/*
 *  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>
 *
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/kdev_t.h>
#include <linux/idr.h>
#include <linux/thermal.h>
#include <linux/spinlock.h>
#include <linux/reboot.h>

MODULE_AUTHOR("Zhang Rui");
MODULE_DESCRIPTION("Generic thermal management sysfs support");
MODULE_LICENSE("GPL");

#define PREFIX "Thermal: "

struct thermal_cooling_device_instance {
        int id;
        char name[THERMAL_NAME_LENGTH];
        struct thermal_zone_device *tz;
        struct thermal_cooling_device *cdev;
        int trip;
        char attr_name[THERMAL_NAME_LENGTH];
        struct device_attribute attr;
        struct list_head node;
};

static DEFINE_IDR(thermal_tz_idr);
static DEFINE_IDR(thermal_cdev_idr);
static DEFINE_MUTEX(thermal_idr_lock);

static LIST_HEAD(thermal_tz_list);
static LIST_HEAD(thermal_cdev_list);
static DEFINE_MUTEX(thermal_list_lock);

static int get_idr(struct idr *idr, struct mutex *lock, int *id)
{
        int err;

      again:
        if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0))
                return -ENOMEM;

        if (lock)
                mutex_lock(lock);
        err = idr_get_new(idr, NULL, id);
        if (lock)
                mutex_unlock(lock);
        if (unlikely(err == -EAGAIN))
                goto again;
        else if (unlikely(err))
                return err;

        *id = *id & MAX_ID_MASK;
        return 0;
}

static void release_idr(struct idr *idr, struct mutex *lock, int id)
{
        if (lock)
                mutex_lock(lock);
        idr_remove(idr, id);
        if (lock)
                mutex_unlock(lock);
}

/* sys I/F for thermal zone */

#define to_thermal_zone(_dev) \
        container_of(_dev, struct thermal_zone_device, device)

static ssize_t
type_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);

        return sprintf(buf, "%s\n", tz->type);
}

static ssize_t
temp_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        long temperature;
        int ret;

        if (!tz->ops->get_temp)
                return -EPERM;

        ret = tz->ops->get_temp(tz, &temperature);

        if (ret)
                return ret;

        return sprintf(buf, "%ld\n", temperature);
}

static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        enum thermal_device_mode mode;
        int result;

        if (!tz->ops->get_mode)
                return -EPERM;

        result = tz->ops->get_mode(tz, &mode);
        if (result)
                return result;

        return sprintf(buf, "%s\n", mode == THERMAL_DEVICE_ENABLED ? "enabled"
                       : "disabled");
}

static ssize_t
mode_store(struct device *dev, struct device_attribute *attr,
           const char *buf, size_t count)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        int result;

        if (!tz->ops->set_mode)
                return -EPERM;

        if (!strncmp(buf, "enabled", sizeof("enabled")))
                result = tz->ops->set_mode(tz, THERMAL_DEVICE_ENABLED);
        else if (!strncmp(buf, "disabled", sizeof("disabled")))
                result = tz->ops->set_mode(tz, THERMAL_DEVICE_DISABLED);
        else
                result = -EINVAL;

        if (result)
                return result;

        return count;
}

static ssize_t
trip_point_type_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        enum thermal_trip_type type;
        int trip, result;

        if (!tz->ops->get_trip_type)
                return -EPERM;

        if (!sscanf(attr->attr.name, "trip_point_%d_type", &trip))
                return -EINVAL;

        result = tz->ops->get_trip_type(tz, trip, &type);
        if (result)
                return result;

        switch (type) {
        case THERMAL_TRIP_CRITICAL:
                return sprintf(buf, "critical\n");
        case THERMAL_TRIP_HOT:
                return sprintf(buf, "hot\n");
        case THERMAL_TRIP_PASSIVE:
                return sprintf(buf, "passive\n");
        case THERMAL_TRIP_ACTIVE:
                return sprintf(buf, "active\n");
        default:
                return sprintf(buf, "unknown\n");
        }
}

