdev = c_rdev;
                    goto err_unlock;
                }

                /* shouldn't happen */
                WARN_ON_ONCE(err != -EALREADY);
            }
        } else {
            *old_contended_rdev = NULL;
        }

        if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) {
            err = regulator_lock_recursive(c_rdev->supply->rdev, new_contended_rdev, old_contended_rdev, ww_ctx);
            if (err) {
                regulator_unlock(c_rdev);
                goto err_unlock;
            }
        }
    }

    return 0;

err_unlock:
    regulator_unlock_recursive(rdev, i);

    return err;
}

/**
 * regulator_unlock_dependent - unlock regulator's suppliers and coupled
 *                regulators
 * @rdev:            regulator source
 * @ww_ctx:            w/w mutex acquire context
 *
 * Unlock all regulators related with rdev by coupling or supplying.
 */
static void regulator_unlock_dependent(struct regulator_dev *rdev, struct ww_acquire_ctx *ww_ctx)
{
    regulator_unlock_recursive(rdev, rdev->coupling_desc.n_coupled);
    ww_acquire_fini(ww_ctx);
}

/**
 * regulator_lock_dependent - lock regulator's suppliers and coupled regulators
 * @rdev:            regulator source
 * @ww_ctx:            w/w mutex acquire context
 *
 * This function as a wrapper on regulator_lock_recursive(), which locks
 * all regulators related with rdev by coupling or supplying.
 */
static void regulator_lock_dependent(struct regulator_dev *rdev, struct ww_acquire_ctx *ww_ctx)
{
    struct regulator_dev *new_contended_rdev = NULL;
    struct regulator_dev *old_contended_rdev = NULL;
    int err;

    mutex_lock(&regulator_list_mutex);

    ww_acquire_init(ww_ctx, &regulator_ww_class);

    do {
        if (new_contended_rdev) {
            ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
            old_contended_rdev = new_contended_rdev;
            old_contended_rdev->ref_cnt++;
        }

        err = regulator_lock_recursive(rdev, &new_contended_rdev, &old_contended_rdev, ww_ctx);

        if (old_contended_rdev) {
            regulator_unlock(old_contended_rdev);
        }
    } while (err == -EDEADLK);
    ww_acquire_done(ww_ctx);
    mutex_unlock(&regulator_list_mutex);
}

/**
 * of_get_child_regulator - get a child regulator device node
 * based on supply name
 * @parent: Parent device node
 * @prop_name: Combination regulator supply name and "-supply"
 *
 * Traverse all child nodes.
 * Extract the child regulator device node corresponding to the supply name.
 * returns the device node corresponding to the regulator if found, else
 * returns NULL.
 */
static struct device_node *of_get_child_regulator(struct device_node *parent, const char *prop_name)
{
    struct device_node *regnode = NULL;
    struct device_node *child = NULL;

    for_each_child_of_node(parent, child)
    {
        regnode = of_parse_phandle(child, prop_name, 0);
        if (!regnode) {
            regnode = of_get_child_regulator(child, prop_name);
            if (regnode) {
                goto err_node_put;
            }
        } else {
            goto err_node_put;
        }
    }
    return NULL;

err_node_put:
    of_node_put(child);
    return regnode;
}

/**
 * of_get_regulator - get a regulator device node based on supply name
 * @dev: Device pointer for the consumer (of regulator) device
 * @supply: regulator supply name
 *
 * Extract the regulator device node corresponding to the supply name.
 * returns the device node corresponding to the regulator if found, else
 * returns NULL.
 */
static struct device_node *of_get_regulator(struct device *dev, const char *supply)
{
    struct device_node *regnode = NULL;
    char prop_name[CORE_SIXTYFOUR]; /* 64 is max size of property name */

    dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);

    (void)snprintf(prop_name, CORE_SIXTYFOUR, "%s-supply", supply);
    regnode = of_parse_phandle(dev->of_node, prop_name, 0);
    if (!regnode) {
        regnode = of_get_child_regulator(dev->of_node, prop_name);
        if (regnode) {
            return regnode;
        }

        dev_dbg(dev, "Looking up %s property in node %pOF failed\n", prop_name, dev->of_node);
        return NULL;
    }
    return regnode;
}

/* Platform voltage constraint check */
int regulator_check_voltage(struct regulator_dev *rdev, int *min_uV, int *max_uV)
{
    BUG_ON(*min_uV > *max_uV);

    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
        rdev_err(rdev, "voltage operation not allowed\n");
        return -EPERM;
    }

    if (*max_uV > rdev->constraints->max_uV) {
        *max_uV = rdev->constraints->max_uV;
    }
    if (*min_uV < rdev->constraints->min_uV) {
        *min_uV = rdev->constraints->min_uV;
    }

    if (*min_uV > *max_uV) {
        rdev_err(rdev, "unsupportable voltage range: %d-%duV\n", *min_uV, *max_uV);
        return -EINVAL;
    }

    return 0;
}

/* return 0 if the state is valid */
static int regulator_check_states(suspend_state_t state)
{
    return (state > PM_SUSPEND_MAX || state == PM_SUSPEND_TO_IDLE);
}

/* Make sure we select a voltage that suits the needs of all
 * regulator consumers
 */
int regulator_check_consumers(struct regulator_dev *rdev, int *min_uV, int *max_uV, suspend_state_t state)
{
    struct regulator *regulator;
    struct regulator_voltage *voltage;

    list_for_each_entry(regulator, &rdev->consumer_list, list)
    {
        voltage = &regulator->voltage[state];
        /*
         * Assume consumers that didn't say anything are OK
         * with anything in the constraint range.
         */
        if (!voltage->min_uV && !voltage->max_uV) {
            continue;
        }

        if (*max_uV > voltage->max_uV) {
            *max_uV = voltage->max_uV;
        }
        if (*min_uV < voltage->min_uV) {
            *min_uV = voltage->min_uV;
        }
    }

    if (*min_uV > *max_uV) {
        rdev_err(rdev, "Restricting voltage, %u-%uuV\n", *min_uV, *max_uV);
        return -EINVAL;
    }

    return 0;
}

/* current constraint check */
static int regulator_check_current_limit(struct regulator_dev *rdev, int *min_uA, int *max_uA)
{
    BUG_ON(*min_uA > *max_uA);

    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_CURRENT)) {
        rdev_err(rdev, "current operation not allowed\n");
        return -EPERM;
    }

    if (*max_uA > rdev->constraints->max_uA) {
        *max_uA = rdev->constraints->max_uA;
    }
    if (*min_uA < rdev->constraints->min_uA) {
        *min_uA = rdev->constraints->min_uA;
    }

    if (*min_uA > *max_uA) {
        rdev_err(rdev, "unsupportable current range: %d-%duA\n", *min_uA, *max_uA);
        return -EINVAL;
    }

    return 0;
}

/* operating mode constraint check */
static int regulator_mode_constrain(struct regulator_dev *rdev, unsigned int *mode)
{
    switch (*mode) {
        case REGULATOR_MODE_FAST:
        case REGULATOR_MODE_NORMAL:
        case REGULATOR_MODE_IDLE:
        case REGULATOR_MODE_STANDBY:
            break;
        default:
            rdev_err(rdev, "invalid mode %x specified\n", *mode);
            return -EINVAL;
    }

    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_MODE)) {
        rdev_err(rdev, "mode operation not allowed\n");
        return -EPERM;
    }

    /* The modes are bitmasks, the most power hungry modes having
     * the lowest values. If the requested mode isn't supported
     * try higher modes. */
    while (*mode) {
        if (rdev->constraints->valid_modes_mask & *mode) {
            return 0;
        }
        *mode /= CORE_TWO;
    }

    return -EINVAL;
}

static inline struct regulator_state *regulator_get_suspend_state(struct regulator_dev *rdev, suspend_state_t state)
{
    if (rdev->constraints == NULL) {
        return NULL;
    }

    switch (state) {
        case PM_SUSPEND_STANDBY:
            return &rdev->constraints->state_standby;
        case PM_SUSPEND_MEM:
            return &rdev->constraints->state_mem;
        case PM_SUSPEND_MAX:
            return &rdev->constraints->state_disk;
        default:
            return NULL;
    }
}

static const struct regulator_state *regulator_get_suspend_state_check(struct regulator_dev *rdev,
                                                                       suspend_state_t state)
{
    const struct regulator_state *rstate;

    rstate = regulator_get_suspend_state(rdev, state);
    if (rstate == NULL) {
        return NULL;
    }

    /* If we have no suspend mode configuration don't set anything;
     * only warn if the driver implements set_suspend_voltage or
     * set_suspend_mode callback.
     */
    if (rstate->enabled != ENABLE_IN_SUSPEND && rstate->enabled != DISABLE_IN_SUSPEND) {
        if (rdev->desc->ops->set_suspend_voltage || rdev->desc->ops->set_suspend_mode) {
            rdev_warn(rdev, "No configuration\n");
        }
        return NULL;
    }

    return rstate;
}

int regulator_get_voltage_rdev(struct regulator_dev *rdev)
{
    int sel, ret;
    bool bypassed;

    if (rdev->desc->ops->get_bypass) {
        ret = rdev->desc->ops->get_bypass(rdev, &bypassed);
        if (ret < 0) {
            return ret;
        }
        if (bypassed) {
            /* if bypassed the regulator must have a supply */
            if (!rdev->supply) {
                rdev_err(rdev, "bypassed regulator has no supply!\n");
                return -EPROBE_DEFER;
            }

            return regulator_get_voltage_rdev(rdev->supply->rdev);
        }
    }

    if (rdev->desc->ops->get_voltage_sel) {
        sel = rdev->desc->ops->get_voltage_sel(rdev);
        if (sel < 0) {
            return sel;
        }
        ret = rdev->desc->ops->list_voltage(rdev, sel);
    } else if (rdev->desc->ops->get_voltage) {
        ret = rdev->desc->ops->get_voltage(rdev);
    } else if (rdev->desc->ops->list_voltage) {
        ret = rdev->desc->ops->list_voltage(rdev, 0);
    } else if (rdev->desc->fixed_uV && (rdev->desc->n_voltages == 1)) {
        ret = rdev->desc->fixed_uV;
    } else if (rdev->supply) {
        ret = regulator_get_voltage_rdev(rdev->supply->rdev);
    } else if (rdev->supply_name) {
        return -EPROBE_DEFER;
    } else {
        return -EINVAL;
    }

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

static ssize_t regulator_uV_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);
    int uV;

    regulator_lock(rdev);
    uV = regulator_get_voltage_rdev(rdev);
    regulator_unlock(rdev);

    if (uV < 0) {
        return uV;
    }
    return sprintf(buf, "%d\n", uV);
}
static DEVICE_ATTR(microvolts, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, regulator_uA_show, NULL);

static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);

    return sprintf(buf, "%s\n", rdev_get_name(rdev));
}
static DEVICE_ATTR_RO(name);

static const char *regulator_opmode_to_str(int mode)
{
    switch (mode) {
        case REGULATOR_MODE_FAST:
            return "fast";
        case REGULATOR_MODE_NORMAL:
            return "normal";
        case REGULATOR_MODE_IDLE:
            return "idle";
        case REGULATOR_MODE_STANDBY:
            return "standby";
        default:
            break;
    }
    return "unknown";
}

static ssize_t regulator_print_opmode(char *buf, int mode)
{
    return sprintf(buf, "%s\n", regulator_opmode_to_str(mode));
}

static ssize_t 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, CORE_FILE_PROPERTY_B, 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;

    regulator_lock(rdev);
    ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
    regulator_unlock(rdev);

    return ret;
}
static DEVICE_ATTR(state, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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;

    regulator_lock(rdev);
    list_for_each_entry(regulator, &rdev->consumer_list, list)
    {
        if (regulator->enable_count) {
            uA += regulator->uA_load;
        }
    }
    regulator_unlock(rdev);
    return sprintf(buf, "%d\n", uA);
}
static DEVICE_ATTR(requested_microamps, CORE_FILE_PROPERTY_B, regulator_total_uA_show, NULL);

static ssize_t num_users_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);
    return sprintf(buf, "%d\n", rdev->use_count);
}
static DEVICE_ATTR_RO(num_users);

static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);

    switch (rdev->desc->type) {
        case REGULATOR_VOLTAGE:
            return sprintf(buf, "voltage\n");
        case REGULATOR_CURRENT:
            return sprintf(buf, "current\n");
    }
    return sprintf(buf, "unknown\n");
}
static DEVICE_ATTR_RO(type);

static ssize_t regulator_suspend_mem_uV_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);

    return sprintf(buf, "%d\n", rdev->constraints->state_mem.uV);
}
static DEVICE_ATTR(suspend_mem_microvolts, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, 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, CORE_FILE_PROPERTY_B, regulator_bypass_show, NULL);

/**
 * regulator_get_voltage - get regulator output voltage
 * @regulator: regulator source
 *
 * This returns the current regulator voltage in uV.
 *
 * NOTE: If the regulator is disabled it will return the voltage value. This
 * function should not be used to determine regulator state.
 */
int regulator_get_voltage(struct regulator *regulator)
{
    struct ww_acquire_ctx ww_ctx;
    int ret;

    regulator_lock_dependent(regulator->rdev, &ww_ctx);
    ret = regulator_get_voltage_rdev(regulator->rdev);
    regulator_unlock_dependent(regulator->rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_get_voltage);

/* Calculate the new optimum regulator operating mode based on the new total
 * consumer load. All locks held by caller */
static int drms_uA_update(struct regulator_dev *rdev)
{
    struct regulator *sibling;
    int current_uA = 0, output_uV, input_uV, err;
    unsigned int mode;

    /*
     * first check to see if we can set modes at all, otherwise just
     * tell the consumer everything is OK.
     */
    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_DRMS)) {
        rdev_dbg(rdev, "DRMS operation not allowed\n");
        return 0;
    }

    if (!rdev->desc->ops->get_optimum_mode && !rdev->desc->ops->set_load) {
        return 0;
    }

    if (!rdev->desc->ops->set_mode && !rdev->desc->ops->set_load) {
        return -EINVAL;
    }

    /* calc total requested load */
    list_for_each_entry(sibling, &rdev->consumer_list, list)
    {
        if (sibling->enable_count) {
            current_uA += sibling->uA_load;
        }
    }

    current_uA += rdev->constraints->system_load;

    if (rdev->desc->ops->set_load) {
        /* set the optimum mode for our new total regulator load */
        err = rdev->desc->ops->set_load(rdev, current_uA);
        if (err < 0) {
            rdev_err(rdev, "failed to set load %d: %pe\n", current_uA, ERR_PTR(err));
        }
    } else {
        /* get output voltage */
        output_uV = regulator_get_voltage_rdev(rdev);
        if (output_uV <= 0) {
            rdev_err(rdev, "invalid output voltage found\n");
            return -EINVAL;
        }

        /* get input voltage */
        input_uV = 0;
        if (rdev->supply) {
            input_uV = regulator_get_voltage(rdev->supply);
        }
        if (input_uV <= 0) {
            input_uV = rdev->constraints->input_uV;
        }
        if (input_uV <= 0) {
            rdev_err(rdev, "invalid input voltage found\n");
            return -EINVAL;
        }

        /* now get the optimum mode for our new total regulator load */
        mode = rdev->desc->ops->get_optimum_mode(rdev, input_uV, output_uV, current_uA);

        /* check the new mode is allowed */
        err = regulator_mode_constrain(rdev, &mode);
        if (err < 0) {
            rdev_err(rdev, "failed to get optimum mode @ %d uA %d -> %d uV: %pe\n", current_uA, input_uV, output_uV,
                     ERR_PTR(err));
            return err;
        }

        err = rdev->desc->ops->set_mode(rdev, mode);
        if (err < 0) {
            rdev_err(rdev, "failed to set optimum mode %x: %pe\n", mode, ERR_PTR(err));
        }
    }

    return err;
}

static int _suspend_set_state(struct regulator_dev *rdev, const struct regulator_state *rstate)
{
    int ret = 0;

    if (rstate->enabled == ENABLE_IN_SUSPEND && rdev->desc->ops->set_suspend_enable) {
        ret = rdev->desc->ops->set_suspend_enable(rdev);
    } else if (rstate->enabled == DISABLE_IN_SUSPEND && rdev->desc->ops->set_suspend_disable) {
        ret = rdev->desc->ops->set_suspend_disable(rdev);
    } else { /* OK if set_suspend_enable or set_suspend_disable is NULL */
        ret = 0;
    }

    if (ret < 0) {
        rdev_err(rdev, "failed to enabled/disable: %pe\n", ERR_PTR(ret));
        return ret;
    }

    if (rdev->desc->ops->set_suspend_voltage && rstate->uV > 0) {
        ret = rdev->desc->ops->set_suspend_voltage(rdev, rstate->uV);
        if (ret < 0) {
            rdev_err(rdev, "failed to set voltage: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->desc->ops->set_suspend_mode && rstate->mode > 0) {
        ret = rdev->desc->ops->set_suspend_mode(rdev, rstate->mode);
        if (ret < 0) {
            rdev_err(rdev, "failed to set mode: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    return ret;
}

static int suspend_set_initial_state(struct regulator_dev *rdev)
{
    const struct regulator_state *rstate;

    rstate = regulator_get_suspend_state_check(rdev, rdev->constraints->initial_state);
    if (!rstate) {
        return 0;
    }

    return _suspend_set_state(rdev, rstate);
}

#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
static void print_constraints_debug(struct regulator_dev *rdev)
{
    struct regulation_constraints *constraints = rdev->constraints;
    char buf[160] = "";
    size_t len = sizeof(buf) - 1;
    int count = 0;
    int ret;

    if (constraints->min_uV && constraints->max_uV) {
        if (constraints->min_uV == constraints->max_uV) {
            count += scnprintf(buf + count, len - count, "%d mV ", constraints->min_uV / CORE_ONETHOUSAND);
        } else {
            count += scnprintf(buf + count, len - count, "%d <--> %d mV ", constraints->min_uV / CORE_ONETHOUSAND,
                               constraints->max_uV / CORE_ONETHOUSAND);
        }
    }

    if (!constraints->min_uV || constraints->min_uV != constraints->max_uV) {
        ret = regulator_get_voltage_rdev(rdev);
        if (ret > 0) {
            count += scnprintf(buf + count, len - count, "at %d mV ", ret / CORE_ONETHOUSAND);
        }
    }

    if (constraints->uV_offset) {
        count += scnprintf(buf + count, len - count, "%dmV offset ", constraints->uV_offset / CORE_ONETHOUSAND);
    }

    if (constraints->min_uA && constraints->max_uA) {
        if (constraints->min_uA == constraints->max_uA) {
            count += scnprintf(buf + count, len - count, "%d mA ", constraints->min_uA / CORE_ONETHOUSAND);
        } else {
            count += scnprintf(buf + count, len - count, "%d <--> %d mA ", constraints->min_uA / CORE_ONETHOUSAND,
                               constraints->max_uA / CORE_ONETHOUSAND);
        }
    }

    if (!constraints->min_uA || constraints->min_uA != constraints->max_uA) {
        ret = _regulator_get_current_limit(rdev);
        if (ret > 0) {
            count += scnprintf(buf + count, len - count, "at %d mA ", ret / CORE_ONETHOUSAND);
        }
    }

    if (constraints->valid_modes_mask & REGULATOR_MODE_FAST) {
        count += scnprintf(buf + count, len - count, "fast ");
    }
    if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL) {
        count += scnprintf(buf + count, len - count, "normal ");
    }
    if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE) {
        count += scnprintf(buf + count, len - count, "idle ");
    }
    if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY) {
        count += scnprintf(buf + count, len - count, "standby ");
    }

    if (!count) {
        count = scnprintf(buf, len, "no parameters");
    } else {
        --count;
    }

    count += scnprintf(buf + count, len - count, ", %s", _regulator_is_enabled(rdev) ? "enabled" : "disabled");

    rdev_dbg(rdev, "%s\n", buf);
}
#else  /* !DEBUG && !CONFIG_DYNAMIC_DEBUG */
static inline void print_constraints_debug(struct regulator_dev *rdev)
{
}
#endif /* !DEBUG && !CONFIG_DYNAMIC_DEBUG */

static void print_constraints(struct regulator_dev *rdev)
{
    struct regulation_constraints *constraints = rdev->constraints;

    print_constraints_debug(rdev);

    if ((constraints->min_uV != constraints->max_uV) && !regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
        rdev_warn(rdev, "Voltage range but no REGULATOR_CHANGE_VOLTAGE\n");
    }
}

static int machine_constraints_voltage(struct regulator_dev *rdev, struct regulation_constraints *constraints)
{
    const struct regulator_ops *ops = rdev->desc->ops;
    int ret;

