OpenHarmony-v6.0-Release/s

// SPDX-License-Identifier: GPL-2.0
/*
 *  thermal.c - Generic Thermal Management Sysfs support.
 *
 *  Copyright (C) 2008 Intel Corp
 *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
 *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/kdev_t.h>
#include <linux/idr.h>
#include <linux/thermal.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/of.h>
#include <linux/suspend.h>

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

#include "thermal_core.h"
#include "thermal_hwmon.h"

#define THERMAL_CORE_TWO 2
#define THERMAL_CORE_ONETHOUSAND 1000

static DEFINE_IDA(thermal_tz_ida);
static DEFINE_IDA(thermal_cdev_ida);

static LIST_HEAD(thermal_tz_list);
static LIST_HEAD(thermal_cdev_list);
static LIST_HEAD(thermal_governor_list);

static DEFINE_MUTEX(thermal_list_lock);
static DEFINE_MUTEX(thermal_governor_lock);
static DEFINE_MUTEX(poweroff_lock);

static atomic_t in_suspend;
static bool power_off_triggered;

static struct thermal_governor *def_governor;

/*
 * Governor section: set of functions to handle thermal governors
 *
 * Functions to help in the life cycle of thermal governors within
 * the thermal core and by the thermal governor code.
 */

static struct thermal_governor *__find_governor(const char *name)
{
    struct thermal_governor *pos;

    if (!name || !name[0]) {
        return def_governor;
    }

    list_for_each_entry(pos, &thermal_governor_list,
                        governor_list) if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH)) return pos;

    return NULL;
}

/**
 * bind_previous_governor() - bind the previous governor of the thermal zone
 * @tz:        a valid pointer to a struct thermal_zone_device
 * @failed_gov_name:    the name of the governor that failed to register
 *
 * Register the previous governor of the thermal zone after a new
 * governor has failed to be bound.
 */
static void bind_previous_governor(struct thermal_zone_device *tz, const char *failed_gov_name)
{
    if (tz->governor && tz->governor->bind_to_tz) {
        if (tz->governor->bind_to_tz(tz)) {
            dev_err(&tz->device,
                    "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no "
                    "governor\n",
                    failed_gov_name, tz->governor->name, tz->type);
            tz->governor = NULL;
        }
    }
}

/**
 * thermal_set_governor() - Switch to another governor
 * @tz:        a valid pointer to a struct thermal_zone_device
 * @new_gov:    pointer to the new governor
 *
 * Change the governor of thermal zone @tz.
 *
 * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
 */
static int thermal_set_governor(struct thermal_zone_device *tz, struct thermal_governor *new_gov)
{
    int ret = 0;

    if (tz->governor && tz->governor->unbind_from_tz) {
        tz->governor->unbind_from_tz(tz);
    }

    if (new_gov && new_gov->bind_to_tz) {
        ret = new_gov->bind_to_tz(tz);
        if (ret) {
            bind_previous_governor(tz, new_gov->name);

            return ret;
        }
    }

    tz->governor = new_gov;

    return ret;
}

int thermal_register_governor(struct thermal_governor *governor)
{
    int err;
    const char *name;
    struct thermal_zone_device *pos;

    if (!governor) {
        return -EINVAL;
    }

    mutex_lock(&thermal_governor_lock);

    err = -EBUSY;
    if (!__find_governor(governor->name)) {
        bool match_default;

        err = 0;
        list_add(&governor->governor_list, &thermal_governor_list);
        match_default = !strncmp(governor->name, DEFAULT_THERMAL_GOVERNOR, THERMAL_NAME_LENGTH);
        if (!def_governor && match_default) {
            def_governor = governor;
        }
    }

    mutex_lock(&thermal_list_lock);

    list_for_each_entry(pos, &thermal_tz_list, node)
    {
        /*
         * only thermal zones with specified tz->tzp->governor_name
         * may run with tz->govenor unset
         */
        if (pos->governor) {
            continue;
        }

        name = pos->tzp->governor_name;

        if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
            int ret;

            ret = thermal_set_governor(pos, governor);
            if (ret) {
                dev_err(&pos->device, "Failed to set governor %s for thermal zone %s: %d\n", governor->name, pos->type,
                        ret);
            }
        }
    }

    mutex_unlock(&thermal_list_lock);
    mutex_unlock(&thermal_governor_lock);

    return err;
}

void thermal_unregister_governor(struct thermal_governor *governor)
{
    struct thermal_zone_device *pos;

    if (!governor) {
        return;
    }

    mutex_lock(&thermal_governor_lock);

    if (!__find_governor(governor->name)) {
        goto exit;
    }

    mutex_lock(&thermal_list_lock);

    list_for_each_entry(pos, &thermal_tz_list, node)
    {
        if (!strncasecmp(pos->governor->name, governor->name, THERMAL_NAME_LENGTH)) {
            thermal_set_governor(pos, NULL);
        }
    }

    mutex_unlock(&thermal_list_lock);
    list_del(&governor->governor_list);
exit:
    mutex_unlock(&thermal_governor_lock);
}

int thermal_zone_device_set_policy(struct thermal_zone_device *tz, char *policy)
{
    struct thermal_governor *gov;
    int ret = -EINVAL;

    mutex_lock(&thermal_governor_lock);
    mutex_lock(&tz->lock);

    gov = __find_governor(strim(policy));
    if (!gov) {
        goto exit;
    }

    ret = thermal_set_governor(tz, gov);

exit:
    mutex_unlock(&tz->lock);
    mutex_unlock(&thermal_governor_lock);

    thermal_notify_tz_gov_change(tz->id, policy);

    return ret;
}

int thermal_build_list_of_policies(char *buf)
{
    struct thermal_governor *pos;
    ssize_t count = 0;

    mutex_lock(&thermal_governor_lock);