static ssize_t
trip_point_temp_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        int trip, ret;
        long temperature;

        if (!tz->ops->get_trip_temp)
                return -EPERM;

        if (!sscanf(attr->attr.name, "trip_point_%d_temp", &trip))
                return -EINVAL;

        ret = tz->ops->get_trip_temp(tz, trip, &temperature);

        if (ret)
                return ret;

        return sprintf(buf, "%ld\n", temperature);
}

static ssize_t
passive_store(struct device *dev, struct device_attribute *attr,
                    const char *buf, size_t count)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);
        struct thermal_cooling_device *cdev = NULL;
        int state;

        if (!sscanf(buf, "%d\n", &state))
                return -EINVAL;

        /* sanity check: values below 1000 millicelcius don't make sense
         * and can cause the system to go into a thermal heart attack
         */
        if (state && state < 1000)
                return -EINVAL;

        if (state && !tz->forced_passive) {
                mutex_lock(&thermal_list_lock);
                list_for_each_entry(cdev, &thermal_cdev_list, node) {
                        if (!strncmp("Processor", cdev->type,
                                     sizeof("Processor")))
                                thermal_zone_bind_cooling_device(tz,
                                                                 THERMAL_TRIPS_NONE,
                                                                 cdev);
                }
                mutex_unlock(&thermal_list_lock);
                if (!tz->passive_delay)
                        tz->passive_delay = 1000;
        } else if (!state && tz->forced_passive) {
                mutex_lock(&thermal_list_lock);
                list_for_each_entry(cdev, &thermal_cdev_list, node) {
                        if (!strncmp("Processor", cdev->type,
                                     sizeof("Processor")))
                                thermal_zone_unbind_cooling_device(tz,
                                                                   THERMAL_TRIPS_NONE,
                                                                   cdev);
                }
                mutex_unlock(&thermal_list_lock);
                tz->passive_delay = 0;
        }

        tz->tc1 = 1;
        tz->tc2 = 1;

        tz->forced_passive = state;

        thermal_zone_device_update(tz);

        return count;
}

static ssize_t
passive_show(struct device *dev, struct device_attribute *attr,
                   char *buf)
{
        struct thermal_zone_device *tz = to_thermal_zone(dev);

        return sprintf(buf, "%d\n", tz->forced_passive);
}

static DEVICE_ATTR(type, 0444, type_show, NULL);
static DEVICE_ATTR(temp, 0444, temp_show, NULL);
static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
static DEVICE_ATTR(passive, S_IRUGO | S_IWUSR, passive_show, \
                   passive_store);

static struct device_attribute trip_point_attrs[] = {
        __ATTR(trip_point_0_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_0_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_1_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_1_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_2_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_2_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_3_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_3_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_4_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_4_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_5_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_5_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_6_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_6_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_7_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_7_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_8_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_8_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_9_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_9_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_10_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_10_temp, 0444, trip_point_temp_show, NULL),
        __ATTR(trip_point_11_type, 0444, trip_point_type_show, NULL),
        __ATTR(trip_point_11_temp, 0444, trip_point_temp_show, NULL),
};

#define TRIP_POINT_ATTR_ADD(_dev, _index, result)     \
do {    \
        result = device_create_file(_dev,       \
                                &trip_point_attrs[_index * 2]); \
        if (result)     \
                break;  \
        result = device_create_file(_dev,       \
                        &trip_point_attrs[_index * 2 + 1]);     \
} while (0)

#define TRIP_POINT_ATTR_REMOVE(_dev, _index)    \
do {    \
        device_remove_file(_dev, &trip_point_attrs[_index * 2]);        \
        device_remove_file(_dev, &trip_point_attrs[_index * 2 + 1]);    \
} while (0)