    /* do we need to apply the constraint voltage */
    if (rdev->constraints->apply_uV && rdev->constraints->min_uV && rdev->constraints->max_uV) {
        int target_min, target_max;
        int current_uV = regulator_get_voltage_rdev(rdev);
        if (current_uV == -ENOTRECOVERABLE) {
            /* This regulator can't be read and must be initialized */
            rdev_info(rdev, "Setting %d-%duV\n", rdev->constraints->min_uV, rdev->constraints->max_uV);
            _regulator_do_set_voltage(rdev, rdev->constraints->min_uV, rdev->constraints->max_uV);
            current_uV = regulator_get_voltage_rdev(rdev);
        }

        if (current_uV < 0) {
            rdev_err(rdev, "failed to get the current voltage: %pe\n", ERR_PTR(current_uV));
            return current_uV;
        }

        /*
         * If we're below the minimum voltage move up to the
         * minimum voltage, if we're above the maximum voltage
         * then move down to the maximum.
         */
        target_min = current_uV;
        target_max = current_uV;

        if (current_uV < rdev->constraints->min_uV) {
            target_min = rdev->constraints->min_uV;
            target_max = rdev->constraints->min_uV;
        }

        if (current_uV > rdev->constraints->max_uV) {
            target_min = rdev->constraints->max_uV;
            target_max = rdev->constraints->max_uV;
        }

        if (target_min != current_uV || target_max != current_uV) {
            rdev_info(rdev, "Bringing %duV into %d-%duV\n", current_uV, target_min, target_max);
            ret = _regulator_do_set_voltage(rdev, target_min, target_max);
            if (ret < 0) {
                rdev_err(rdev, "failed to apply %d-%duV constraint: %pe\n", target_min, target_max, ERR_PTR(ret));
                return ret;
            }
        }
    }

    /* constrain machine-level voltage specs to fit
     * the actual range supported by this regulator.
     */
    if (ops->list_voltage && rdev->desc->n_voltages) {
        int count = rdev->desc->n_voltages;
        int i;
        int min_uV = INT_MAX;
        int max_uV = INT_MIN;
        int cmin = constraints->min_uV;
        int cmax = constraints->max_uV;

        /* it's safe to autoconfigure fixed-voltage supplies
           and the constraints are used by list_voltage. */
        if (count == 1 && !cmin) {
            cmin = 1;
            cmax = INT_MAX;
            constraints->min_uV = cmin;
            constraints->max_uV = cmax;
        }

        /* voltage constraints are optional */
        if ((cmin == 0) && (cmax == 0)) {
            return 0;
        }

        /* else require explicit machine-level constraints */
        if (cmin <= 0 || cmax <= 0 || cmax < cmin) {
            rdev_err(rdev, "invalid voltage constraints\n");
            return -EINVAL;
        }

        /* no need to loop voltages if range is continuous */
        if (rdev->desc->continuous_voltage_range) {
            return 0;
        }

        /* initial: [cmin..cmax] valid, [min_uV..max_uV] not */
        for (i = 0; i < count; i++) {
            int value;

            value = ops->list_voltage(rdev, i);
            if (value <= 0) {
                continue;
            }

            /* maybe adjust [min_uV..max_uV] */
            if (value >= cmin && value < min_uV) {
                min_uV = value;
            }
            if (value <= cmax && value > max_uV) {
                max_uV = value;
            }
        }

        /* final: [min_uV..max_uV] valid iff constraints valid */
        if (max_uV < min_uV) {
            rdev_err(rdev, "unsupportable voltage constraints %u-%uuV\n", min_uV, max_uV);
            return -EINVAL;
        }

        /* use regulator's subset of machine constraints */
        if (constraints->min_uV < min_uV) {
            rdev_dbg(rdev, "override min_uV, %d -> %d\n", constraints->min_uV, min_uV);
            constraints->min_uV = min_uV;
        }
        if (constraints->max_uV > max_uV) {
            rdev_dbg(rdev, "override max_uV, %d -> %d\n", constraints->max_uV, max_uV);
            constraints->max_uV = max_uV;
        }
    }

    return 0;
}

static int machine_constraints_current(struct regulator_dev *rdev, struct regulation_constraints *constraints)
{
    const struct regulator_ops *ops = rdev->desc->ops;
    int ret;

    if (!constraints->min_uA && !constraints->max_uA) {
        return 0;
    }

    if (constraints->min_uA > constraints->max_uA) {
        rdev_err(rdev, "Invalid current constraints\n");
        return -EINVAL;
    }

    if (!ops->set_current_limit || !ops->get_current_limit) {
        rdev_warn(rdev, "Operation of current configuration missing\n");
        return 0;
    }

    /* Set regulator current in constraints range */
    ret = ops->set_current_limit(rdev, constraints->min_uA, constraints->max_uA);
    if (ret < 0) {
        rdev_err(rdev, "Failed to set current constraint, %d\n", ret);
        return ret;
    }

    return 0;
}

/**
 * _regulator_handle_consumer_disable - handle that a consumer disabled
 * @regulator: regulator source
 *
 * The opposite of _regulator_handle_consumer_enable().
 *
 * Returns 0 upon no error; -error upon error.
 */
static int _regulator_handle_consumer_disable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;

    lockdep_assert_held_once(&rdev->mutex.base);

    if (!regulator->enable_count) {
        rdev_err(rdev, "Underflow of regulator enable count\n");
        return -EINVAL;
    }

    regulator->enable_count--;
    if (regulator->uA_load && regulator->enable_count == 0) {
        return drms_uA_update(rdev);
    }

    return 0;
}

/**
 * _regulator_handle_consumer_enable - handle that a consumer enabled
 * @regulator: regulator source
 *
 * Some things on a regulator consumer (like the contribution towards total
 * load on the regulator) only have an effect when the consumer wants the
 * regulator enabled.  Explained in example with two consumers of the same
 * regulator:
 *   consumer A: set_load(100);       => total load = 0
 *   consumer A: regulator_enable();  => total load = 100
 *   consumer B: set_load(1000);      => total load = 100
 *   consumer B: regulator_enable();  => total load = 1100
 *   consumer A: regulator_disable(); => total_load = 1000
 *
 * This function (together with _regulator_handle_consumer_disable) is
 * responsible for keeping track of the refcount for a given regulator consumer
 * and applying / unapplying these things.
 *
 * Returns 0 upon no error; -error upon error.
 */
static int _regulator_handle_consumer_enable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;

    lockdep_assert_held_once(&rdev->mutex.base);

    regulator->enable_count++;
    if (regulator->uA_load && regulator->enable_count == 1) {
        return drms_uA_update(rdev);
    }

    return 0;
}

static int _regulator_do_enable(struct regulator_dev *rdev);

/* locks held by regulator_enable() */
static int _regulator_enable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    int ret;

    lockdep_assert_held_once(&rdev->mutex.base);

    if (rdev->use_count == 0 && rdev->supply) {
        ret = _regulator_enable(rdev->supply);
        if (ret < 0) {
            return ret;
        }
    }

    /* balance only if there are regulators coupled */
    if (rdev->coupling_desc.n_coupled > 1) {
        ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
        if (ret < 0) {
            goto err_disable_supply;
        }
    }

    ret = _regulator_handle_consumer_enable(regulator);
    if (ret < 0) {
        goto err_disable_supply;
    }

    if (rdev->use_count == 0) {
        /* The regulator may on if it's not switchable or left on */
        ret = _regulator_is_enabled(rdev);
        if (ret == -EINVAL || ret == 0) {
            if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) {
                ret = -EPERM;
                goto err_consumer_disable;
            }

            ret = _regulator_do_enable(rdev);
            if (ret < 0) {
                goto err_consumer_disable;
            }

            _notifier_call_chain(rdev, REGULATOR_EVENT_ENABLE, NULL);
        } else if (ret < 0) {
            rdev_err(rdev, "is_enabled() failed: %pe\n", ERR_PTR(ret));
            goto err_consumer_disable;
        }
        /* Fallthrough on positive return values - already enabled */
    }

    rdev->use_count++;

    return 0;

err_consumer_disable:
    _regulator_handle_consumer_disable(regulator);

err_disable_supply:
    if (rdev->use_count == 0 && rdev->supply) {
        _regulator_disable(rdev->supply);
    }

    return ret;
}

/**
 * regulator_enable - enable regulator output
 * @regulator: regulator source
 *
 * Request that the regulator be enabled with the regulator output at
 * the predefined voltage or current value.  Calls to regulator_enable()
 * must be balanced with calls to regulator_disable().
 *
 * NOTE: the output value can be set by other drivers, boot loader or may be
 * hardwired in the regulator.
 */
int regulator_enable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct ww_acquire_ctx ww_ctx;
    int ret;

    regulator_lock_dependent(rdev, &ww_ctx);
    ret = _regulator_enable(regulator);
    regulator_unlock_dependent(rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_enable);

/**
 * set_machine_constraints - sets regulator constraints
 * @rdev: regulator source
 *
 * Allows platform initialisation code to define and constrain
 * regulator circuits e.g. valid voltage/current ranges, etc.  NOTE:
 * Constraints *must* be set by platform code in order for some
 * regulator operations to proceed i.e. set_voltage, set_current_limit,
 * set_mode.
 */
static int set_machine_constraints(struct regulator_dev *rdev)
{
    int ret = 0;
    const struct regulator_ops *ops = rdev->desc->ops;

    ret = machine_constraints_voltage(rdev, rdev->constraints);
    if (ret != 0) {
        return ret;
    }

    ret = machine_constraints_current(rdev, rdev->constraints);
    if (ret != 0) {
        return ret;
    }

    if (rdev->constraints->ilim_uA && ops->set_input_current_limit) {
        ret = ops->set_input_current_limit(rdev, rdev->constraints->ilim_uA);
        if (ret < 0) {
            rdev_err(rdev, "failed to set input limit: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    /* do we need to setup our suspend state */
    if (rdev->constraints->initial_state) {
        ret = suspend_set_initial_state(rdev);
        if (ret < 0) {
            rdev_err(rdev, "failed to set suspend state: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->constraints->initial_mode) {
        if (!ops->set_mode) {
            rdev_err(rdev, "no set_mode operation\n");
            return -EINVAL;
        }

        ret = ops->set_mode(rdev, rdev->constraints->initial_mode);
        if (ret < 0) {
            rdev_err(rdev, "failed to set initial mode: %pe\n", ERR_PTR(ret));
            return ret;
        }
    } else if (rdev->constraints->system_load) {
        /*
         * We'll only apply the initial system load if an
         * initial mode wasn't specified.
         */
        drms_uA_update(rdev);
    }

    if ((rdev->constraints->ramp_delay || rdev->constraints->ramp_disable) && ops->set_ramp_delay) {
        ret = ops->set_ramp_delay(rdev, rdev->constraints->ramp_delay);
        if (ret < 0) {
            rdev_err(rdev, "failed to set ramp_delay: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->constraints->pull_down && ops->set_pull_down) {
        ret = ops->set_pull_down(rdev);
        if (ret < 0) {
            rdev_err(rdev, "failed to set pull down: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->constraints->soft_start && ops->set_soft_start) {
        ret = ops->set_soft_start(rdev);
        if (ret < 0) {
            rdev_err(rdev, "failed to set soft start: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->constraints->over_current_protection && ops->set_over_current_protection) {
        ret = ops->set_over_current_protection(rdev);
        if (ret < 0) {
            rdev_err(rdev, "failed to set over current protection: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    if (rdev->constraints->active_discharge && ops->set_active_discharge) {
        bool ad_state = (rdev->constraints->active_discharge == REGULATOR_ACTIVE_DISCHARGE_ENABLE) ? true : false;

        ret = ops->set_active_discharge(rdev, ad_state);
        if (ret < 0) {
            rdev_err(rdev, "failed to set active discharge: %pe\n", ERR_PTR(ret));
            return ret;
        }
    }

    /* If the constraints say the regulator should be on at this point
     * and we have control then make sure it is enabled.
     */
    if (rdev->constraints->always_on || rdev->constraints->boot_on) {
        /* If we want to enable this regulator, make sure that we know
         * the supplying regulator.
         */
        if (rdev->supply_name && !rdev->supply) {
            return -EPROBE_DEFER;
        }

        if (rdev->supply) {
            ret = regulator_enable(rdev->supply);
            if (ret < 0) {
                _regulator_put(rdev->supply);
                rdev->supply = NULL;
                return ret;
            }
        }

        ret = _regulator_do_enable(rdev);
        if (ret < 0 && ret != -EINVAL) {
            rdev_err(rdev, "failed to enable: %pe\n", ERR_PTR(ret));
            return ret;
        }

        if (rdev->constraints->always_on) {
            rdev->use_count++;
        }
    } else if (rdev->desc->off_on_delay) {
        rdev->last_off_jiffy = jiffies;
    }

    print_constraints(rdev);
    return 0;
}

/**
 * set_supply - set regulator supply regulator
 * @rdev: regulator name
 * @supply_rdev: supply regulator name
 *
 * Called by platform initialisation code to set the supply regulator for this
 * regulator. This ensures that a regulators supply will also be enabled by the
 * core if it's child is enabled.
 */
static int set_supply(struct regulator_dev *rdev, struct regulator_dev *supply_rdev)
{
    int err;

    rdev_info(rdev, "supplied by %s\n", rdev_get_name(supply_rdev));

    if (!try_module_get(supply_rdev->owner)) {
        return -ENODEV;
    }

    rdev->supply = create_regulator(supply_rdev, &rdev->dev, "SUPPLY");
    if (rdev->supply == NULL) {
        err = -ENOMEM;
        return err;
    }
    supply_rdev->open_count++;

    return 0;
}

/**
 * set_consumer_device_supply - Bind a regulator to a symbolic supply
 * @rdev:         regulator source
 * @consumer_dev_name: dev_name() string for device supply applies to
 * @supply:       symbolic name for supply
 *
 * Allows platform initialisation code to map physical regulator
 * sources to symbolic names for supplies for use by devices.  Devices
 * should use these symbolic names to request regulators, avoiding the
 * need to provide board-specific regulator names as platform data.
 */
static int set_consumer_device_supply(struct regulator_dev *rdev, const char *consumer_dev_name, const char *supply)
{
    struct regulator_map *node, *new_node;
    int has_dev;

    if (supply == NULL) {
        return -EINVAL;
    }

    if (consumer_dev_name != NULL) {
        has_dev = 1;
    } else {
        has_dev = 0;
    }

    new_node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
    if (new_node == NULL) {
        return -ENOMEM;
    }

    new_node->regulator = rdev;
    new_node->supply = supply;

    if (has_dev) {
        new_node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
        if (new_node->dev_name == NULL) {
            kfree(new_node);
            return -ENOMEM;
        }
    }

    mutex_lock(&regulator_list_mutex);
    list_for_each_entry(node, &regulator_map_list, list)
    {
        if (node->dev_name && consumer_dev_name) {
            if (strcmp(node->dev_name, consumer_dev_name) != 0) {
                continue;
            }
        } else if (node->dev_name || consumer_dev_name) {
            continue;
        }

        if (strcmp(node->supply, supply) != 0) {
            continue;
        }

        pr_debug("%s: %s/%s is '%s' supply; fail %s/%s\n", consumer_dev_name, dev_name(&node->regulator->dev),
                 node->regulator->desc->name, supply, dev_name(&rdev->dev), rdev_get_name(rdev));
        goto fail;
    }

    list_add(&new_node->list, &regulator_map_list);
    mutex_unlock(&regulator_list_mutex);

    return 0;

fail:
    mutex_unlock(&regulator_list_mutex);
    kfree(new_node->dev_name);
    kfree(new_node);
    return -EBUSY;
}

static void unset_regulator_supplies(struct regulator_dev *rdev)
{
    struct regulator_map *node, *n;

    list_for_each_entry_safe(node, n, &regulator_map_list, list)
    {
        if (rdev == node->regulator) {
            list_del(&node->list);
            kfree(node->dev_name);
            kfree(node);
        }
    }
}

#ifdef CONFIG_DEBUG_FS
static ssize_t constraint_flags_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos)
{
    const struct regulator *regulator = file->private_data;
    const struct regulation_constraints *c = regulator->rdev->constraints;
    char *buf;
    ssize_t ret;

    if (!c) {
        return 0;
    }

    buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!buf) {
        return -ENOMEM;
    }

    ret = snprintf(buf, PAGE_SIZE,
                   "always_on: %u\n"
                   "boot_on: %u\n"
                   "apply_uV: %u\n"
                   "ramp_disable: %u\n"
                   "soft_start: %u\n"
                   "pull_down: %u\n"
                   "over_current_protection: %u\n",
                   c->always_on, c->boot_on, c->apply_uV, c->ramp_disable, c->soft_start, c->pull_down,
                   c->over_current_protection);

    ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
    kfree(buf);

    return ret;
}

#endif

static const struct file_operations constraint_flags_fops = {
#ifdef CONFIG_DEBUG_FS
    .open = simple_open,
    .read = constraint_flags_read_file,
    .llseek = default_llseek,
#endif
};

#define REG_STR_SIZE 64

static struct regulator *create_regulator(struct regulator_dev *rdev, struct device *dev, const char *supply_name)
{
    struct regulator *regulator;
    int err = 0;

    if (dev) {
        char buf[REG_STR_SIZE];
        int size;

        size = snprintf(buf, REG_STR_SIZE, "%s-%s", dev->kobj.name, supply_name);
        if (size >= REG_STR_SIZE) {
            return NULL;
        }

        supply_name = kstrdup(buf, GFP_KERNEL);
        if (supply_name == NULL) {
            return NULL;
        }
    } else {
        supply_name = kstrdup_const(supply_name, GFP_KERNEL);
        if (supply_name == NULL) {
            return NULL;
        }
    }

    regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
    if (regulator == NULL) {
        kfree(supply_name);
        return NULL;
    }

    regulator->rdev = rdev;
    regulator->supply_name = supply_name;

    regulator_lock(rdev);
    list_add(&regulator->list, &rdev->consumer_list);
    regulator_unlock(rdev);

    if (dev) {
        regulator->dev = dev;

        /* Add a link to the device sysfs entry */
        err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj, supply_name);
        if (err) {
            rdev_dbg(rdev, "could not add device link %s: %pe\n", dev->kobj.name, ERR_PTR(err));
            /* non-fatal */
        }
    }

    if (err != -EEXIST) {
        regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs);
    }
    if (!regulator->debugfs) {
        rdev_dbg(rdev, "Failed to create debugfs directory\n");
    } else {
        debugfs_create_u32("uA_load", CORE_FILE_PROPERTY_B, regulator->debugfs, &regulator->uA_load);
        debugfs_create_u32("min_uV", CORE_FILE_PROPERTY_B, regulator->debugfs,
                           &regulator->voltage[PM_SUSPEND_ON].min_uV);
        debugfs_create_u32("max_uV", CORE_FILE_PROPERTY_B, regulator->debugfs,
                           &regulator->voltage[PM_SUSPEND_ON].max_uV);
        debugfs_create_file("constraint_flags", CORE_FILE_PROPERTY_B, regulator->debugfs, regulator,
                            &constraint_flags_fops);
    }

    /*
     * Check now if the regulator is an always on regulator - if
     * it is then we don't need to do nearly so much work for
     * enable/disable calls.
     */
    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS) && _regulator_is_enabled(rdev)) {
        regulator->always_on = true;
    }

    return regulator;
}

static int _regulator_get_enable_time(struct regulator_dev *rdev)
{
    if (rdev->constraints && rdev->constraints->enable_time) {
        return rdev->constraints->enable_time;
    }
    if (rdev->desc->ops->enable_time) {
        return rdev->desc->ops->enable_time(rdev);
    }
    return rdev->desc->enable_time;
}

static struct regulator_supply_alias *regulator_find_supply_alias(struct device *dev, const char *supply)
{
    struct regulator_supply_alias *map;

    list_for_each_entry(map, &regulator_supply_alias_list,
                        list) if (map->src_dev == dev && strcmp(map->src_supply, supply) == 0) return map;

    return NULL;
}

static void regulator_supply_alias(struct device **dev, const char **supply)
{
    struct regulator_supply_alias *map;

    map = regulator_find_supply_alias(*dev, *supply);
    if (map) {
        dev_dbg(*dev, "Mapping supply %s to %s,%s\n", *supply, map->alias_supply, dev_name(map->alias_dev));
        *dev = map->alias_dev;
        *supply = map->alias_supply;
    }
}

static int regulator_match(struct device *dev, const void *data)
{
    struct regulator_dev *r = dev_to_rdev(dev);

    return strcmp(rdev_get_name(r), data) == 0;
}

static struct regulator_dev *regulator_lookup_by_name(const char *name)
{
    struct device *dev;

    dev = class_find_device(&regulator_class, NULL, name, regulator_match);

    return dev ? dev_to_rdev(dev) : NULL;
}

/**
 * regulator_dev_lookup - lookup a regulator device.
 * @dev: device for regulator "consumer".
 * @supply: Supply name or regulator ID.
 *
 * If successful, returns a struct regulator_dev that corresponds to the name
 * @supply and with the embedded struct device refcount incremented by one.
 * The refcount must be dropped by calling put_device().
 * On failure one of the following ERR-PTR-encoded values is returned:
 * -ENODEV if lookup fails permanently, -EPROBE_DEFER if lookup could succeed
 * in the future.
 */
static struct regulator_dev *regulator_dev_lookup(struct device *dev, const char *supply)
{
    struct regulator_dev *r = NULL;
    struct device_node *node;
    struct regulator_map *map;
    const char *devname = NULL;

    regulator_supply_alias(&dev, &supply);

