Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1601 insertions, 0 deletions

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
new file mode 100644
index 0000000000..1494ffa597
--- /dev/null
+++ b/drivers/thermal/thermal_core.c
@@ -0,0 +1,1601 @@
+// 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 atomic_t in_suspend;
+
+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);
+
+	if (!device_is_registered(&tz->device))
+		goto exit;
+
+	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 += sysfs_emit_at(buf, count, "%s ", pos->name);
+	}
+	count += sysfs_emit_at(buf, 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,
+					    unsigned long delay)
+{
+	if (delay)
+		mod_delayed_work(system_freezable_power_efficient_wq,
+				 &tz->poll_queue, delay);
+	else
+		cancel_delayed_work(&tz->poll_queue);
+}
+
+static void monitor_thermal_zone(struct thermal_zone_device *tz)
+{
+	if (tz->mode != THERMAL_DEVICE_ENABLED)
+		thermal_zone_device_set_polling(tz, 0);
+	else if (tz->passive)
+		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 void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
+{
+	tz->governor ? tz->governor->throttle(tz, trip) :
+		       def_governor->throttle(tz, trip);
+}
+
+void thermal_zone_device_critical(struct thermal_zone_device *tz)
+{
+	/*
+	 * 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;
+
+	dev_emerg(&tz->device, "%s: critical temperature reached, "
+		  "shutting down\n", tz->type);
+
+	hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
+}
+EXPORT_SYMBOL(thermal_zone_device_critical);
+
+static void handle_critical_trips(struct thermal_zone_device *tz,
+				  int trip, int trip_temp, enum thermal_trip_type trip_type)
+{
+	/* 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 (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
+		tz->ops->hot(tz);
+	else if (trip_type == THERMAL_TRIP_CRITICAL)
+		tz->ops->critical(tz);
+}
+
+static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
+{
+	struct thermal_trip trip;
+
+	/* Ignore disabled trip points */
+	if (test_bit(trip_id, &tz->trips_disabled))
+		return;
+
+	__thermal_zone_get_trip(tz, trip_id, &trip);
+
+	if (trip.temperature == THERMAL_TEMP_INVALID)
+		return;
+
+	if (tz->last_temperature != THERMAL_TEMP_INVALID) {
+		if (tz->last_temperature < trip.temperature &&
+		    tz->temperature >= trip.temperature)
+			thermal_notify_tz_trip_up(tz->id, trip_id,
+						  tz->temperature);
+		if (tz->last_temperature >= trip.temperature &&
+		    tz->temperature < (trip.temperature - trip.hysteresis))
+			thermal_notify_tz_trip_down(tz->id, trip_id,
+						    tz->temperature);
+	}
+
+	if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
+		handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
+	else
+		handle_non_critical_trips(tz, trip_id);
+}
+
+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;
+	}
+
+	tz->last_temperature = tz->temperature;
+	tz->temperature = temp;
+
+	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;
+}
+
+void __thermal_zone_device_update(struct thermal_zone_device *tz,
+				  enum thermal_notify_event event)
+{
+	int count;
+
+	if (atomic_read(&in_suspend))
+		return;
+
+	if (WARN_ONCE(!tz->ops->get_temp,
+		      "'%s' must not be called without 'get_temp' ops set\n",
+		      __func__))
+		return;
+
+	if (!thermal_zone_device_is_enabled(tz))
+		return;
+
+	update_temperature(tz);
+
+	__thermal_zone_set_trips(tz);
+
+	tz->notify_event = event;
+
+	for (count = 0; count < tz->num_trips; count++)
+		handle_thermal_trip(tz, count);
+
+	monitor_thermal_zone(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 (!device_is_registered(&tz->device)) {
+		mutex_unlock(&tz->lock);
+
+		return -ENODEV;
+	}
+
+	if (tz->ops->change_mode)
+		ret = tz->ops->change_mode(tz, mode);
+
+	if (!ret)
+		tz->mode = mode;
+
+	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
+
+	mutex_unlock(&tz->lock);
+
+	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)
+{
+	lockdep_assert_held(&tz->lock);
+
+	return tz->mode == THERMAL_DEVICE_ENABLED;
+}
+
+void thermal_zone_device_update(struct thermal_zone_device *tz,
+				enum thermal_notify_event event)
+{
+	mutex_lock(&tz->lock);
+	if (device_is_registered(&tz->device))
+		__thermal_zone_device_update(tz, event);
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_device_update);
+
+/**
+ * thermal_zone_device_exec - Run a callback under the zone lock.
