// 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 "thermal_trace.h"

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

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 struct thermal_governor *def_governor;

static bool thermal_pm_suspended;

static struct workqueue_struct *thermal_wq __ro_after_init;

/*
 * 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;

        guard(mutex)(&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;
        }

        guard(mutex)(&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);
                }
        }

        return err;
}

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

        if (!governor)
                return;

        guard(mutex)(&thermal_governor_lock);

        if (!__find_governor(governor->name))
                return;

        list_del(&governor->governor_list);

        guard(mutex)(&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);
        }
}

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

        guard(mutex)(&thermal_governor_lock);
        guard(thermal_zone)(tz);

        gov = __find_governor(strim(policy));
        if (gov)
                ret = thermal_set_governor(tz, gov);

        thermal_notify_tz_gov_change(tz, policy);

        return ret;
}

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

        guard(mutex)(&thermal_governor_lock);

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

        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;
}

static int __thermal_zone_device_set_mode(struct thermal_zone_device *tz,
                                          enum thermal_device_mode mode)
{
        if (tz->ops.change_mode) {
                int ret;

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

        tz->mode = mode;

        return 0;
}

static void thermal_zone_broken_disable(struct thermal_zone_device *tz)
{
        struct thermal_trip_desc *td;

        dev_err(&tz->device, "Unable to get temperature, disabling!\n");
        /*
         * This function only runs for enabled thermal zones, so no need to
         * check for the current mode.
         */
        __thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
        thermal_notify_tz_disable(tz);

        for_each_trip_desc(tz, td) {
                if (td->trip.type == THERMAL_TRIP_CRITICAL &&
                    td->trip.temperature > THERMAL_TEMP_INVALID) {
                        dev_crit(&tz->device,
                                 "Disabled thermal zone with critical trip point\n");
                        return;
                }
        }
}

/*
 * 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,
                                            unsigned long delay)
{
        if (delay > HZ)
                delay = round_jiffies_relative(delay);

        mod_delayed_work(thermal_wq, &tz->poll_queue, delay);
}

static void thermal_zone_recheck(struct thermal_zone_device *tz, int error)
{
        if (error == -EAGAIN) {
                thermal_zone_device_set_polling(tz, THERMAL_RECHECK_DELAY);
                return;
        }

        /*
         * Print the message once to reduce log noise.  It will be followed by
         * another one if the temperature cannot be determined after multiple
         * attempts.
         */
        if (tz->recheck_delay_jiffies == THERMAL_RECHECK_DELAY)
                dev_info(&tz->device, "Temperature check failed (%d)\n", error);

        thermal_zone_device_set_polling(tz, tz->recheck_delay_jiffies);

        tz->recheck_delay_jiffies += max(tz->recheck_delay_jiffies >> 1, 1ULL);
        if (tz->recheck_delay_jiffies > THERMAL_MAX_RECHECK_DELAY) {
                thermal_zone_broken_disable(tz);
                /*
                 * Restore the original recheck delay value to allow the thermal
                 * zone to try to recover when it is reenabled by user space.
                 */
                tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;
        }
}

static void monitor_thermal_zone(struct thermal_zone_device *tz)
{
        if (tz->passive > 0 && tz->passive_delay_jiffies)
                thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
        else if (tz->polling_delay_jiffies)
                thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
}

static struct thermal_governor *thermal_get_tz_governor(struct thermal_zone_device *tz)
{
        if (tz->governor)
                return tz->governor;

        return def_governor;
}

void thermal_governor_update_tz(struct thermal_zone_device *tz,
                                enum thermal_notify_event reason)
{
        if (!tz->governor || !tz->governor->update_tz)
                return;

        tz->governor->update_tz(tz, reason);
}

static void thermal_zone_device_halt(struct thermal_zone_device *tz,
                                     enum hw_protection_action action)
{
        /*
         * poweroff_delay_ms must be a carefully profiled positive value.
         * Its a must for forced_emergency_poweroff_work to be scheduled.
         */
        int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
        const char *msg = "Temperature too high";

        dev_emerg(&tz->device, "%s: critical temperature reached\n", tz->type);

        __hw_protection_trigger(msg, poweroff_delay_ms, action);
}

void thermal_zone_device_critical(struct thermal_zone_device *tz)
{
        thermal_zone_device_halt(tz, HWPROT_ACT_DEFAULT);
}
EXPORT_SYMBOL(thermal_zone_device_critical);

void thermal_zone_device_critical_shutdown(struct thermal_zone_device *tz)
{
        thermal_zone_device_halt(tz, HWPROT_ACT_SHUTDOWN);
}

void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz)
{
        thermal_zone_device_halt(tz, HWPROT_ACT_REBOOT);
}

static void handle_critical_trips(struct thermal_zone_device *tz,
                                  const struct thermal_trip *trip)
{
        trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, trip), trip->type);

        if (trip->type == THERMAL_TRIP_CRITICAL)
                tz->ops.critical(tz);
        else if (tz->ops.hot)
                tz->ops.hot(tz);
}

static void move_trip_to_sorted_list(struct thermal_trip_desc *td,
                                     struct list_head *list)
{
        struct thermal_trip_desc *entry;