/* sys I/F for cooling device */
#define to_cooling_device(_dev) \
        container_of(_dev, struct thermal_cooling_device, device)

static ssize_t
thermal_cooling_device_type_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
{
        struct thermal_cooling_device *cdev = to_cooling_device(dev);

        return sprintf(buf, "%s\n", cdev->type);
}

static ssize_t
thermal_cooling_device_max_state_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
{
        struct thermal_cooling_device *cdev = to_cooling_device(dev);
        unsigned long state;
        int ret;

        ret = cdev->ops->get_max_state(cdev, &state);
        if (ret)
                return ret;
        return sprintf(buf, "%ld\n", state);
}

static ssize_t
thermal_cooling_device_cur_state_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
{
        struct thermal_cooling_device *cdev = to_cooling_device(dev);
        unsigned long state;
        int ret;

        ret = cdev->ops->get_cur_state(cdev, &state);
        if (ret)
                return ret;
        return sprintf(buf, "%ld\n", state);
}

static ssize_t
thermal_cooling_device_cur_state_store(struct device *dev,
                                       struct device_attribute *attr,
                                       const char *buf, size_t count)
{
        struct thermal_cooling_device *cdev = to_cooling_device(dev);
        unsigned long state;
        int result;

        if (!sscanf(buf, "%ld\n", &state))
                return -EINVAL;

        if ((long)state < 0)
                return -EINVAL;

        result = cdev->ops->set_cur_state(cdev, state);
        if (result)
                return result;
        return count;
}

static struct device_attribute dev_attr_cdev_type =
__ATTR(type, 0444, thermal_cooling_device_type_show, NULL);
static DEVICE_ATTR(max_state, 0444,
                   thermal_cooling_device_max_state_show, NULL);
static DEVICE_ATTR(cur_state, 0644,
                   thermal_cooling_device_cur_state_show,
                   thermal_cooling_device_cur_state_store);

static ssize_t
thermal_cooling_device_trip_point_show(struct device *dev,
                                       struct device_attribute *attr, char *buf)
{
        struct thermal_cooling_device_instance *instance;

        instance =
            container_of(attr, struct thermal_cooling_device_instance, attr);

        if (instance->trip == THERMAL_TRIPS_NONE)
                return sprintf(buf, "-1\n");
        else
                return sprintf(buf, "%d\n", instance->trip);
}

/* Device management */

#if defined(CONFIG_THERMAL_HWMON)

/* hwmon sys I/F */
#include <linux/hwmon.h>
static LIST_HEAD(thermal_hwmon_list);

static ssize_t
name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct thermal_hwmon_device *hwmon = dev_get_drvdata(dev);
        return sprintf(buf, "%s\n", hwmon->type);
}
static DEVICE_ATTR(name, 0444, name_show, NULL);

static ssize_t
temp_input_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        long temperature;
        int ret;
        struct thermal_hwmon_attr *hwmon_attr
                        = container_of(attr, struct thermal_hwmon_attr, attr);
        struct thermal_zone_device *tz
                        = container_of(hwmon_attr, struct thermal_zone_device,
                                       temp_input);

        ret = tz->ops->get_temp(tz, &temperature);

        if (ret)
                return ret;

        return sprintf(buf, "%ld\n", temperature);
}

static ssize_t
temp_crit_show(struct device *dev, struct device_attribute *attr,
                char *buf)
{
        struct thermal_hwmon_attr *hwmon_attr
                        = container_of(attr, struct thermal_hwmon_attr, attr);
        struct thermal_zone_device *tz
                        = container_of(hwmon_attr, struct thermal_zone_device,
                                       temp_crit);
        long temperature;
        int ret;

        ret = tz->ops->get_trip_temp(tz, 0, &temperature);
        if (ret)
                return ret;

        return sprintf(buf, "%ld\n", temperature);
}


static int
thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
{
        struct thermal_hwmon_device *hwmon;
        int new_hwmon_device = 1;
        int result;

        mutex_lock(&thermal_list_lock);
        list_for_each_entry(hwmon, &thermal_hwmon_list, node)
                if (!strcmp(hwmon->type, tz->type)) {
                        new_hwmon_device = 0;
                        mutex_unlock(&thermal_list_lock);
                        goto register_sys_interface;
                }
        mutex_unlock(&thermal_list_lock);

        hwmon = kzalloc(sizeof(struct thermal_hwmon_device), GFP_KERNEL);
        if (!hwmon)
                return -ENOMEM;

