// 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/thermal.h>
#include <linux/acpi.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
#include <linux/units.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

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

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 nocrt;
module_param(nocrt, int, 0);
MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");

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;

static int acpi_thermal_add(struct acpi_device *device);
static int acpi_thermal_remove(struct acpi_device *device);
static void acpi_thermal_notify(struct acpi_device *device, u32 event);

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

#ifdef CONFIG_PM_SLEEP
static int acpi_thermal_suspend(struct device *dev);
static int acpi_thermal_resume(struct device *dev);
#else
#define acpi_thermal_suspend NULL
#define acpi_thermal_resume NULL
#endif
static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);

static struct acpi_driver acpi_thermal_driver = {
        .name = "thermal",
        .class = ACPI_THERMAL_CLASS,
        .ids = thermal_device_ids,
        .ops = {
                .add = acpi_thermal_add,
                .remove = acpi_thermal_remove,
                .notify = acpi_thermal_notify,
                },
        .drv.pm = &acpi_thermal_pm,
};

struct acpi_thermal_state {
        u8 critical:1;
        u8 hot:1;
        u8 passive:1;
        u8 active:1;
        u8 reserved:4;
        int active_index;
};

struct acpi_thermal_state_flags {
        u8 valid:1;
        u8 enabled:1;
        u8 reserved:6;
};

struct acpi_thermal_critical {
        struct acpi_thermal_state_flags flags;
        unsigned long temperature;
};

struct acpi_thermal_hot {
        struct acpi_thermal_state_flags flags;
        unsigned long temperature;
};

struct acpi_thermal_passive {
        struct acpi_thermal_state_flags flags;
        unsigned long temperature;
        unsigned long tc1;
        unsigned long tc2;
        unsigned long tsp;
        struct acpi_handle_list devices;
};

struct acpi_thermal_active {
        struct acpi_thermal_state_flags flags;
        unsigned long temperature;
        struct acpi_handle_list devices;
};

struct acpi_thermal_trips {
        struct acpi_thermal_critical critical;
        struct acpi_thermal_hot hot;
        struct acpi_thermal_passive passive;
        struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
};

struct acpi_thermal_flags {
        u8 cooling_mode:1;      /* _SCP */
        u8 devices:1;           /* _TZD */
        u8 reserved:6;
};

struct acpi_thermal {
        struct acpi_device * device;
        acpi_bus_id name;
        unsigned long temperature;
        unsigned long last_temperature;
        unsigned long polling_frequency;
        volatile u8 zombie;
        struct acpi_thermal_flags flags;
        struct acpi_thermal_state state;
        struct acpi_thermal_trips trips;
        struct acpi_handle_list devices;
        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_temperature = tz->temperature;

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

        tz->temperature = tmp;

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

        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_set_cooling_mode(struct acpi_thermal *tz, int mode)
{
        if (!tz)
                return -EINVAL;

        if (ACPI_FAILURE(acpi_execute_simple_method(tz->device->handle,
                                                    "_SCP", mode)))
                return -ENODEV;

        return 0;
}

#define ACPI_TRIPS_CRITICAL     0x01
#define ACPI_TRIPS_HOT          0x02
#define ACPI_TRIPS_PASSIVE      0x04
#define ACPI_TRIPS_ACTIVE       0x08
#define ACPI_TRIPS_DEVICES      0x10

#define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
#define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES

#define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
                              ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
                              ACPI_TRIPS_DEVICES)

/*
 * 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(flags, tz, str)    \
do {    \
        if (flags != ACPI_TRIPS_INIT)   \
                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 acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
{
        acpi_status status = AE_OK;
        unsigned long long tmp;
        struct acpi_handle_list devices;
        int valid = 0;
        int i;