        /*
         * Delete upfront and then add to make relocation within the same list
         * work.
         */
        list_del(&td->list_node);

        /* Assume that the new entry is likely to be the last one. */
        list_for_each_entry_reverse(entry, list, list_node) {
                if (entry->threshold <= td->threshold) {
                        list_add(&td->list_node, &entry->list_node);
                        return;
                }
        }
        list_add(&td->list_node, list);
}

static void move_to_trips_high(struct thermal_zone_device *tz,
                               struct thermal_trip_desc *td)
{
        td->threshold = td->trip.temperature;
        move_trip_to_sorted_list(td, &tz->trips_high);
}

static void move_to_trips_reached(struct thermal_zone_device *tz,
                                  struct thermal_trip_desc *td)
{
        td->threshold = td->trip.temperature - td->trip.hysteresis;
        move_trip_to_sorted_list(td, &tz->trips_reached);
}

static void move_to_trips_invalid(struct thermal_zone_device *tz,
                                  struct thermal_trip_desc *td)
{
        td->threshold = INT_MAX;
        list_move(&td->list_node, &tz->trips_invalid);
}

static void thermal_governor_trip_crossed(struct thermal_governor *governor,
                                          struct thermal_zone_device *tz,
                                          const struct thermal_trip *trip,
                                          bool upward)
{
        if (trip->type == THERMAL_TRIP_HOT || trip->type == THERMAL_TRIP_CRITICAL)
                return;

        if (governor->trip_crossed)
                governor->trip_crossed(tz, trip, upward);
}

static void thermal_trip_crossed(struct thermal_zone_device *tz,
                                 struct thermal_trip_desc *td,
                                 struct thermal_governor *governor,
                                 bool upward)
{
        const struct thermal_trip *trip = &td->trip;

        if (upward) {
                if (trip->type == THERMAL_TRIP_PASSIVE)
                        tz->passive++;
                else if (trip->type == THERMAL_TRIP_CRITICAL ||
                         trip->type == THERMAL_TRIP_HOT)
                        handle_critical_trips(tz, trip);

                thermal_notify_tz_trip_up(tz, trip);
                thermal_debug_tz_trip_up(tz, trip);
        } else {
                if (trip->type == THERMAL_TRIP_PASSIVE) {
                        tz->passive--;
                        WARN_ON(tz->passive < 0);
                }
                thermal_notify_tz_trip_down(tz, trip);
                thermal_debug_tz_trip_down(tz, trip);
        }
        thermal_governor_trip_crossed(governor, tz, trip, upward);
}

void thermal_zone_set_trip_hyst(struct thermal_zone_device *tz,
                                struct thermal_trip *trip, int hyst)
{
        struct thermal_trip_desc *td = trip_to_trip_desc(trip);

        WRITE_ONCE(trip->hysteresis, hyst);
        thermal_notify_tz_trip_change(tz, trip);
        /*
         * If the zone temperature is above or at the trip temperature, the trip
         * is in the trips_reached list and its threshold is equal to its low
         * temperature.  It needs to stay in that list, but its threshold needs
         * to be updated and the list ordering may need to be restored.
         */
        if (tz->temperature >= td->threshold)
                move_to_trips_reached(tz, td);
}

void thermal_zone_set_trip_temp(struct thermal_zone_device *tz,
                                struct thermal_trip *trip, int temp)
{
        struct thermal_trip_desc *td = trip_to_trip_desc(trip);
        int old_temp = trip->temperature;

        if (old_temp == temp)
                return;

        WRITE_ONCE(trip->temperature, temp);
        thermal_notify_tz_trip_change(tz, trip);

        if (old_temp == THERMAL_TEMP_INVALID) {
                /*
                 * The trip was invalid before the change, so move it to the
                 * trips_high list regardless of the new temperature value
                 * because there is no mitigation under way for it.  If a
                 * mitigation needs to be started, the trip will be moved to the
                 * trips_reached list later.
                 */
                move_to_trips_high(tz, td);
                return;
        }

        if (temp == THERMAL_TEMP_INVALID) {
                /*
                 * If the trip is in the trips_reached list, mitigation is under
                 * way for it and it needs to be stopped because the trip is
                 * effectively going away.
                 */
                if (tz->temperature >= td->threshold)
                        thermal_trip_crossed(tz, td, thermal_get_tz_governor(tz), false);

                move_to_trips_invalid(tz, td);
                return;
        }

        /*
         * The trip stays on its current list, but its threshold needs to be
         * updated due to the temperature change and the list ordering may need
         * to be restored.
         */
        if (tz->temperature >= td->threshold)
                move_to_trips_reached(tz, td);
        else
                move_to_trips_high(tz, td);
}
EXPORT_SYMBOL_GPL(thermal_zone_set_trip_temp);

static void thermal_zone_handle_trips(struct thermal_zone_device *tz,
                                      struct thermal_governor *governor,
                                      int *low, int *high)
{
        struct thermal_trip_desc *td, *next;
        LIST_HEAD(way_down_list);