        INIT_LIST_HEAD(&hwmon->tz_list);
        strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH);
        hwmon->device = hwmon_device_register(NULL);
        if (IS_ERR(hwmon->device)) {
                result = PTR_ERR(hwmon->device);
                goto free_mem;
        }
        dev_set_drvdata(hwmon->device, hwmon);
        result = device_create_file(hwmon->device, &dev_attr_name);
        if (result)
                goto unregister_hwmon_device;

 register_sys_interface:
        tz->hwmon = hwmon;
        hwmon->count++;

        snprintf(tz->temp_input.name, THERMAL_NAME_LENGTH,
                 "temp%d_input", hwmon->count);
        tz->temp_input.attr.attr.name = tz->temp_input.name;
        tz->temp_input.attr.attr.mode = 0444;
        tz->temp_input.attr.show = temp_input_show;
        sysfs_attr_init(&tz->temp_input.attr.attr);
        result = device_create_file(hwmon->device, &tz->temp_input.attr);
        if (result)
                goto unregister_hwmon_device;

        if (tz->ops->get_crit_temp) {
                unsigned long temperature;
                if (!tz->ops->get_crit_temp(tz, &temperature)) {
                        snprintf(tz->temp_crit.name, THERMAL_NAME_LENGTH,
                                "temp%d_crit", hwmon->count);
                        tz->temp_crit.attr.attr.name = tz->temp_crit.name;
                        tz->temp_crit.attr.attr.mode = 0444;
                        tz->temp_crit.attr.show = temp_crit_show;
                        sysfs_attr_init(&tz->temp_crit.attr.attr);
                        result = device_create_file(hwmon->device,
                                                    &tz->temp_crit.attr);
                        if (result)
                                goto unregister_hwmon_device;
                }
        }

        mutex_lock(&thermal_list_lock);
        if (new_hwmon_device)
                list_add_tail(&hwmon->node, &thermal_hwmon_list);
        list_add_tail(&tz->hwmon_node, &hwmon->tz_list);
        mutex_unlock(&thermal_list_lock);

        return 0;

 unregister_hwmon_device:
        device_remove_file(hwmon->device, &tz->temp_crit.attr);
        device_remove_file(hwmon->device, &tz->temp_input.attr);
        if (new_hwmon_device) {
                device_remove_file(hwmon->device, &dev_attr_name);
                hwmon_device_unregister(hwmon->device);
        }
 free_mem:
        if (new_hwmon_device)
                kfree(hwmon);

        return result;
}

static void
thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
{
        struct thermal_hwmon_device *hwmon = tz->hwmon;

        tz->hwmon = NULL;
        device_remove_file(hwmon->device, &tz->temp_input.attr);
        device_remove_file(hwmon->device, &tz->temp_crit.attr);

        mutex_lock(&thermal_list_lock);
        list_del(&tz->hwmon_node);
        if (!list_empty(&hwmon->tz_list)) {
                mutex_unlock(&thermal_list_lock);
                return;
        }
        list_del(&hwmon->node);
        mutex_unlock(&thermal_list_lock);

        device_remove_file(hwmon->device, &dev_attr_name);
        hwmon_device_unregister(hwmon->device);
        kfree(hwmon);
}
#else
static int
thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
{
        return 0;
}

static void
thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
{
}
#endif

static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
                                            int delay)
{
        cancel_delayed_work(&(tz->poll_queue));

        if (!delay)
                return;

        if (delay > 1000)
                schedule_delayed_work(&(tz->poll_queue),
                                      round_jiffies(msecs_to_jiffies(delay)));
        else
                schedule_delayed_work(&(tz->poll_queue),
                                      msecs_to_jiffies(delay));
}

static void thermal_zone_device_passive(struct thermal_zone_device *tz,
                                        int temp, int trip_temp, int trip)
{
        int trend = 0;
        struct thermal_cooling_device_instance *instance;
        struct thermal_cooling_device *cdev;
        long state, max_state;