    /* first do a dt based lookup */
    if (dev && dev->of_node) {
        node = of_get_regulator(dev, supply);
        if (node) {
            r = of_find_regulator_by_node(node);
            if (r) {
                return r;
            }

            /*
             * We have a node, but there is no device.
             * assume it has not registered yet.
             */
            return ERR_PTR(-EPROBE_DEFER);
        }
    }

    /* if not found, try doing it non-dt way */
    if (dev) {
        devname = dev_name(dev);
    }

    mutex_lock(&regulator_list_mutex);
    list_for_each_entry(map, &regulator_map_list, list)
    {
        /* If the mapping has a device set up it must match */
        if (map->dev_name && (!devname || strcmp(map->dev_name, devname))) {
            continue;
        }

        if (strcmp(map->supply, supply) == 0 && get_device(&map->regulator->dev)) {
            r = map->regulator;
            break;
        }
    }
    mutex_unlock(&regulator_list_mutex);

    if (r) {
        return r;
    }

    r = regulator_lookup_by_name(supply);
    if (r) {
        return r;
    }

    return ERR_PTR(-ENODEV);
}

static int regulator_resolve_supply(struct regulator_dev *rdev)
{
    struct regulator_dev *r;
    struct device *dev = rdev->dev.parent;
    int ret = 0;

    /* No supply to resolve? */
    if (!rdev->supply_name) {
        return 0;
    }

    /* Supply already resolved? (fast-path without locking contention) */
    if (rdev->supply) {
        return 0;
    }

    r = regulator_dev_lookup(dev, rdev->supply_name);
    if (IS_ERR(r)) {
        ret = PTR_ERR(r);
        /* Did the lookup explicitly defer for us? */
        if (ret == -EPROBE_DEFER) {
            goto out;
        }

        if (have_full_constraints()) {
            r = dummy_regulator_rdev;
            get_device(&r->dev);
        } else {
            dev_err(dev, "Failed to resolve %s-supply for %s\n", rdev->supply_name, rdev->desc->name);
            ret = -EPROBE_DEFER;
            goto out;
        }
    }

    if (r == rdev) {
        dev_err(dev, "Supply for %s (%s) resolved to itself\n", rdev->desc->name, rdev->supply_name);
        if (!have_full_constraints()) {
            ret = -EINVAL;
            goto out;
        }
        r = dummy_regulator_rdev;
        get_device(&r->dev);
    }

    /*
     * If the supply's parent device is not the same as the
     * regulator's parent device, then ensure the parent device
     * is bound before we resolve the supply, in case the parent
     * device get probe deferred and unregisters the supply.
     */
    if (r->dev.parent && r->dev.parent != rdev->dev.parent) {
        if (!device_is_bound(r->dev.parent)) {
            put_device(&r->dev);
            ret = -EPROBE_DEFER;
            goto out;
        }
    }

    /* Recursively resolve the supply of the supply */
    ret = regulator_resolve_supply(r);
    if (ret < 0) {
        put_device(&r->dev);
        goto out;
    }

    /*
     * Recheck rdev->supply with rdev->mutex lock held to avoid a race
     * between rdev->supply null check and setting rdev->supply in
     * set_supply() from concurrent tasks.
     */
    regulator_lock(rdev);

    /* Supply just resolved by a concurrent task? */
    if (rdev->supply) {
        regulator_unlock(rdev);
        put_device(&r->dev);
        goto out;
    }

    ret = set_supply(rdev, r);
    if (ret < 0) {
        regulator_unlock(rdev);
        put_device(&r->dev);
        goto out;
    }

    regulator_unlock(rdev);

    /*
     * In set_machine_constraints() we may have turned this regulator on
     * but we couldn't propagate to the supply if it hadn't been resolved
     * yet.  Do it now.
     */
    if (rdev->use_count) {
        ret = regulator_enable(rdev->supply);
        if (ret < 0) {
            _regulator_put(rdev->supply);
            rdev->supply = NULL;
            goto out;
        }
    }

out:
    return ret;
}

/* Internal regulator request function */
struct regulator *_regulator_get(struct device *dev, const char *id, enum regulator_get_type get_type)
{
    struct regulator_dev *rdev;
    struct regulator *regulator;
    struct device_link *link;
    int ret;

    if (get_type >= MAX_GET_TYPE) {
        dev_err(dev, "invalid type %d in %s\n", get_type, __func__);
        return ERR_PTR(-EINVAL);
    }

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

    rdev = regulator_dev_lookup(dev, id);
    if (IS_ERR(rdev)) {
        ret = PTR_ERR(rdev);
        /*
         * If regulator_dev_lookup() fails with error other
         * than -ENODEV our job here is done, we simply return it.
         */
        if (ret != -ENODEV) {
            return ERR_PTR(ret);
        }

        if (!have_full_constraints()) {
            dev_warn(dev, "incomplete constraints, dummy supplies not allowed\n");
            return ERR_PTR(-ENODEV);
        }

        switch (get_type) {
            case NORMAL_GET:
                /*
                 * Assume that a regulator is physically present and
                 * enabled, even if it isn't hooked up, and just
                 * provide a dummy.
                 */
                dev_warn(dev, "supply %s not found, using dummy regulator\n", id);
                rdev = dummy_regulator_rdev;
                get_device(&rdev->dev);
                break;

            case EXCLUSIVE_GET:
                dev_warn(dev, "dummy supplies not allowed for exclusive requests\n");
                fallthrough;

            default:
                return ERR_PTR(-ENODEV);
        }
    }

    if (rdev->exclusive) {
        regulator = ERR_PTR(-EPERM);
        put_device(&rdev->dev);
        return regulator;
    }

    if (get_type == EXCLUSIVE_GET && rdev->open_count) {
        regulator = ERR_PTR(-EBUSY);
        put_device(&rdev->dev);
        return regulator;
    }

    mutex_lock(&regulator_list_mutex);
    ret = (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled);
    mutex_unlock(&regulator_list_mutex);

    if (ret != 0) {
        regulator = ERR_PTR(-EPROBE_DEFER);
        put_device(&rdev->dev);
        return regulator;
    }

    ret = regulator_resolve_supply(rdev);
    if (ret < 0) {
        regulator = ERR_PTR(ret);
        put_device(&rdev->dev);
        return regulator;
    }

    if (!try_module_get(rdev->owner)) {
        regulator = ERR_PTR(-EPROBE_DEFER);
        put_device(&rdev->dev);
        return regulator;
    }

    regulator = create_regulator(rdev, dev, id);
    if (regulator == NULL) {
        regulator = ERR_PTR(-ENOMEM);
        module_put(rdev->owner);
        put_device(&rdev->dev);
        return regulator;
    }

    rdev->open_count++;
    if (get_type == EXCLUSIVE_GET) {
        rdev->exclusive = 1;

        ret = _regulator_is_enabled(rdev);
        if (ret > 0) {
            rdev->use_count = 1;
            regulator->enable_count = 1;
        } else {
            rdev->use_count = 0;
            regulator->enable_count = 0;
        }
    }

    link = device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
    if (!IS_ERR_OR_NULL(link)) {
        regulator->device_link = true;
    }

    return regulator;
}

/**
 * regulator_get - lookup and obtain a reference to a regulator.
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Returns a struct regulator corresponding to the regulator producer,
 * or IS_ERR() condition containing errno.
 *
 * Use of supply names configured via 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, NORMAL_GET);
}
EXPORT_SYMBOL_GPL(regulator_get);

/**
 * regulator_get_exclusive - obtain exclusive access to a regulator.
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Returns a struct regulator corresponding to the regulator producer,
 * or IS_ERR() condition containing errno.  Other consumers will be
 * unable to obtain this regulator while this reference is held and the
 * use count for the regulator will be initialised to reflect the current
 * state of the regulator.
 *
 * This is intended for use by consumers which cannot tolerate shared
 * use of the regulator such as those which need to force the
 * regulator off for correct operation of the hardware they are
 * controlling.
 *
 * Use of supply names configured via 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, EXCLUSIVE_GET);
}
EXPORT_SYMBOL_GPL(regulator_get_exclusive);

/**
 * regulator_get_optional - obtain optional access to a regulator.
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Returns a struct regulator corresponding to the regulator producer,
 * or IS_ERR() condition containing errno.
 *
 * This is intended for use by consumers for devices which can have
 * some supplies unconnected in normal use, such as some MMC devices.
 * It can allow the regulator core to provide stub supplies for other
 * supplies requested using normal regulator_get() calls without
 * disrupting the operation of drivers that can handle absent
 * supplies.
 *
 * Use of supply names configured via regulator_set_device_supply() is
 * strongly encouraged.  It is recommended that the supply name used
 * should match the name used for the supply and/or the relevant
 * device pins in the datasheet.
 */
struct regulator *regulator_get_optional(struct device *dev, const char *id)
{
    return _regulator_get(dev, id, OPTIONAL_GET);
}
EXPORT_SYMBOL_GPL(regulator_get_optional);

static void destroy_regulator(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;

    debugfs_remove_recursive(regulator->debugfs);

    if (regulator->dev) {
        if (regulator->device_link) {
            device_link_remove(regulator->dev, &rdev->dev);
        }

        /* remove any sysfs entries */
        sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
    }

    regulator_lock(rdev);
    list_del(&regulator->list);

    rdev->open_count--;
    rdev->exclusive = 0;
    regulator_unlock(rdev);

    kfree_const(regulator->supply_name);
    kfree(regulator);
}

/* regulator_list_mutex lock held by regulator_put() */
static void _regulator_put(struct regulator *regulator)
{
    struct regulator_dev *rdev;

    if (IS_ERR_OR_NULL(regulator)) {
        return;
    }

    lockdep_assert_held_once(&regulator_list_mutex);

    /* Docs say you must disable before calling regulator_put() */
    WARN_ON(regulator->enable_count);

    rdev = regulator->rdev;

    destroy_regulator(regulator);

    module_put(rdev->owner);
    put_device(&rdev->dev);
}

/**
 * regulator_put - "free" the regulator source
 * @regulator: regulator source
 *
 * Note: drivers must ensure that all regulator_enable calls made on this
 * regulator source are balanced by regulator_disable calls prior to calling
 * this function.
 */
void regulator_put(struct regulator *regulator)
{
    mutex_lock(&regulator_list_mutex);
    _regulator_put(regulator);
    mutex_unlock(&regulator_list_mutex);
}
EXPORT_SYMBOL_GPL(regulator_put);

/**
 * regulator_register_supply_alias - Provide device alias for supply lookup
 *
 * @dev: device that will be given as the regulator "consumer"
 * @id: Supply name or regulator ID
 * @alias_dev: device that should be used to lookup the supply
 * @alias_id: Supply name or regulator ID that should be used to lookup the
 * supply
 *
 * All lookups for id on dev will instead be conducted for alias_id on
 * alias_dev.
 */
int regulator_register_supply_alias(struct device *dev, const char *id, struct device *alias_dev, const char *alias_id)
{
    struct regulator_supply_alias *map;

    map = regulator_find_supply_alias(dev, id);
    if (map) {
        return -EEXIST;
    }

    map = kzalloc(sizeof(struct regulator_supply_alias), GFP_KERNEL);
    if (!map) {
        return -ENOMEM;
    }

    map->src_dev = dev;
    map->src_supply = id;
    map->alias_dev = alias_dev;
    map->alias_supply = alias_id;

    list_add(&map->list, &regulator_supply_alias_list);

    pr_info("Adding alias for supply %s,%s -> %s,%s\n", id, dev_name(dev), alias_id, dev_name(alias_dev));

    return 0;
}
EXPORT_SYMBOL_GPL(regulator_register_supply_alias);

/**
 * regulator_unregister_supply_alias - Remove device alias
 *
 * @dev: device that will be given as the regulator "consumer"
 * @id: Supply name or regulator ID
 *
 * Remove a lookup alias if one exists for id on dev.
 */
void regulator_unregister_supply_alias(struct device *dev, const char *id)
{
    struct regulator_supply_alias *map;

    map = regulator_find_supply_alias(dev, id);
    if (map) {
        list_del(&map->list);
        kfree(map);
    }
}
EXPORT_SYMBOL_GPL(regulator_unregister_supply_alias);

/**
 * regulator_bulk_register_supply_alias - register multiple aliases
 *
 * @dev: device that will be given as the regulator "consumer"
 * @id: List of supply names or regulator IDs
 * @alias_dev: device that should be used to lookup the supply
 * @alias_id: List of supply names or regulator IDs that should be used to
 * lookup the supply
 * @num_id: Number of aliases to register
 *
 * @return 0 on success, an errno on failure.
 *
 * This helper function allows drivers to register several supply
 * aliases in one operation.  If any of the aliases cannot be
 * registered any aliases that were registered will be removed
 * before returning to the caller.
 */
int regulator_bulk_register_supply_alias(struct device *dev, const char *const *id, struct device *alias_dev,
                                         const char *const *alias_id, int num_id)
{
    int i;
    int ret;

    for (i = 0; i < num_id; ++i) {
        ret = regulator_register_supply_alias(dev, id[i], alias_dev, alias_id[i]);
        if (ret < 0) {
            goto err;
        }
    }

    return 0;

err:
    dev_err(dev, "Failed to create supply alias %s,%s -> %s,%s\n", id[i], dev_name(dev), alias_id[i],
            dev_name(alias_dev));

    while (--i >= 0) {
        regulator_unregister_supply_alias(dev, id[i]);
    }

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_register_supply_alias);

/**
 * regulator_bulk_unregister_supply_alias - unregister multiple aliases
 *
 * @dev: device that will be given as the regulator "consumer"
 * @id: List of supply names or regulator IDs
 * @num_id: Number of aliases to unregister
 *
 * This helper function allows drivers to unregister several supply
 * aliases in one operation.
 */
void regulator_bulk_unregister_supply_alias(struct device *dev, const char *const *id, int num_id)
{
    int i;

    for (i = 0; i < num_id; ++i) {
        regulator_unregister_supply_alias(dev, id[i]);
    }
}
EXPORT_SYMBOL_GPL(regulator_bulk_unregister_supply_alias);

/* Manage enable GPIO list. Same GPIO pin can be shared among regulators */
static int regulator_ena_gpio_request(struct regulator_dev *rdev, const struct regulator_config *config)
{
    struct regulator_enable_gpio *pin, *new_pin;
    struct gpio_desc *gpiod;

    gpiod = config->ena_gpiod;
    new_pin = kzalloc(sizeof(*new_pin), GFP_KERNEL);

    mutex_lock(&regulator_list_mutex);

    list_for_each_entry(pin, &regulator_ena_gpio_list, list)
    {
        if (pin->gpiod == gpiod) {
            rdev_dbg(rdev, "GPIO is already used\n");
            goto update_ena_gpio_to_rdev;
        }
    }

    if (new_pin == NULL) {
        mutex_unlock(&regulator_list_mutex);
        return -ENOMEM;
    }

    pin = new_pin;
    new_pin = NULL;

    pin->gpiod = gpiod;
    list_add(&pin->list, &regulator_ena_gpio_list);

update_ena_gpio_to_rdev:
    pin->request_count++;
    rdev->ena_pin = pin;

    mutex_unlock(&regulator_list_mutex);
    kfree(new_pin);

    return 0;
}

static void regulator_ena_gpio_free(struct regulator_dev *rdev)
{
    struct regulator_enable_gpio *pin, *n;

    if (!rdev->ena_pin) {
        return;
    }

    /* Free the GPIO only in case of no use */
    list_for_each_entry_safe(pin, n, &regulator_ena_gpio_list, list)
    {
        if (pin != rdev->ena_pin) {
            continue;
        }

        if (--pin->request_count) {
            break;
        }

        gpiod_put(pin->gpiod);
        list_del(&pin->list);
        kfree(pin);
        break;
    }

    rdev->ena_pin = NULL;
}

/**
 * regulator_ena_gpio_ctrl - balance enable_count of each GPIO and actual GPIO pin control
 * @rdev: regulator_dev structure
 * @enable: enable GPIO at initial use?
 *
 * GPIO is enabled in case of initial use. (enable_count is 0)
 * GPIO is disabled when it is not shared any more. (enable_count <= 1)
 */
static int regulator_ena_gpio_ctrl(struct regulator_dev *rdev, bool enable)
{
    struct regulator_enable_gpio *pin = rdev->ena_pin;

    if (!pin) {
        return -EINVAL;
    }

    if (enable) {
        /* Enable GPIO at initial use */
        if (pin->enable_count == 0) {
            gpiod_set_value_cansleep(pin->gpiod, 1);
        }

        pin->enable_count++;
    } else {
        if (pin->enable_count > 1) {
            pin->enable_count--;
            return 0;
        }

        /* Disable GPIO if not used */
        if (pin->enable_count <= 1) {
            gpiod_set_value_cansleep(pin->gpiod, 0);
            pin->enable_count = 0;
        }
    }

    return 0;
}

/**
 * _regulator_enable_delay - a delay helper function
 * @delay: time to delay in microseconds
 *
 * Delay for the requested amount of time as per the guidelines in:
 *
 *     Documentation/timers/timers-howto.rst
 *
 * The assumption here is that regulators will never be enabled in
 * atomic context and therefore sleeping functions can be used.
 */
static void _regulator_enable_delay(unsigned int delay)
{
    unsigned int ms = delay / CORE_ONETHOUSAND;
    unsigned int us = delay % CORE_ONETHOUSAND;

    if (ms > 0) {
        /*
         * For small enough values, handle super-millisecond
         * delays in the usleep_range() call below.
         */
        if (ms < CORE_TWENTY) {
            us += ms * CORE_ONETHOUSAND;
        } else {
            msleep(ms);
        }
    }

    /*
     * Give the scheduler some room to coalesce with any other
     * wakeup sources. For delays shorter than 10 us, don't even
     * bother setting up high-resolution timers and just busy-
     * loop.
     */
    if (us >= 0xA) {
        usleep_range(us, us + 0x64);
    } else {
        udelay(us);
    }
}

/**
 * _regulator_check_status_enabled
 *
 * A helper function to check if the regulator status can be interpreted
 * as 'regulator is enabled'.
 * @rdev: the regulator device to check
 *
 * Return:
 * * 1            - if status shows regulator is in enabled state
 * * 0            - if not enabled state
 * * Error Value    - as received from ops->get_status()
 */
static inline int _regulator_check_status_enabled(struct regulator_dev *rdev)
{
    int ret = rdev->desc->ops->get_status(rdev);
    if (ret < 0) {
        rdev_info(rdev, "get_status returned error: %d\n", ret);
        return ret;
    }
    switch (ret) {
        case REGULATOR_STATUS_OFF:
        case REGULATOR_STATUS_ERROR:
        case REGULATOR_STATUS_UNDEFINED:
            return 0;
        default:
            return 1;
    }
}

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

    /* Query before enabling in case configuration dependent.  */
    ret = _regulator_get_enable_time(rdev);
    if (ret >= 0) {
        delay = ret;
    } else {
        rdev_warn(rdev, "enable_time() failed: %pe\n", ERR_PTR(ret));
        delay = 0;
    }

    trace_regulator_enable(rdev_get_name(rdev));

    if (rdev->desc->off_on_delay) {
        /* if needed, keep a distance of off_on_delay from last time
         * this regulator was disabled.
         */
        unsigned long start_jiffy = jiffies;
        unsigned long intended, max_delay, remaining;

        max_delay = usecs_to_jiffies(rdev->desc->off_on_delay);
        intended = rdev->last_off_jiffy + max_delay;

        if (time_before(start_jiffy, intended)) {
            /* calc remaining jiffies to deal with one-time
             * timer wrapping.
             * in case of multiple timer wrapping, either it can be
             * detected by out-of-range remaining, or it cannot be
             * detected and we get a penalty of
             * _regulator_enable_delay().
             */
            remaining = intended - start_jiffy;
            if (remaining <= max_delay) {
                _regulator_enable_delay(jiffies_to_usecs(remaining));
            }
        }
    }