        /* Critical Shutdown */
        if (flag & ACPI_TRIPS_CRITICAL) {
                status = acpi_evaluate_integer(tz->device->handle,
                                "_CRT", NULL, &tmp);
                tz->trips.critical.temperature = tmp;
                /*
                 * Treat freezing temperatures as invalid as well; some
                 * BIOSes return really low values and cause reboots at startup.
                 * Below zero (Celsius) values clearly aren't right for sure..
                 * ... so lets discard those as invalid.
                 */
                if (ACPI_FAILURE(status)) {
                        tz->trips.critical.flags.valid = 0;
                        acpi_handle_debug(tz->device->handle,
                                          "No critical threshold\n");
                } else if (tmp <= 2732) {
                        pr_info(FW_BUG "Invalid critical threshold (%llu)\n",
                                tmp);
                        tz->trips.critical.flags.valid = 0;
                } else {
                        tz->trips.critical.flags.valid = 1;
                        acpi_handle_debug(tz->device->handle,
                                          "Found critical threshold [%lu]\n",
                                          tz->trips.critical.temperature);
                }
                if (tz->trips.critical.flags.valid == 1) {
                        if (crt == -1) {
                                tz->trips.critical.flags.valid = 0;
                        } else if (crt > 0) {
                                unsigned long crt_k = celsius_to_deci_kelvin(crt);

                                /*
                                 * Allow override critical threshold
                                 */
                                if (crt_k > tz->trips.critical.temperature)
                                        pr_info("Critical threshold %d C\n", crt);

                                tz->trips.critical.temperature = crt_k;
                        }
                }
        }

        /* Critical Sleep (optional) */
        if (flag & ACPI_TRIPS_HOT) {
                status = acpi_evaluate_integer(tz->device->handle,
                                "_HOT", NULL, &tmp);
                if (ACPI_FAILURE(status)) {
                        tz->trips.hot.flags.valid = 0;
                        acpi_handle_debug(tz->device->handle,
                                          "No hot threshold\n");
                } else {
                        tz->trips.hot.temperature = tmp;
                        tz->trips.hot.flags.valid = 1;
                        acpi_handle_debug(tz->device->handle,
                                          "Found hot threshold [%lu]\n",
                                          tz->trips.hot.temperature);
                }
        }

        /* Passive (optional) */
        if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
                (flag == ACPI_TRIPS_INIT)) {
                valid = tz->trips.passive.flags.valid;
                if (psv == -1) {
                        status = AE_SUPPORT;
                } else if (psv > 0) {
                        tmp = celsius_to_deci_kelvin(psv);
                        status = AE_OK;
                } else {
                        status = acpi_evaluate_integer(tz->device->handle,
                                "_PSV", NULL, &tmp);
                }

                if (ACPI_FAILURE(status))
                        tz->trips.passive.flags.valid = 0;
                else {
                        tz->trips.passive.temperature = tmp;
                        tz->trips.passive.flags.valid = 1;
                        if (flag == ACPI_TRIPS_INIT) {
                                status = acpi_evaluate_integer(
                                                tz->device->handle, "_TC1",
                                                NULL, &tmp);
                                if (ACPI_FAILURE(status))
                                        tz->trips.passive.flags.valid = 0;
                                else
                                        tz->trips.passive.tc1 = tmp;
                                status = acpi_evaluate_integer(
                                                tz->device->handle, "_TC2",
                                                NULL, &tmp);
                                if (ACPI_FAILURE(status))
                                        tz->trips.passive.flags.valid = 0;
                                else
                                        tz->trips.passive.tc2 = tmp;
                                status = acpi_evaluate_integer(
                                                tz->device->handle, "_TSP",
                                                NULL, &tmp);
                                if (ACPI_FAILURE(status))
                                        tz->trips.passive.flags.valid = 0;
                                else
                                        tz->trips.passive.tsp = tmp;
                        }
                }
        }
        if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
                memset(&devices, 0, sizeof(struct acpi_handle_list));
                status = acpi_evaluate_reference(tz->device->handle, "_PSL",
                                                        NULL, &devices);
                if (ACPI_FAILURE(status)) {
                        acpi_handle_info(tz->device->handle,
                                         "Invalid passive threshold\n");
                        tz->trips.passive.flags.valid = 0;
                }
                else
                        tz->trips.passive.flags.valid = 1;

                if (memcmp(&tz->trips.passive.devices, &devices,
                                sizeof(struct acpi_handle_list))) {
                        memcpy(&tz->trips.passive.devices, &devices,
                                sizeof(struct acpi_handle_list));
                        ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
                }
        }
        if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
                if (valid != tz->trips.passive.flags.valid)
                                ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
        }