        /*
         * Above Trip?
         * -----------
         * Calculate the thermal trend (using the passive cooling equation)
         * and modify the performance limit for all passive cooling devices
         * accordingly.  Note that we assume symmetry.
         */
        if (temp >= trip_temp) {
                tz->passive = true;

                trend = (tz->tc1 * (temp - tz->last_temperature)) +
                        (tz->tc2 * (temp - trip_temp));

                /* Heating up? */
                if (trend > 0) {
                        list_for_each_entry(instance, &tz->cooling_devices,
                                            node) {
                                if (instance->trip != trip)
                                        continue;
                                cdev = instance->cdev;
                                cdev->ops->get_cur_state(cdev, &state);
                                cdev->ops->get_max_state(cdev, &max_state);
                                if (state++ < max_state)
                                        cdev->ops->set_cur_state(cdev, state);
                        }
                } else if (trend < 0) { /* Cooling off? */
                        list_for_each_entry(instance, &tz->cooling_devices,
                                            node) {
                                if (instance->trip != trip)
                                        continue;
                                cdev = instance->cdev;
                                cdev->ops->get_cur_state(cdev, &state);
                                cdev->ops->get_max_state(cdev, &max_state);
                                if (state > 0)
                                        cdev->ops->set_cur_state(cdev, --state);
                        }
                }
                return;
        }

        /*
         * Below Trip?
         * -----------
         * Implement passive cooling hysteresis to slowly increase performance
         * and avoid thrashing around the passive trip point.  Note that we
         * assume symmetry.
         */
        list_for_each_entry(instance, &tz->cooling_devices, node) {
                if (instance->trip != trip)
                        continue;
                cdev = instance->cdev;
                cdev->ops->get_cur_state(cdev, &state);
                cdev->ops->get_max_state(cdev, &max_state);
                if (state > 0)
                        cdev->ops->set_cur_state(cdev, --state);
                if (state == 0)
                        tz->passive = false;
        }
}

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_zone_bind_cooling_device - bind a cooling device to a thermal zone
 * @tz:         thermal zone device
 * @trip:       indicates which trip point the cooling devices is
 *              associated with in this thermal zone.
 * @cdev:       thermal cooling device
 *
 * This function is usually called in the thermal zone device .bind callback.
 */
int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
                                     int trip,
                                     struct thermal_cooling_device *cdev)
{
        struct thermal_cooling_device_instance *dev;
        struct thermal_cooling_device_instance *pos;
        struct thermal_zone_device *pos1;
        struct thermal_cooling_device *pos2;
        int result;

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

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

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

        dev =
            kzalloc(sizeof(struct thermal_cooling_device_instance), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;
        dev->tz = tz;
        dev->cdev = cdev;
        dev->trip = trip;
        result = get_idr(&tz->idr, &tz->lock, &dev->id);
        if (result)
                goto free_mem;

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

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

        mutex_lock(&tz->lock);
        list_for_each_entry(pos, &tz->cooling_devices, node)
            if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
                result = -EEXIST;
                break;
        }
        if (!result)
                list_add_tail(&dev->node, &tz->cooling_devices);
        mutex_unlock(&tz->lock);

        if (!result)
                return 0;

        device_remove_file(&tz->device, &dev->attr);
      remove_symbol_link:
        sysfs_remove_link(&tz->device.kobj, dev->name);
      release_idr:
        release_idr(&tz->idr, &tz->lock, dev->id);
      free_mem:
        kfree(dev);
        return result;
}

EXPORT_SYMBOL(thermal_zone_bind_cooling_device);

/**
 * thermal_zone_unbind_cooling_device - unbind a cooling device from a thermal zone
 * @tz:         thermal zone device
 * @trip:       indicates which trip point the cooling devices is
 *              associated with in this thermal zone.
 * @cdev:       thermal cooling device
 *
 * This function is usually called in the thermal zone device .unbind callback.
 */
int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
                                       int trip,
                                       struct thermal_cooling_device *cdev)
{
        struct thermal_cooling_device_instance *pos, *next;