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

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

    /* If poll_enabled_time is set, poll upto the delay calculated
     * above, delaying poll_enabled_time uS to check if the regulator
     * actually got enabled.
     * If the regulator isn't enabled after enable_delay has
     * expired, return -ETIMEDOUT.
     */
    if (rdev->desc->poll_enabled_time) {
        unsigned int time_remaining = delay;

        while (time_remaining > 0) {
            _regulator_enable_delay(rdev->desc->poll_enabled_time);

            if (rdev->desc->ops->get_status) {
                ret = _regulator_check_status_enabled(rdev);
                if (ret < 0) {
                    return ret;
                } else if (ret) {
                    break;
                }
            } else if (rdev->desc->ops->is_enabled(rdev)) {
                break;
            }

            time_remaining -= rdev->desc->poll_enabled_time;
        }

        if (time_remaining <= 0) {
            rdev_err(rdev, "Enabled check timed out\n");
            return -ETIMEDOUT;
        }
    } else {
        _regulator_enable_delay(delay);
    }

    trace_regulator_enable_complete(rdev_get_name(rdev));

    return 0;
}

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

    trace_regulator_disable(rdev_get_name(rdev));

    if (rdev->ena_pin) {
        if (rdev->ena_gpio_state) {
            ret = regulator_ena_gpio_ctrl(rdev, false);
            if (ret < 0) {
                return ret;
            }
            rdev->ena_gpio_state = 0;
        }
    } else if (rdev->desc->ops->disable) {
        ret = rdev->desc->ops->disable(rdev);
        if (ret != 0) {
            return ret;
        }
    }

    /* cares about last_off_jiffy only if off_on_delay is required by
     * device.
     */
    if (rdev->desc->off_on_delay) {
        rdev->last_off_jiffy = jiffies;
    }

    trace_regulator_disable_complete(rdev_get_name(rdev));

    return 0;
}

/* locks held by regulator_disable() */
static int _regulator_disable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    int ret = 0;

    lockdep_assert_held_once(&rdev->mutex.base);

    if (WARN(rdev->use_count <= 0, "unbalanced disables for %s\n", rdev_get_name(rdev))) {
        return -EIO;
    }

    /* are we the last user and permitted to disable ? */
    if (rdev->use_count == 1 && (rdev->constraints && !rdev->constraints->always_on)) {
        /* we are last user */
        if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) {
            ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_DISABLE, NULL);
            if (ret & NOTIFY_STOP_MASK) {
                return -EINVAL;
            }

            ret = _regulator_do_disable(rdev);
            if (ret < 0) {
                rdev_err(rdev, "failed to disable: %pe\n", ERR_PTR(ret));
                _notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_DISABLE, NULL);
                return ret;
            }
            _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, NULL);
        }
        rdev->use_count = 0;
    } else if (rdev->use_count > 1) {
        rdev->use_count--;
    }

    if (ret == 0) {
        ret = _regulator_handle_consumer_disable(regulator);
    }

    if (ret == 0 && rdev->coupling_desc.n_coupled > 1) {
        ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
    }

    if (ret == 0 && rdev->use_count == 0 && rdev->supply) {
        ret = _regulator_disable(rdev->supply);
    }

    return ret;
}

/**
 * regulator_disable - disable regulator output
 * @regulator: regulator source
 *
 * Disable the regulator output voltage or current.  Calls to
 * regulator_enable() must be balanced with calls to
 * regulator_disable().
 *
 * NOTE: this will only disable the regulator output if no other consumer
 * devices have it enabled, the regulator device supports disabling and
 * machine constraints permit this operation.
 */
int regulator_disable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct ww_acquire_ctx ww_ctx;
    int ret;

    regulator_lock_dependent(rdev, &ww_ctx);
    ret = _regulator_disable(regulator);
    regulator_unlock_dependent(rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_disable);

/* locks held by regulator_force_disable() */
static int _regulator_force_disable(struct regulator_dev *rdev)
{
    int ret = 0;

    lockdep_assert_held_once(&rdev->mutex.base);

    ret = _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE | REGULATOR_EVENT_PRE_DISABLE, NULL);
    if (ret & NOTIFY_STOP_MASK) {
        return -EINVAL;
    }

    ret = _regulator_do_disable(rdev);
    if (ret < 0) {
        rdev_err(rdev, "failed to force disable: %pe\n", ERR_PTR(ret));
        _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE | REGULATOR_EVENT_ABORT_DISABLE, NULL);
        return ret;
    }

    _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE | REGULATOR_EVENT_DISABLE, NULL);

    return 0;
}

/**
 * regulator_force_disable - force disable regulator output
 * @regulator: regulator source
 *
 * Forcibly disable the regulator output voltage or current.
 * NOTE: this *will* disable the regulator output even if other consumer
 * devices have it enabled. This should be used for situations when device
 * damage will likely occur if the regulator is not disabled (e.g. over temp).
 */
int regulator_force_disable(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct ww_acquire_ctx ww_ctx;
    int ret;

    regulator_lock_dependent(rdev, &ww_ctx);

    ret = _regulator_force_disable(regulator->rdev);

    if (rdev->coupling_desc.n_coupled > 1) {
        regulator_balance_voltage(rdev, PM_SUSPEND_ON);
    }

    if (regulator->uA_load) {
        regulator->uA_load = 0;
        ret = drms_uA_update(rdev);
    }

    if (rdev->use_count != 0 && rdev->supply) {
        _regulator_disable(rdev->supply);
    }

    regulator_unlock_dependent(rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_force_disable);

static void regulator_disable_work(struct work_struct *work)
{
    struct regulator_dev *rdev = container_of(work, struct regulator_dev, disable_work.work);
    struct ww_acquire_ctx ww_ctx;
    int count, i, ret;
    struct regulator *regulator;
    int total_count = 0;

    regulator_lock_dependent(rdev, &ww_ctx);

    /*
     * Workqueue functions queue the new work instance while the previous
     * work instance is being processed. Cancel the queued work instance
     * as the work instance under processing does the job of the queued
     * work instance.
     */
    cancel_delayed_work(&rdev->disable_work);

    list_for_each_entry(regulator, &rdev->consumer_list, list)
    {
        count = regulator->deferred_disables;

        if (!count) {
            continue;
        }

        total_count += count;
        regulator->deferred_disables = 0;

        for (i = 0; i < count; i++) {
            ret = _regulator_disable(regulator);
            if (ret != 0) {
                rdev_err(rdev, "Deferred disable failed: %pe\n", ERR_PTR(ret));
            }
        }
    }
    WARN_ON(!total_count);

    if (rdev->coupling_desc.n_coupled > 1) {
        regulator_balance_voltage(rdev, PM_SUSPEND_ON);
    }

    regulator_unlock_dependent(rdev, &ww_ctx);
}

/**
 * regulator_disable_deferred - disable regulator output with delay
 * @regulator: regulator source
 * @ms: milliseconds until the regulator is disabled
 *
 * Execute regulator_disable() on the regulator after a delay.  This
 * is intended for use with devices that require some time to quiesce.
 *
 * NOTE: this will only disable the regulator output if no other consumer
 * devices have it enabled, the regulator device supports disabling and
 * machine constraints permit this operation.
 */
int regulator_disable_deferred(struct regulator *regulator, int ms)
{
    struct regulator_dev *rdev = regulator->rdev;

    if (!ms) {
        return regulator_disable(regulator);
    }

    regulator_lock(rdev);
    regulator->deferred_disables++;
    mod_delayed_work(system_power_efficient_wq, &rdev->disable_work, msecs_to_jiffies(ms));
    regulator_unlock(rdev);

    return 0;
}
EXPORT_SYMBOL_GPL(regulator_disable_deferred);

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

    /* If we don't know then assume that the regulator is always on */
    if (!rdev->desc->ops->is_enabled) {
        return 1;
    }

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

static int _regulator_list_voltage(struct regulator_dev *rdev, unsigned selector, int lock)
{
    const struct regulator_ops *ops = rdev->desc->ops;
    int ret;

    if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1 && !selector) {
        return rdev->desc->fixed_uV;
    }

    if (ops->list_voltage) {
        if (selector >= rdev->desc->n_voltages) {
            return -EINVAL;
        }
        if (lock) {
            regulator_lock(rdev);
        }
        ret = ops->list_voltage(rdev, selector);
        if (lock) {
            regulator_unlock(rdev);
        }
    } else if (rdev->is_switch && rdev->supply) {
        ret = _regulator_list_voltage(rdev->supply->rdev, selector, lock);
    } else {
        return -EINVAL;
    }

    if (ret > 0) {
        if (ret < rdev->constraints->min_uV) {
            ret = 0;
        } else if (ret > rdev->constraints->max_uV) {
            ret = 0;
        }
    }

    return ret;
}

/**
 * regulator_is_enabled - is the regulator output enabled
 * @regulator: regulator source
 *
 * Returns positive if the regulator driver backing the source/client
 * has requested that the device be enabled, zero if it hasn't, else a
 * negative errno code.
 *
 * Note that the device backing this regulator handle can have multiple
 * users, so it might be enabled even if regulator_enable() was never
 * called for this particular source.
 */
int regulator_is_enabled(struct regulator *regulator)
{
    int ret;

    if (regulator->always_on) {
        return 1;
    }

    regulator_lock(regulator->rdev);
    ret = _regulator_is_enabled(regulator->rdev);
    regulator_unlock(regulator->rdev);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_is_enabled);

/**
 * regulator_count_voltages - count regulator_list_voltage() selectors
 * @regulator: regulator source
 *
 * Returns number of selectors, or negative errno.  Selectors are
 * numbered starting at zero, and typically correspond to bitfields
 * in hardware registers.
 */
int regulator_count_voltages(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;

    if (rdev->desc->n_voltages) {
        return rdev->desc->n_voltages;
    }

    if (!rdev->is_switch || !rdev->supply) {
        return -EINVAL;
    }

    return regulator_count_voltages(rdev->supply);
}
EXPORT_SYMBOL_GPL(regulator_count_voltages);

/**
 * regulator_list_voltage - enumerate supported voltages
 * @regulator: regulator source
 * @selector: identify voltage to list
 * Context: can sleep
 *
 * Returns a voltage that can be passed to @regulator_set_voltage(),
 * zero if this selector code can't be used on this system, or a
 * negative errno.
 */
int regulator_list_voltage(struct regulator *regulator, unsigned selector)
{
    return _regulator_list_voltage(regulator->rdev, selector, 1);
}
EXPORT_SYMBOL_GPL(regulator_list_voltage);

/**
 * regulator_get_regmap - get the regulator's register map
 * @regulator: regulator source
 *
 * Returns the register map for the given regulator, or an ERR_PTR value
 * if the regulator doesn't use regmap.
 */
struct regmap *regulator_get_regmap(struct regulator *regulator)
{
    struct regmap *map = regulator->rdev->regmap;

    return map ? map : ERR_PTR(-EOPNOTSUPP);
}

/**
 * regulator_get_hardware_vsel_register - get the HW voltage selector register
 * @regulator: regulator source
 * @vsel_reg: voltage selector register, output parameter
 * @vsel_mask: mask for voltage selector bitfield, output parameter
 *
 * Returns the hardware register offset and bitmask used for setting the
 * regulator voltage. This might be useful when configuring voltage-scaling
 * hardware or firmware that can make I2C requests behind the kernel's back,
 * for example.
 *
 * On success, the output parameters @vsel_reg and @vsel_mask are filled in
 * and 0 is returned, otherwise a negative errno is returned.
 */
int regulator_get_hardware_vsel_register(struct regulator *regulator, unsigned *vsel_reg, unsigned *vsel_mask)
{
    struct regulator_dev *rdev = regulator->rdev;
    const struct regulator_ops *ops = rdev->desc->ops;

    if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap) {
        return -EOPNOTSUPP;
    }

    *vsel_reg = rdev->desc->vsel_reg;
    *vsel_mask = rdev->desc->vsel_mask;

    return 0;
}
EXPORT_SYMBOL_GPL(regulator_get_hardware_vsel_register);

/**
 * regulator_list_hardware_vsel - get the HW-specific register value for a selector
 * @regulator: regulator source
 * @selector: identify voltage to list
 *
 * Converts the selector to a hardware-specific voltage selector that can be
 * directly written to the regulator registers. The address of the voltage
 * register can be determined by calling @regulator_get_hardware_vsel_register.
 *
 * On error a negative errno is returned.
 */
int regulator_list_hardware_vsel(struct regulator *regulator, unsigned selector)
{
    struct regulator_dev *rdev = regulator->rdev;
    const struct regulator_ops *ops = rdev->desc->ops;

    if (selector >= rdev->desc->n_voltages) {
        return -EINVAL;
    }
    if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap) {
        return -EOPNOTSUPP;
    }

    return selector;
}
EXPORT_SYMBOL_GPL(regulator_list_hardware_vsel);

/**
 * regulator_get_linear_step - return the voltage step size between VSEL values
 * @regulator: regulator source
 *
 * Returns the voltage step size between VSEL values for linear
 * regulators, or return 0 if the regulator isn't a linear regulator.
 */
unsigned int regulator_get_linear_step(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;

    return rdev->desc->uV_step;
}
EXPORT_SYMBOL_GPL(regulator_get_linear_step);

/**
 * regulator_is_supported_voltage - check if a voltage range can be supported
 *
 * @regulator: Regulator to check.
 * @min_uV: Minimum required voltage in uV.
 * @max_uV: Maximum required voltage in uV.
 *
 * Returns a boolean.
 */
int regulator_is_supported_voltage(struct regulator *regulator, int min_uV, int max_uV)
{
    struct regulator_dev *rdev = regulator->rdev;
    int i, voltages, ret;

    /* If we can't change voltage check the current voltage */
    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
        ret = regulator_get_voltage(regulator);
        if (ret >= 0) {
            return min_uV <= ret && ret <= max_uV;
        } else {
            return ret;
        }
    }

    /* Any voltage within constrains range is fine? */
    if (rdev->desc->continuous_voltage_range) {
        return min_uV >= rdev->constraints->min_uV && max_uV <= rdev->constraints->max_uV;
    }

    ret = regulator_count_voltages(regulator);
    if (ret < 0) {
        return 0;
    }
    voltages = ret;
    for (i = 0; i < voltages; i++) {
        ret = regulator_list_voltage(regulator, i);
        if (ret >= min_uV && ret <= max_uV) {
            return 1;
        }
    }
    return 0;
}
EXPORT_SYMBOL_GPL(regulator_is_supported_voltage);

static int regulator_map_voltage(struct regulator_dev *rdev, int min_uV, int max_uV)
{
    const struct regulator_desc *desc = rdev->desc;

    if (desc->ops->map_voltage) {
        return desc->ops->map_voltage(rdev, min_uV, max_uV);
    }

    if (desc->ops->list_voltage == regulator_list_voltage_linear) {
        return regulator_map_voltage_linear(rdev, min_uV, max_uV);
    }

    if (desc->ops->list_voltage == regulator_list_voltage_linear_range) {
        return regulator_map_voltage_linear_range(rdev, min_uV, max_uV);
    }

    if (desc->ops->list_voltage == regulator_list_voltage_pickable_linear_range) {
        return regulator_map_voltage_pickable_linear_range(rdev, min_uV, max_uV);
    }

    return regulator_map_voltage_iterate(rdev, min_uV, max_uV);
}

static int _regulator_call_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV, unsigned *selector)
{
    struct pre_voltage_change_data data;
    int ret;

    data.old_uV = regulator_get_voltage_rdev(rdev);
    data.min_uV = min_uV;
    data.max_uV = max_uV;
    ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE, &data);
    if (ret & NOTIFY_STOP_MASK) {
        return -EINVAL;
    }

    ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV, selector);
    if (ret >= 0) {
        return ret;
    }

    _notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE, (void *)data.old_uV);

    return ret;
}

static int _regulator_call_set_voltage_sel(struct regulator_dev *rdev, int uV, unsigned selector)
{
    struct pre_voltage_change_data data;
    int ret;

    data.old_uV = regulator_get_voltage_rdev(rdev);
    data.min_uV = uV;
    data.max_uV = uV;
    ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE, &data);
    if (ret & NOTIFY_STOP_MASK) {
        return -EINVAL;
    }

    ret = rdev->desc->ops->set_voltage_sel(rdev, selector);
    if (ret >= 0) {
        return ret;
    }

    _notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE, (void *)data.old_uV);

    return ret;
}

static int _regulator_set_voltage_sel_step(struct regulator_dev *rdev, int uV, int new_selector)
{
    const struct regulator_ops *ops = rdev->desc->ops;
    int diff, old_sel, curr_sel, ret;

    /* Stepping is only needed if the regulator is enabled. */
    if (!_regulator_is_enabled(rdev)) {
        goto final_set;
    }

    if (!ops->get_voltage_sel) {
        return -EINVAL;
    }

    old_sel = ops->get_voltage_sel(rdev);
    if (old_sel < 0) {
        return old_sel;
    }

    diff = new_selector - old_sel;
    if (diff == 0) {
        return 0; /* No change needed. */
    }

    if (diff > 0) {
        /* Stepping up. */
        for (curr_sel = old_sel + rdev->desc->vsel_step; curr_sel < new_selector; curr_sel += rdev->desc->vsel_step) {
            /*
             * Call the callback directly instead of using
             * _regulator_call_set_voltage_sel() as we don't
             * want to notify anyone yet. Same in the branch
             * below.
             */
            ret = ops->set_voltage_sel(rdev, curr_sel);
            if (ret) {
                goto try_revert;
            }
        }
    } else {
        /* Stepping down. */
        for (curr_sel = old_sel - rdev->desc->vsel_step; curr_sel > new_selector; curr_sel -= rdev->desc->vsel_step) {
            ret = ops->set_voltage_sel(rdev, curr_sel);
            if (ret) {
                goto try_revert;
            }
        }
    }

final_set:
    /* The final selector will trigger the notifiers. */
    return _regulator_call_set_voltage_sel(rdev, uV, new_selector);

try_revert:
    /*
     * At least try to return to the previous voltage if setting a new
     * one failed.
     */
    (void)ops->set_voltage_sel(rdev, old_sel);
    return ret;
}

static int _regulator_set_voltage_time(struct regulator_dev *rdev, int old_uV, int new_uV)
{
    unsigned int ramp_delay = 0;

    if (rdev->constraints->ramp_delay) {
        ramp_delay = rdev->constraints->ramp_delay;
    } else if (rdev->desc->ramp_delay) {
        ramp_delay = rdev->desc->ramp_delay;
    } else if (rdev->constraints->settling_time) {
        return rdev->constraints->settling_time;
    } else if (rdev->constraints->settling_time_up && (new_uV > old_uV)) {
        return rdev->constraints->settling_time_up;
    } else if (rdev->constraints->settling_time_down && (new_uV < old_uV)) {
        return rdev->constraints->settling_time_down;
    }

    if (ramp_delay == 0) {
        rdev_dbg(rdev, "ramp_delay not set\n");
        return 0;
    }

    return DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay);
}

static int _regulator_do_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV)
{
    int ret;
    int delay = 0;
    int best_val = 0;
    unsigned int selector;
    int old_selector = -1;
    const struct regulator_ops *ops = rdev->desc->ops;
    int old_uV = regulator_get_voltage_rdev(rdev);

    trace_regulator_set_voltage(rdev_get_name(rdev), min_uV, max_uV);

    min_uV += rdev->constraints->uV_offset;
    max_uV += rdev->constraints->uV_offset;