        /* Active (optional) */
        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
                valid = tz->trips.active[i].flags.valid;

                if (act == -1)
                        break; /* disable all active trip points */

                if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
                        tz->trips.active[i].flags.valid)) {
                        status = acpi_evaluate_integer(tz->device->handle,
                                                        name, NULL, &tmp);
                        if (ACPI_FAILURE(status)) {
                                tz->trips.active[i].flags.valid = 0;
                                if (i == 0)
                                        break;
                                if (act <= 0)
                                        break;
                                if (i == 1)
                                        tz->trips.active[0].temperature =
                                                celsius_to_deci_kelvin(act);
                                else
                                        /*
                                         * Don't allow override higher than
                                         * the next higher trip point
                                         */
                                        tz->trips.active[i - 1].temperature =
                                                (tz->trips.active[i - 2].temperature <
                                                celsius_to_deci_kelvin(act) ?
                                                tz->trips.active[i - 2].temperature :
                                                celsius_to_deci_kelvin(act));
                                break;
                        } else {
                                tz->trips.active[i].temperature = tmp;
                                tz->trips.active[i].flags.valid = 1;
                        }
                }

                name[2] = 'L';
                if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
                        memset(&devices, 0, sizeof(struct acpi_handle_list));
                        status = acpi_evaluate_reference(tz->device->handle,
                                                name, NULL, &devices);
                        if (ACPI_FAILURE(status)) {
                                acpi_handle_info(tz->device->handle,
                                                 "Invalid active%d threshold\n", i);
                                tz->trips.active[i].flags.valid = 0;
                        }
                        else
                                tz->trips.active[i].flags.valid = 1;

                        if (memcmp(&tz->trips.active[i].devices, &devices,
                                        sizeof(struct acpi_handle_list))) {
                                memcpy(&tz->trips.active[i].devices, &devices,
                                        sizeof(struct acpi_handle_list));
                                ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
                        }
                }
                if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
                        if (valid != tz->trips.active[i].flags.valid)
                                ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");

                if (!tz->trips.active[i].flags.valid)
                        break;
        }

        if (flag & ACPI_TRIPS_DEVICES) {
                memset(&devices, 0, sizeof(devices));
                status = acpi_evaluate_reference(tz->device->handle, "_TZD",
                                                NULL, &devices);
                if (ACPI_SUCCESS(status)
                    && memcmp(&tz->devices, &devices, sizeof(devices))) {
                        tz->devices = devices;
                        ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
                }
        }

        return 0;
}

static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
{
        int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);

        if (ret)
                return ret;

        valid = tz->trips.critical.flags.valid |
                tz->trips.hot.flags.valid |
                tz->trips.passive.flags.valid;

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
                valid |= tz->trips.active[i].flags.valid;

        if (!valid) {
                pr_warn(FW_BUG "No valid trip found\n");
                return -ENODEV;
        }
        return 0;
}

/* 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->devdata;
        int result;

        if (!tz)
                return -EINVAL;

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

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

static int thermal_get_trip_type(struct thermal_zone_device *thermal,
                                 int trip, enum thermal_trip_type *type)
{
        struct acpi_thermal *tz = thermal->devdata;
        int i;

        if (!tz || trip < 0)
                return -EINVAL;

        if (tz->trips.critical.flags.valid) {
                if (!trip) {
                        *type = THERMAL_TRIP_CRITICAL;
                        return 0;
                }
                trip--;
        }

        if (tz->trips.hot.flags.valid) {
                if (!trip) {
                        *type = THERMAL_TRIP_HOT;
                        return 0;
                }
                trip--;
        }

        if (tz->trips.passive.flags.valid) {
                if (!trip) {
                        *type = THERMAL_TRIP_PASSIVE;
                        return 0;
                }
                trip--;
        }

