// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 *  This driver fully implements the ACPI thermal policy as described in the
 *  ACPI 2.0 Specification.
 *
 *  TBD: 1. Implement passive cooling hysteresis.
 *       2. Enhance passive cooling (CPU) states/limit interface to support
 *          concepts of 'multiple limiters', upper/lower limits, etc.
 */

#define pr_fmt(fmt) "ACPI: thermal: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/kmod.h>
#include <linux/reboot.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>
#include <linux/acpi.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
#include <linux/units.h>

#include "internal.h"

#define ACPI_THERMAL_CLASS              "thermal_zone"
#define ACPI_THERMAL_DEVICE_NAME        "Thermal Zone"
#define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
#define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
#define ACPI_THERMAL_NOTIFY_DEVICES     0x82
#define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
#define ACPI_THERMAL_NOTIFY_HOT         0xF1
#define ACPI_THERMAL_MODE_ACTIVE        0x00

#define ACPI_THERMAL_MAX_ACTIVE         10
#define ACPI_THERMAL_MAX_LIMIT_STR_LEN  65

#define ACPI_THERMAL_TRIP_PASSIVE       (-1)

#define ACPI_THERMAL_MAX_NR_TRIPS       (ACPI_THERMAL_MAX_ACTIVE + 3)

/*
 * This exception is thrown out in two cases:
 * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 *   when re-evaluating the AML code.
 * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 */
#define ACPI_THERMAL_TRIPS_EXCEPTION(tz, str) \
do { \
        acpi_handle_info(tz->device->handle, \
                         "ACPI thermal trip point %s changed\n" \
                         "Please report to linux-acpi@vger.kernel.org\n", str); \
} while (0)

static int act;
module_param(act, int, 0644);
MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");

static int crt;
module_param(crt, int, 0644);
MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");

static int tzp;
module_param(tzp, int, 0444);
MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");

static int off;
module_param(off, int, 0);
MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");

static int psv;
module_param(psv, int, 0644);
MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");

static struct workqueue_struct *acpi_thermal_pm_queue;

struct acpi_thermal_trip {
        unsigned long temp_dk;
        struct acpi_handle_list devices;
};

struct acpi_thermal_passive {
        struct acpi_thermal_trip trip;
        unsigned long tc1;
        unsigned long tc2;
        unsigned long delay;
};

struct acpi_thermal_active {
        struct acpi_thermal_trip trip;
};

struct acpi_thermal_trips {
        struct acpi_thermal_passive passive;
        struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
};

struct acpi_thermal {
        struct acpi_device *device;
        acpi_bus_id name;
        unsigned long temp_dk;
        unsigned long last_temp_dk;
        unsigned long polling_frequency;
        volatile u8 zombie;
        struct acpi_thermal_trips trips;
        struct thermal_zone_device *thermal_zone;
        int kelvin_offset;      /* in millidegrees */
        struct work_struct thermal_check_work;
        struct mutex thermal_check_lock;
        refcount_t thermal_check_count;
};

/* --------------------------------------------------------------------------
                             Thermal Zone Management
   -------------------------------------------------------------------------- */

static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
{
        acpi_status status = AE_OK;
        unsigned long long tmp;

        if (!tz)
                return -EINVAL;

        tz->last_temp_dk = tz->temp_dk;

        status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        tz->temp_dk = tmp;

        acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
                          tz->temp_dk);

        return 0;
}

static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
{
        acpi_status status = AE_OK;
        unsigned long long tmp;

        if (!tz)
                return -EINVAL;

        status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        tz->polling_frequency = tmp;
        acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
                          tz->polling_frequency);

        return 0;
}

static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k)
{
        int temp;

        if (temp_deci_k == THERMAL_TEMP_INVALID)
                return THERMAL_TEMP_INVALID;

        temp = deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
                                                       tz->kelvin_offset);
        if (temp <= 0)
                return THERMAL_TEMP_INVALID;

        return temp;
}

static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip)
{
        return acpi_trip->temp_dk != THERMAL_TEMP_INVALID;
}