        /* Check the trips that were below or at the zone temperature. */
        list_for_each_entry_safe_reverse(td, next, &tz->trips_reached, list_node) {
                if (td->threshold <= tz->temperature)
                        break;

                thermal_trip_crossed(tz, td, governor, false);
                /*
                 * The current trips_high list needs to be processed before
                 * adding new entries to it, so put them on a temporary list.
                 */
                list_move(&td->list_node, &way_down_list);
        }
        /* Check the trips that were previously above the zone temperature. */
        list_for_each_entry_safe(td, next, &tz->trips_high, list_node) {
                if (td->threshold > tz->temperature)
                        break;

                thermal_trip_crossed(tz, td, governor, true);
                move_to_trips_reached(tz, td);
        }
        /* Move all of the trips from the temporary list to trips_high. */
        list_for_each_entry_safe(td, next, &way_down_list, list_node)
                move_to_trips_high(tz, td);

        if (!list_empty(&tz->trips_reached)) {
                td = list_last_entry(&tz->trips_reached,
                                     struct thermal_trip_desc, list_node);
                /*
                 * Set the "low" value below the current trip threshold in case
                 * the zone temperature is at that threshold and stays there,
                 * which would trigger a new interrupt immediately in vain.
                 */
                *low = td->threshold - 1;
        }
        if (!list_empty(&tz->trips_high)) {
                td = list_first_entry(&tz->trips_high,
                                      struct thermal_trip_desc, list_node);
                *high = td->threshold;
        }
}

void __thermal_zone_device_update(struct thermal_zone_device *tz,
                                  enum thermal_notify_event event)
{
        struct thermal_governor *governor = thermal_get_tz_governor(tz);
        int low = -INT_MAX, high = INT_MAX;
        int temp, ret;

        if (tz->state != TZ_STATE_READY || tz->mode != THERMAL_DEVICE_ENABLED)
                return;

        ret = __thermal_zone_get_temp(tz, &temp);
        if (ret) {
                thermal_zone_recheck(tz, ret);
                return;
        } else if (temp <= THERMAL_TEMP_INVALID) {
                /*
                 * Special case: No valid temperature value is available, but
                 * the zone owner does not want the core to do anything about
                 * it.  Continue regular zone polling if needed, so that this
                 * function can be called again, but skip everything else.
                 */
                goto monitor;
        }

        tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;

        tz->last_temperature = tz->temperature;
        tz->temperature = temp;

        trace_thermal_temperature(tz);

        thermal_genl_sampling_temp(tz->id, temp);

        tz->notify_event = event;

        thermal_zone_handle_trips(tz, governor, &low, &high);

        thermal_thresholds_handle(tz, &low, &high);

        thermal_zone_set_trips(tz, low, high);

        if (governor->manage)
                governor->manage(tz);

        thermal_debug_update_trip_stats(tz);

monitor:
        monitor_thermal_zone(tz);
}

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

        guard(thermal_zone)(tz);

        /* do nothing if mode isn't changing */
        if (mode == tz->mode)
                return 0;

        ret = __thermal_zone_device_set_mode(tz, mode);
        if (ret)
                return ret;

        __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);

        if (mode == THERMAL_DEVICE_ENABLED)
                thermal_notify_tz_enable(tz);
        else
                thermal_notify_tz_disable(tz);

        return 0;
}

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);

static bool thermal_zone_is_present(struct thermal_zone_device *tz)
{
        return !list_empty(&tz->node);
}

void thermal_zone_device_update(struct thermal_zone_device *tz,
                                enum thermal_notify_event event)
{
        guard(thermal_zone)(tz);

        if (thermal_zone_is_present(tz))
                __thermal_zone_device_update(tz, event);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_update);

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

        guard(mutex)(&thermal_governor_lock);

        list_for_each_entry(gov, &thermal_governor_list, governor_list) {
                int ret;

                ret = cb(gov, data);
                if (ret)
                        return ret;
        }

        return 0;
}

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

        guard(mutex)(&thermal_list_lock);

        list_for_each_entry(cdev, &thermal_cdev_list, node) {
                int ret;

                ret = cb(cdev, data);
                if (ret)
                        return ret;
        }

        return 0;
}

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

        guard(mutex)(&thermal_list_lock);

        list_for_each_entry(tz, &thermal_tz_list, node) {
                int ret;

                ret = cb(tz, data);
                if (ret)
                        return ret;
        }