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

        return -ENODEV;

      unbind:
        device_remove_file(&tz->device, &pos->attr);
        sysfs_remove_link(&tz->device.kobj, pos->name);
        release_idr(&tz->idr, &tz->lock, pos->id);
        kfree(pos);
        return 0;
}

EXPORT_SYMBOL(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);
                kfree(tz);
        } else {
                cdev = to_cooling_device(dev);
                kfree(cdev);
        }
}

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

/**
 * 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.
 */
struct thermal_cooling_device *thermal_cooling_device_register(char *type,
                                                               void *devdata,
                                                               struct
                                                               thermal_cooling_device_ops
                                                               *ops)
{
        struct thermal_cooling_device *cdev;
        struct thermal_zone_device *pos;
        int result;

        if (strlen(type) >= THERMAL_NAME_LENGTH)
                return ERR_PTR(-EINVAL);

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

        cdev = kzalloc(sizeof(struct thermal_cooling_device), GFP_KERNEL);
        if (!cdev)
                return ERR_PTR(-ENOMEM);

        result = get_idr(&thermal_cdev_idr, &thermal_idr_lock, &cdev->id);
        if (result) {
                kfree(cdev);
                return ERR_PTR(result);
        }

        strcpy(cdev->type, type);
        cdev->ops = ops;
        cdev->device.class = &thermal_class;
        cdev->devdata = devdata;
        dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
        result = device_register(&cdev->device);
        if (result) {
                release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
                kfree(cdev);
                return ERR_PTR(result);
        }

        /* sys I/F */
        if (type) {
                result = device_create_file(&cdev->device, &dev_attr_cdev_type);
                if (result)
                        goto unregister;
        }

        result = device_create_file(&cdev->device, &dev_attr_max_state);
        if (result)
                goto unregister;

        result = device_create_file(&cdev->device, &dev_attr_cur_state);
        if (result)
                goto unregister;

        mutex_lock(&thermal_list_lock);
        list_add(&cdev->node, &thermal_cdev_list);
        list_for_each_entry(pos, &thermal_tz_list, node) {
                if (!pos->ops->bind)
                        continue;
                result = pos->ops->bind(pos, cdev);
                if (result)
                        break;

        }
        mutex_unlock(&thermal_list_lock);

        if (!result)
                return cdev;

      unregister:
        release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
        device_unregister(&cdev->device);
        return ERR_PTR(result);
}

EXPORT_SYMBOL(thermal_cooling_device_register);

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

        if (!cdev)
                return;

        mutex_lock(&thermal_list_lock);
        list_for_each_entry(pos, &thermal_cdev_list, node)
            if (pos == cdev)
                break;
        if (pos != cdev) {
                /* thermal cooling device not found */
                mutex_unlock(&thermal_list_lock);
                return;
        }
        list_del(&cdev->node);
        list_for_each_entry(tz, &thermal_tz_list, node) {
                if (!tz->ops->unbind)
                        continue;
                tz->ops->unbind(tz, cdev);
        }
        mutex_unlock(&thermal_list_lock);
        if (cdev->type[0])
                device_remove_file(&cdev->device, &dev_attr_cdev_type);
        device_remove_file(&cdev->device, &dev_attr_max_state);
        device_remove_file(&cdev->device, &dev_attr_cur_state);

        release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
        device_unregister(&cdev->device);
        return;
}

EXPORT_SYMBOL(thermal_cooling_device_unregister);