    /*
     * If we can't obtain the old selector there is not enough
     * info to call set_voltage_time_sel().
     */
    if (_regulator_is_enabled(rdev) && ops->set_voltage_time_sel && ops->get_voltage_sel) {
        old_selector = ops->get_voltage_sel(rdev);
        if (old_selector < 0) {
            return old_selector;
        }
    }

    if (ops->set_voltage) {
        ret = _regulator_call_set_voltage(rdev, min_uV, max_uV, &selector);
        if (ret >= 0) {
            if (ops->list_voltage) {
                best_val = ops->list_voltage(rdev, selector);
            } else {
                best_val = regulator_get_voltage_rdev(rdev);
            }
        }
    } else if (ops->set_voltage_sel) {
        ret = regulator_map_voltage(rdev, min_uV, max_uV);
        if (ret >= 0) {
            best_val = ops->list_voltage(rdev, ret);
            if (min_uV <= best_val && max_uV >= best_val) {
                selector = ret;
                if (old_selector == selector) {
                    ret = 0;
                } else if (rdev->desc->vsel_step) {
                    ret = _regulator_set_voltage_sel_step(rdev, best_val, selector);
                } else {
                    ret = _regulator_call_set_voltage_sel(rdev, best_val, selector);
                }
            } else {
                ret = -EINVAL;
            }
        }
    } else {
        ret = -EINVAL;
    }

    if (ret) {
        goto out;
    }

    if (ops->set_voltage_time_sel) {
        /*
         * Call set_voltage_time_sel if successfully obtained
         * old_selector
         */
        if (old_selector >= 0 && old_selector != selector) {
            delay = ops->set_voltage_time_sel(rdev, old_selector, selector);
        }
    } else {
        if (old_uV != best_val) {
            if (ops->set_voltage_time) {
                delay = ops->set_voltage_time(rdev, old_uV, best_val);
            } else {
                delay = _regulator_set_voltage_time(rdev, old_uV, best_val);
            }
        }
    }

    if (delay < 0) {
        rdev_warn(rdev, "failed to get delay: %pe\n", ERR_PTR(delay));
        delay = 0;
    }

    /* Insert any necessary delays */
    if (delay >= CORE_ONETHOUSAND) {
        mdelay(delay / CORE_ONETHOUSAND);
        udelay(delay % CORE_ONETHOUSAND);
    } else if (delay) {
        udelay(delay);
    }

    if (best_val >= 0) {
        unsigned long data = best_val;

        _notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, (void *)data);
    }

out:
    trace_regulator_set_voltage_complete(rdev_get_name(rdev), best_val);

    return ret;
}

static int _regulator_do_set_suspend_voltage(struct regulator_dev *rdev, int min_uV, int max_uV, suspend_state_t state)
{
    struct regulator_state *rstate;
    int uV, sel;

    rstate = regulator_get_suspend_state(rdev, state);
    if (rstate == NULL) {
        return -EINVAL;
    }

    if (min_uV < rstate->min_uV) {
        min_uV = rstate->min_uV;
    }
    if (max_uV > rstate->max_uV) {
        max_uV = rstate->max_uV;
    }

    sel = regulator_map_voltage(rdev, min_uV, max_uV);
    if (sel < 0) {
        return sel;
    }

    uV = rdev->desc->ops->list_voltage(rdev, sel);
    if (uV >= min_uV && uV <= max_uV) {
        rstate->uV = uV;
    }

    return 0;
}

static int regulator_set_voltage_unlocked(struct regulator *regulator, int min_uV, int max_uV, suspend_state_t state)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct regulator_voltage *voltage = &regulator->voltage[state];
    int ret = 0;
    int old_min_uV, old_max_uV;
    int current_uV;

    /* If we're setting the same range as last time the change
     * should be a noop (some cpufreq implementations use the same
     * voltage for multiple frequencies, for example).
     */
    if (voltage->min_uV == min_uV && voltage->max_uV == max_uV) {
        goto out;
    }

    /* If we're trying to set a range that overlaps the current voltage,
     * return successfully even though the regulator does not support
     * changing the voltage.
     */
    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
        current_uV = regulator_get_voltage_rdev(rdev);
        if (min_uV <= current_uV && current_uV <= max_uV) {
            voltage->min_uV = min_uV;
            voltage->max_uV = max_uV;
            goto out;
        }
    }

    /* sanity check */
    if (!rdev->desc->ops->set_voltage && !rdev->desc->ops->set_voltage_sel) {
        ret = -EINVAL;
        goto out;
    }

    /* constraints check */
    ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
    if (ret < 0) {
        goto out;
    }

    /* restore original values in case of error */
    old_min_uV = voltage->min_uV;
    old_max_uV = voltage->max_uV;
    voltage->min_uV = min_uV;
    voltage->max_uV = max_uV;

    /* for not coupled regulators this will just set the voltage */
    ret = regulator_balance_voltage(rdev, state);
    if (ret < 0) {
        voltage->min_uV = old_min_uV;
        voltage->max_uV = old_max_uV;
    }

out:
    return ret;
}

int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV, int max_uV, suspend_state_t state)
{
    int best_supply_uV = 0;
    int supply_change_uV = 0;
    int ret;

    if (rdev->supply && regulator_ops_is_valid(rdev->supply->rdev, REGULATOR_CHANGE_VOLTAGE) &&
        (rdev->desc->min_dropout_uV || !(rdev->desc->ops->get_voltage || rdev->desc->ops->get_voltage_sel))) {
        int current_supply_uV;
        int selector;

        selector = regulator_map_voltage(rdev, min_uV, max_uV);
        if (selector < 0) {
            ret = selector;
            goto out;
        }

        best_supply_uV = _regulator_list_voltage(rdev, selector, 0);
        if (best_supply_uV < 0) {
            ret = best_supply_uV;
            goto out;
        }

        best_supply_uV += rdev->desc->min_dropout_uV;

        current_supply_uV = regulator_get_voltage_rdev(rdev->supply->rdev);
        if (current_supply_uV < 0) {
            ret = current_supply_uV;
            goto out;
        }

        supply_change_uV = best_supply_uV - current_supply_uV;
    }

    if (supply_change_uV > 0) {
        ret = regulator_set_voltage_unlocked(rdev->supply, best_supply_uV, INT_MAX, state);
        if (ret) {
            dev_err(&rdev->dev, "Failed to increase supply voltage: %pe\n", ERR_PTR(ret));
            goto out;
        }
    }

    if (state == PM_SUSPEND_ON) {
        ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
    } else {
        ret = _regulator_do_set_suspend_voltage(rdev, min_uV, max_uV, state);
    }
    if (ret < 0) {
        goto out;
    }

    if (supply_change_uV < 0) {
        ret = regulator_set_voltage_unlocked(rdev->supply, best_supply_uV, INT_MAX, state);
        if (ret) {
            dev_warn(&rdev->dev, "Failed to decrease supply voltage: %pe\n", ERR_PTR(ret));
        }
        /* No need to fail here */
        ret = 0;
    }

out:
    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_voltage_rdev);

static int regulator_limit_voltage_step(struct regulator_dev *rdev, int *current_uV, int *min_uV)
{
    struct regulation_constraints *constraints = rdev->constraints;

    /* Limit voltage change only if necessary */
    if (!constraints->max_uV_step || !_regulator_is_enabled(rdev)) {
        return 1;
    }

    if (*current_uV < 0) {
        *current_uV = regulator_get_voltage_rdev(rdev);

        if (*current_uV < 0) {
            return *current_uV;
        }
    }

    if (abs(*current_uV - *min_uV) <= constraints->max_uV_step) {
        return 1;
    }

    /* Clamp target voltage within the given step */
    if (*current_uV < *min_uV) {
        *min_uV = min(*current_uV + constraints->max_uV_step, *min_uV);
    } else {
        *min_uV = max(*current_uV - constraints->max_uV_step, *min_uV);
    }

    return 0;
}

static int regulator_get_optimal_voltage(struct regulator_dev *rdev, int *current_uV, int *min_uV, int *max_uV,
                                         suspend_state_t state, int n_coupled)
{
    struct coupling_desc *c_desc = &rdev->coupling_desc;
    struct regulator_dev **c_rdevs = c_desc->coupled_rdevs;
    struct regulation_constraints *constraints = rdev->constraints;
    int desired_min_uV = 0, desired_max_uV = INT_MAX;
    int max_current_uV = 0, min_current_uV = INT_MAX;
    int highest_min_uV = 0, target_uV, possible_uV;
    int i, ret, max_spread;
    bool done;

    *current_uV = -1;

    /*
     * If there are no coupled regulators, simply set the voltage
     * demanded by consumers.
     */
    if (n_coupled == 1) {
        /*
         * If consumers don't provide any demands, set voltage
         * to min_uV
         */
        desired_min_uV = constraints->min_uV;
        desired_max_uV = constraints->max_uV;

        ret = regulator_check_consumers(rdev, &desired_min_uV, &desired_max_uV, state);
        if (ret < 0) {
            return ret;
        }

        possible_uV = desired_min_uV;
        done = true;

        goto finish;
    }

    /* Find highest min desired voltage */
    for (i = 0; i < n_coupled; i++) {
        int tmp_min = 0;
        int tmp_max = INT_MAX;

        lockdep_assert_held_once(&c_rdevs[i]->mutex.base);

        ret = regulator_check_consumers(c_rdevs[i], &tmp_min, &tmp_max, state);
        if (ret < 0) {
            return ret;
        }

        ret = regulator_check_voltage(c_rdevs[i], &tmp_min, &tmp_max);
        if (ret < 0) {
            return ret;
        }

        highest_min_uV = max(highest_min_uV, tmp_min);

        if (i == 0) {
            desired_min_uV = tmp_min;
            desired_max_uV = tmp_max;
        }
    }

    max_spread = constraints->max_spread[0];

    /*
     * Let target_uV be equal to the desired one if possible.
     * If not, set it to minimum voltage, allowed by other coupled
     * regulators.
     */
    target_uV = max(desired_min_uV, highest_min_uV - max_spread);

    /*
     * Find min and max voltages, which currently aren't violating
     * max_spread.
     */
    for (i = 1; i < n_coupled; i++) {
        int tmp_act;

        if (!_regulator_is_enabled(c_rdevs[i])) {
            continue;
        }

        tmp_act = regulator_get_voltage_rdev(c_rdevs[i]);
        if (tmp_act < 0) {
            return tmp_act;
        }

        min_current_uV = min(tmp_act, min_current_uV);
        max_current_uV = max(tmp_act, max_current_uV);
    }

    /* There aren't any other regulators enabled */
    if (max_current_uV == 0) {
        possible_uV = target_uV;
    } else {
        /*
         * Correct target voltage, so as it currently isn't
         * violating max_spread
         */
        possible_uV = max(target_uV, max_current_uV - max_spread);
        possible_uV = min(possible_uV, min_current_uV + max_spread);
    }

    if (possible_uV > desired_max_uV) {
        return -EINVAL;
    }

    done = (possible_uV == target_uV);
    desired_min_uV = possible_uV;

finish:
    /* Apply max_uV_step constraint if necessary */
    if (state == PM_SUSPEND_ON) {
        ret = regulator_limit_voltage_step(rdev, current_uV, &desired_min_uV);
        if (ret < 0) {
            return ret;
        }

        if (ret == 0) {
            done = false;
        }
    }

    /* Set current_uV if wasn't done earlier in the code and if necessary */
    if (n_coupled > 1 && *current_uV == -1) {
        if (_regulator_is_enabled(rdev)) {
            ret = regulator_get_voltage_rdev(rdev);
            if (ret < 0) {
                return ret;
            }

            *current_uV = ret;
        } else {
            *current_uV = desired_min_uV;
        }
    }

    *min_uV = desired_min_uV;
    *max_uV = desired_max_uV;

    return done;
}

int regulator_do_balance_voltage(struct regulator_dev *rdev, suspend_state_t state, bool skip_coupled)
{
    struct regulator_dev **c_rdevs;
    struct regulator_dev *best_rdev;
    struct coupling_desc *c_desc = &rdev->coupling_desc;
    int i, ret, n_coupled, best_min_uV, best_max_uV, best_c_rdev;
    unsigned int delta, best_delta;
    unsigned long c_rdev_done = 0;
    bool best_c_rdev_done;

    c_rdevs = c_desc->coupled_rdevs;
    n_coupled = skip_coupled ? 1 : c_desc->n_coupled;

    /*
     * Find the best possible voltage change on each loop. Leave the loop
     * if there isn't any possible change.
     */
    do {
        best_c_rdev_done = false;
        best_delta = 0;
        best_min_uV = 0;
        best_max_uV = 0;
        best_c_rdev = 0;
        best_rdev = NULL;

        /*
         * Find highest difference between optimal voltage
         * and current voltage.
         */
        for (i = 0; i < n_coupled; i++) {
            /*
             * optimal_uV is the best voltage that can be set for
             * i-th regulator at the moment without violating
             * max_spread constraint in order to balance
             * the coupled voltages.
             */
            int optimal_uV = 0, optimal_max_uV = 0, current_uV = 0;

            if (test_bit(i, &c_rdev_done)) {
                continue;
            }

            ret =
                regulator_get_optimal_voltage(c_rdevs[i], &current_uV, &optimal_uV, &optimal_max_uV, state, n_coupled);
            if (ret < 0) {
                goto out;
            }
            delta = abs(optimal_uV - current_uV);
            if (delta && best_delta <= delta) {
                best_c_rdev_done = ret;
                best_delta = delta;
                best_rdev = c_rdevs[i];
                best_min_uV = optimal_uV;
                best_max_uV = optimal_max_uV;
                best_c_rdev = i;
            }
        }
        /* Nothing to change, return successfully */
        if (!best_rdev) {
            ret = 0;
            goto out;
        }
        ret = regulator_set_voltage_rdev(best_rdev, best_min_uV, best_max_uV, state);
        if (ret < 0) {
            goto out;
        }
        if (best_c_rdev_done) {
            set_bit(best_c_rdev, &c_rdev_done);
        }
    } while (n_coupled > 1);
out:
    return ret;
}

static int regulator_balance_voltage(struct regulator_dev *rdev, suspend_state_t state)
{
    struct coupling_desc *c_desc = &rdev->coupling_desc;
    struct regulator_coupler *coupler = c_desc->coupler;
    bool skip_coupled = false;

    /*
     * If system is in a state other than PM_SUSPEND_ON, don't check
     * other coupled regulators.
     */
    if (state != PM_SUSPEND_ON) {
        skip_coupled = true;
    }

    if (c_desc->n_resolved < c_desc->n_coupled) {
        rdev_err(rdev, "Not all coupled regulators registered\n");
        return -EPERM;
    }

    /* Invoke custom balancer for customized couplers */
    if (coupler && coupler->balance_voltage) {
        return coupler->balance_voltage(coupler, rdev, state);
    }

    return regulator_do_balance_voltage(rdev, state, skip_coupled);
}

/**
 * regulator_set_voltage - set regulator output voltage
 * @regulator: regulator source
 * @min_uV: Minimum required voltage in uV
 * @max_uV: Maximum acceptable voltage in uV
 *
 * Sets a voltage regulator to the desired output voltage. This can be set
 * during any regulator state. IOW, regulator can be disabled or enabled.
 *
 * If the regulator is enabled then the voltage will change to the new value
 * immediately otherwise if the regulator is disabled the regulator will
 * output at the new voltage when enabled.
 *
 * NOTE: If the regulator is shared between several devices then the lowest
 * request voltage that meets the system constraints will be used.
 * Regulator system constraints must be set for this regulator before
 * calling this function otherwise this call will fail.
 */
int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
{
    struct ww_acquire_ctx ww_ctx;
    int ret;

    regulator_lock_dependent(regulator->rdev, &ww_ctx);

    ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV, PM_SUSPEND_ON);

    regulator_unlock_dependent(regulator->rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_voltage);

static inline int regulator_suspend_toggle(struct regulator_dev *rdev, suspend_state_t state, bool en)
{
    struct regulator_state *rstate;

    rstate = regulator_get_suspend_state(rdev, state);
    if (rstate == NULL) {
        return -EINVAL;
    }

    if (!rstate->changeable) {
        return -EPERM;
    }

    rstate->enabled = (en) ? ENABLE_IN_SUSPEND : DISABLE_IN_SUSPEND;

    return 0;
}

int regulator_suspend_enable(struct regulator_dev *rdev, suspend_state_t state)
{
    return regulator_suspend_toggle(rdev, state, true);
}
EXPORT_SYMBOL_GPL(regulator_suspend_enable);

int regulator_suspend_disable(struct regulator_dev *rdev, suspend_state_t state)
{
    struct regulator *regulator;
    struct regulator_voltage *voltage;

    /*
     * if any consumer wants this regulator device keeping on in
     * suspend states, don't set it as disabled.
     */
    list_for_each_entry(regulator, &rdev->consumer_list, list)
    {
        voltage = &regulator->voltage[state];
        if (voltage->min_uV || voltage->max_uV) {
            return 0;
        }
    }

    return regulator_suspend_toggle(rdev, state, false);
}
EXPORT_SYMBOL_GPL(regulator_suspend_disable);

static int _regulator_set_suspend_voltage(struct regulator *regulator, int min_uV, int max_uV, suspend_state_t state)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct regulator_state *rstate;

    rstate = regulator_get_suspend_state(rdev, state);
    if (rstate == NULL) {
        return -EINVAL;
    }

    if (rstate->min_uV == rstate->max_uV) {
        rdev_err(rdev, "The suspend voltage can't be changed!\n");
        return -EPERM;
    }

    return regulator_set_voltage_unlocked(regulator, min_uV, max_uV, state);
}

int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV, int max_uV, suspend_state_t state)
{
    struct ww_acquire_ctx ww_ctx;
    int ret;

    /* PM_SUSPEND_ON is handled by regulator_set_voltage() */
    if (regulator_check_states(state) || state == PM_SUSPEND_ON) {
        return -EINVAL;
    }

    regulator_lock_dependent(regulator->rdev, &ww_ctx);

    ret = _regulator_set_suspend_voltage(regulator, min_uV, max_uV, state);

    regulator_unlock_dependent(regulator->rdev, &ww_ctx);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_suspend_voltage);

/**
 * regulator_set_voltage_time - get raise/fall time
 * @regulator: regulator source
 * @old_uV: starting voltage in microvolts
 * @new_uV: target voltage in microvolts
 *
 * Provided with the starting and ending voltage, this function attempts to
 * calculate the time in microseconds required to rise or fall to this new
 * voltage.
 */
int regulator_set_voltage_time(struct regulator *regulator, int old_uV, int new_uV)
{
    struct regulator_dev *rdev = regulator->rdev;
    const struct regulator_ops *ops = rdev->desc->ops;
    int old_sel = -1;
    int new_sel = -1;
    int voltage;
    int i;

    if (ops->set_voltage_time) {
        return ops->set_voltage_time(rdev, old_uV, new_uV);
    } else if (!ops->set_voltage_time_sel) {
        return _regulator_set_voltage_time(rdev, old_uV, new_uV);
    }

    /* Currently requires operations to do this */
    if (!ops->list_voltage || !rdev->desc->n_voltages) {
        return -EINVAL;
    }

    for (i = 0; i < rdev->desc->n_voltages; i++) {
        /* We only look for exact voltage matches here */

        if (old_sel >= 0 && new_sel >= 0) {
            break;
        }

        voltage = regulator_list_voltage(regulator, i);
        if (voltage < 0) {
            return -EINVAL;
        }
        if (voltage == 0) {
            continue;
        }
        if (voltage == old_uV) {
            old_sel = i;
        }
        if (voltage == new_uV) {
            new_sel = i;
        }
    }

    if (old_sel < 0 || new_sel < 0) {
        return -EINVAL;
    }

    return ops->set_voltage_time_sel(rdev, old_sel, new_sel);
}
EXPORT_SYMBOL_GPL(regulator_set_voltage_time);

/**
 * regulator_set_voltage_time_sel - get raise/fall time
 * @rdev: regulator source device
 * @old_selector: selector for starting voltage
 * @new_selector: selector for target voltage
 *
 * Provided with the starting and target voltage selectors, this function
 * returns time in microseconds required to rise or fall to this new voltage
 *
 * Drivers providing ramp_delay in regulation_constraints can use this as their
 * set_voltage_time_sel() operation.
 */
int regulator_set_voltage_time_sel(struct regulator_dev *rdev, unsigned int old_selector, unsigned int new_selector)
{
    int old_volt, new_volt;

    /* sanity check */
    if (!rdev->desc->ops->list_voltage) {
        return -EINVAL;
    }

    old_volt = rdev->desc->ops->list_voltage(rdev, old_selector);
    new_volt = rdev->desc->ops->list_voltage(rdev, new_selector);

    if (rdev->desc->ops->set_voltage_time) {
        return rdev->desc->ops->set_voltage_time(rdev, old_volt, new_volt);
    } else {
        return _regulator_set_voltage_time(rdev, old_volt, new_volt);
    }
}
EXPORT_SYMBOL_GPL(regulator_set_voltage_time_sel);