        return 0;
}

struct thermal_zone_device *thermal_zone_get_by_id(int id)
{
        struct thermal_zone_device *tz;

        guard(mutex)(&thermal_list_lock);

        list_for_each_entry(tz, &thermal_tz_list, node) {
                if (tz->id == id) {
                        get_device(&tz->device);
                        return tz;
                }
        }

        return NULL;
}

/*
 * 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.
 */

static int thermal_instance_add(struct thermal_instance *new_instance,
                                struct thermal_cooling_device *cdev,
                                struct thermal_trip_desc *td)
{
        struct thermal_instance *instance;

        list_for_each_entry(instance, &td->thermal_instances, trip_node) {
                if (instance->cdev == cdev)
                        return -EEXIST;
        }

        list_add_tail(&new_instance->trip_node, &td->thermal_instances);

        guard(cooling_dev)(cdev);

        list_add_tail(&new_instance->cdev_node, &cdev->thermal_instances);

        return 0;
}

/**
 * thermal_bind_cdev_to_trip - bind a cooling device to a thermal zone
 * @tz:         pointer to struct thermal_zone_device
 * @td:         descriptor of the trip point to bind @cdev to
 * @cdev:       pointer to struct thermal_cooling_device
 * @cool_spec:  cooling specification for the trip point and @cdev
 *
 * 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.
 */
static int thermal_bind_cdev_to_trip(struct thermal_zone_device *tz,
                                     struct thermal_trip_desc *td,
                                     struct thermal_cooling_device *cdev,
                                     struct cooling_spec *cool_spec)
{
        struct thermal_instance *dev;
        bool upper_no_limit;
        int result;

        /* lower default 0, upper default max_state */
        if (cool_spec->lower == THERMAL_NO_LIMIT)
                cool_spec->lower = 0;

        if (cool_spec->upper == THERMAL_NO_LIMIT) {
                cool_spec->upper = cdev->max_state;
                upper_no_limit = true;
        } else {
                upper_no_limit = false;
        }

        if (cool_spec->lower > cool_spec->upper || cool_spec->upper > cdev->max_state)
                return -EINVAL;

        dev = kzalloc_obj(*dev);
        if (!dev)
                return -ENOMEM;

        dev->cdev = cdev;
        dev->trip = &td->trip;
        dev->upper = cool_spec->upper;
        dev->upper_no_limit = upper_no_limit;
        dev->lower = cool_spec->lower;
        dev->target = THERMAL_NO_TARGET;
        dev->weight = cool_spec->weight;

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

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

        snprintf(dev->attr_name, sizeof(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;

        snprintf(dev->weight_attr_name, sizeof(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;

        result = thermal_instance_add(dev, cdev, td);
        if (result)
                goto remove_weight_file;

        thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);

        return 0;

remove_weight_file:
        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_free(&tz->ida, dev->id);
free_mem:
        kfree(dev);
        return result;
}

static void thermal_instance_delete(struct thermal_instance *instance)
{
        list_del(&instance->trip_node);

        guard(cooling_dev)(instance->cdev);

        list_del(&instance->cdev_node);
}

/**
 * thermal_unbind_cdev_from_trip - unbind a cooling device from a thermal zone.
 * @tz:         pointer to a struct thermal_zone_device.
 * @td:         descriptor of the trip point to unbind @cdev from
 * @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.
 */
static void thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
                                          struct thermal_trip_desc *td,
                                          struct thermal_cooling_device *cdev)
{
        struct thermal_instance *pos, *next;

        list_for_each_entry_safe(pos, next, &td->thermal_instances, trip_node) {
                if (pos->cdev == cdev) {
                        thermal_instance_delete(pos);
                        goto unbind;
                }
        }

        return;

unbind:
        thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);

        device_remove_file(&tz->device, &pos->weight_attr);
        device_remove_file(&tz->device, &pos->attr);
        sysfs_remove_link(&tz->device.kobj, pos->name);
        ida_free(&tz->ida, pos->id);
        kfree(pos);
}

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);
                mutex_destroy(&tz->lock);
                complete(&tz->removal);
        } else if (!strncmp(dev_name(dev), "cooling_device",
                            sizeof("cooling_device") - 1)) {
                cdev = to_cooling_device(dev);
                thermal_cooling_device_destroy_sysfs(cdev);
                kfree_const(cdev->type);
                ida_free(&thermal_cdev_ida, cdev->id);
                kfree(cdev);
        }
}

static struct class *thermal_class;