/**
 * thermal_zone_device_update - force an update of a thermal zone's state
 * @ttz:        the thermal zone to update
 */

void thermal_zone_device_update(struct thermal_zone_device *tz)
{
        int count, ret = 0;
        long temp, trip_temp;
        enum thermal_trip_type trip_type;
        struct thermal_cooling_device_instance *instance;
        struct thermal_cooling_device *cdev;

        mutex_lock(&tz->lock);

        if (tz->ops->get_temp(tz, &temp)) {
                /* get_temp failed - retry it later */
                printk(KERN_WARNING PREFIX "failed to read out thermal zone "
                       "%d\n", tz->id);
                goto leave;
        }

        for (count = 0; count < tz->trips; count++) {
                tz->ops->get_trip_type(tz, count, &trip_type);
                tz->ops->get_trip_temp(tz, count, &trip_temp);

                switch (trip_type) {
                case THERMAL_TRIP_CRITICAL:
                        if (temp >= trip_temp) {
                                if (tz->ops->notify)
                                        ret = tz->ops->notify(tz, count,
                                                              trip_type);
                                if (!ret) {
                                        printk(KERN_EMERG
                                               "Critical temperature reached (%ld C), shutting down.\n",
                                               temp/1000);
                                        orderly_poweroff(true);
                                }
                        }
                        break;
                case THERMAL_TRIP_HOT:
                        if (temp >= trip_temp)
                                if (tz->ops->notify)
                                        tz->ops->notify(tz, count, trip_type);
                        break;
                case THERMAL_TRIP_ACTIVE:
                        list_for_each_entry(instance, &tz->cooling_devices,
                                            node) {
                                if (instance->trip != count)
                                        continue;

                                cdev = instance->cdev;

                                if (temp >= trip_temp)
                                        cdev->ops->set_cur_state(cdev, 1);
                                else
                                        cdev->ops->set_cur_state(cdev, 0);
                        }
                        break;
                case THERMAL_TRIP_PASSIVE:
                        if (temp >= trip_temp || tz->passive)
                                thermal_zone_device_passive(tz, temp,
                                                            trip_temp, count);
                        break;
                }
        }

        if (tz->forced_passive)
                thermal_zone_device_passive(tz, temp, tz->forced_passive,
                                            THERMAL_TRIPS_NONE);

        tz->last_temperature = temp;

      leave:
        if (tz->passive)
                thermal_zone_device_set_polling(tz, tz->passive_delay);
        else if (tz->polling_delay)
                thermal_zone_device_set_polling(tz, tz->polling_delay);
        else
                thermal_zone_device_set_polling(tz, 0);
        mutex_unlock(&tz->lock);
}
EXPORT_SYMBOL(thermal_zone_device_update);

/**
 * thermal_zone_device_register - register a new thermal zone device
 * @type:       the thermal zone device type
 * @trips:      the number of trip points the thermal zone support
 * @devdata:    private device data
 * @ops:        standard thermal zone device callbacks
 * @tc1:        thermal coefficient 1 for passive calculations
 * @tc2:        thermal coefficient 2 for passive calculations
 * @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)
 *
 * thermal_zone_device_unregister() must be called when the device is no
 * longer needed. The passive cooling formula uses tc1 and tc2 as described in
 * section 11.1.5.1 of the ACPI specification 3.0.
 */
struct thermal_zone_device *thermal_zone_device_register(char *type,
                                                         int trips,
                                                         void *devdata, struct
                                                         thermal_zone_device_ops
                                                         *ops, int tc1, int
                                                         tc2,
                                                         int passive_delay,
                                                         int polling_delay)
{
        struct thermal_zone_device *tz;
        struct thermal_cooling_device *pos;
        enum thermal_trip_type trip_type;
        int result;
        int count;
        int passive = 0;

        if (strlen(type) >= THERMAL_NAME_LENGTH)
                return ERR_PTR(-EINVAL);

        if (trips > THERMAL_MAX_TRIPS || trips < 0)
                return ERR_PTR(-EINVAL);

        if (!ops || !ops->get_temp)
                return ERR_PTR(-EINVAL);

        tz = kzalloc(sizeof(struct thermal_zone_device), GFP_KERNEL);
        if (!tz)
                return ERR_PTR(-ENOMEM);