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
                tz->trips.active[i].flags.valid; i++) {
                if (!trip) {
                        *type = THERMAL_TRIP_ACTIVE;
                        return 0;
                }
                trip--;
        }

        return -EINVAL;
}

static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
                                 int trip, int *temp)
{
        struct acpi_thermal *tz = thermal->devdata;
        int i;

        if (!tz || trip < 0)
                return -EINVAL;

        if (tz->trips.critical.flags.valid) {
                if (!trip) {
                        *temp = deci_kelvin_to_millicelsius_with_offset(
                                tz->trips.critical.temperature,
                                tz->kelvin_offset);
                        return 0;
                }
                trip--;
        }

        if (tz->trips.hot.flags.valid) {
                if (!trip) {
                        *temp = deci_kelvin_to_millicelsius_with_offset(
                                tz->trips.hot.temperature,
                                tz->kelvin_offset);
                        return 0;
                }
                trip--;
        }

        if (tz->trips.passive.flags.valid) {
                if (!trip) {
                        *temp = deci_kelvin_to_millicelsius_with_offset(
                                tz->trips.passive.temperature,
                                tz->kelvin_offset);
                        return 0;
                }
                trip--;
        }

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
                tz->trips.active[i].flags.valid; i++) {
                if (!trip) {
                        *temp = deci_kelvin_to_millicelsius_with_offset(
                                tz->trips.active[i].temperature,
                                tz->kelvin_offset);
                        return 0;
                }
                trip--;
        }

        return -EINVAL;
}

static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
                                int *temperature)
{
        struct acpi_thermal *tz = thermal->devdata;

        if (tz->trips.critical.flags.valid) {
                *temperature = deci_kelvin_to_millicelsius_with_offset(
                                tz->trips.critical.temperature,
                                tz->kelvin_offset);
                return 0;
        } else
                return -EINVAL;
}

static int thermal_get_trend(struct thermal_zone_device *thermal,
                                int trip, enum thermal_trend *trend)
{
        struct acpi_thermal *tz = thermal->devdata;
        enum thermal_trip_type type;
        int i;

        if (thermal_get_trip_type(thermal, trip, &type))
                return -EINVAL;

        if (type == THERMAL_TRIP_ACTIVE) {
                int trip_temp;
                int temp = deci_kelvin_to_millicelsius_with_offset(
                                        tz->temperature, tz->kelvin_offset);
                if (thermal_get_trip_temp(thermal, trip, &trip_temp))
                        return -EINVAL;

                if (temp > trip_temp) {
                        *trend = THERMAL_TREND_RAISING;
                        return 0;
                } else {
                        /* Fall back on default trend */
                        return -EINVAL;
                }
        }

        /*
         * tz->temperature has already been updated by generic thermal layer,
         * before this callback being invoked
         */
        i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
                + (tz->trips.passive.tc2
                * (tz->temperature - tz->trips.passive.temperature));

        if (i > 0)
                *trend = THERMAL_TREND_RAISING;
        else if (i < 0)
                *trend = THERMAL_TREND_DROPPING;
        else
                *trend = THERMAL_TREND_STABLE;
        return 0;
}

static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
{
        struct acpi_thermal *tz = thermal->devdata;

        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->devdata;