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

static bool __thermal_zone_cdev_bind(struct thermal_zone_device *tz,
                                     struct thermal_cooling_device *cdev)
{
        struct thermal_trip_desc *td;
        bool update_tz = false;

        if (!tz->ops.should_bind)
                return false;

        for_each_trip_desc(tz, td) {
                struct cooling_spec c = {
                        .upper = THERMAL_NO_LIMIT,
                        .lower = THERMAL_NO_LIMIT,
                        .weight = THERMAL_WEIGHT_DEFAULT
                };
                int ret;

                if (!tz->ops.should_bind(tz, &td->trip, cdev, &c))
                        continue;

                ret = thermal_bind_cdev_to_trip(tz, td, cdev, &c);
                if (ret) {
                        print_bind_err_msg(tz, td, cdev, ret);
                        continue;
                }

                update_tz = true;
        }

        return update_tz;
}

static void thermal_zone_cdev_bind(struct thermal_zone_device *tz,
                                   struct thermal_cooling_device *cdev)
{
        guard(thermal_zone)(tz);

        if (__thermal_zone_cdev_bind(tz, cdev))
                __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
}

static void thermal_cooling_device_init_complete(struct thermal_cooling_device *cdev)
{
        struct thermal_zone_device *tz;

        guard(mutex)(&thermal_list_lock);

        list_add(&cdev->node, &thermal_cdev_list);

        list_for_each_entry(tz, &thermal_tz_list, node)
                thermal_zone_cdev_bind(tz, cdev);
}

/**
 * __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;
        unsigned long current_state;
        int id, ret;

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

        if (!thermal_class)
                return ERR_PTR(-ENODEV);

        cdev = kzalloc_obj(*cdev);
        if (!cdev)
                return ERR_PTR(-ENOMEM);

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

        cdev->type = kstrdup_const(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;

        ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
        if (ret)
                goto out_cdev_type;

        /*
         * The cooling device's current state is only needed for debug
         * initialization below, so a failure to get it does not cause
         * the entire cooling device initialization to fail.  However,
         * the debug will not work for the device if its initial state
         * cannot be determined and drivers are responsible for ensuring
         * that this will not happen.
         */
        ret = cdev->ops->get_cur_state(cdev, &current_state);
        if (ret)
                current_state = ULONG_MAX;

        thermal_cooling_device_setup_sysfs(cdev);

        ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
        if (ret)
                goto out_cooling_dev;

        ret = device_register(&cdev->device);
        if (ret) {
                /* thermal_release() handles rest of the cleanup */
                put_device(&cdev->device);
                return ERR_PTR(ret);
        }

        if (current_state <= cdev->max_state)
                thermal_debug_cdev_add(cdev, current_state);

        thermal_cooling_device_init_complete(cdev);

        return cdev;

out_cooling_dev:
        thermal_cooling_device_destroy_sysfs(cdev);
out_cdev_type:
        kfree_const(cdev->type);
out_ida_remove:
        ida_free(&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,
                                const 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 bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
{
        struct thermal_cooling_device *pos = NULL;

        list_for_each_entry(pos, &thermal_cdev_list, node) {
                if (pos == cdev)
                        return true;
        }

        return false;
}

/**
 * thermal_cooling_device_update - Update a cooling device object
 * @cdev: Target cooling device.
 *
 * Update @cdev to reflect a change of the underlying hardware or platform.
 *
 * Must be called when the maximum cooling state of @cdev becomes invalid and so
 * its .get_max_state() callback needs to be run to produce the new maximum
 * cooling state value.
 */
void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
{
        struct thermal_instance *ti;
        unsigned long state;

        if (IS_ERR_OR_NULL(cdev))
                return;

        /*
         * Hold thermal_list_lock throughout the update to prevent the device
         * from going away while being updated.
         */
        guard(mutex)(&thermal_list_lock);

        if (!thermal_cooling_device_present(cdev))
                return;

        /*
         * Update under the cdev lock to prevent the state from being set beyond
         * the new limit concurrently.
         */
        guard(cooling_dev)(cdev);

        if (cdev->ops->get_max_state(cdev, &cdev->max_state))
                return;

        thermal_cooling_device_stats_reinit(cdev);

        list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
                if (ti->upper == cdev->max_state)
                        continue;

                if (ti->upper < cdev->max_state) {
                        if (ti->upper_no_limit)
                                ti->upper = cdev->max_state;

                        continue;
                }

                ti->upper = cdev->max_state;
                if (ti->lower > ti->upper)
                        ti->lower = ti->upper;

                if (ti->target == THERMAL_NO_TARGET)
                        continue;

                if (ti->target > ti->upper)
                        ti->target = ti->upper;
        }

        if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
                return;

        thermal_cooling_device_stats_update(cdev, state);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_update);

static void __thermal_zone_cdev_unbind(struct thermal_zone_device *tz,
                                       struct thermal_cooling_device *cdev)
{
        struct thermal_trip_desc *td;

        for_each_trip_desc(tz, td)
                thermal_unbind_cdev_from_trip(tz, td, cdev);
}

static void thermal_zone_cdev_unbind(struct thermal_zone_device *tz,
                                     struct thermal_cooling_device *cdev)
{
        guard(thermal_zone)(tz);