+ * @tz: Thermal zone.
+ * @cb: Callback to run.
+ * @data: Data to pass to the callback.
+ */
+void thermal_zone_device_exec(struct thermal_zone_device *tz,
+			      void (*cb)(struct thermal_zone_device *,
+					 unsigned long),
+			      unsigned long data)
+{
+	mutex_lock(&tz->lock);
+
+	cb(tz, data);
+
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_device_exec);
+
+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);
+}
+
+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;
+}
+
+/*
+ * 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_index:	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_index,
+				     struct thermal_cooling_device *cdev,
+				     unsigned long upper, unsigned long lower,
+				     unsigned int weight)
+{
+	struct thermal_instance *dev;
+	struct thermal_instance *pos;
+	struct thermal_zone_device *pos1;
+	struct thermal_cooling_device *pos2;
+	const struct thermal_trip *trip;
+	bool upper_no_limit;
+	int result;
+
+	if (trip_index >= tz->num_trips || trip_index < 0)
+		return -EINVAL;
+
+	trip = &tz->trips[trip_index];
+
+	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;
+
+	/* lower default 0, upper default max_state */
+	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
+
+	if (upper == THERMAL_NO_LIMIT) {
+		upper = cdev->max_state;
+		upper_no_limit = true;
+	} else {
+		upper_no_limit = false;
+	}
+
+	if (lower > upper || upper > cdev->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->upper_no_limit = upper_no_limit;
+	dev->lower = lower;
+	dev->target = THERMAL_NO_TARGET;
+	dev->weight = 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;
+
+	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_free(&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_index:	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_index,
+				       struct thermal_cooling_device *cdev)
+{
+	struct thermal_instance *pos, *next;
+	const struct thermal_trip *trip;
+
+	mutex_lock(&tz->lock);
+	mutex_lock(&cdev->lock);
+	trip = &tz->trips[trip_index];
+	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_free(&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);
+		mutex_destroy(&tz->lock);
+		kfree(tz);
+	} else if (!strncmp(dev_name(dev), "cooling_device",
+			    sizeof("cooling_device") - 1)) {
+		cdev = to_cooling_device(dev);
+		thermal_cooling_device_destroy_sysfs(cdev);
+		kfree(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,
+			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_cdev(struct thermal_cooling_device *cdev)
+{
+	int ret;
+	struct thermal_zone_device *pos = NULL;
+
+	list_for_each_entry(pos, &thermal_tz_list, node) {
+		if (pos->ops->bind) {
+			ret = pos->ops->bind(pos, cdev);
+			if (ret)
+				print_bind_err_msg(pos, cdev, ret);
+		}
+	}
+}
+
+/**
+ * __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);
+
+	if (!thermal_class)
+		return ERR_PTR(-ENODEV);
+
+	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+	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(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;
+
+	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);
+	}
+
+	/* Add 'this' new cdev to the global cdev list */
+	mutex_lock(&thermal_list_lock);
+
+	list_add(&cdev->node, &thermal_cdev_list);
+
+	/* Update binding information for 'this' new cdev */
+	bind_cdev(cdev);
+
+	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_cooling_dev:
+	thermal_cooling_device_destroy_sysfs(cdev);
+out_cdev_type:
+	kfree(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,
+				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.
+	 */
+	mutex_lock(&thermal_list_lock);
+
+	if (!thermal_cooling_device_present(cdev))
+		goto unlock_list;
+
+	/*
+	 * Update under the cdev lock to prevent the state from being set beyond
+	 * the new limit concurrently.