        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 int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
                                        struct thermal_cooling_device *cdev,
                                        bool bind)
{
        struct acpi_device *device = cdev->devdata;
        struct acpi_thermal *tz = thermal->devdata;
        struct acpi_device *dev;
        acpi_status status;
        acpi_handle handle;
        int i;
        int j;
        int trip = -1;
        int result = 0;

        if (tz->trips.critical.flags.valid)
                trip++;

        if (tz->trips.hot.flags.valid)
                trip++;

        if (tz->trips.passive.flags.valid) {
                trip++;
                for (i = 0; i < tz->trips.passive.devices.count;
                    i++) {
                        handle = tz->trips.passive.devices.handles[i];
                        status = acpi_bus_get_device(handle, &dev);
                        if (ACPI_FAILURE(status) || dev != device)
                                continue;
                        if (bind)
                                result =
                                        thermal_zone_bind_cooling_device
                                        (thermal, trip, cdev,
                                         THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
                                         THERMAL_WEIGHT_DEFAULT);
                        else
                                result =
                                        thermal_zone_unbind_cooling_device
                                        (thermal, trip, cdev);
                        if (result)
                                goto failed;
                }
        }

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                if (!tz->trips.active[i].flags.valid)
                        break;
                trip++;
                for (j = 0;
                    j < tz->trips.active[i].devices.count;
                    j++) {
                        handle = tz->trips.active[i].devices.handles[j];
                        status = acpi_bus_get_device(handle, &dev);
                        if (ACPI_FAILURE(status) || dev != device)
                                continue;
                        if (bind)
                                result = thermal_zone_bind_cooling_device
                                        (thermal, trip, cdev,
                                         THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
                                         THERMAL_WEIGHT_DEFAULT);
                        else
                                result = thermal_zone_unbind_cooling_device
                                        (thermal, trip, cdev);
                        if (result)
                                goto failed;
                }
        }

failed:
        return result;
}

static int
acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
                                        struct thermal_cooling_device *cdev)
{
        return acpi_thermal_cooling_device_cb(thermal, cdev, true);
}

static int
acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
                                        struct thermal_cooling_device *cdev)
{
        return acpi_thermal_cooling_device_cb(thermal, cdev, false);
}

static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
        .bind = acpi_thermal_bind_cooling_device,
        .unbind = acpi_thermal_unbind_cooling_device,
        .get_temp = thermal_get_temp,
        .get_trip_type = thermal_get_trip_type,
        .get_trip_temp = thermal_get_trip_temp,
        .get_crit_temp = thermal_get_crit_temp,
        .get_trend = thermal_get_trend,
        .hot = acpi_thermal_zone_device_hot,
        .critical = acpi_thermal_zone_device_critical,
};

static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
{
        int trips = 0;
        int result;
        acpi_status status;
        int i;

        if (tz->trips.critical.flags.valid)
                trips++;

        if (tz->trips.hot.flags.valid)
                trips++;

        if (tz->trips.passive.flags.valid)
                trips++;

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
                        tz->trips.active[i].flags.valid; i++, trips++);

        if (tz->trips.passive.flags.valid)
                tz->thermal_zone =
                        thermal_zone_device_register("acpitz", trips, 0, tz,
                                                &acpi_thermal_zone_ops, NULL,
                                                     tz->trips.passive.tsp*100,
                                                     tz->polling_frequency*100);
        else
                tz->thermal_zone =
                        thermal_zone_device_register("acpitz", trips, 0, tz,
                                                &acpi_thermal_zone_ops, NULL,
                                                0, tz->polling_frequency*100);
        if (IS_ERR(tz->thermal_zone))
                return -ENODEV;

        result = sysfs_create_link(&tz->device->dev.kobj,
                                   &tz->thermal_zone->device.kobj, "thermal_zone");
        if (result)
                goto unregister_tzd;

        result = sysfs_create_link(&tz->thermal_zone->device.kobj,
                                   &tz->device->dev.kobj, "device");
        if (result)
                goto remove_tz_link;

        status =  acpi_bus_attach_private_data(tz->device->handle,
                                               tz->thermal_zone);
        if (ACPI_FAILURE(status)) {
                result = -ENODEV;
                goto remove_dev_link;
        }