/**
 * regulator_sync_voltage - re-apply last regulator output voltage
 * @regulator: regulator source
 *
 * Re-apply the last configured voltage.  This is intended to be used
 * where some external control source the consumer is cooperating with
 * has caused the configured voltage to change.
 */
int regulator_sync_voltage(struct regulator *regulator)
{
    struct regulator_dev *rdev = regulator->rdev;
    struct regulator_voltage *voltage = &regulator->voltage[PM_SUSPEND_ON];
    int ret, min_uV, max_uV;

    regulator_lock(rdev);

    if (!rdev->desc->ops->set_voltage && !rdev->desc->ops->set_voltage_sel) {
        ret = -EINVAL;
        goto out;
    }

    /* This is only going to work if we've had a voltage configured. */
    if (!voltage->min_uV && !voltage->max_uV) {
        ret = -EINVAL;
        goto out;
    }

    min_uV = voltage->min_uV;
    max_uV = voltage->max_uV;

    /* This should be a paranoia check... */
    ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
    if (ret < 0) {
        goto out;
    }

    ret = regulator_check_consumers(rdev, &min_uV, &max_uV, 0);
    if (ret < 0) {
        goto out;
    }

    ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);

out:
    regulator_unlock(rdev);
    return ret;
}
EXPORT_SYMBOL_GPL(regulator_sync_voltage);

/**
 * regulator_set_current_limit - set regulator output current limit
 * @regulator: regulator source
 * @min_uA: Minimum supported current in uA
 * @max_uA: Maximum supported current in uA
 *
 * Sets current sink to the desired output current. This can be set during
 * any regulator state. IOW, regulator can be disabled or enabled.
 *
 * If the regulator is enabled then the current will change to the new value
 * immediately otherwise if the regulator is disabled the regulator will
 * output at the new current when enabled.
 *
 * NOTE: Regulator system constraints must be set for this regulator before
 * calling this function otherwise this call will fail.
 */
int regulator_set_current_limit(struct regulator *regulator, int min_uA, int max_uA)
{
    struct regulator_dev *rdev = regulator->rdev;
    int ret;

    regulator_lock(rdev);

    /* sanity check */
    if (!rdev->desc->ops->set_current_limit) {
        ret = -EINVAL;
        goto out;
    }

    /* constraints check */
    ret = regulator_check_current_limit(rdev, &min_uA, &max_uA);
    if (ret < 0) {
        goto out;
    }

    ret = rdev->desc->ops->set_current_limit(rdev, min_uA, max_uA);
out:
    regulator_unlock(rdev);
    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_current_limit);

static int _regulator_get_current_limit_unlocked(struct regulator_dev *rdev)
{
    /* sanity check */
    if (!rdev->desc->ops->get_current_limit) {
        return -EINVAL;
    }

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

static int _regulator_get_current_limit(struct regulator_dev *rdev)
{
    int ret;

    regulator_lock(rdev);
    ret = _regulator_get_current_limit_unlocked(rdev);
    regulator_unlock(rdev);

    return ret;
}

/**
 * regulator_get_current_limit - get regulator output current
 * @regulator: regulator source
 *
 * This returns the current supplied by the specified current sink in uA.
 *
 * NOTE: If the regulator is disabled it will return the current value. This
 * function should not be used to determine regulator state.
 */
int regulator_get_current_limit(struct regulator *regulator)
{
    return _regulator_get_current_limit(regulator->rdev);
}
EXPORT_SYMBOL_GPL(regulator_get_current_limit);

/**
 * regulator_set_mode - set regulator operating mode
 * @regulator: regulator source
 * @mode: operating mode - one of the REGULATOR_MODE constants
 *
 * Set regulator operating mode to increase regulator efficiency or improve
 * regulation performance.
 *
 * NOTE: Regulator system constraints must be set for this regulator before
 * calling this function otherwise this call will fail.
 */
int regulator_set_mode(struct regulator *regulator, unsigned int mode)
{
    struct regulator_dev *rdev = regulator->rdev;
    int ret;
    int regulator_curr_mode;

    regulator_lock(rdev);

    /* sanity check */
    if (!rdev->desc->ops->set_mode) {
        ret = -EINVAL;
        goto out;
    }

    /* return if the same mode is requested */
    if (rdev->desc->ops->get_mode) {
        regulator_curr_mode = rdev->desc->ops->get_mode(rdev);
        if (regulator_curr_mode == mode) {
            ret = 0;
            goto out;
        }
    }

    /* constraints check */
    ret = regulator_mode_constrain(rdev, &mode);
    if (ret < 0) {
        goto out;
    }

    ret = rdev->desc->ops->set_mode(rdev, mode);
out:
    regulator_unlock(rdev);
    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_mode);

static unsigned int _regulator_get_mode_unlocked(struct regulator_dev *rdev)
{
    /* sanity check */
    if (!rdev->desc->ops->get_mode) {
        return -EINVAL;
    }

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

static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
{
    int ret;

    regulator_lock(rdev);
    ret = _regulator_get_mode_unlocked(rdev);
    regulator_unlock(rdev);

    return ret;
}

/**
 * regulator_get_mode - get regulator operating mode
 * @regulator: regulator source
 *
 * Get the current regulator operating mode.
 */
unsigned int regulator_get_mode(struct regulator *regulator)
{
    return _regulator_get_mode(regulator->rdev);
}
EXPORT_SYMBOL_GPL(regulator_get_mode);

static int _regulator_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
{
    int ret;

    regulator_lock(rdev);

    /* sanity check */
    if (!rdev->desc->ops->get_error_flags) {
        ret = -EINVAL;
        goto out;
    }

    ret = rdev->desc->ops->get_error_flags(rdev, flags);
out:
    regulator_unlock(rdev);
    return ret;
}

/**
 * regulator_get_error_flags - get regulator error information
 * @regulator: regulator source
 * @flags: pointer to store error flags
 *
 * Get the current regulator error information.
 */
int regulator_get_error_flags(struct regulator *regulator, unsigned int *flags)
{
    return _regulator_get_error_flags(regulator->rdev, flags);
}
EXPORT_SYMBOL_GPL(regulator_get_error_flags);

/**
 * regulator_set_load - set regulator load
 * @regulator: regulator source
 * @uA_load: load current
 *
 * Notifies the regulator core of a new device load. This is then used by
 * DRMS (if enabled by constraints) to set the most efficient regulator
 * operating mode for the new regulator loading.
 *
 * Consumer devices notify their supply regulator of the maximum power
 * they will require (can be taken from device datasheet in the power
 * consumption tables) when they change operational status and hence power
 * state. Examples of operational state changes that can affect power
 * consumption are :-
 *
 *    o Device is opened / closed.
 *    o Device I/O is about to begin or has just finished.
 *    o Device is idling in between work.
 *
 * This information is also exported via sysfs to userspace.
 *
 * DRMS will sum the total requested load on the regulator and change
 * to the most efficient operating mode if platform constraints allow.
 *
 * NOTE: when a regulator consumer requests to have a regulator
 * disabled then any load that consumer requested no longer counts
 * toward the total requested load.  If the regulator is re-enabled
 * then the previously requested load will start counting again.
 *
 * If a regulator is an always-on regulator then an individual consumer's
 * load will still be removed if that consumer is fully disabled.
 *
 * On error a negative errno is returned.
 */
int regulator_set_load(struct regulator *regulator, int uA_load)
{
    struct regulator_dev *rdev = regulator->rdev;
    int old_uA_load;
    int ret = 0;

    regulator_lock(rdev);
    old_uA_load = regulator->uA_load;
    regulator->uA_load = uA_load;
    if (regulator->enable_count && old_uA_load != uA_load) {
        ret = drms_uA_update(rdev);
        if (ret < 0) {
            regulator->uA_load = old_uA_load;
        }
    }
    regulator_unlock(rdev);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_set_load);

/**
 * regulator_allow_bypass - allow the regulator to go into bypass mode
 *
 * @regulator: Regulator to configure
 * @enable: enable or disable bypass mode
 *
 * Allow the regulator to go into bypass mode if all other consumers
 * for the regulator also enable bypass mode and the machine
 * constraints allow this.  Bypass mode means that the regulator is
 * simply passing the input directly to the output with no regulation.
 */
int regulator_allow_bypass(struct regulator *regulator, bool enable)
{
    struct regulator_dev *rdev = regulator->rdev;
    const char *name = rdev_get_name(rdev);
    int ret = 0;

    if (!rdev->desc->ops->set_bypass) {
        return 0;
    }

    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_BYPASS)) {
        return 0;
    }

    regulator_lock(rdev);

    if (enable && !regulator->bypass) {
        rdev->bypass_count++;

        if (rdev->bypass_count == rdev->open_count) {
            trace_regulator_bypass_enable(name);

            ret = rdev->desc->ops->set_bypass(rdev, enable);
            if (ret != 0) {
                rdev->bypass_count--;
            } else {
                trace_regulator_bypass_enable_complete(name);
            }
        }
    } else if (!enable && regulator->bypass) {
        rdev->bypass_count--;

        if (rdev->bypass_count != rdev->open_count) {
            trace_regulator_bypass_disable(name);

            ret = rdev->desc->ops->set_bypass(rdev, enable);
            if (ret != 0) {
                rdev->bypass_count++;
            } else {
                trace_regulator_bypass_disable_complete(name);
            }
        }
    }

    if (ret == 0) {
        regulator->bypass = enable;
    }

    regulator_unlock(rdev);

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_allow_bypass);

/**
 * regulator_register_notifier - register regulator event notifier
 * @regulator: regulator source
 * @nb: notifier block
 *
 * Register notifier block to receive regulator events.
 */
int regulator_register_notifier(struct regulator *regulator, struct notifier_block *nb)
{
    return blocking_notifier_chain_register(&regulator->rdev->notifier, nb);
}
EXPORT_SYMBOL_GPL(regulator_register_notifier);

/**
 * regulator_unregister_notifier - unregister regulator event notifier
 * @regulator: regulator source
 * @nb: notifier block
 *
 * Unregister regulator event notifier block.
 */
int regulator_unregister_notifier(struct regulator *regulator, struct notifier_block *nb)
{
    return blocking_notifier_chain_unregister(&regulator->rdev->notifier, nb);
}
EXPORT_SYMBOL_GPL(regulator_unregister_notifier);

/* notify regulator consumers and downstream regulator consumers.
 * Note mutex must be held by caller.
 */
static int _notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data)
{
    /* call rdev chain first */
    return blocking_notifier_call_chain(&rdev->notifier, event, data);
}

/**
 * regulator_bulk_get - get multiple regulator consumers
 *
 * @dev:           Device to supply
 * @num_consumers: Number of consumers to register
 * @consumers:     Configuration of consumers; clients are stored here.
 *
 * @return 0 on success, an errno on failure.
 *
 * This helper function allows drivers to get several regulator
 * consumers in one operation.  If any of the regulators cannot be
 * acquired then any regulators that were allocated will be freed
 * before returning to the caller.
 */
int regulator_bulk_get(struct device *dev, int num_consumers, struct regulator_bulk_data *consumers)
{
    int i;
    int ret;

    for (i = 0; i < num_consumers; i++) {
        consumers[i].consumer = NULL;
    }

    for (i = 0; i < num_consumers; i++) {
        consumers[i].consumer = regulator_get(dev, consumers[i].supply);
        if (IS_ERR(consumers[i].consumer)) {
            ret = PTR_ERR(consumers[i].consumer);
            consumers[i].consumer = NULL;
            goto err;
        }
    }

    return 0;

err:
    if (ret != -EPROBE_DEFER) {
        dev_err(dev, "Failed to get supply '%s': %pe\n", consumers[i].supply, ERR_PTR(ret));
    } else {
        dev_dbg(dev, "Failed to get supply '%s', deferring\n", consumers[i].supply);
    }

    while (--i >= 0) {
        regulator_put(consumers[i].consumer);
    }

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_get);

static void regulator_bulk_enable_async(void *data, async_cookie_t cookie)
{
    struct regulator_bulk_data *bulk = data;

    bulk->ret = regulator_enable(bulk->consumer);
}

/**
 * regulator_bulk_enable - enable multiple regulator consumers
 *
 * @num_consumers: Number of consumers
 * @consumers:     Consumer data; clients are stored here.
 * @return         0 on success, an errno on failure
 *
 * This convenience API allows consumers to enable multiple regulator
 * clients in a single API call.  If any consumers cannot be enabled
 * then any others that were enabled will be disabled again prior to
 * return.
 */
int regulator_bulk_enable(int num_consumers, struct regulator_bulk_data *consumers)
{
    ASYNC_DOMAIN_EXCLUSIVE(async_domain);
    int i;
    int ret = 0;

    for (i = 0; i < num_consumers; i++) {
        async_schedule_domain(regulator_bulk_enable_async, &consumers[i], &async_domain);
    }

    async_synchronize_full_domain(&async_domain);

    /* If any consumer failed we need to unwind any that succeeded */
    for (i = 0; i < num_consumers; i++) {
        if (consumers[i].ret != 0) {
            ret = consumers[i].ret;
            goto err;
        }
    }

    return 0;

err:
    for (i = 0; i < num_consumers; i++) {
        if (consumers[i].ret < 0) {
            pr_err("Failed to enable %s: %pe\n", consumers[i].supply, ERR_PTR(consumers[i].ret));
        } else {
            regulator_disable(consumers[i].consumer);
        }
    }

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_enable);

/**
 * regulator_bulk_disable - disable multiple regulator consumers
 *
 * @num_consumers: Number of consumers
 * @consumers:     Consumer data; clients are stored here.
 * @return         0 on success, an errno on failure
 *
 * This convenience API allows consumers to disable multiple regulator
 * clients in a single API call.  If any consumers cannot be disabled
 * then any others that were disabled will be enabled again prior to
 * return.
 */
int regulator_bulk_disable(int num_consumers, struct regulator_bulk_data *consumers)
{
    int i;
    int ret, r;

    for (i = num_consumers - 1; i >= 0; --i) {
        ret = regulator_disable(consumers[i].consumer);
        if (ret != 0) {
            goto err;
        }
    }

    return 0;

err:
    pr_err("Failed to disable %s: %pe\n", consumers[i].supply, ERR_PTR(ret));
    for (++i; i < num_consumers; ++i) {
        r = regulator_enable(consumers[i].consumer);
        if (r != 0) {
            pr_err("Failed to re-enable %s: %pe\n", consumers[i].supply, ERR_PTR(r));
        }
    }

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_disable);

/**
 * regulator_bulk_force_disable - force disable multiple regulator consumers
 *
 * @num_consumers: Number of consumers
 * @consumers:     Consumer data; clients are stored here.
 * @return         0 on success, an errno on failure
 *
 * This convenience API allows consumers to forcibly disable multiple regulator
 * clients in a single API call.
 * NOTE: This should be used for situations when device damage will
 * likely occur if the regulators are not disabled (e.g. over temp).
 * Although regulator_force_disable function call for some consumers can
 * return error numbers, the function is called for all consumers.
 */
int regulator_bulk_force_disable(int num_consumers, struct regulator_bulk_data *consumers)
{
    int i;
    int ret = 0;

    for (i = 0; i < num_consumers; i++) {
        consumers[i].ret = regulator_force_disable(consumers[i].consumer);

        /* Store first error for reporting */
        if (consumers[i].ret && !ret) {
            ret = consumers[i].ret;
        }
    }

    return ret;
}
EXPORT_SYMBOL_GPL(regulator_bulk_force_disable);

/**
 * regulator_bulk_free - free multiple regulator consumers
 *
 * @num_consumers: Number of consumers
 * @consumers:     Consumer data; clients are stored here.
 *
 * This convenience API allows consumers to free multiple regulator
 * clients in a single API call.
 */
void regulator_bulk_free(int num_consumers, struct regulator_bulk_data *consumers)
{
    int i;

    for (i = 0; i < num_consumers; i++) {
        regulator_put(consumers[i].consumer);
        consumers[i].consumer = NULL;
    }
}
EXPORT_SYMBOL_GPL(regulator_bulk_free);

/**
 * regulator_notifier_call_chain - call regulator event notifier
 * @rdev: regulator source
 * @event: notifier block
 * @data: callback-specific data.
 *
 * Called by regulator drivers to notify clients a regulator event has
 * occurred.
 */
int regulator_notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data)
{
    _notifier_call_chain(rdev, event, data);
    return NOTIFY_DONE;
}
EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);

/**
 * regulator_mode_to_status - convert a regulator mode into a status
 *
 * @mode: Mode to convert
 *
 * Convert a regulator mode into a status.
 */
int regulator_mode_to_status(unsigned int mode)
{
    switch (mode) {
        case REGULATOR_MODE_FAST:
            return REGULATOR_STATUS_FAST;
        case REGULATOR_MODE_NORMAL:
            return REGULATOR_STATUS_NORMAL;
        case REGULATOR_MODE_IDLE:
            return REGULATOR_STATUS_IDLE;
        case REGULATOR_MODE_STANDBY:
            return REGULATOR_STATUS_STANDBY;
        default:
            return REGULATOR_STATUS_UNDEFINED;
    }
}
EXPORT_SYMBOL_GPL(regulator_mode_to_status);

static struct attribute *regulator_dev_attrs[] = {&dev_attr_name.attr,
                                                  &dev_attr_num_users.attr,
                                                  &dev_attr_type.attr,
                                                  &dev_attr_microvolts.attr,
                                                  &dev_attr_microamps.attr,
                                                  &dev_attr_opmode.attr,
                                                  &dev_attr_state.attr,
                                                  &dev_attr_status.attr,
                                                  &dev_attr_bypass.attr,
                                                  &dev_attr_requested_microamps.attr,
                                                  &dev_attr_min_microvolts.attr,
                                                  &dev_attr_max_microvolts.attr,
                                                  &dev_attr_min_microamps.attr,
                                                  &dev_attr_max_microamps.attr,
                                                  &dev_attr_suspend_standby_state.attr,
                                                  &dev_attr_suspend_mem_state.attr,
                                                  &dev_attr_suspend_disk_state.attr,
                                                  &dev_attr_suspend_standby_microvolts.attr,
                                                  &dev_attr_suspend_mem_microvolts.attr,
                                                  &dev_attr_suspend_disk_microvolts.attr,
                                                  &dev_attr_suspend_standby_mode.attr,
                                                  &dev_attr_suspend_mem_mode.attr,
                                                  &dev_attr_suspend_disk_mode.attr,
                                                  NULL};

/*
 * To avoid cluttering sysfs (and memory) with useless state, only
 * create attributes that can be meaningfully displayed.
 */
static umode_t regulator_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
{
    struct device *dev = kobj_to_dev(kobj);
    struct regulator_dev *rdev = dev_to_rdev(dev);
    const struct regulator_ops *ops = rdev->desc->ops;
    umode_t mode = attr->mode;

    /* these three are always present */
    if (attr == &dev_attr_name.attr || attr == &dev_attr_num_users.attr || attr == &dev_attr_type.attr) {
        return mode;
    }

    /* some attributes need specific methods to be displayed */
    if (attr == &dev_attr_microvolts.attr) {
        if ((ops->get_voltage && ops->get_voltage(rdev) >= 0) ||
            (ops->get_voltage_sel && ops->get_voltage_sel(rdev) >= 0) ||
            (ops->list_voltage && ops->list_voltage(rdev, 0) >= 0) ||
            (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1)) {
            return mode;
        }
        return 0;
    }

    if (attr == &dev_attr_microamps.attr) {
        return ops->get_current_limit ? mode : 0;
    }

    if (attr == &dev_attr_opmode.attr) {
        return ops->get_mode ? mode : 0;
    }

    if (attr == &dev_attr_state.attr) {
        return (rdev->ena_pin || ops->is_enabled) ? mode : 0;
    }

    if (attr == &dev_attr_status.attr) {
        return ops->get_status ? mode : 0;
    }

    if (attr == &dev_attr_bypass.attr) {
        return ops->get_bypass ? mode : 0;
    }