        __thermal_zone_cdev_unbind(tz, cdev);
}

static bool thermal_cooling_device_exit(struct thermal_cooling_device *cdev)
{
        struct thermal_zone_device *tz;

        guard(mutex)(&thermal_list_lock);

        if (!thermal_cooling_device_present(cdev))
                return false;

        list_del(&cdev->node);

        list_for_each_entry(tz, &thermal_tz_list, node)
                thermal_zone_cdev_unbind(tz, cdev);

        return true;
}

/**
 * thermal_cooling_device_unregister() - removes a thermal cooling device
 * @cdev: Thermal cooling device to remove.
 */
void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
{
        if (!cdev)
                return;

        thermal_debug_cdev_remove(cdev);

        if (thermal_cooling_device_exit(cdev))
                device_unregister(&cdev->device);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);

int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
{
        const struct thermal_trip_desc *td;
        int ret = -EINVAL;

        if (tz->ops.get_crit_temp)
                return tz->ops.get_crit_temp(tz, temp);

        guard(thermal_zone)(tz);

        for_each_trip_desc(tz, td) {
                const struct thermal_trip *trip = &td->trip;

                if (trip->type == THERMAL_TRIP_CRITICAL) {
                        *temp = trip->temperature;
                        ret = 0;
                        break;
                }
        }

        return ret;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);

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);
}

static void thermal_zone_device_init(struct thermal_zone_device *tz)
{
        struct thermal_trip_desc *td, *next;

        INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);

        tz->temperature = THERMAL_TEMP_INIT;
        tz->passive = 0;
        tz->prev_low_trip = -INT_MAX;
        tz->prev_high_trip = INT_MAX;
        for_each_trip_desc(tz, td) {
                struct thermal_instance *instance;

                list_for_each_entry(instance, &td->thermal_instances, trip_node)
                        instance->initialized = false;
        }
        /*
         * At this point, all valid trips need to be moved to trips_high so that
         * mitigation can be started if the zone temperature is above them.
         */
        list_for_each_entry_safe(td, next, &tz->trips_invalid, list_node) {
                if (td->trip.temperature != THERMAL_TEMP_INVALID)
                        move_to_trips_high(tz, td);
        }
        /* The trips_reached list may not be empty during system resume. */
        list_for_each_entry_safe(td, next, &tz->trips_reached, list_node) {
                if (td->trip.temperature == THERMAL_TEMP_INVALID)
                        move_to_trips_invalid(tz, td);
                else
                        move_to_trips_high(tz, td);
        }
}

static int thermal_zone_init_governor(struct thermal_zone_device *tz)
{
        struct thermal_governor *governor;

        guard(mutex)(&thermal_governor_lock);

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

        return thermal_set_governor(tz, governor);
}

static void thermal_zone_init_complete(struct thermal_zone_device *tz)
{
        struct thermal_cooling_device *cdev;

        guard(mutex)(&thermal_list_lock);

        list_add_tail(&tz->node, &thermal_tz_list);

        guard(thermal_zone)(tz);

        /* Bind cooling devices for this zone. */
        list_for_each_entry(cdev, &thermal_cdev_list, node)
                __thermal_zone_cdev_bind(tz, cdev);

        tz->state &= ~TZ_STATE_FLAG_INIT;
        /*
         * If system suspend or resume is in progress at this point, the
         * new thermal zone needs to be marked as suspended because
         * thermal_pm_notify() has run already.
         */
        if (thermal_pm_suspended)
                tz->state |= TZ_STATE_FLAG_SUSPENDED;

        __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
}

/**
 * thermal_zone_device_register_with_trips() - register a new thermal zone device
 * @type:       the thermal zone device type
 * @trips:      a pointer to an array of thermal trips
 * @num_trips:  the number of trip points the thermal zone support
 * @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_with_trips(const char *type,
                                        const struct thermal_trip *trips,
                                        int num_trips, void *devdata,
                                        const struct thermal_zone_device_ops *ops,
                                        const struct thermal_zone_params *tzp,
                                        unsigned int passive_delay,
                                        unsigned int polling_delay)
{
        const struct thermal_trip *trip = trips;
        struct thermal_zone_device *tz;
        struct thermal_trip_desc *td;
        size_t type_len = 0;
        int id;
        int result;

        if (type)
                type_len = strnlen(type, THERMAL_NAME_LENGTH);

        if (type_len == 0) {
                pr_err("No thermal zone type defined\n");
                return ERR_PTR(-EINVAL);
        }

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

        if (num_trips < 0) {
                pr_err("Incorrect number of thermal trips\n");
                return ERR_PTR(-EINVAL);
        }

        if (!ops || !ops->get_temp) {
                pr_err("Thermal zone device ops not defined or invalid\n");
                return ERR_PTR(-EINVAL);
        }

        if (num_trips > 0 && !trips)
                return ERR_PTR(-EINVAL);

        if (polling_delay && passive_delay > polling_delay)
                return ERR_PTR(-EINVAL);

        if (!thermal_class)
                return ERR_PTR(-ENODEV);

        tz = kzalloc_flex(*tz, trips, num_trips);
        if (!tz)
                return ERR_PTR(-ENOMEM);

        if (tzp) {
                tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
                if (!tz->tzp) {
                        result = -ENOMEM;
                        goto free_tz;
                }
        }