    list_for_each_entry(pos, &thermal_governor_list, governor_list)
    {
        count += scnprintf(buf + count, PAGE_SIZE - count, "%s ", pos->name);
    }
    count += scnprintf(buf + count, PAGE_SIZE - count, "\n");

    mutex_unlock(&thermal_governor_lock);

    return count;
}

static void __init thermal_unregister_governors(void)
{
    struct thermal_governor **governor;

    for_each_governor_table(governor) thermal_unregister_governor(*governor);
}

static int __init thermal_register_governors(void)
{
    int ret = 0;
    struct thermal_governor **governor;

    for_each_governor_table(governor)
    {
        ret = thermal_register_governor(*governor);
        if (ret) {
            pr_err("Failed to register governor: '%s'", (*governor)->name);
            break;
        }

        pr_info("Registered thermal governor '%s'", (*governor)->name);
    }

    if (ret) {
        struct thermal_governor **gov;

        for_each_governor_table(gov)
        {
            if (gov == governor) {
                break;
            }
            thermal_unregister_governor(*gov);
        }
    }

    return ret;
}

/*
 * Zone update section: main control loop applied to each zone while monitoring
 *
 * in polling mode. The monitoring is done using a workqueue.
 * Same update may be done on a zone by calling thermal_zone_device_update().
 *
 * An update means:
 * - Non-critical trips will invoke the governor responsible for that zone;
 * - Hot trips will produce a notification to userspace;
 * - Critical trip point will cause a system shutdown.
 */
static void thermal_zone_device_set_polling(struct thermal_zone_device *tz, int delay)
{
    if (delay > THERMAL_CORE_ONETHOUSAND) {
        mod_delayed_work(system_freezable_power_efficient_wq, &tz->poll_queue, round_jiffies(msecs_to_jiffies(delay)));
    } else if (delay) {
        mod_delayed_work(system_freezable_power_efficient_wq, &tz->poll_queue, msecs_to_jiffies(delay));
    } else {
        cancel_delayed_work(&tz->poll_queue);
    }
}

static inline bool should_stop_polling(struct thermal_zone_device *tz)
{
    return !thermal_zone_device_is_enabled(tz);
}

static void monitor_thermal_zone(struct thermal_zone_device *tz)
{
    bool stop;

    stop = should_stop_polling(tz);

    mutex_lock(&tz->lock);

    if (!stop && tz->passive) {
        thermal_zone_device_set_polling(tz, tz->passive_delay);
    } else if (!stop && tz->polling_delay) {
        thermal_zone_device_set_polling(tz, tz->polling_delay);
    } else {
        thermal_zone_device_set_polling(tz, 0);
    }

    mutex_unlock(&tz->lock);
}

static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
{
    tz->governor ? tz->governor->throttle(tz, trip) : def_governor->throttle(tz, trip);
}

/**
 * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 * @work: work_struct associated with the emergency poweroff function
 *
 * This function is called in very critical situations to force
 * a kernel poweroff after a configurable timeout value.
 */
static void thermal_emergency_poweroff_func(struct work_struct *work)
{
    /*
     * We have reached here after the emergency thermal shutdown
     * Waiting period has expired. This means orderly_poweroff has
     * not been able to shut off the system for some reason.
     * Try to shut down the system immediately using kernel_power_off
     * if populated
     */
    WARN(1, "Attempting kernel_power_off: Temperature too high\n");
    kernel_power_off();

    /*
     * Worst of the worst case trigger emergency restart
     */
    WARN(1, "Attempting emergency_restart: Temperature too high\n");
    emergency_restart();
}

static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work, thermal_emergency_poweroff_func);

/**
 * thermal_emergency_poweroff - Trigger an emergency system poweroff
 *
 * This may be called from any critical situation to trigger a system shutdown
 * after a known period of time. By default this is not scheduled.
 */
static void thermal_emergency_poweroff(void)
{
    int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
    /*
     * poweroff_delay_ms must be a carefully profiled positive value.
     * Its a must for thermal_emergency_poweroff_work to be scheduled
     */
    if (poweroff_delay_ms <= 0) {
        return;
    }
    schedule_delayed_work(&thermal_emergency_poweroff_work, msecs_to_jiffies(poweroff_delay_ms));
}

static void handle_critical_trips(struct thermal_zone_device *tz, int trip, enum thermal_trip_type trip_type)
{
    int trip_temp;

    tz->ops->get_trip_temp(tz, trip, &trip_temp);

    /* If we have not crossed the trip_temp, we do not care. */
    if (trip_temp <= 0 || tz->temperature < trip_temp) {
        return;
    }

    trace_thermal_zone_trip(tz, trip, trip_type);

    if (tz->ops->notify) {
        tz->ops->notify(tz, trip, trip_type);
    }

    if (trip_type == THERMAL_TRIP_CRITICAL) {
        dev_emerg(&tz->device, "critical temperature reached (%d C), shutting down\n",
                  tz->temperature / THERMAL_CORE_ONETHOUSAND);
        mutex_lock(&poweroff_lock);
        if (!power_off_triggered) {
            /*
             * Queue a backup emergency shutdown in the event of
             * orderly_poweroff failure
             */
            thermal_emergency_poweroff();
            orderly_poweroff(true);
            power_off_triggered = true;
        }
        mutex_unlock(&poweroff_lock);
    }
}

static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
{
    enum thermal_trip_type type;
    int trip_temp, hyst = 0;