static int active_trip_index(struct acpi_thermal *tz,
                             struct acpi_thermal_trip *acpi_trip)
{
        struct acpi_thermal_active *active;

        active = container_of(acpi_trip, struct acpi_thermal_active, trip);
        return active - tz->trips.active;
}

static long get_passive_temp(struct acpi_thermal *tz)
{
        int temp;

        if (acpi_passive_trip_temp(tz->device, &temp))
                return THERMAL_TEMP_INVALID;

        return temp;
}

static long get_active_temp(struct acpi_thermal *tz, int index)
{
        int temp;

        if (acpi_active_trip_temp(tz->device, index, &temp))
                return THERMAL_TEMP_INVALID;

        /*
         * If an override has been provided, apply it so there are no active
         * trips with thresholds greater than the override.
         */
        if (act > 0) {
                unsigned long long override = celsius_to_deci_kelvin(act);

                if (temp > override)
                        return override;
        }
        return temp;
}

static void acpi_thermal_update_trip(struct acpi_thermal *tz,
                                     const struct thermal_trip *trip)
{
        struct acpi_thermal_trip *acpi_trip = trip->priv;

        if (trip->type == THERMAL_TRIP_PASSIVE) {
                if (psv > 0)
                        return;

                acpi_trip->temp_dk = get_passive_temp(tz);
        } else {
                int index = active_trip_index(tz, acpi_trip);

                acpi_trip->temp_dk = get_active_temp(tz, index);
        }

        if (!acpi_thermal_trip_valid(acpi_trip))
                ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
}

static bool update_trip_devices(struct acpi_thermal *tz,
                                struct acpi_thermal_trip *acpi_trip,
                                int index, bool compare)
{
        struct acpi_handle_list devices = { 0 };
        char method[] = "_PSL";

        if (index != ACPI_THERMAL_TRIP_PASSIVE) {
                method[1] = 'A';
                method[2] = 'L';
                method[3] = '0' + index;
        }

        if (!acpi_evaluate_reference(tz->device->handle, method, NULL, &devices)) {
                acpi_handle_info(tz->device->handle, "%s evaluation failure\n", method);
                return false;
        }

        if (acpi_handle_list_equal(&acpi_trip->devices, &devices)) {
                acpi_handle_list_free(&devices);
                return true;
        }

        if (compare)
                ACPI_THERMAL_TRIPS_EXCEPTION(tz, "device");

        acpi_handle_list_replace(&acpi_trip->devices, &devices);
        return true;
}

static void acpi_thermal_update_trip_devices(struct acpi_thermal *tz,
                                             const struct thermal_trip *trip)
{
        struct acpi_thermal_trip *acpi_trip = trip->priv;
        int index = trip->type == THERMAL_TRIP_PASSIVE ?
                        ACPI_THERMAL_TRIP_PASSIVE : active_trip_index(tz, acpi_trip);

        if (update_trip_devices(tz, acpi_trip, index, true))
                return;

        acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
        ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
}

struct adjust_trip_data {
        struct acpi_thermal *tz;
        u32 event;
};

static int acpi_thermal_adjust_trip(struct thermal_trip *trip, void *data)
{
        struct acpi_thermal_trip *acpi_trip = trip->priv;
        struct adjust_trip_data *atd = data;
        struct acpi_thermal *tz = atd->tz;
        int temp;

        if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
                return 0;

        if (atd->event == ACPI_THERMAL_NOTIFY_THRESHOLDS)
                acpi_thermal_update_trip(tz, trip);
        else
                acpi_thermal_update_trip_devices(tz, trip);

        if (acpi_thermal_trip_valid(acpi_trip))
                temp = acpi_thermal_temp(tz, acpi_trip->temp_dk);
        else
                temp = THERMAL_TEMP_INVALID;

        thermal_zone_set_trip_temp(tz->thermal_zone, trip, temp);

        return 0;
}

static void acpi_queue_thermal_check(struct acpi_thermal *tz)
{
        if (!work_pending(&tz->thermal_check_work))
                queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
}

static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
{
        struct adjust_trip_data atd = { .tz = tz, .event = event };
        struct acpi_device *adev = tz->device;