        INIT_LIST_HEAD(&tz->node);
        INIT_LIST_HEAD(&tz->trips_high);
        INIT_LIST_HEAD(&tz->trips_reached);
        INIT_LIST_HEAD(&tz->trips_invalid);
        ida_init(&tz->ida);
        mutex_init(&tz->lock);
        init_completion(&tz->removal);
        init_completion(&tz->resume);
        id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
        if (id < 0) {
                result = id;
                goto free_tzp;
        }

        tz->id = id;
        strscpy(tz->type, type, sizeof(tz->type));

        tz->ops = *ops;
        if (!tz->ops.critical)
                tz->ops.critical = thermal_zone_device_critical;

        tz->device.class = thermal_class;
        tz->devdata = devdata;
        tz->num_trips = num_trips;
        for_each_trip_desc(tz, td) {
                td->trip = *trip++;
                INIT_LIST_HEAD(&td->thermal_instances);
                INIT_LIST_HEAD(&td->list_node);
                /*
                 * Mark all thresholds as invalid to start with even though
                 * this only matters for the trips that start as invalid and
                 * become valid later.
                 */
                move_to_trips_invalid(tz, td);
        }

        tz->polling_delay_jiffies = msecs_to_jiffies(polling_delay);
        tz->passive_delay_jiffies = msecs_to_jiffies(passive_delay);
        tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;

        tz->state = TZ_STATE_FLAG_INIT;

        result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
        if (result)
                goto remove_id;

        thermal_zone_device_init(tz);

        result = thermal_zone_init_governor(tz);
        if (result)
                goto remove_id;

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

        result = device_register(&tz->device);
        if (result)
                goto release_device;

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

        result = thermal_thresholds_init(tz);
        if (result)
                goto remove_hwmon;

        thermal_zone_init_complete(tz);

        thermal_notify_tz_create(tz);

        thermal_debug_tz_add(tz);

        return tz;

remove_hwmon:
        thermal_remove_hwmon_sysfs(tz);
unregister:
        device_del(&tz->device);
release_device:
        put_device(&tz->device);
        wait_for_completion(&tz->removal);
remove_id:
        ida_free(&thermal_tz_ida, id);
free_tzp:
        kfree(tz->tzp);
free_tz:
        kfree(tz);
        return ERR_PTR(result);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);

struct thermal_zone_device *thermal_tripless_zone_device_register(
                                        const char *type,
                                        void *devdata,
                                        const struct thermal_zone_device_ops *ops,
                                        const struct thermal_zone_params *tzp)
{
        return thermal_zone_device_register_with_trips(type, NULL, 0, devdata,
                                                       ops, tzp, 0, 0);
}
EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);

void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
{
        return tzd->devdata;
}
EXPORT_SYMBOL_GPL(thermal_zone_device_priv);

const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
{
        return tzd->type;
}
EXPORT_SYMBOL_GPL(thermal_zone_device_type);

int thermal_zone_device_id(struct thermal_zone_device *tzd)
{
        return tzd->id;
}
EXPORT_SYMBOL_GPL(thermal_zone_device_id);

struct device *thermal_zone_device(struct thermal_zone_device *tzd)
{
        return &tzd->device;
}
EXPORT_SYMBOL_GPL(thermal_zone_device);

static bool thermal_zone_exit(struct thermal_zone_device *tz)
{
        struct thermal_cooling_device *cdev;

        guard(mutex)(&thermal_list_lock);

        if (list_empty(&tz->node))
                return false;

        guard(thermal_zone)(tz);

        tz->state |= TZ_STATE_FLAG_EXIT;
        list_del_init(&tz->node);

        /* Unbind all cdevs associated with this thermal zone. */
        list_for_each_entry(cdev, &thermal_cdev_list, node)
                __thermal_zone_cdev_unbind(tz, cdev);

        return true;
}

/**
 * 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)
{
        if (!tz)
                return;

        thermal_debug_tz_remove(tz);

        if (!thermal_zone_exit(tz))
                return;

        cancel_delayed_work_sync(&tz->poll_queue);

        thermal_set_governor(tz, NULL);

        thermal_thresholds_exit(tz);
        thermal_remove_hwmon_sysfs(tz);
        ida_free(&thermal_tz_ida, tz->id);
        ida_destroy(&tz->ida);

        device_del(&tz->device);
        put_device(&tz->device);

        thermal_notify_tz_delete(tz);

        wait_for_completion(&tz->removal);
        kfree(tz->tzp);
        kfree(tz);
}
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)
                return ERR_PTR(-EINVAL);

        guard(mutex)(&thermal_list_lock);