        INIT_LIST_HEAD(&tz->cooling_devices);
        idr_init(&tz->idr);
        mutex_init(&tz->lock);
        result = get_idr(&thermal_tz_idr, &thermal_idr_lock, &tz->id);
        if (result) {
                kfree(tz);
                return ERR_PTR(result);
        }

        strcpy(tz->type, type);
        tz->ops = ops;
        tz->device.class = &thermal_class;
        tz->devdata = devdata;
        tz->trips = trips;
        tz->tc1 = tc1;
        tz->tc2 = tc2;
        tz->passive_delay = passive_delay;
        tz->polling_delay = polling_delay;

        dev_set_name(&tz->device, "thermal_zone%d", tz->id);
        result = device_register(&tz->device);
        if (result) {
                release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
                kfree(tz);
                return ERR_PTR(result);
        }

        /* sys I/F */
        if (type) {
                result = device_create_file(&tz->device, &dev_attr_type);
                if (result)
                        goto unregister;
        }

        result = device_create_file(&tz->device, &dev_attr_temp);
        if (result)
                goto unregister;

        if (ops->get_mode) {
                result = device_create_file(&tz->device, &dev_attr_mode);
                if (result)
                        goto unregister;
        }

        for (count = 0; count < trips; count++) {
                TRIP_POINT_ATTR_ADD(&tz->device, count, result);
                if (result)
                        goto unregister;
                tz->ops->get_trip_type(tz, count, &trip_type);
                if (trip_type == THERMAL_TRIP_PASSIVE)
                        passive = 1;
        }

        if (!passive)
                result = device_create_file(&tz->device,
                                            &dev_attr_passive);

        if (result)
                goto unregister;

        result = thermal_add_hwmon_sysfs(tz);
        if (result)
                goto unregister;

        mutex_lock(&thermal_list_lock);
        list_add_tail(&tz->node, &thermal_tz_list);
        if (ops->bind)
                list_for_each_entry(pos, &thermal_cdev_list, node) {
                result = ops->bind(tz, pos);
                if (result)
                        break;
                }
        mutex_unlock(&thermal_list_lock);

        INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);

        thermal_zone_device_update(tz);

        if (!result)
                return tz;

      unregister:
        release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
        device_unregister(&tz->device);
        return ERR_PTR(result);
}

EXPORT_SYMBOL(thermal_zone_device_register);

/**
 * thermal_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)
{
        struct thermal_cooling_device *cdev;
        struct thermal_zone_device *pos = NULL;
        int count;

        if (!tz)
                return;

        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);
        if (tz->ops->unbind)
                list_for_each_entry(cdev, &thermal_cdev_list, node)
                    tz->ops->unbind(tz, cdev);
        mutex_unlock(&thermal_list_lock);

        thermal_zone_device_set_polling(tz, 0);

        if (tz->type[0])
                device_remove_file(&tz->device, &dev_attr_type);
        device_remove_file(&tz->device, &dev_attr_temp);
        if (tz->ops->get_mode)
                device_remove_file(&tz->device, &dev_attr_mode);

        for (count = 0; count < tz->trips; count++)
                TRIP_POINT_ATTR_REMOVE(&tz->device, count);

        thermal_remove_hwmon_sysfs(tz);
        release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
        idr_destroy(&tz->idr);
        mutex_destroy(&tz->lock);
        device_unregister(&tz->device);
        return;
}

EXPORT_SYMBOL(thermal_zone_device_unregister);

static int __init thermal_init(void)
{
        int result = 0;

        result = class_register(&thermal_class);
        if (result) {
                idr_destroy(&thermal_tz_idr);
                idr_destroy(&thermal_cdev_idr);
                mutex_destroy(&thermal_idr_lock);
                mutex_destroy(&thermal_list_lock);
        }
        return result;
}

static void __exit thermal_exit(void)
{
        class_unregister(&thermal_class);
        idr_destroy(&thermal_tz_idr);
        idr_destroy(&thermal_cdev_idr);
        mutex_destroy(&thermal_idr_lock);
        mutex_destroy(&thermal_list_lock);
}

subsys_initcall(thermal_init);
module_exit(thermal_exit);