        /*
         * Use thermal_zone_for_each_trip() to carry out the trip points
         * update, so as to protect thermal_get_trend() from getting stale
         * trip point temperatures and to prevent thermal_zone_device_update()
         * invoked from acpi_thermal_check_fn() from producing inconsistent
         * results.
         */
        thermal_zone_for_each_trip(tz->thermal_zone,
                                   acpi_thermal_adjust_trip, &atd);
        acpi_queue_thermal_check(tz);
        acpi_bus_generate_netlink_event(adev->pnp.device_class,
                                        dev_name(&adev->dev), event, 0);
}

static int acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
{
        int temp;

        if (crt > 0) {
                temp = celsius_to_deci_kelvin(crt);
                goto set;
        }
        if (crt == -1) {
                acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
                return THERMAL_TEMP_INVALID;
        }

        if (acpi_critical_trip_temp(tz->device, &temp))
                return THERMAL_TEMP_INVALID;

        if (temp <= 2732) {
                /*
                 * Below zero (Celsius) values clearly aren't right for sure,
                 * so discard them as invalid.
                 */
                pr_info(FW_BUG "Invalid critical threshold (%d)\n", temp);
                return THERMAL_TEMP_INVALID;
        }

set:
        acpi_handle_debug(tz->device->handle, "Critical threshold [%d]\n", temp);
        return temp;
}

static int acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
{
        int temp;

        if (acpi_hot_trip_temp(tz->device, &temp) || temp == THERMAL_TEMP_INVALID) {
                acpi_handle_debug(tz->device->handle, "No hot threshold\n");
                return THERMAL_TEMP_INVALID;
        }

        acpi_handle_debug(tz->device->handle, "Hot threshold [%d]\n", temp);
        return temp;
}

static bool passive_trip_params_init(struct acpi_thermal *tz)
{
        unsigned long long tmp;
        acpi_status status;

        status = acpi_evaluate_integer(tz->device->handle, "_TC1", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return false;

        tz->trips.passive.tc1 = tmp;

        status = acpi_evaluate_integer(tz->device->handle, "_TC2", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return false;

        tz->trips.passive.tc2 = tmp;

        status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
        if (ACPI_SUCCESS(status)) {
                tz->trips.passive.delay = tmp;
                return true;
        }

        status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
        if (ACPI_FAILURE(status))
                return false;

        tz->trips.passive.delay = tmp * 100;

        return true;
}

static bool acpi_thermal_init_trip(struct acpi_thermal *tz, int index)
{
        struct acpi_thermal_trip *acpi_trip;
        long temp;

        if (index == ACPI_THERMAL_TRIP_PASSIVE) {
                acpi_trip = &tz->trips.passive.trip;

                if (psv == -1)
                        goto fail;

                if (!passive_trip_params_init(tz))
                        goto fail;

                temp = psv > 0 ? celsius_to_deci_kelvin(psv) :
                                 get_passive_temp(tz);
        } else {
                acpi_trip = &tz->trips.active[index].trip;

                if (act == -1)
                        goto fail;

                temp = get_active_temp(tz, index);
        }

        if (temp == THERMAL_TEMP_INVALID)
                goto fail;

        if (!update_trip_devices(tz, acpi_trip, index, false))
                goto fail;

        acpi_trip->temp_dk = temp;
        return true;

fail:
        acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
        return false;
}

static void acpi_thermal_get_trip_points(struct acpi_thermal *tz)
{
        int i;

        acpi_thermal_init_trip(tz, ACPI_THERMAL_TRIP_PASSIVE);

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                if (!acpi_thermal_init_trip(tz, i))
                        break;
        }

        while (++i < ACPI_THERMAL_MAX_ACTIVE)
                tz->trips.active[i].trip.temp_dk = THERMAL_TEMP_INVALID;
}