    /* Ignore disabled trip points */
    if (test_bit(trip, &tz->trips_disabled)) {
        return;
    }

    tz->ops->get_trip_temp(tz, trip, &trip_temp);
    tz->ops->get_trip_type(tz, trip, &type);
    if (tz->ops->get_trip_hyst) {
        tz->ops->get_trip_hyst(tz, trip, &hyst);
    }

    if (tz->last_temperature != THERMAL_TEMP_INVALID) {
        if (tz->last_temperature < trip_temp && tz->temperature >= trip_temp) {
            thermal_notify_tz_trip_up(tz->id, trip);
        }
        if (tz->last_temperature >= trip_temp && tz->temperature < (trip_temp - hyst)) {
            thermal_notify_tz_trip_down(tz->id, trip);
        }
    }

    if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT) {
        handle_critical_trips(tz, trip, type);
    } else {
        handle_non_critical_trips(tz, trip);
    }
    /*
     * Alright, we handled this trip successfully.
     * So, start monitoring again.
     */
    monitor_thermal_zone(tz);
}

static void update_temperature(struct thermal_zone_device *tz)
{
    int temp, ret;

    ret = thermal_zone_get_temp(tz, &temp);
    if (ret) {
        if (ret != -EAGAIN) {
            dev_warn(&tz->device, "failed to read out thermal zone (%d)\n", ret);
        }
        return;
    }

    mutex_lock(&tz->lock);
    tz->last_temperature = tz->temperature;
    tz->temperature = temp;
    mutex_unlock(&tz->lock);

    trace_thermal_temperature(tz);

    thermal_genl_sampling_temp(tz->id, temp);
}

static void thermal_zone_device_init(struct thermal_zone_device *tz)
{
    struct thermal_instance *pos;
    tz->temperature = THERMAL_TEMP_INVALID;
    tz->prev_low_trip = -INT_MAX;
    tz->prev_high_trip = INT_MAX;
    list_for_each_entry(pos, &tz->thermal_instances, tz_node) pos->initialized = false;
}

static void thermal_zone_device_reset(struct thermal_zone_device *tz)
{
    tz->passive = 0;
    thermal_zone_device_init(tz);
}

static int thermal_zone_device_set_mode(struct thermal_zone_device *tz, enum thermal_device_mode mode)
{
    int ret = 0;

    mutex_lock(&tz->lock);

    /* do nothing if mode isn't changing */
    if (mode == tz->mode) {
        mutex_unlock(&tz->lock);

        return ret;
    }

    if (tz->ops->change_mode) {
        ret = tz->ops->change_mode(tz, mode);
    }

    if (!ret) {
        tz->mode = mode;
    }

    mutex_unlock(&tz->lock);

    thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);

    if (mode == THERMAL_DEVICE_ENABLED) {
        thermal_notify_tz_enable(tz->id);
    } else {
        thermal_notify_tz_disable(tz->id);
    }

    return ret;
}

int thermal_zone_device_enable(struct thermal_zone_device *tz)
{
    return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_enable);

int thermal_zone_device_disable(struct thermal_zone_device *tz)
{
    return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_disable);

int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
{
    enum thermal_device_mode mode;

    mutex_lock(&tz->lock);

    mode = tz->mode;

    mutex_unlock(&tz->lock);

    return mode == THERMAL_DEVICE_ENABLED;
}
EXPORT_SYMBOL_GPL(thermal_zone_device_is_enabled);

void thermal_zone_device_update(struct thermal_zone_device *tz, enum thermal_notify_event event)
{
    int count;

    if (should_stop_polling(tz)) {
        return;
    }

    if (atomic_read(&in_suspend)) {
        return;
    }

    if (!tz->ops->get_temp) {
        return;
    }

    update_temperature(tz);

    thermal_zone_set_trips(tz);

    tz->notify_event = event;

    for (count = 0; count < tz->trips; count++) {
        handle_thermal_trip(tz, count);
    }
}
EXPORT_SYMBOL_GPL(thermal_zone_device_update);

/**
 * thermal_notify_framework - Sensor drivers use this API to notify framework
 * @tz:        thermal zone device
 * @trip:    indicates which trip point has been crossed
 *
 * This function handles the trip events from sensor drivers. It starts
 * throttling the cooling devices according to the policy configured.
 * For CRITICAL and HOT trip points, this notifies the respective drivers,
 * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 * The throttling policy is based on the configured platform data; if no
 * platform data is provided, this uses the step_wise throttling policy.
 */
void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
{
    handle_thermal_trip(tz, trip);
}
EXPORT_SYMBOL_GPL(thermal_notify_framework);

static void thermal_zone_device_check(struct work_struct *work)
{
    struct thermal_zone_device *tz = container_of(work, struct thermal_zone_device, poll_queue.work);
    thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
}

/*
 * Power actor section: interface to power actors to estimate power
 *
 * Set of functions used to interact to cooling devices that know
 * how to estimate their devices power consumption.
 */

/**
 * power_actor_get_max_power() - get the maximum power that a cdev can consume
 * @cdev:    pointer to &thermal_cooling_device
 * @max_power:    pointer in which to store the maximum power
 *
 * Calculate the maximum power consumption in milliwats that the
 * cooling device can currently consume and store it in @max_power.
 *
 * Return: 0 on success, -EINVAL if @cdev doesn't support the
 * power_actor API or -E* on other error.
 */
int power_actor_get_max_power(struct thermal_cooling_device *cdev, u32 *max_power)
{
    if (!cdev_is_power_actor(cdev)) {
        return -EINVAL;
    }

    return cdev->ops->state2power(cdev, 0, max_power);
}

/**
 * power_actor_get_min_power() - get the mainimum power that a cdev can consume
 * @cdev:    pointer to &thermal_cooling_device
 * @min_power:    pointer in which to store the minimum power
 *
 * Calculate the minimum power consumption in milliwatts that the
 * cooling device can currently consume and store it in @min_power.
 *
 * Return: 0 on success, -EINVAL if @cdev doesn't support the
 * power_actor API or -E* on other error.
 */
int power_actor_get_min_power(struct thermal_cooling_device *cdev, u32 *min_power)
{
    unsigned long max_state;
    int ret;

    if (!cdev_is_power_actor(cdev)) {
        return -EINVAL;
    }

    ret = cdev->ops->get_max_state(cdev, &max_state);
    if (ret) {
        return ret;
    }