    /* constraints need specific supporting methods */
    if (attr == &dev_attr_min_microvolts.attr || attr == &dev_attr_max_microvolts.attr) {
        return (ops->set_voltage || ops->set_voltage_sel) ? mode : 0;
    }

    if (attr == &dev_attr_min_microamps.attr || attr == &dev_attr_max_microamps.attr) {
        return ops->set_current_limit ? mode : 0;
    }

    if (attr == &dev_attr_suspend_standby_state.attr || attr == &dev_attr_suspend_mem_state.attr ||
        attr == &dev_attr_suspend_disk_state.attr) {
        return mode;
    }

    if (attr == &dev_attr_suspend_standby_microvolts.attr || attr == &dev_attr_suspend_mem_microvolts.attr ||
        attr == &dev_attr_suspend_disk_microvolts.attr) {
        return ops->set_suspend_voltage ? mode : 0;
    }

    if (attr == &dev_attr_suspend_standby_mode.attr || attr == &dev_attr_suspend_mem_mode.attr ||
        attr == &dev_attr_suspend_disk_mode.attr) {
        return ops->set_suspend_mode ? mode : 0;
    }

    return mode;
}

static const struct attribute_group regulator_dev_group = {
    .attrs = regulator_dev_attrs,
    .is_visible = regulator_attr_is_visible,
};

static const struct attribute_group *regulator_dev_groups[] = {&regulator_dev_group, NULL};

static void regulator_dev_release(struct device *dev)
{
    struct regulator_dev *rdev = dev_get_drvdata(dev);

    kfree(rdev->constraints);
    of_node_put(rdev->dev.of_node);
    kfree(rdev);
}

#ifdef CONFIG_DEBUG_FS

#define MAX_DEBUG_BUF_LEN 50
#define REGULATOR_ALLOW_WRITE_DEBUGFS

#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS

static int reg_debug_enable_set(void *data, u64 val)
{
    struct regulator *regulator = data;
    int ret;

    if (val) {
        ret = regulator_enable(regulator);
        if (ret) {
            rdev_err(regulator->rdev, "enable failed, ret=%d\n", ret);
        }
    } else {
        ret = regulator_disable(regulator);
        if (ret) {
            rdev_err(regulator->rdev, "disable failed, ret=%d\n", ret);
        }
    }

    return ret;
}

static int reg_debug_force_disable_set(void *data, u64 val)
{
    struct regulator *regulator = data;
    int ret = 0;

    if (val > 0) {
        ret = regulator_force_disable(regulator);
        if (ret) {
            rdev_err(regulator->rdev, "force_disable failed, ret=%d\n", ret);
        }
    }

    return ret;
}

static ssize_t reg_debug_voltage_write(struct file *file, const char __user *ubuf, size_t count, loff_t *ppos)
{
    struct regulator *regulator = file->private_data;
    struct regulator_dev *rdev = regulator->rdev;
    struct regulator *reg;

    char buf[MAX_DEBUG_BUF_LEN];
    int ret;
    int min_uV, max_uV = -1;

    if (count < MAX_DEBUG_BUF_LEN) {
        if (copy_from_user(buf, ubuf, count)) {
            return -EFAULT;
        }

        buf[count] = '\0';
        ret = kstrtoint(buf, 10, &min_uV);

        /* Check that target voltage were specified. */
        if (ret || min_uV < 0) {
            rdev_err(regulator->rdev, "incorrect values specified: \"%s\"; should be: \"target_uV\"\n", buf);
            return -EINVAL;
        }

        max_uV = rdev->constraints->max_uV;

        list_for_each_entry(reg, &rdev->consumer_list, list)
        {
            if ((!reg->voltage->min_uV && !reg->voltage->max_uV) || (reg == regulator)) {
                continue;
            }
            reg->voltage->min_uV = min_uV;
            reg->voltage->max_uV = max_uV;
        }

        ret = regulator_set_voltage(regulator, min_uV, max_uV);
        if (ret) {
            rdev_err(regulator->rdev, "set voltage(%d, %d) failed, ret=%d\n", min_uV, max_uV, ret);
            return ret;
        }
    } else {
        rdev_err(regulator->rdev, "voltage request string exceeds maximum buffer size\n");
        return -EINVAL;
    }

    return count;
}

static int reg_debug_mode_set(void *data, u64 val)
{
    struct regulator *regulator = data;
    unsigned int mode = val;
    int ret;

    ret = regulator_set_mode(regulator, mode);
    if (ret) {
        rdev_err(regulator->rdev, "set mode=%u failed, ret=%d\n", mode, ret);
    }

    return ret;
}

static int reg_debug_set_load(void *data, u64 val)
{
    struct regulator *regulator = data;
    int load = val;
    int ret;

    ret = regulator_set_load(regulator, load);
    if (ret) {
        rdev_err(regulator->rdev, "set load=%d failed, ret=%d\n", load, ret);
    }

    return ret;
}

#else
#define reg_debug_enable_set NULL
#define reg_debug_force_disable_set NULL
#define reg_debug_voltage_write NULL
#define reg_debug_mode_set NULL
#define reg_debug_set_load NULL
#endif

static int reg_debug_enable_get(void *data, u64 *val)
{
    struct regulator *regulator = data;

    *val = regulator_is_enabled(regulator);

    return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(reg_enable_fops, reg_debug_enable_get, reg_debug_enable_set, "%llu\n");

DEFINE_DEBUGFS_ATTRIBUTE(reg_force_disable_fops, reg_debug_enable_get, reg_debug_force_disable_set, "%llu\n");

static ssize_t reg_debug_voltage_read(struct file *file, char __user *ubuf, size_t count, loff_t *ppos)
{
    struct regulator *regulator = file->private_data;
    char buf[MAX_DEBUG_BUF_LEN];
    int voltage, ret;

    voltage = regulator_get_voltage(regulator);

    ret = snprintf(buf, MAX_DEBUG_BUF_LEN - 1, "%d\n", voltage);

    return simple_read_from_buffer(ubuf, count, ppos, buf, ret);
}

static int reg_debug_voltage_open(struct inode *inode, struct file *file)
{
    file->private_data = inode->i_private;

    return 0;
}

static const struct file_operations reg_voltage_fops = {
    .write = reg_debug_voltage_write,
    .open = reg_debug_voltage_open,
    .read = reg_debug_voltage_read,
};

static int reg_debug_mode_get(void *data, u64 *val)
{
    struct regulator *regulator = data;
    int mode;

    mode = regulator_get_mode(regulator);
    if (mode < 0) {
        rdev_err(regulator->rdev, "get mode failed, ret=%d\n", mode);
        return mode;
    }

    *val = mode;

    return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(reg_mode_fops, reg_debug_mode_get, reg_debug_mode_set, "%llu\n");

DEFINE_DEBUGFS_ATTRIBUTE(reg_set_load_fops, reg_debug_mode_get, reg_debug_set_load, "%llu\n");

static int reg_debug_consumers_show(struct seq_file *m, void *v)
{
    struct regulator_dev *rdev = m->private;
    struct regulator *reg;
    const char *supply_name;

    regulator_lock(rdev);

    /* Print a header if there are consumers. */
    if (rdev->open_count) {
        seq_printf(m, "%-32s   Min_uV   Max_uV  load_uA\n", "Device-Supply");
    }

    list_for_each_entry(reg, &rdev->consumer_list, list)
    {
        if (reg->supply_name) {
            supply_name = reg->supply_name;
        } else {
            supply_name = "(null)-(null)";
        }

        seq_printf(m, "%-32s %8d %8d %8d\n", supply_name, reg->voltage->min_uV, reg->voltage->max_uV, reg->uA_load);
    }

    regulator_unlock(rdev);

    return 0;
}

static int reg_debug_consumers_open(struct inode *inode, struct file *file)
{
    return single_open(file, reg_debug_consumers_show, inode->i_private);
}

static const struct file_operations reg_consumers_fops = {
    .owner = THIS_MODULE,
    .open = reg_debug_consumers_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static void rdev_deinit_debugfs(struct regulator_dev *rdev)
{
    struct regulator_limit_volt *reg_debug, *n;

    debugfs_remove_recursive(rdev->debugfs);

    list_for_each_entry_safe(reg_debug, n, &regulator_debug_list, list)
    {
        if (reg_debug->reg->rdev == rdev) {
            reg_debug->reg->debugfs = NULL;
            list_del(&reg_debug->list);
            regulator_put(reg_debug->reg);
            kfree(reg_debug);
        }
    }
}

static void rdev_init_debugfs(struct regulator_dev *rdev)
{
    struct device *parent = rdev->dev.parent;
    const char *rname = rdev_get_name(rdev);
    char name[NAME_MAX];
    struct regulator *regulator;
    const struct regulator_ops *ops;
    struct regulator_limit_volt *reg_debug;
    mode_t mode;

    /* Avoid duplicate debugfs directory names */
    if (parent && rname == rdev->desc->name) {
        snprintf(name, sizeof(name), "%s-%s", dev_name(parent), rname);
        rname = name;
    }

    rdev->debugfs = debugfs_create_dir(rname, debugfs_root);
    if (!rdev->debugfs) {
        rdev_warn(rdev, "Failed to create debugfs directory\n");
        return;
    }

    debugfs_create_u32("use_count", CORE_FILE_PROPERTY_B, rdev->debugfs, &rdev->use_count);
    debugfs_create_u32("open_count", CORE_FILE_PROPERTY_B, rdev->debugfs, &rdev->open_count);
    debugfs_create_u32("bypass_count", CORE_FILE_PROPERTY_B, rdev->debugfs, &rdev->bypass_count);
    debugfs_create_file("consumers", CORE_FILE_PROPERTY_B, rdev->debugfs, rdev, &reg_consumers_fops);

    regulator = regulator_get(NULL, rdev_get_name(rdev));
    if (IS_ERR(regulator)) {
        rdev_err(rdev, "regulator get failed, ret=%ld\n", PTR_ERR(regulator));
        return;
    }

    reg_debug = kzalloc(sizeof(*reg_debug), GFP_KERNEL);
    if (reg_debug == NULL) {
        regulator_put(regulator);
        return;
    }
    reg_debug->reg = regulator;
    list_add(&reg_debug->list, &regulator_debug_list);

    ops = rdev->desc->ops;

    mode = CORE_FILE_PROPERTY_B;
#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS
    mode |= CORE_FILE_PROPERTY_A;
#endif
    debugfs_create_file("enable", mode, rdev->debugfs, regulator, &reg_enable_fops);

    mode = 0;
    if (ops->is_enabled) {
        mode |= CORE_FILE_PROPERTY_B;
    }
#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS
    if (ops->disable) {
        mode |= CORE_FILE_PROPERTY_A;
    }
#endif
    if (mode) {
        debugfs_create_file("force_disable", mode, rdev->debugfs, regulator, &reg_force_disable_fops);
    }

    mode = 0;
    if (ops->get_voltage || ops->get_voltage_sel) {
        mode |= CORE_FILE_PROPERTY_B;
    }
#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS
    if (ops->set_voltage || ops->set_voltage_sel) {
        mode |= CORE_FILE_PROPERTY_A;
    }
#endif
    if (mode) {
        debugfs_create_file("voltage", mode, rdev->debugfs, regulator, &reg_voltage_fops);
    }

    mode = 0;
    if (ops->get_mode) {
        mode |= CORE_FILE_PROPERTY_B;
    }
#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS
    if (ops->set_mode) {
        mode |= CORE_FILE_PROPERTY_A;
    }
#endif
    if (mode) {
        debugfs_create_file("mode", mode, rdev->debugfs, regulator, &reg_mode_fops);
    }

    mode = 0;
    if (ops->get_mode) {
        mode |= CORE_FILE_PROPERTY_B;
    }
#ifdef REGULATOR_ALLOW_WRITE_DEBUGFS
    if (ops->set_load || (ops->get_optimum_mode && ops->set_mode)) {
        mode |= CORE_FILE_PROPERTY_A;
    }
#endif
    if (mode) {
        debugfs_create_file("load", mode, rdev->debugfs, regulator, &reg_set_load_fops);
    }
}

#else
static inline void rdev_deinit_debugfs(struct regulator_dev *rdev)
{
}

static inline void rdev_init_debugfs(struct regulator_dev *rdev)
{
}
#endif

static int regulator_register_resolve_supply(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);

    if (regulator_resolve_supply(rdev)) {
        rdev_dbg(rdev, "unable to resolve supply\n");
    }

    return 0;
}

int regulator_coupler_register(struct regulator_coupler *coupler)
{
    mutex_lock(&regulator_list_mutex);
    list_add_tail(&coupler->list, &regulator_coupler_list);
    mutex_unlock(&regulator_list_mutex);

    return 0;
}

static struct regulator_coupler *regulator_find_coupler(struct regulator_dev *rdev)
{
    struct regulator_coupler *coupler;
    int err;

    /*
     * Note that regulators are appended to the list and the generic
     * coupler is registered first, hence it will be attached at last
     * if nobody cared.
     */
    list_for_each_entry_reverse(coupler, &regulator_coupler_list, list)
    {
        err = coupler->attach_regulator(coupler, rdev);
        if (!err) {
            if (!coupler->balance_voltage && rdev->coupling_desc.n_coupled > CORE_TWO) {
                goto err_unsupported;
            }

            return coupler;
        }

        if (err < 0) {
            return ERR_PTR(err);
        }

        if (err == 1) {
            continue;
        }

        break;
    }

    return ERR_PTR(-EINVAL);

err_unsupported:
    if (coupler->detach_regulator) {
        coupler->detach_regulator(coupler, rdev);
    }

    rdev_err(rdev, "Voltage balancing for multiple regulator couples is unimplemented\n");

    return ERR_PTR(-EPERM);
}

static void regulator_resolve_coupling(struct regulator_dev *rdev)
{
    struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
    struct coupling_desc *c_desc = &rdev->coupling_desc;
    int n_coupled = c_desc->n_coupled;
    struct regulator_dev *c_rdev;
    int i;

    for (i = 1; i < n_coupled; i++) {
        /* already resolved */
        if (c_desc->coupled_rdevs[i]) {
            continue;
        }
        c_rdev = of_parse_coupled_regulator(rdev, i - 1);
        if (!c_rdev) {
            continue;
        }
        if (c_rdev->coupling_desc.coupler != coupler) {
            rdev_err(rdev, "coupler mismatch with %s\n", rdev_get_name(c_rdev));
            return;
        }

        c_desc->coupled_rdevs[i] = c_rdev;
        c_desc->n_resolved++;

        regulator_resolve_coupling(c_rdev);
    }
}

static void regulator_remove_coupling(struct regulator_dev *rdev)
{
    struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
    struct coupling_desc *_c_desc, *c_desc = &rdev->coupling_desc;
    struct regulator_dev *_c_rdev, *c_rdev;
    unsigned int _n_coupled, n_coupled;
    int i, k;
    int err;

    n_coupled = c_desc->n_coupled;

    for (i = 1; i < n_coupled; i++) {
        c_rdev = c_desc->coupled_rdevs[i];

        if (!c_rdev) {
            continue;
        }

        regulator_lock(c_rdev);

        _c_desc = &c_rdev->coupling_desc;
        _n_coupled = _c_desc->n_coupled;

        for (k = 1; k < _n_coupled; k++) {
            _c_rdev = _c_desc->coupled_rdevs[k];

            if (_c_rdev == rdev) {
                _c_desc->coupled_rdevs[k] = NULL;
                _c_desc->n_resolved--;
                break;
            }
        }

        regulator_unlock(c_rdev);

        c_desc->coupled_rdevs[i] = NULL;
        c_desc->n_resolved--;
    }

    if (coupler && coupler->detach_regulator) {
        err = coupler->detach_regulator(coupler, rdev);
        if (err) {
            rdev_err(rdev, "failed to detach from coupler: %pe\n", ERR_PTR(err));
        }
    }

    kfree(rdev->coupling_desc.coupled_rdevs);
    rdev->coupling_desc.coupled_rdevs = NULL;
}

static int regulator_init_coupling(struct regulator_dev *rdev)
{
    struct regulator_dev **coupled;
    int err, n_phandles;

    if (!IS_ENABLED(CONFIG_OF)) {
        n_phandles = 0;
    } else {
        n_phandles = of_get_n_coupled(rdev);
    }

    coupled = kcalloc(n_phandles + 1, sizeof(*coupled), GFP_KERNEL);
    if (!coupled) {
        return -ENOMEM;
    }

    rdev->coupling_desc.coupled_rdevs = coupled;

    /*
     * Every regulator should always have coupling descriptor filled with
     * at least pointer to itself.
     */
    rdev->coupling_desc.coupled_rdevs[0] = rdev;
    rdev->coupling_desc.n_coupled = n_phandles + 1;
    rdev->coupling_desc.n_resolved++;

    /* regulator isn't coupled */
    if (n_phandles == 0) {
        return 0;
    }

    if (!of_check_coupling_data(rdev)) {
        return -EPERM;
    }

    mutex_lock(&regulator_list_mutex);
    rdev->coupling_desc.coupler = regulator_find_coupler(rdev);
    mutex_unlock(&regulator_list_mutex);

    if (IS_ERR(rdev->coupling_desc.coupler)) {
        err = PTR_ERR(rdev->coupling_desc.coupler);
        rdev_err(rdev, "failed to get coupler: %pe\n", ERR_PTR(err));
        return err;
    }

    return 0;
}

static int generic_coupler_attach(struct regulator_coupler *coupler, struct regulator_dev *rdev)
{
    if (rdev->coupling_desc.n_coupled > CORE_TWO) {
        rdev_err(rdev, "Voltage balancing for multiple regulator couples is unimplemented\n");
        return -EPERM;
    }

    if (!rdev->constraints->always_on) {
        rdev_err(rdev, "Coupling of a non always-on regulator is unimplemented\n");
        return -ENOTSUPP;
    }

    return 0;
}

static struct regulator_coupler generic_regulator_coupler = {
    .attach_regulator = generic_coupler_attach,
};

/**
 * regulator_register - register regulator
 * @regulator_desc: regulator to register
 * @cfg: runtime configuration for regulator
 *
 * Called by regulator drivers to register a regulator.
 * Returns a valid pointer to struct regulator_dev on success
 * or an ERR_PTR() on error.
 */
struct regulator_dev *regulator_register(const struct regulator_desc *regulator_desc,
                                         const struct regulator_config *cfg)
{
    const struct regulator_init_data *init_data;
    struct regulator_config *config = NULL;
    static atomic_t regulator_no = ATOMIC_INIT(-1);
    struct regulator_dev *rdev;
    bool dangling_cfg_gpiod = false;
    bool dangling_of_gpiod = false;
    struct device *dev;
    int ret, i;

    if (cfg == NULL) {
        return ERR_PTR(-EINVAL);
    }
    if (cfg->ena_gpiod) {
        dangling_cfg_gpiod = true;
    }
    if (regulator_desc == NULL) {
        ret = -EINVAL;
        goto rinse;
    }

    dev = cfg->dev;
    WARN_ON(!dev);

    if (regulator_desc->name == NULL || regulator_desc->ops == NULL) {
        ret = -EINVAL;
        goto rinse;
    }

    if (regulator_desc->type != REGULATOR_VOLTAGE && regulator_desc->type != REGULATOR_CURRENT) {
        ret = -EINVAL;
        goto rinse;
    }

    /* Only one of each should be implemented */
    WARN_ON(regulator_desc->ops->get_voltage && regulator_desc->ops->get_voltage_sel);
    WARN_ON(regulator_desc->ops->set_voltage && regulator_desc->ops->set_voltage_sel);

    /* If we're using selectors we must implement list_voltage. */
    if (regulator_desc->ops->get_voltage_sel && !regulator_desc->ops->list_voltage) {
        ret = -EINVAL;
        goto rinse;
    }
    if (regulator_desc->ops->set_voltage_sel && !regulator_desc->ops->list_voltage) {
        ret = -EINVAL;
        goto rinse;
    }

    rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);
    if (rdev == NULL) {
        ret = -ENOMEM;
        goto rinse;
    }
    device_initialize(&rdev->dev);

    /*
     * Duplicate the config so the driver could override it after
     * parsing init data.
     */
    config = kmemdup(cfg, sizeof(*cfg), GFP_KERNEL);
    if (config == NULL) {
        ret = -ENOMEM;
        goto clean;
    }
    init_data = regulator_of_get_init_data(dev, regulator_desc, config, &rdev->dev.of_node);
    /*
     * Sometimes not all resources are probed already so we need to take
     * that into account. This happens most the time if the ena_gpiod comes
     * from a gpio extender or something else.
     */
    if (PTR_ERR(init_data) == -EPROBE_DEFER) {
        ret = -EPROBE_DEFER;
        goto clean;
    }