/* sys I/F for generic thermal sysfs support */

static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
{
        struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
        int result;

        if (!tz)
                return -EINVAL;

        result = acpi_thermal_get_temperature(tz);
        if (result)
                return result;

        *temp = deci_kelvin_to_millicelsius_with_offset(tz->temp_dk,
                                                        tz->kelvin_offset);
        return 0;
}

static int thermal_get_trend(struct thermal_zone_device *thermal,
                             const struct thermal_trip *trip,
                             enum thermal_trend *trend)
{
        struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
        struct acpi_thermal_trip *acpi_trip;
        int t;

        if (!tz || !trip)
                return -EINVAL;

        acpi_trip = trip->priv;
        if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
                return -EINVAL;

        switch (trip->type) {
        case THERMAL_TRIP_PASSIVE:
                t = tz->trips.passive.tc1 * (tz->temp_dk -
                                                tz->last_temp_dk) +
                        tz->trips.passive.tc2 * (tz->temp_dk -
                                                acpi_trip->temp_dk);
                if (t > 0)
                        *trend = THERMAL_TREND_RAISING;
                else if (t < 0)
                        *trend = THERMAL_TREND_DROPPING;
                else
                        *trend = THERMAL_TREND_STABLE;

                return 0;

        case THERMAL_TRIP_ACTIVE:
                t = acpi_thermal_temp(tz, tz->temp_dk);
                if (t <= trip->temperature)
                        break;

                *trend = THERMAL_TREND_RAISING;

                return 0;

        default:
                break;
        }

        return -EINVAL;
}

static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
{
        struct acpi_thermal *tz = thermal_zone_device_priv(thermal);

        acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
                                        dev_name(&tz->device->dev),
                                        ACPI_THERMAL_NOTIFY_HOT, 1);
}

static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)
{
        struct acpi_thermal *tz = thermal_zone_device_priv(thermal);

        acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
                                        dev_name(&tz->device->dev),
                                        ACPI_THERMAL_NOTIFY_CRITICAL, 1);

        thermal_zone_device_critical(thermal);
}

static bool acpi_thermal_should_bind_cdev(struct thermal_zone_device *thermal,
                                          const struct thermal_trip *trip,
                                          struct thermal_cooling_device *cdev,
                                          struct cooling_spec *c)
{
        struct acpi_thermal_trip *acpi_trip = trip->priv;
        struct acpi_device *cdev_adev = cdev->devdata;
        int i;

        /* Skip critical and hot trips. */
        if (!acpi_trip)
                return false;

        for (i = 0; i < acpi_trip->devices.count; i++) {
                acpi_handle handle = acpi_trip->devices.handles[i];

                if (acpi_fetch_acpi_dev(handle) == cdev_adev)
                        return true;
        }

        return false;
}

static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
        .should_bind = acpi_thermal_should_bind_cdev,
        .get_temp = thermal_get_temp,
        .get_trend = thermal_get_trend,
        .hot = acpi_thermal_zone_device_hot,
        .critical = acpi_thermal_zone_device_critical,
};

static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
{
        struct device *tzdev = thermal_zone_device(tz->thermal_zone);
        int ret;

        ret = sysfs_create_link(&tz->device->dev.kobj,
                                &tzdev->kobj, "thermal_zone");
        if (ret)
                return ret;

        ret = sysfs_create_link(&tzdev->kobj,
                                   &tz->device->dev.kobj, "device");
        if (ret)
                sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");

        return ret;
}

static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
{
        struct device *tzdev = thermal_zone_device(tz->thermal_zone);

        sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
        sysfs_remove_link(&tzdev->kobj, "device");
}

static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz,
                                              const struct thermal_trip *trip_table,
                                              unsigned int trip_count,
                                              int passive_delay)
{
        int result;