    return cdev->ops->state2power(cdev, max_state, min_power);
}

/**
 * power_actor_set_power() - limit the maximum power a cooling device consumes
 * @cdev:    pointer to &thermal_cooling_device
 * @instance:    thermal instance to update
 * @power:    the power in milliwatts
 *
 * Set the cooling device to consume at most @power milliwatts. The limit is
 * expected to be a cap at the maximum power consumption.
 *
 * Return: 0 on success, -EINVAL if the cooling device does not
 * implement the power actor API or -E* for other failures.
 */
int power_actor_set_power(struct thermal_cooling_device *cdev, struct thermal_instance *instance, u32 power)
{
    unsigned long state;
    int ret;

    if (!cdev_is_power_actor(cdev)) {
        return -EINVAL;
    }

    ret = cdev->ops->power2state(cdev, power, &state);
    if (ret) {
        return ret;
    }

    instance->target = state;
    mutex_lock(&cdev->lock);
    cdev->updated = false;
    mutex_unlock(&cdev->lock);
    thermal_cdev_update(cdev);

    return 0;
}

void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz, const char *cdev_type, size_t size)
{
    struct thermal_cooling_device *cdev = NULL;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(cdev, &thermal_cdev_list, node)
    {
        /* skip non matching cdevs */
        if (strncmp(cdev_type, cdev->type, size)) {
            continue;
        }

        /* re binding the exception matching the type pattern */
        thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev, THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
                                         THERMAL_WEIGHT_DEFAULT);
    }
    mutex_unlock(&thermal_list_lock);
}

int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *), void *data)
{
    struct thermal_governor *gov;
    int ret = 0;

    mutex_lock(&thermal_governor_lock);
    list_for_each_entry(gov, &thermal_governor_list, governor_list)
    {
        ret = cb(gov, data);
        if (ret) {
            break;
        }
    }
    mutex_unlock(&thermal_governor_lock);

    return ret;
}

int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *, void *), void *data)
{
    struct thermal_cooling_device *cdev;
    int ret = 0;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(cdev, &thermal_cdev_list, node)
    {
        ret = cb(cdev, data);
        if (ret) {
            break;
        }
    }
    mutex_unlock(&thermal_list_lock);

    return ret;
}

int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *), void *data)
{
    struct thermal_zone_device *tz;
    int ret = 0;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(tz, &thermal_tz_list, node)
    {
        ret = cb(tz, data);
        if (ret) {
            break;
        }
    }
    mutex_unlock(&thermal_list_lock);

    return ret;
}

struct thermal_zone_device *thermal_zone_get_by_id(int id)
{
    struct thermal_zone_device *tz, *match = NULL;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(tz, &thermal_tz_list, node)
    {
        if (tz->id == id) {
            match = tz;
            break;
        }
    }
    mutex_unlock(&thermal_list_lock);

    return match;
}

void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz, const char *cdev_type, size_t size)
{
    struct thermal_cooling_device *cdev = NULL;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(cdev, &thermal_cdev_list, node)
    {
        /* skip non matching cdevs */
        if (strncmp(cdev_type, cdev->type, size)) {
            continue;
        }
        /* unbinding the exception matching the type pattern */
        thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev);
    }
    mutex_unlock(&thermal_list_lock);
}

/*
 * Device management section: cooling devices, zones devices, and binding
 *
 * Set of functions provided by the thermal core for:
 * - cooling devices lifecycle: registration, unregistration,
 *                binding, and unbinding.
 * - thermal zone devices lifecycle: registration, unregistration,
 *                     binding, and unbinding.
 */

/**
 * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 * @tz:        pointer to struct thermal_zone_device
 * @trip:    indicates which trip point the cooling devices is
 *        associated with in this thermal zone.
 * @cdev:    pointer to struct thermal_cooling_device
 * @upper:    the Maximum cooling state for this trip point.
 *        THERMAL_NO_LIMIT means no upper limit,
 *        and the cooling device can be in max_state.
 * @lower:    the Minimum cooling state can be used for this trip point.
 *        THERMAL_NO_LIMIT means no lower limit,
 *        and the cooling device can be in cooling state 0.
 * @weight:    The weight of the cooling device to be bound to the
 *        thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 *        default value
 *
 * This interface function bind a thermal cooling device to the certain trip
 * point of a thermal zone device.
 * This function is usually called in the thermal zone device .bind callback.
 *
 * Return: 0 on success, the proper error value otherwise.
 */
int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, int trip,
    struct thermal_cooling_device *cdev, unsigned long upper, unsigned long lower, unsigned int weight)
{
    struct thermal_instance *dev, *pos;
    struct thermal_zone_device *pos1;
    struct thermal_cooling_device *pos2;
    unsigned long max_state;
    int result, ret;

    if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE)) {
        return -EINVAL;
    }

    list_for_each_entry(pos1, &thermal_tz_list, node) {
        if (pos1 == tz) {
            break;
        }
    }
    list_for_each_entry(pos2, &thermal_cdev_list, node) {
        if (pos2 == cdev) {
            break;
        }
    }

    if (tz != pos1 || cdev != pos2) {
        return -EINVAL;
    }

    ret = cdev->ops->get_max_state(cdev, &max_state);
    if (ret) {
        return ret;
    }