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

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

        return 0;

acpi_bus_detach:
        acpi_bus_detach_private_data(tz->device->handle);
remove_dev_link:
        sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
remove_tz_link:
        sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
unregister_tzd:
        thermal_zone_device_unregister(tz->thermal_zone);

        return result;
}

static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
{
        sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
        sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
        thermal_zone_device_unregister(tz->thermal_zone);
        tz->thermal_zone = NULL;
        acpi_bus_detach_private_data(tz->device->handle);
}


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

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_notify(struct acpi_device *device, u32 event)
{
        struct acpi_thermal *tz = acpi_driver_data(device);


        if (!tz)
                return;

        switch (event) {
        case ACPI_THERMAL_NOTIFY_TEMPERATURE:
                acpi_queue_thermal_check(tz);
                break;
        case ACPI_THERMAL_NOTIFY_THRESHOLDS:
                acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
                acpi_queue_thermal_check(tz);
                acpi_bus_generate_netlink_event(device->pnp.device_class,
                                                  dev_name(&device->dev), event, 0);
                break;
        case ACPI_THERMAL_NOTIFY_DEVICES:
                acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
                acpi_queue_thermal_check(tz);
                acpi_bus_generate_netlink_event(device->pnp.device_class,
                                                  dev_name(&device->dev), event, 0);
                break;
        default:
                acpi_handle_debug(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);
}

static int acpi_thermal_get_info(struct acpi_thermal *tz)
{
        int result = 0;


        if (!tz)
                return -EINVAL;

        acpi_thermal_aml_dependency_fix(tz);

        /* Get trip points [_CRT, _PSV, etc.] (required) */
        result = acpi_thermal_get_trip_points(tz);
        if (result)
                return result;

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

        /* Set the cooling mode [_SCP] to active cooling (default) */
        result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
        if (!result)
                tz->flags.cooling_mode = 1;

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

        return 0;
}

/*
 * 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)
{
        if (tz->trips.critical.flags.valid &&
            (tz->trips.critical.temperature % 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 int acpi_thermal_add(struct acpi_device *device)
{
        int result = 0;
        struct acpi_thermal *tz = NULL;


        if (!device)
                return -EINVAL;

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

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

        result = acpi_thermal_get_info(tz);
        if (result)
                goto free_memory;

        acpi_thermal_guess_offset(tz);

        result = acpi_thermal_register_thermal_zone(tz);
        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->temperature));
        goto end;

free_memory:
        kfree(tz);
end:
        return result;
}

static int acpi_thermal_remove(struct acpi_device *device)
{
        struct acpi_thermal *tz = NULL;

        if (!device || !acpi_driver_data(device))
                return -EINVAL;

        flush_workqueue(acpi_thermal_pm_queue);
        tz = acpi_driver_data(device);

        acpi_thermal_unregister_thermal_zone(tz);
        kfree(tz);
        return 0;
}

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

static int acpi_thermal_resume(struct device *dev)
{
        struct acpi_thermal *tz;
        int i, j, power_state, result;

        if (!dev)
                return -EINVAL;

        tz = acpi_driver_data(to_acpi_device(dev));
        if (!tz)
                return -EINVAL;

        for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
                if (!(&tz->trips.active[i]))
                        break;
                if (!tz->trips.active[i].flags.valid)
                        break;
                tz->trips.active[i].flags.enabled = 1;
                for (j = 0; j < tz->trips.active[i].devices.count; j++) {
                        result = acpi_bus_update_power(
                                        tz->trips.active[i].devices.handles[j],
                                        &power_state);
                        if (result || (power_state != ACPI_STATE_D0)) {
                                tz->trips.active[i].flags.enabled = 0;
                                break;
                        }
                }
                tz->state.active |= tz->trips.active[i].flags.enabled;
        }

        acpi_queue_thermal_check(tz);

        return AE_OK;
}
#endif

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);
        nocrt = 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 = 0;

        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, 0);
        if (!acpi_thermal_pm_queue)
                return -ENODEV;

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

        return 0;
}

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

        return;
}

module_init(acpi_thermal_init);
module_exit(acpi_thermal_exit);