        if (trip_count)
                tz->thermal_zone = thermal_zone_device_register_with_trips(
                                        "acpitz", trip_table, trip_count, tz,
                                        &acpi_thermal_zone_ops, NULL, passive_delay,
                                        tz->polling_frequency * 100);
        else
                tz->thermal_zone = thermal_tripless_zone_device_register(
                                        "acpitz", tz, &acpi_thermal_zone_ops, NULL);

        if (IS_ERR(tz->thermal_zone))
                return PTR_ERR(tz->thermal_zone);

        result = acpi_thermal_zone_sysfs_add(tz);
        if (result)
                goto unregister_tzd;

        result = thermal_zone_device_enable(tz->thermal_zone);
        if (result)
                goto remove_links;

        dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
                 thermal_zone_device_id(tz->thermal_zone));

        return 0;

remove_links:
        acpi_thermal_zone_sysfs_remove(tz);
unregister_tzd:
        thermal_zone_device_unregister(tz->thermal_zone);

        return result;
}

static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
{
        thermal_zone_device_disable(tz->thermal_zone);
        acpi_thermal_zone_sysfs_remove(tz);
        thermal_zone_device_unregister(tz->thermal_zone);
        tz->thermal_zone = NULL;
}


/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
{
        struct acpi_thermal *tz = data;

        if (!tz)
                return;

        switch (event) {
        case ACPI_THERMAL_NOTIFY_TEMPERATURE:
                acpi_queue_thermal_check(tz);
                break;
        case ACPI_THERMAL_NOTIFY_THRESHOLDS:
        case ACPI_THERMAL_NOTIFY_DEVICES:
                acpi_thermal_trips_update(tz, event);
                break;
        default:
                acpi_handle_debug(tz->device->handle,
                                  "Unsupported event [0x%x]\n", event);
                break;
        }
}

/*
 * On some platforms, the AML code has dependency about
 * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
 * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
 *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
 * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
 *    if _TMP has never been evaluated.
 *
 * As this dependency is totally transparent to OS, evaluate
 * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
 * _TMP, before they are actually used.
 */
static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
{
        acpi_handle handle = tz->device->handle;
        unsigned long long value;
        int i;

        acpi_evaluate_integer(handle, "_CRT", NULL, &value);
        acpi_evaluate_integer(handle, "_HOT", NULL, &value);
        acpi_evaluate_integer(handle, "_PSV", NULL, &value);
        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
                acpi_status status;

                status = acpi_evaluate_integer(handle, name, NULL, &value);
                if (status == AE_NOT_FOUND)
                        break;
        }
        acpi_evaluate_integer(handle, "_TMP", NULL, &value);
}

/*
 * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
 * handles temperature values with a single decimal place. As a consequence,
 * some implementations use an offset of 273.1 and others use an offset of
 * 273.2. Try to find out which one is being used, to present the most
 * accurate and visually appealing number.
 *
 * The heuristic below should work for all ACPI thermal zones which have a
 * critical trip point with a value being a multiple of 0.5 degree Celsius.
 */
static void acpi_thermal_guess_offset(struct acpi_thermal *tz, long crit_temp)
{
        if (crit_temp != THERMAL_TEMP_INVALID && crit_temp % 5 == 1)
                tz->kelvin_offset = 273100;
        else
                tz->kelvin_offset = 273200;
}

static void acpi_thermal_check_fn(struct work_struct *work)
{
        struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
                                               thermal_check_work);

        /*
         * In general, it is not sufficient to check the pending bit, because
         * subsequent instances of this function may be queued after one of them
         * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
         * one of them is running, though, because it may have done the actual
         * check some time ago, so allow at least one of them to block on the
         * mutex while another one is running the update.
         */
        if (!refcount_dec_not_one(&tz->thermal_check_count))
                return;

        mutex_lock(&tz->thermal_check_lock);

        thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);

        refcount_inc(&tz->thermal_check_count);

        mutex_unlock(&tz->thermal_check_lock);
}

static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz)
{
        int i;

        acpi_handle_list_free(&tz->trips.passive.trip.devices);
        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
                acpi_handle_list_free(&tz->trips.active[i].trip.devices);