    /* lower default 0, upper default max_state */
    lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
    upper = upper == THERMAL_NO_LIMIT ? max_state : upper;

    if (lower > upper || upper > max_state) {
        return -EINVAL;
    }

    dev = kzalloc(sizeof(*dev), GFP_KERNEL);
    if (!dev) {
        return -ENOMEM;
    }
    dev->tz = tz;
    dev->cdev = cdev;
    dev->trip = trip;
    dev->upper = upper;
    dev->lower = lower;
    dev->target = THERMAL_NO_TARGET;
    dev->weight = weight;

    result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
    if (result < 0) {
        goto free_mem;
    }

    dev->id = result;
    ret = sprintf(dev->name, "cdev%d", dev->id);
    result = sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
    if (result) {
        goto release_ida;
    }

    ret = sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
    sysfs_attr_init(&dev->attr.attr);
    dev->attr.attr.name = dev->attr_name;
    dev->attr.attr.mode = 0444;
    dev->attr.show = trip_point_show;
    result = device_create_file(&tz->device, &dev->attr);
    if (result) {
        goto remove_symbol_link;
    }

    ret = sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
    sysfs_attr_init(&dev->weight_attr.attr);
    dev->weight_attr.attr.name = dev->weight_attr_name;
    dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
    dev->weight_attr.show = weight_show;
    dev->weight_attr.store = weight_store;
    result = device_create_file(&tz->device, &dev->weight_attr);
    if (result) {
        goto remove_trip_file;
    }

    mutex_lock(&tz->lock);
    mutex_lock(&cdev->lock);
    list_for_each_entry(pos, &tz->thermal_instances,
                        tz_node) if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
        result = -EEXIST;
        break;
    }
    if (!result) {
        list_add_tail(&dev->tz_node, &tz->thermal_instances);
        list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
        atomic_set(&tz->need_update, 1);
    }
    mutex_unlock(&cdev->lock);
    mutex_unlock(&tz->lock);

    if (!result) {
        return 0;
    }

    device_remove_file(&tz->device, &dev->weight_attr);
remove_trip_file:
    device_remove_file(&tz->device, &dev->attr);
remove_symbol_link:
    sysfs_remove_link(&tz->device.kobj, dev->name);
release_ida:
    ida_simple_remove(&tz->ida, dev->id);
free_mem:
    kfree(dev);
    return result;
}
EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);

/**
 * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 *                      thermal zone.
 * @tz:        pointer to a struct thermal_zone_device.
 * @trip:    indicates which trip point the cooling devices is
 *        associated with in this thermal zone.
 * @cdev:    pointer to a struct thermal_cooling_device.
 *
 * This interface function unbind a thermal cooling device from the certain
 * trip point of a thermal zone device.
 * This function is usually called in the thermal zone device .unbind callback.
 *
 * Return: 0 on success, the proper error value otherwise.
 */
int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, int trip, struct thermal_cooling_device *cdev)
{
    struct thermal_instance *pos, *next;

    mutex_lock(&tz->lock);
    mutex_lock(&cdev->lock);
    list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node)
    {
        if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
            list_del(&pos->tz_node);
            list_del(&pos->cdev_node);
            mutex_unlock(&cdev->lock);
            mutex_unlock(&tz->lock);
            goto unbind;
        }
    }
    mutex_unlock(&cdev->lock);
    mutex_unlock(&tz->lock);

    return -ENODEV;

unbind:
    device_remove_file(&tz->device, &pos->weight_attr);
    device_remove_file(&tz->device, &pos->attr);
    sysfs_remove_link(&tz->device.kobj, pos->name);
    ida_simple_remove(&tz->ida, pos->id);
    kfree(pos);
    return 0;
}
EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);

static void thermal_release(struct device *dev)
{
    struct thermal_zone_device *tz;
    struct thermal_cooling_device *cdev;

    if (!strncmp(dev_name(dev), "thermal_zone", sizeof("thermal_zone") - 1)) {
        tz = to_thermal_zone(dev);
        thermal_zone_destroy_device_groups(tz);
        kfree(tz);
    } else if (!strncmp(dev_name(dev), "cooling_device", sizeof("cooling_device") - 1)) {
        cdev = to_cooling_device(dev);
        kfree(cdev);
    }
}

static struct class thermal_class = {
    .name = "thermal",
    .dev_release = thermal_release,
};

static inline void print_bind_err_msg(struct thermal_zone_device *tz, struct thermal_cooling_device *cdev, int ret)
{
    dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n", tz->type, cdev->type, ret);
}

static void __bind(struct thermal_zone_device *tz, int mask, struct thermal_cooling_device *cdev, unsigned long *limits,
                   unsigned int weight)
{
    int i, ret;

    for (i = 0; i < tz->trips; i++) {
        if (mask & (1 << i)) {
            unsigned long upper, lower;

            upper = THERMAL_NO_LIMIT;
            lower = THERMAL_NO_LIMIT;
            if (limits) {
                lower = limits[i * THERMAL_CORE_TWO];
                upper = limits[i * THERMAL_CORE_TWO + 1];
            }
            ret = thermal_zone_bind_cooling_device(tz, i, cdev, upper, lower, weight);
            if (ret) {
                print_bind_err_msg(tz, cdev, ret);
            }
        }
    }
}

static void bind_cdev(struct thermal_cooling_device *cdev)
{
    int i, ret;
    const struct thermal_zone_params *tzp;
    struct thermal_zone_device *pos = NULL;

    mutex_lock(&thermal_list_lock);

    list_for_each_entry(pos, &thermal_tz_list, node)
    {
        if (!pos->tzp && !pos->ops->bind) {
            continue;
        }

        if (pos->ops->bind) {
            ret = pos->ops->bind(pos, cdev);
            if (ret) {
                print_bind_err_msg(pos, cdev, ret);
            }
            continue;
        }

        tzp = pos->tzp;
        if (!tzp || !tzp->tbp) {
            continue;
        }

        for (i = 0; i < tzp->num_tbps; i++) {
            if (tzp->tbp[i].cdev || !tzp->tbp[i].match) {
                continue;
            }
            if (tzp->tbp[i].match(pos, cdev)) {
                continue;
            }
            tzp->tbp[i].cdev = cdev;
            __bind(pos, tzp->tbp[i].trip_mask, cdev, tzp->tbp[i].binding_limits, tzp->tbp[i].weight);
        }
    }