+	 */
+	mutex_lock(&cdev->lock);
+
+	if (cdev->ops->get_max_state(cdev, &cdev->max_state))
+		goto unlock;
+
+	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)
+		goto unlock;
+
+	thermal_cooling_device_stats_update(cdev, state);
+
+unlock:
+	mutex_unlock(&cdev->lock);
+
+unlock_list:
+	mutex_unlock(&thermal_list_lock);
+}
+EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
+
+/**
+ * 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)
+{
+	struct thermal_zone_device *tz;
+
+	if (!cdev)
+		return;
+
+	mutex_lock(&thermal_list_lock);
+
+	if (!thermal_cooling_device_present(cdev)) {
+		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);
+	}
+
+	mutex_unlock(&thermal_list_lock);
+
+	device_unregister(&cdev->device);
+}
+EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
+
+static void bind_tz(struct thermal_zone_device *tz)
+{
+	int ret;
+	struct thermal_cooling_device *pos = NULL;
+
+	if (!tz->ops->bind)
+		return;
+
+	mutex_lock(&thermal_list_lock);
+
+	list_for_each_entry(pos, &thermal_cdev_list, node) {
+		ret = tz->ops->bind(tz, pos);
+		if (ret)
+			print_bind_err_msg(tz, pos, ret);
+	}
+
+	mutex_unlock(&thermal_list_lock);
+}
+
+static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
+{
+	*delay_jiffies = msecs_to_jiffies(delay_ms);
+	if (delay_ms > 1000)
+		*delay_jiffies = round_jiffies(*delay_jiffies);
+}
+
+int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
+{
+	int i, ret = -EINVAL;
+
+	if (tz->ops->get_crit_temp)
+		return tz->ops->get_crit_temp(tz, temp);
+
+	if (!tz->trips)
+		return -EINVAL;
+
+	mutex_lock(&tz->lock);
+
+	for (i = 0; i < tz->num_trips; i++) {
+		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = tz->trips[i].temperature;
+			ret = 0;
+			break;
+		}
+	}
+
+	mutex_unlock(&tz->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
+
+/**
+ * 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
+ * @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_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
+					void *devdata, struct thermal_zone_device_ops *ops,
+					const struct thermal_zone_params *tzp, int passive_delay,
+					int polling_delay)
+{
+	struct thermal_zone_device *tz;
+	int id;
+	int result;
+	int count;
+	struct thermal_governor *governor;
+
+	if (!type || strlen(type) == 0) {
+		pr_err("No thermal zone type defined\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (strlen(type) >= 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);
+	}
+
+	/*
+	 * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
+	 * For example, shifting by 32 will result in compiler warning:
+	 * warning: right shift count >= width of type [-Wshift-count- overflow]
+	 *
+	 * Also "mask >> num_trips" will always be true with 32 bit shift.
+	 * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
+	 * mask >> 32 = 0x80000000
+	 * This will result in failure for the below condition.
+	 *
+	 * Check will be true when the bit 31 of the mask is set.
+	 * 32 bit shift will cause overflow of 4 byte integer.
+	 */
+	if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
+		pr_err("Incorrect number of thermal trips\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!ops) {
+		pr_err("Thermal zone device ops not defined\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (num_trips > 0 && !trips)
+		return ERR_PTR(-EINVAL);
+
+	if (!thermal_class)
+		return ERR_PTR(-ENODEV);
+
+	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
+	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->thermal_instances);
+	ida_init(&tz->ida);
+	mutex_init(&tz->lock);
+	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));
+
+	if (!ops->critical)
+		ops->critical = thermal_zone_device_critical;
+
+	tz->ops = ops;
+	tz->device.class = thermal_class;
+	tz->devdata = devdata;
+	tz->trips = trips;
+	tz->num_trips = num_trips;
+
+	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
+	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, 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);
+
+	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
+	if (result) {
+		thermal_zone_destroy_device_groups(tz);
+		goto remove_id;
+	}
+	result = device_register(&tz->device);
+	if (result)
+		goto release_device;
+
+	for (count = 0; count < num_trips; count++) {
+		struct thermal_trip trip;
+
+		result = thermal_zone_get_trip(tz, count, &trip);
+		if (result || !trip.temperature)
+			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_init(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);
+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,
+					struct thermal_zone_device_ops *ops,
+					const struct thermal_zone_params *tzp)
+{
+	return thermal_zone_device_register_with_trips(type, NULL, 0, 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);
+
+/**
+ * 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 tz_id;
+	struct thermal_cooling_device *cdev;
+	struct thermal_zone_device *pos = NULL;
+
+	if (!tz)
+		return;
+
+	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);
+
+	mutex_unlock(&thermal_list_lock);
+
+	cancel_delayed_work_sync(&tz->poll_queue);
+
+	thermal_set_governor(tz, NULL);
+
+	thermal_remove_hwmon_sysfs(tz);
+	ida_free(&thermal_tz_ida, tz->id);
+	ida_destroy(&tz->ida);
+
+	mutex_lock(&tz->lock);
+	device_del(&tz->device);
+	mutex_unlock(&tz->lock);
+
+	kfree(tz->tzp);
+
+	put_device(&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) {
+			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 unregister_netlink;
+
+	thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
+	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();
+unregister_netlink:
+	thermal_netlink_exit();
+error:
+	mutex_destroy(&thermal_list_lock);
+	mutex_destroy(&thermal_governor_lock);
+	return result;
+}
+postcore_initcall(thermal_init);