        kfree(tz);
}

static int acpi_thermal_probe(struct platform_device *pdev)
{
        struct thermal_trip trip_table[ACPI_THERMAL_MAX_NR_TRIPS] = { 0 };
        struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
        struct acpi_thermal_trip *acpi_trip;
        struct thermal_trip *trip;
        struct acpi_thermal *tz;
        int crit_temp, hot_temp;
        int passive_delay = 0;
        int result;
        int i;

        if (!device)
                return -EINVAL;

        tz = kzalloc_obj(struct acpi_thermal);
        if (!tz)
                return -ENOMEM;

        platform_set_drvdata(pdev, tz);

        tz->device = device;
        strscpy(tz->name, device->pnp.bus_id);
        strscpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
        strscpy(acpi_device_class(device), ACPI_THERMAL_CLASS);

        acpi_thermal_aml_dependency_fix(tz);

        /*
         * Set the cooling mode [_SCP] to active cooling. This needs to happen before
         * we retrieve the trip point values.
         */
        acpi_execute_simple_method(tz->device->handle, "_SCP", ACPI_THERMAL_MODE_ACTIVE);

        /* Get trip points [_ACi, _PSV, etc.] (required). */
        acpi_thermal_get_trip_points(tz);

        crit_temp = acpi_thermal_get_critical_trip(tz);
        hot_temp = acpi_thermal_get_hot_trip(tz);

        /* Get temperature [_TMP] (required). */
        result = acpi_thermal_get_temperature(tz);
        if (result)
                goto free_memory;

        /* Determine the default polling frequency [_TZP]. */
        if (tzp)
                tz->polling_frequency = tzp;
        else
                acpi_thermal_get_polling_frequency(tz);

        acpi_thermal_guess_offset(tz, crit_temp);

        trip = trip_table;

        if (crit_temp != THERMAL_TEMP_INVALID) {
                trip->type = THERMAL_TRIP_CRITICAL;
                trip->temperature = acpi_thermal_temp(tz, crit_temp);
                trip++;
        }

        if (hot_temp != THERMAL_TEMP_INVALID) {
                trip->type = THERMAL_TRIP_HOT;
                trip->temperature = acpi_thermal_temp(tz, hot_temp);
                trip++;
        }

        acpi_trip = &tz->trips.passive.trip;
        if (acpi_thermal_trip_valid(acpi_trip)) {
                passive_delay = tz->trips.passive.delay;

                trip->type = THERMAL_TRIP_PASSIVE;
                trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
                trip->priv = acpi_trip;
                trip++;
        }

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                acpi_trip =  &tz->trips.active[i].trip;

                if (!acpi_thermal_trip_valid(acpi_trip))
                        break;

                trip->type = THERMAL_TRIP_ACTIVE;
                trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
                trip->priv = acpi_trip;
                trip++;
        }

        if (trip == trip_table)
                pr_warn(FW_BUG "No valid trip points!\n");

        result = acpi_thermal_register_thermal_zone(tz, trip_table,
                                                    trip - trip_table,
                                                    passive_delay);
        if (result)
                goto free_memory;

        refcount_set(&tz->thermal_check_count, 3);
        mutex_init(&tz->thermal_check_lock);
        INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);

        pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
                acpi_device_bid(device), deci_kelvin_to_celsius(tz->temp_dk));

        result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
                                                 acpi_thermal_notify, tz);
        if (result)
                goto flush_wq;

        return 0;

flush_wq:
        flush_workqueue(acpi_thermal_pm_queue);
        acpi_thermal_unregister_thermal_zone(tz);
free_memory:
        acpi_thermal_free_thermal_zone(tz);

        return result;
}

static void acpi_thermal_remove(struct platform_device *pdev)
{
        struct acpi_thermal *tz = platform_get_drvdata(pdev);

        acpi_dev_remove_notify_handler(tz->device, ACPI_DEVICE_NOTIFY,
                                       acpi_thermal_notify);

        flush_workqueue(acpi_thermal_pm_queue);
        acpi_thermal_unregister_thermal_zone(tz);
        acpi_thermal_free_thermal_zone(tz);
}