    mutex_unlock(&thermal_list_lock);
}

/**
 * __thermal_cooling_device_register() - register a new thermal cooling device
 * @np:        a pointer to a device tree node.
 * @type:    the thermal cooling device type.
 * @devdata:    device private data.
 * @ops:        standard thermal cooling devices callbacks.
 *
 * This interface function adds a new thermal cooling device (fan/processor/...)
 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 * to all the thermal zone devices registered at the same time.
 * It also gives the opportunity to link the cooling device to a device tree
 * node, so that it can be bound to a thermal zone created out of device tree.
 *
 * Return: a pointer to the created struct thermal_cooling_device or an
 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 */
static struct thermal_cooling_device *__thermal_cooling_device_register(
    struct device_node *np, const char *type, void *devdata, const struct thermal_cooling_device_ops *ops)
{
    struct thermal_cooling_device *cdev;
    struct thermal_zone_device *pos = NULL;
    int id, ret;

    if (!ops || !ops->get_max_state || !ops->get_cur_state || !ops->set_cur_state) {
        return ERR_PTR(-EINVAL);
    }

    cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
    if (!cdev) {
        return ERR_PTR(-ENOMEM);
    }

    ret = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
    if (ret < 0) {
        goto out_kfree_cdev;
    }
    cdev->id = ret;
    id = ret;

    cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
    if (!cdev->type) {
        ret = -ENOMEM;
        goto out_ida_remove;
    }

    mutex_init(&cdev->lock);
    INIT_LIST_HEAD(&cdev->thermal_instances);
    cdev->np = np;
    cdev->ops = ops;
    cdev->updated = false;
    cdev->device.class = &thermal_class;
    cdev->devdata = devdata;
    thermal_cooling_device_setup_sysfs(cdev);
    dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
    ret = device_register(&cdev->device);
    if (ret) {
        goto out_kfree_type;
    }

    mutex_lock(&thermal_list_lock);
    list_add(&cdev->node, &thermal_cdev_list);
    mutex_unlock(&thermal_list_lock);
    bind_cdev(cdev);

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(pos, &thermal_tz_list, node) if (atomic_cmpxchg(&pos->need_update, 1, 0))
        thermal_zone_device_update(pos, THERMAL_EVENT_UNSPECIFIED);
    mutex_unlock(&thermal_list_lock);
    return cdev;

out_kfree_type:
    thermal_cooling_device_destroy_sysfs(cdev);
    kfree(cdev->type);
    put_device(&cdev->device);
    cdev = NULL;
out_ida_remove:
    ida_simple_remove(&thermal_cdev_ida, id);
out_kfree_cdev:
    kfree(cdev);
    return ERR_PTR(ret);
}

/**
 * thermal_cooling_device_register() - register a new thermal cooling device
 * @type:    the thermal cooling device type.
 * @devdata:    device private data.
 * @ops:        standard thermal cooling devices callbacks.
 *
 * This interface function adds a new thermal cooling device (fan/processor/...)
 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 * to all the thermal zone devices registered at the same time.
 *
 * Return: a pointer to the created struct thermal_cooling_device or an
 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 */
struct thermal_cooling_device *thermal_cooling_device_register(const char *type, void *devdata,
                                                               const struct thermal_cooling_device_ops *ops)
{
    return __thermal_cooling_device_register(NULL, type, devdata, ops);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_register);

/**
 * thermal_of_cooling_device_register() - register an OF thermal cooling device
 * @np:        a pointer to a device tree node.
 * @type:    the thermal cooling device type.
 * @devdata:    device private data.
 * @ops:        standard thermal cooling devices callbacks.
 *
 * This function will register a cooling device with device tree node reference.
 * This interface function adds a new thermal cooling device (fan/processor/...)
 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 * to all the thermal zone devices registered at the same time.
 *
 * Return: a pointer to the created struct thermal_cooling_device or an
 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 */
struct thermal_cooling_device *thermal_of_cooling_device_register(struct device_node *np, const char *type,
                                                                  void *devdata,
                                                                  const struct thermal_cooling_device_ops *ops)
{
    return __thermal_cooling_device_register(np, type, devdata, ops);
}
EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);

static void thermal_cooling_device_release(struct device *dev, void *res)
{
    thermal_cooling_device_unregister(*(struct thermal_cooling_device **)res);
}

/**
 * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
 *                           device
 * @dev:    a valid struct device pointer of a sensor device.
 * @np:        a pointer to a device tree node.
 * @type:    the thermal cooling device type.
 * @devdata:    device private data.
 * @ops:    standard thermal cooling devices callbacks.
 *
 * This function will register a cooling device with device tree node reference.
 * This interface function adds a new thermal cooling device (fan/processor/...)
 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 * to all the thermal zone devices registered at the same time.
 *
 * Return: a pointer to the created struct thermal_cooling_device or an
 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 */
struct thermal_cooling_device *devm_thermal_of_cooling_device_register(struct device *dev, struct device_node *np,
                                                                       char *type, void *devdata,
                                                                       const struct thermal_cooling_device_ops *ops)
{
    struct thermal_cooling_device **ptr, *tcd;

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

    tcd = __thermal_cooling_device_register(np, type, devdata, ops);
    if (IS_ERR(tcd)) {
        devres_free(ptr);
        return tcd;
    }

    *ptr = tcd;
    devres_add(dev, ptr);

    return tcd;
}
EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);

static void __unbind(struct thermal_zone_device *tz, int mask, struct thermal_cooling_device *cdev)
{
    int i;

    for (i = 0; i < tz->trips; i++) {
        if (mask & (1 << i)) {
            thermal_zone_unbind_cooling_device(tz, i, cdev);
        }
    }
}

/**
 * thermal_cooling_device_unregister - removes a thermal cooling device
 * @cdev:    the thermal cooling device to remove.
 *
 * thermal_cooling_device_unregister() must be called when a registered
 * thermal cooling device is no longer needed.
 */
void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
{
    int i;
    const struct thermal_zone_params *tzp;
    struct thermal_zone_device *tz;
    struct thermal_cooling_device *pos = NULL;

    if (!cdev) {
        return;
    }

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(pos, &thermal_cdev_list, node) if (pos == cdev) break;
    if (pos != cdev) {
        /* thermal cooling device not found */
        mutex_unlock(&thermal_list_lock);
        return;
    }
    list_del(&cdev->node);