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

        if (!found)
                return ERR_PTR(-ENODEV);

        /* Success only when one zone is found. */
        if (found > 1)
                return ERR_PTR(-EEXIST);

        return ref;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);

static void thermal_zone_device_resume(struct work_struct *work)
{
        struct thermal_zone_device *tz;

        tz = container_of(work, struct thermal_zone_device, poll_queue.work);

        guard(thermal_zone)(tz);

        /* If the thermal zone is going away, there's nothing to do. */
        if (tz->state & TZ_STATE_FLAG_EXIT)
                return;

        tz->state &= ~(TZ_STATE_FLAG_SUSPENDED | TZ_STATE_FLAG_RESUMING);

        thermal_debug_tz_resume(tz);
        thermal_zone_device_init(tz);
        thermal_governor_update_tz(tz, THERMAL_TZ_RESUME);
        __thermal_zone_device_update(tz, THERMAL_TZ_RESUME);

        complete(&tz->resume);
}

static void thermal_zone_pm_prepare(struct thermal_zone_device *tz)
{
        guard(thermal_zone)(tz);

        if (tz->state & TZ_STATE_FLAG_RESUMING) {
                /*
                 * thermal_zone_device_resume() queued up for this zone has not
                 * acquired the lock yet, so release it to let the function run
                 * and wait util it has done the work.
                 */
                scoped_guard(thermal_zone_reverse, tz) {
                        wait_for_completion(&tz->resume);
                }
        }

        tz->state |= TZ_STATE_FLAG_SUSPENDED;

        /* Prevent new work from getting to the workqueue subsequently. */
        cancel_delayed_work(&tz->poll_queue);
}

static void thermal_pm_notify_prepare(void)
{
        struct thermal_zone_device *tz;

        guard(mutex)(&thermal_list_lock);

        thermal_pm_suspended = true;

        list_for_each_entry(tz, &thermal_tz_list, node)
                thermal_zone_pm_prepare(tz);
}

static void thermal_zone_pm_complete(struct thermal_zone_device *tz)
{
        guard(thermal_zone)(tz);

        reinit_completion(&tz->resume);
        tz->state |= TZ_STATE_FLAG_RESUMING;

        /*
         * Replace the work function with the resume one, which will restore the
         * original work function and schedule the polling work if needed.
         */
        INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_resume);
        /* Queue up the work without a delay. */
        mod_delayed_work(thermal_wq, &tz->poll_queue, 0);
}

static void thermal_pm_notify_complete(void)
{
        struct thermal_zone_device *tz;

        guard(mutex)(&thermal_list_lock);

        thermal_pm_suspended = false;

        list_for_each_entry(tz, &thermal_tz_list, node)
                thermal_zone_pm_complete(tz);
}

static int thermal_pm_notify(struct notifier_block *nb,
                             unsigned long mode, void *_unused)
{
        switch (mode) {
        case PM_HIBERNATION_PREPARE:
        case PM_RESTORE_PREPARE:
        case PM_SUSPEND_PREPARE:
                thermal_pm_notify_prepare();
                /*
                 * Allow any leftover thermal work items already on the
                 * worqueue to complete so they don't get in the way later.
                 */
                flush_workqueue(thermal_wq);
                break;
        case PM_POST_HIBERNATION:
        case PM_POST_RESTORE:
        case PM_POST_SUSPEND:
                thermal_pm_notify_complete();
                break;
        default:
                break;
        }
        return 0;
}

static struct notifier_block thermal_pm_nb = {
        .notifier_call = thermal_pm_notify,
        /*
         * Run at the lowest priority to avoid interference between the thermal
         * zone resume work items spawned by thermal_pm_notify() and the other
         * PM notifiers.
         */
        .priority = INT_MIN,
};

static int __init thermal_init(void)
{
        int result;

        thermal_debug_init();

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

        thermal_wq = alloc_workqueue("thermal_events",
                                      WQ_FREEZABLE | WQ_POWER_EFFICIENT | WQ_PERCPU, 0);
        if (!thermal_wq) {
                result = -ENOMEM;
                goto unregister_netlink;
        }

        result = thermal_register_governors();
        if (result)
                goto destroy_workqueue;

        thermal_class = kzalloc_obj(*thermal_class);
        if (!thermal_class) {
                result = -ENOMEM;
                goto unregister_governors;
        }

        thermal_class->name = "thermal";
        thermal_class->dev_release = thermal_release;

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

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

        return 0;

unregister_governors:
        thermal_unregister_governors();
destroy_workqueue:
        destroy_workqueue(thermal_wq);
unregister_netlink:
        thermal_netlink_exit();
error:
        mutex_destroy(&thermal_list_lock);
        mutex_destroy(&thermal_governor_lock);
        return result;
}
postcore_initcall(thermal_init);