#ifdef CONFIG_PM_SLEEP
static int acpi_thermal_prepare(struct device *dev)
{
        /* Make sure the previously queued thermal check work has been done */
        flush_workqueue(acpi_thermal_pm_queue);
        return 0;
}

static void acpi_thermal_complete(struct device *dev)
{
        acpi_queue_thermal_check(dev_get_drvdata(dev));
}

static const struct dev_pm_ops acpi_thermal_pm_ops = {
        .prepare = acpi_thermal_prepare,
        .complete = acpi_thermal_complete,
};
#define ACPI_THERMAL_PM &acpi_thermal_pm_ops
#else /* !CONFIG_PM_SLEEP */
#define ACPI_THERMAL_PM NULL
#endif /* CONFIG_PM_SLEEP */

static const struct acpi_device_id  thermal_device_ids[] = {
        {ACPI_THERMAL_HID, 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, thermal_device_ids);

static struct platform_driver acpi_thermal_driver = {
        .probe = acpi_thermal_probe,
        .remove = acpi_thermal_remove,
        .driver = {
                .name = "acpi-thermal",
                .acpi_match_table = thermal_device_ids,
                .pm = ACPI_THERMAL_PM,
        },
};

static int thermal_act(const struct dmi_system_id *d)
{
        if (act == 0) {
                pr_notice("%s detected: disabling all active thermal trip points\n",
                          d->ident);
                act = -1;
        }
        return 0;
}

static int thermal_nocrt(const struct dmi_system_id *d)
{
        pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
                  d->ident);
        crt = -1;
        return 0;
}

static int thermal_tzp(const struct dmi_system_id *d)
{
        if (tzp == 0) {
                pr_notice("%s detected: enabling thermal zone polling\n",
                          d->ident);
                tzp = 300;      /* 300 dS = 30 Seconds */
        }
        return 0;
}

static int thermal_psv(const struct dmi_system_id *d)
{
        if (psv == 0) {
                pr_notice("%s detected: disabling all passive thermal trip points\n",
                          d->ident);
                psv = -1;
        }
        return 0;
}

static const struct dmi_system_id thermal_dmi_table[] __initconst = {
        /*
         * Award BIOS on this AOpen makes thermal control almost worthless.
         * http://bugzilla.kernel.org/show_bug.cgi?id=8842
         */
        {
         .callback = thermal_act,
         .ident = "AOpen i915GMm-HFS",
         .matches = {
                DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
                DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
                },
        },
        {
         .callback = thermal_psv,
         .ident = "AOpen i915GMm-HFS",
         .matches = {
                DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
                DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
                },
        },
        {
         .callback = thermal_tzp,
         .ident = "AOpen i915GMm-HFS",
         .matches = {
                DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
                DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
                },
        },
        {
         .callback = thermal_nocrt,
         .ident = "Gigabyte GA-7ZX",
         .matches = {
                DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
                DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
                },
        },
        {}
};

static int __init acpi_thermal_init(void)
{
        int result;

        dmi_check_system(thermal_dmi_table);

        if (off) {
                pr_notice("thermal control disabled\n");
                return -ENODEV;
        }

        acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
                                                WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_PERCPU,
                                                0);
        if (!acpi_thermal_pm_queue)
                return -ENODEV;

        result = platform_driver_register(&acpi_thermal_driver);
        if (result < 0) {
                destroy_workqueue(acpi_thermal_pm_queue);
                return -ENODEV;
        }

        return 0;
}

static void __exit acpi_thermal_exit(void)
{
        platform_driver_unregister(&acpi_thermal_driver);
        destroy_workqueue(acpi_thermal_pm_queue);
}

module_init(acpi_thermal_init);
module_exit(acpi_thermal_exit);

MODULE_IMPORT_NS("ACPI_THERMAL");
MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
MODULE_LICENSE("GPL");