    /* Unbind all thermal zones associated with 'this' cdev */
    list_for_each_entry(tz, &thermal_tz_list, node)
    {
        if (tz->ops->unbind) {
            tz->ops->unbind(tz, cdev);
            continue;
        }

        if (!tz->tzp || !tz->tzp->tbp) {
            continue;
        }

        tzp = tz->tzp;
        for (i = 0; i < tzp->num_tbps; i++) {
            if (tzp->tbp[i].cdev == cdev) {
                __unbind(tz, tzp->tbp[i].trip_mask, cdev);
                tzp->tbp[i].cdev = NULL;
            }
        }
    }

    mutex_unlock(&thermal_list_lock);

    ida_simple_remove(&thermal_cdev_ida, cdev->id);
    device_del(&cdev->device);
    thermal_cooling_device_destroy_sysfs(cdev);
    kfree(cdev->type);
    put_device(&cdev->device);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);

static void bind_tz(struct thermal_zone_device *tz)
{
    int i, ret;
    struct thermal_cooling_device *pos = NULL;
    const struct thermal_zone_params *tzp = tz->tzp;

    if (!tzp && !tz->ops->bind) {
        return;
    }

    mutex_lock(&thermal_list_lock);

    /* If there is ops->bind, try to use ops->bind */
    if (tz->ops->bind) {
        list_for_each_entry(pos, &thermal_cdev_list, node)
        {
            ret = tz->ops->bind(tz, pos);
            if (ret) {
                print_bind_err_msg(tz, pos, ret);
            }
        }
        goto exit;
    }

    if (!tzp || !tzp->tbp) {
        goto exit;
    }

    list_for_each_entry(pos, &thermal_cdev_list, node)
    {
        for (i = 0; i < tzp->num_tbps; i++) {
            if (tzp->tbp[i].cdev || !tzp->tbp[i].match) {
                continue;
            }
            if (tzp->tbp[i].match(tz, pos)) {
                continue;
            }
            tzp->tbp[i].cdev = pos;
            __bind(tz, tzp->tbp[i].trip_mask, pos, tzp->tbp[i].binding_limits, tzp->tbp[i].weight);
        }
    }
exit:
    mutex_unlock(&thermal_list_lock);
}

/**
 * thermal_zone_device_register() - register a new thermal zone device
 * @type:    the thermal zone device type
 * @trips:    the number of trip points the thermal zone support
 * @mask:    a bit string indicating the writeablility of trip points
 * @devdata:    private device data
 * @ops:    standard thermal zone device callbacks
 * @tzp:    thermal zone platform parameters
 * @passive_delay: number of milliseconds to wait between polls when
 *           performing passive cooling
 * @polling_delay: number of milliseconds to wait between polls when checking
 *           whether trip points have been crossed (0 for interrupt
 *           driven systems)
 *
 * This interface function adds a new thermal zone device (sensor) to
 * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
 * thermal cooling devices registered at the same time.
 * thermal_zone_device_unregister() must be called when the device is no
 * longer needed. The passive cooling depends on the .get_trend() return value.
 *
 * Return: a pointer to the created struct thermal_zone_device or an
 * in case of error, an ERR_PTR. Caller must check return value with
 * IS_ERR*() helpers.
 */
struct thermal_zone_device *thermal_zone_device_register(const char *type, int trips, int mask, void *devdata,
                                                         struct thermal_zone_device_ops *ops,
                                                         struct thermal_zone_params *tzp, int passive_delay,
                                                         int polling_delay)
{
    struct thermal_zone_device *tz;
    enum thermal_trip_type trip_type;
    int trip_temp;
    int id;
    int result;
    int count;
    struct thermal_governor *governor;

    if (!type || strlen(type) == 0) {
        pr_err("Error: No thermal zone type defined\n");
        return ERR_PTR(-EINVAL);
    }

    if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
        pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n", type, THERMAL_NAME_LENGTH);
        return ERR_PTR(-EINVAL);
    }

    if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
        pr_err("Error: Incorrect number of thermal trips\n");
        return ERR_PTR(-EINVAL);
    }

    if (!ops) {
        pr_err("Error: Thermal zone device ops not defined\n");
        return ERR_PTR(-EINVAL);
    }

    if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp)) {
        return ERR_PTR(-EINVAL);
    }

    tz = kzalloc(sizeof(*tz), GFP_KERNEL);
    if (!tz) {
        return ERR_PTR(-ENOMEM);
    }

    INIT_LIST_HEAD(&tz->thermal_instances);
    ida_init(&tz->ida);
    mutex_init(&tz->lock);
    id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
    if (id < 0) {
        result = id;
        goto free_tz;
    }

    tz->id = id;
    strlcpy(tz->type, type, sizeof(tz->type));
    tz->ops = ops;
    tz->tzp = tzp;
    tz->device.class = &thermal_class;
    tz->devdata = devdata;
    tz->trips = trips;
    tz->passive_delay = passive_delay;
    tz->polling_delay = polling_delay;

    /* sys I/F */
    /* Add nodes that are always present via .groups */
    result = thermal_zone_create_device_groups(tz, mask);
    if (result) {
        goto remove_id;
    }

    /* A new thermal zone needs to be updated anyway. */
    atomic_set(&tz->need_update, 1);

    dev_set_name(&tz->device, "thermal_zone%d", tz->id);
    result = device_register(&tz->device);
    if (result) {
        goto release_device;
    }

    for (count = 0; count < trips; count++) {
        if (tz->ops->get_trip_type(tz, count, &trip_type)) {
            set_bit(count, &tz->trips_disabled);
        }
        if (tz->ops->get_trip_temp(tz, count, &trip_temp)) {
            set_bit(count, &tz->trips_disabled);
        }
        /* Check for bogus trip points */
        if (trip_temp == 0) {
            set_bit(count, &tz->trips_disabled);
        }
    }