    /*
     * We need to keep track of any GPIO descriptor coming from the
     * device tree until we have handled it over to the core. If the
     * config that was passed in to this function DOES NOT contain
     * a descriptor, and the config after this call DOES contain
     * a descriptor, we definitely got one from parsing the device
     * tree.
     */
    if (!cfg->ena_gpiod && config->ena_gpiod) {
        dangling_of_gpiod = true;
    }
    if (!init_data) {
        init_data = config->init_data;
        rdev->dev.of_node = of_node_get(config->of_node);
    }

    ww_mutex_init(&rdev->mutex, &regulator_ww_class);
    rdev->reg_data = config->driver_data;
    rdev->owner = regulator_desc->owner;
    rdev->desc = regulator_desc;
    if (config->regmap) {
        rdev->regmap = config->regmap;
    } else if (dev_get_regmap(dev, NULL)) {
        rdev->regmap = dev_get_regmap(dev, NULL);
    } else if (dev->parent) {
        rdev->regmap = dev_get_regmap(dev->parent, NULL);
    }
    INIT_LIST_HEAD(&rdev->consumer_list);
    INIT_LIST_HEAD(&rdev->list);
    BLOCKING_INIT_NOTIFIER_HEAD(&rdev->notifier);
    INIT_DELAYED_WORK(&rdev->disable_work, regulator_disable_work);

    /* preform any regulator specific init */
    if (init_data && init_data->regulator_init) {
        ret = init_data->regulator_init(rdev->reg_data);
        if (ret < 0) {
            goto clean;
        }
    }

    if (config->ena_gpiod) {
        ret = regulator_ena_gpio_request(rdev, config);
        if (ret != 0) {
            rdev_err(rdev, "Failed to request enable GPIO: %pe\n", ERR_PTR(ret));
            goto clean;
        }
        /* The regulator core took over the GPIO descriptor */
        dangling_cfg_gpiod = false;
        dangling_of_gpiod = false;
    }

    /* register with sysfs */
    rdev->dev.class = &regulator_class;
    rdev->dev.parent = dev;
    dev_set_name(&rdev->dev, "regulator.%lu", (unsigned long)atomic_inc_return(&regulator_no));
    dev_set_drvdata(&rdev->dev, rdev);

    /* set regulator constraints */
    if (init_data) {
        rdev->constraints = kmemdup(&init_data->constraints, sizeof(*rdev->constraints), GFP_KERNEL);
    } else {
        rdev->constraints = kzalloc(sizeof(*rdev->constraints), GFP_KERNEL);
    }
    if (!rdev->constraints) {
        ret = -ENOMEM;
        goto wash;
    }

    if (init_data && init_data->supply_regulator) {
        rdev->supply_name = init_data->supply_regulator;
    } else if (regulator_desc->supply_name) {
        rdev->supply_name = regulator_desc->supply_name;
    }

    ret = set_machine_constraints(rdev);
    if (ret == -EPROBE_DEFER) {
        /* Regulator might be in bypass mode and so needs its supply
         * to set the constraints */
        /* this currently triggers a chicken-and-egg problem
         * when creating -SUPPLY symlink in sysfs to a regulator
         * that is just being created */
        ret = regulator_resolve_supply(rdev);
        if (!ret) {
            ret = set_machine_constraints(rdev);
        } else {
            rdev_dbg(rdev, "unable to resolve supply early: %pe\n", ERR_PTR(ret));
        }
    }
    if (ret < 0) {
        goto wash;
    }

    ret = regulator_init_coupling(rdev);
    if (ret < 0) {
        goto wash;
    }

    /* add consumers devices */
    if (init_data) {
        for (i = 0; i < init_data->num_consumer_supplies; i++) {
            ret = set_consumer_device_supply(rdev, init_data->consumer_supplies[i].dev_name,
                                             init_data->consumer_supplies[i].supply);
            if (ret < 0) {
                dev_err(dev, "Failed to set supply %s\n", init_data->consumer_supplies[i].supply);
                goto unset_supplies;
            }
        }
    }

    if (!rdev->desc->ops->get_voltage && !rdev->desc->ops->list_voltage && !rdev->desc->fixed_uV) {
        rdev->is_switch = true;
    }

    ret = device_add(&rdev->dev);
    if (ret != 0) {
        goto unset_supplies;
    }

    rdev_init_debugfs(rdev);

    /* try to resolve regulators coupling since a new one was registered */
    mutex_lock(&regulator_list_mutex);
    regulator_resolve_coupling(rdev);
    mutex_unlock(&regulator_list_mutex);

    /* try to resolve regulators supply since a new one was registered */
    class_for_each_device(&regulator_class, NULL, NULL, regulator_register_resolve_supply);
    kfree(config);
    return rdev;

unset_supplies:
    mutex_lock(&regulator_list_mutex);
    unset_regulator_supplies(rdev);
    regulator_remove_coupling(rdev);
    mutex_unlock(&regulator_list_mutex);
wash:
    kfree(rdev->coupling_desc.coupled_rdevs);
    mutex_lock(&regulator_list_mutex);
    regulator_ena_gpio_free(rdev);
    mutex_unlock(&regulator_list_mutex);
clean:
    if (dangling_of_gpiod) {
        gpiod_put(config->ena_gpiod);
    }
    kfree(config);
    put_device(&rdev->dev);
rinse:
    if (dangling_cfg_gpiod) {
        gpiod_put(cfg->ena_gpiod);
    }
    return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(regulator_register);

/**
 * regulator_unregister - unregister regulator
 * @rdev: regulator to unregister
 *
 * Called by regulator drivers to unregister a regulator.
 */
void regulator_unregister(struct regulator_dev *rdev)
{
    if (rdev == NULL) {
        return;
    }

    if (rdev->supply) {
        while (rdev->use_count--) {
            regulator_disable(rdev->supply);
        }
        regulator_put(rdev->supply);
    }

    flush_work(&rdev->disable_work.work);

    mutex_lock(&regulator_list_mutex);

    rdev_deinit_debugfs(rdev);
    WARN_ON(rdev->open_count);
    regulator_remove_coupling(rdev);
    unset_regulator_supplies(rdev);
    list_del(&rdev->list);
    regulator_ena_gpio_free(rdev);
    device_unregister(&rdev->dev);

    mutex_unlock(&regulator_list_mutex);
}
EXPORT_SYMBOL_GPL(regulator_unregister);

#ifdef CONFIG_SUSPEND
/**
 * regulator_suspend - prepare regulators for system wide suspend
 * @dev: ``&struct device`` pointer that is passed to _regulator_suspend()
 *
 * Configure each regulator with it's suspend operating parameters for state.
 */
static int regulator_suspend(struct device *dev)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    suspend_state_t state = pm_suspend_target_state;
    int ret;
    const struct regulator_state *rstate;

    rstate = regulator_get_suspend_state_check(rdev, state);
    if (!rstate) {
        return 0;
    }

    regulator_lock(rdev);
    ret = _suspend_set_state(rdev, rstate);
    regulator_unlock(rdev);

    return ret;
}

static int regulator_resume(struct device *dev)
{
    suspend_state_t state = pm_suspend_target_state;
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct regulator_state *rstate;
    int ret = 0;

    rstate = regulator_get_suspend_state(rdev, state);
    if (rstate == NULL) {
        return 0;
    }

    /* Avoid grabbing the lock if we don't need to */
    if (!rdev->desc->ops->resume) {
        return 0;
    }

    regulator_lock(rdev);

    if (rstate->enabled == ENABLE_IN_SUSPEND || rstate->enabled == DISABLE_IN_SUSPEND) {
        ret = rdev->desc->ops->resume(rdev);
    }

    regulator_unlock(rdev);

    return ret;
}
#else /* !CONFIG_SUSPEND */

#define regulator_suspend NULL
#define regulator_resume NULL

#endif /* !CONFIG_SUSPEND */

#ifdef CONFIG_PM
static const struct dev_pm_ops __maybe_unused regulator_pm_ops = {
    .suspend = regulator_suspend,
    .resume = regulator_resume,
};
#endif

struct class regulator_class = {
    .name = "regulator",
    .dev_release = regulator_dev_release,
    .dev_groups = regulator_dev_groups,
#ifdef CONFIG_PM
    .pm = &regulator_pm_ops,
#endif
};
/**
 * regulator_has_full_constraints - the system has fully specified constraints
 *
 * Calling this function will cause the regulator API to disable all
 * regulators which have a zero use count and don't have an always_on
 * constraint in a late_initcall.
 *
 * The intention is that this will become the default behaviour in a
 * future kernel release so users are encouraged to use this facility
 * now.
 */
void regulator_has_full_constraints(void)
{
    has_full_constraints = 1;
}
EXPORT_SYMBOL_GPL(regulator_has_full_constraints);

/**
 * rdev_get_drvdata - get rdev regulator driver data
 * @rdev: regulator
 *
 * Get rdev regulator driver private data. This call can be used in the
 * regulator driver context.
 */
void *rdev_get_drvdata(struct regulator_dev *rdev)
{
    return rdev->reg_data;
}
EXPORT_SYMBOL_GPL(rdev_get_drvdata);

/**
 * regulator_get_drvdata - get regulator driver data
 * @regulator: regulator
 *
 * Get regulator driver private data. This call can be used in the consumer
 * driver context when non API regulator specific functions need to be called.
 */
void *regulator_get_drvdata(struct regulator *regulator)
{
    return regulator->rdev->reg_data;
}
EXPORT_SYMBOL_GPL(regulator_get_drvdata);

/**
 * regulator_set_drvdata - set regulator driver data
 * @regulator: regulator
 * @data: data
 */
void regulator_set_drvdata(struct regulator *regulator, void *data)
{
    regulator->rdev->reg_data = data;
}
EXPORT_SYMBOL_GPL(regulator_set_drvdata);

/**
 * regulator_get_id - get regulator ID
 * @rdev: regulator
 */
int rdev_get_id(struct regulator_dev *rdev)
{
    return rdev->desc->id;
}
EXPORT_SYMBOL_GPL(rdev_get_id);

struct device *rdev_get_dev(struct regulator_dev *rdev)
{
    return &rdev->dev;
}
EXPORT_SYMBOL_GPL(rdev_get_dev);

struct regmap *rdev_get_regmap(struct regulator_dev *rdev)
{
    return rdev->regmap;
}
EXPORT_SYMBOL_GPL(rdev_get_regmap);

void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data)
{
    return reg_init_data->driver_data;
}
EXPORT_SYMBOL_GPL(regulator_get_init_drvdata);

#ifdef CONFIG_DEBUG_FS
static int supply_map_show(struct seq_file *sf, void *data)
{
    struct regulator_map *map;

    list_for_each_entry(map, &regulator_map_list, list)
    {
        seq_printf(sf, "%s -> %s.%s\n", rdev_get_name(map->regulator), map->dev_name, map->supply);
    }

    return 0;
}
DEFINE_SHOW_ATTRIBUTE(supply_map);

struct summary_data {
    struct seq_file *s;
    struct regulator_dev *parent;
    int level;
};

static void regulator_summary_show_subtree(struct seq_file *s, struct regulator_dev *rdev, int level);

static int regulator_summary_show_children(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct summary_data *summary_data = data;

    if (rdev->supply && rdev->supply->rdev == summary_data->parent) {
        regulator_summary_show_subtree(summary_data->s, rdev, summary_data->level + 1);
    }

    return 0;
}

static void regulator_summary_show_subtree(struct seq_file *s, struct regulator_dev *rdev, int level)
{
    struct regulation_constraints *c;
    struct regulator *consumer;
    struct summary_data summary_data;
    unsigned int opmode;

    if (!rdev) {
        return;
    }

    opmode = _regulator_get_mode_unlocked(rdev);
    seq_printf(s, "%*s%-*s %3d %4d %6d %7s ", level * CORE_THREE + 1, "", CORE_THIRTY - level * CORE_THREE,
               rdev_get_name(rdev), rdev->use_count, rdev->open_count, rdev->bypass_count,
               regulator_opmode_to_str(opmode));

    seq_printf(s, "%5dmV ", regulator_get_voltage_rdev(rdev) / CORE_ONETHOUSAND);
    seq_printf(s, "%5dmA ", _regulator_get_current_limit_unlocked(rdev) / CORE_ONETHOUSAND);

    c = rdev->constraints;
    if (c) {
        switch (rdev->desc->type) {
            case REGULATOR_VOLTAGE:
                seq_printf(s, "%5dmV %5dmV ", c->min_uV / CORE_ONETHOUSAND, c->max_uV / CORE_ONETHOUSAND);
                break;
            case REGULATOR_CURRENT:
                seq_printf(s, "%5dmA %5dmA ", c->min_uA / CORE_ONETHOUSAND, c->max_uA / CORE_ONETHOUSAND);
                break;
        }
    }

    seq_puts(s, "\n");

    list_for_each_entry(consumer, &rdev->consumer_list, list)
    {
        if (consumer->dev && consumer->dev->class == &regulator_class) {
            continue;
        }

        seq_printf(s, "%*s%-*s ", (level + 1) * CORE_THREE + 1, "", CORE_THIRTY - (level + 1) * CORE_THREE,
                   consumer->supply_name ? consumer->supply_name
                   : consumer->dev       ? dev_name(consumer->dev)
                                         : "deviceless");

        switch (rdev->desc->type) {
            case REGULATOR_VOLTAGE:
                seq_printf(s, "%3d %33dmA%c%5dmV %5dmV", consumer->enable_count, consumer->uA_load / CORE_ONETHOUSAND,
                           consumer->uA_load && !consumer->enable_count ? '*' : ' ',
                           consumer->voltage[PM_SUSPEND_ON].min_uV / CORE_ONETHOUSAND,
                           consumer->voltage[PM_SUSPEND_ON].max_uV / CORE_ONETHOUSAND);
                break;
            case REGULATOR_CURRENT:
                break;
        }

        seq_puts(s, "\n");
    }

    summary_data.s = s;
    summary_data.level = level;
    summary_data.parent = rdev;

    class_for_each_device(&regulator_class, NULL, &summary_data, regulator_summary_show_children);
}

struct summary_lock_data {
    struct ww_acquire_ctx *ww_ctx;
    struct regulator_dev **new_contended_rdev;
    struct regulator_dev **old_contended_rdev;
};

static int regulator_summary_lock_one(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct summary_lock_data *lock_data = data;
    int ret = 0;

    if (rdev != *lock_data->old_contended_rdev) {
        ret = regulator_lock_nested(rdev, lock_data->ww_ctx);
        if (ret == -EDEADLK) {
            *lock_data->new_contended_rdev = rdev;
        } else {
            WARN_ON_ONCE(ret);
        }
    } else {
        *lock_data->old_contended_rdev = NULL;
    }
    return ret;
}

static int regulator_summary_unlock_one(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct summary_lock_data *lock_data = data;

    if (lock_data) {
        if (rdev == *lock_data->new_contended_rdev) {
            return -EDEADLK;
        }
    }

    regulator_unlock(rdev);

    return 0;
}

static int regulator_summary_lock_all(struct ww_acquire_ctx *ww_ctx, struct regulator_dev **new_contended_rdev,
                                      struct regulator_dev **old_contended_rdev)
{
    struct summary_lock_data lock_data;
    int ret;

    lock_data.ww_ctx = ww_ctx;
    lock_data.new_contended_rdev = new_contended_rdev;
    lock_data.old_contended_rdev = old_contended_rdev;

    ret = class_for_each_device(&regulator_class, NULL, &lock_data, regulator_summary_lock_one);
    if (ret) {
        class_for_each_device(&regulator_class, NULL, &lock_data, regulator_summary_unlock_one);
    }

    return ret;
}

static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx)
{
    struct regulator_dev *new_contended_rdev = NULL;
    struct regulator_dev *old_contended_rdev = NULL;
    int err;

    mutex_lock(&regulator_list_mutex);

    ww_acquire_init(ww_ctx, &regulator_ww_class);

    do {
        if (new_contended_rdev) {
            ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
            old_contended_rdev = new_contended_rdev;
            old_contended_rdev->ref_cnt++;
        }

        err = regulator_summary_lock_all(ww_ctx, &new_contended_rdev, &old_contended_rdev);

        if (old_contended_rdev) {
            regulator_unlock(old_contended_rdev);
        }
    } while (err == -EDEADLK);
    ww_acquire_done(ww_ctx);
}

static void regulator_summary_unlock(struct ww_acquire_ctx *ww_ctx)
{
    class_for_each_device(&regulator_class, NULL, NULL, regulator_summary_unlock_one);
    ww_acquire_fini(ww_ctx);

    mutex_unlock(&regulator_list_mutex);
}

static int regulator_summary_show_roots(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct seq_file *s = data;

    if (!rdev->supply) {
        regulator_summary_show_subtree(s, rdev, 0);
    }

    return 0;
}

static int regulator_summary_show(struct seq_file *s, void *data)
{
    struct ww_acquire_ctx ww_ctx;

    seq_puts(s, " regulator                      use open bypass  opmode voltage current     min     max\n");
    seq_puts(s, "---------------------------------------------------------------------------------------\n");

    regulator_summary_lock(&ww_ctx);

    class_for_each_device(&regulator_class, NULL, s, regulator_summary_show_roots);

    regulator_summary_unlock(&ww_ctx);

    return 0;
}
DEFINE_SHOW_ATTRIBUTE(regulator_summary);
#endif /* CONFIG_DEBUG_FS */

static int __init regulator_init(void)
{
    int ret;

    ret = class_register(&regulator_class);

    debugfs_root = debugfs_create_dir("regulator", NULL);
    if (!debugfs_root) {
        pr_warn("regulator: Failed to create debugfs directory\n");
    }

#ifdef CONFIG_DEBUG_FS
    debugfs_create_file("supply_map", CORE_FILE_PROPERTY_B, debugfs_root, NULL, &supply_map_fops);

    debugfs_create_file("regulator_summary", CORE_FILE_PROPERTY_B, debugfs_root, NULL, &regulator_summary_fops);
#endif
    regulator_dummy_init();

    regulator_coupler_register(&generic_regulator_coupler);

    return ret;
}

/* init early to allow our consumers to complete system booting */
#ifdef CONFIG_ROCKCHIP_THUNDER_BOOT
core_initcall_sync(regulator_init);
#else
core_initcall(regulator_init);
#endif

static int regulator_late_cleanup(struct device *dev, void *data)
{
    struct regulator_dev *rdev = dev_to_rdev(dev);
    struct regulation_constraints *c = rdev->constraints;
    int ret;

    if (c && c->always_on) {
        return 0;
    }

    if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) {
        return 0;
    }

    regulator_lock(rdev);

    if (rdev->use_count) {
        goto unlock;
    }

 	/* If reading the status failed, assume that it's off. */
    if (_regulator_is_enabled(rdev) <= 0) {
        goto unlock;
    }

    if (have_full_constraints()) {
        /* We log since this may kill the system if it goes
         * wrong. */
        rdev_info(rdev, "disabling\n");
        ret = _regulator_do_disable(rdev);
        if (ret != 0) {
            rdev_err(rdev, "couldn't disable: %pe\n", ERR_PTR(ret));
        }
    } else {
        /* The intention is that in future we will
         * assume that full constraints are provided
         * so warn even if we aren't going to do
         * anything here.
         */
        rdev_warn(rdev, "incomplete constraints, leaving on\n");
    }

unlock:
    regulator_unlock(rdev);

    return 0;
}

static void regulator_init_complete_work_function(struct work_struct *work)
{
    /*
     * Regulators may had failed to resolve their input supplies
     * when were registered, either because the input supply was
     * not registered yet or because its parent device was not
     * bound yet. So attempt to resolve the input supplies for
     * pending regulators before trying to disable unused ones.
     */
    class_for_each_device(&regulator_class, NULL, NULL, regulator_register_resolve_supply);

    /* If we have a full configuration then disable any regulators
     * we have permission to change the status for and which are
     * not in use or always_on.  This is effectively the default
     * for DT and ACPI as they have full constraints.
     */
    class_for_each_device(&regulator_class, NULL, NULL, regulator_late_cleanup);
}

static DECLARE_DELAYED_WORK(regulator_init_complete_work, regulator_init_complete_work_function);

static int __init regulator_init_complete(void)
{
    /*
     * Since DT doesn't provide an idiomatic mechanism for
     * enabling full constraints and since it's much more natural
     * with DT to provide them just assume that a DT enabled
     * system has full constraints.
     */
    if (of_have_populated_dt()) {
        has_full_constraints = true;
    }

    /*
     * We punt completion for an arbitrary amount of time since
     * systems like distros will load many drivers from userspace
     * so consumers might not always be ready yet, this is
     * particularly an issue with laptops where this might bounce
     * the display off then on.  Ideally we'd get a notification
     * from userspace when this happens but we don't so just wait
     * a bit and hope we waited long enough.  It'd be better if
     * we'd only do this on systems that need it, and a kernel
     * command line option might be useful.
     */
    schedule_delayed_work(&regulator_init_complete_work, msecs_to_jiffies(CORE_THIRTYTHOUSAND));

    return 0;
}
late_initcall_sync(regulator_init_complete);