    /* Update 'this' zone's governor information */
    mutex_lock(&thermal_governor_lock);

    if (tz->tzp) {
        governor = __find_governor(tz->tzp->governor_name);
    } else {
        governor = def_governor;
    }

    result = thermal_set_governor(tz, governor);
    if (result) {
        mutex_unlock(&thermal_governor_lock);
        goto unregister;
    }

    mutex_unlock(&thermal_governor_lock);

    if (!tz->tzp || !tz->tzp->no_hwmon) {
        result = thermal_add_hwmon_sysfs(tz);
        if (result) {
            goto unregister;
        }
    }

    mutex_lock(&thermal_list_lock);
    list_add_tail(&tz->node, &thermal_tz_list);
    mutex_unlock(&thermal_list_lock);

    /* Bind cooling devices for this zone */
    bind_tz(tz);

    INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);

    thermal_zone_device_reset(tz);
    /* Update the new thermal zone and mark it as already updated. */
    if (atomic_cmpxchg(&tz->need_update, 1, 0)) {
        thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
    }

    thermal_notify_tz_create(tz->id, tz->type);

    return tz;

unregister:
    device_del(&tz->device);
release_device:
    put_device(&tz->device);
    tz = NULL;
remove_id:
    ida_simple_remove(&thermal_tz_ida, id);
free_tz:
    kfree(tz);
    return ERR_PTR(result);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_register);

/**
 * thermal_zone_device_unregister - removes the registered thermal zone device
 * @tz: the thermal zone device to remove
 */
void thermal_zone_device_unregister(struct thermal_zone_device *tz)
{
    int i, tz_id;
    const struct thermal_zone_params *tzp;
    struct thermal_cooling_device *cdev;
    struct thermal_zone_device *pos = NULL;

    if (!tz) {
        return;
    }

    tzp = tz->tzp;
    tz_id = tz->id;

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(pos, &thermal_tz_list, node) if (pos == tz) break;
    if (pos != tz) {
        /* thermal zone device not found */
        mutex_unlock(&thermal_list_lock);
        return;
    }
    list_del(&tz->node);

    /* Unbind all cdevs associated with 'this' thermal zone */
    list_for_each_entry(cdev, &thermal_cdev_list, node)
    {
        if (tz->ops->unbind) {
            tz->ops->unbind(tz, cdev);
            continue;
        }

        if (!tzp || !tzp->tbp) {
            break;
        }

        for (i = 0; i < tzp->num_tbps; i++) {
            if (tzp->tbp[i].cdev == cdev) {
                __unbind(tz, tzp->tbp[i].trip_mask, cdev);
                tzp->tbp[i].cdev = NULL;
            }
        }
    }

    mutex_unlock(&thermal_list_lock);

    cancel_delayed_work_sync(&tz->poll_queue);

    thermal_set_governor(tz, NULL);

    thermal_remove_hwmon_sysfs(tz);
    ida_simple_remove(&thermal_tz_ida, tz->id);
    ida_destroy(&tz->ida);
    mutex_destroy(&tz->lock);
    device_unregister(&tz->device);

    thermal_notify_tz_delete(tz_id);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);

/**
 * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
 * @name: thermal zone name to fetch the temperature
 *
 * When only one zone is found with the passed name, returns a reference to it.
 *
 * Return: On success returns a reference to an unique thermal zone with
 * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
 * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
 */
struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
{
    struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
    unsigned int found = 0;

    if (!name) {
        goto exit;
    }

    mutex_lock(&thermal_list_lock);
    list_for_each_entry(pos, &thermal_tz_list, node) if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
        found++;
        ref = pos;
    }
    mutex_unlock(&thermal_list_lock);

    /* nothing has been found, thus an error code for it */
    if (found == 0) {
        ref = ERR_PTR(-ENODEV);
    } else if (found > 1) {
        /* Success only when an unique zone is found */
        ref = ERR_PTR(-EEXIST);
    }

exit:
    return ref;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);

static int thermal_pm_notify(struct notifier_block *nb, unsigned long mode, void *_unused)
{
    struct thermal_zone_device *tz;

    switch (mode) {
        case PM_HIBERNATION_PREPARE:
        case PM_RESTORE_PREPARE:
        case PM_SUSPEND_PREPARE:
            atomic_set(&in_suspend, 1);
            break;
        case PM_POST_HIBERNATION:
        case PM_POST_RESTORE:
        case PM_POST_SUSPEND:
            atomic_set(&in_suspend, 0);
            list_for_each_entry(tz, &thermal_tz_list, node)
            {
                if (!thermal_zone_device_is_enabled(tz)) {
                    continue;
                }

                thermal_zone_device_init(tz);
                thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
            }
            break;
        default:
            break;
    }
    return 0;
}

static struct notifier_block thermal_pm_nb = {
    .notifier_call = thermal_pm_notify,
};

static int __init thermal_init(void)
{
    int result;

    result = thermal_netlink_init();
    if (result) {
        goto error;
    }

    result = thermal_register_governors();
    if (result) {
        goto error;
    }

    result = class_register(&thermal_class);
    if (result) {
        goto unregister_governors;
    }

    result = of_parse_thermal_zones();
    if (result) {
        goto unregister_class;
    }

    result = register_pm_notifier(&thermal_pm_nb);
    if (result) {
        pr_warn("Thermal: Can not register suspend notifier, return %d\n", result);
    }

    return 0;

unregister_class:
    class_unregister(&thermal_class);
unregister_governors:
    thermal_unregister_governors();
error:
    ida_destroy(&thermal_tz_ida);
    ida_destroy(&thermal_cdev_ida);
    mutex_destroy(&thermal_list_lock);
    mutex_destroy(&thermal_governor_lock);
    mutex_destroy(&poweroff_lock);
    return result;
}
postcore_initcall(thermal_init);