linux-imx

/*

 *  step_wise.c - A step-by-step Thermal throttling governor

 *

 *  Copyright (C) 2012 Intel Corp

 *  Copyright (C) 2012 Durgadoss R <durgadoss.r@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/thermal.h>

#include <trace/events/thermal.h>

​

#include "thermal_core.h"

​

/*

 * If the temperature is higher than a trip point,

 *    a. if the trend is THERMAL_TREND_RAISING, use higher cooling

 *       state for this trip point

 *    b. if the trend is THERMAL_TREND_DROPPING, do nothing

 *    c. if the trend is THERMAL_TREND_RAISE_FULL, use upper limit

 *       for this trip point

 *    d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit

 *       for this trip point

 * If the temperature is lower than a trip point,

 *    a. if the trend is THERMAL_TREND_RAISING, do nothing

 *    b. if the trend is THERMAL_TREND_DROPPING, use lower cooling

 *       state for this trip point, if the cooling state already

 *       equals lower limit, deactivate the thermal instance

 *    c. if the trend is THERMAL_TREND_RAISE_FULL, do nothing

 *    d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit,

 *       if the cooling state already equals lower limit,

 *       deactivate the thermal instance

 */

static unsigned long get_target_state(struct thermal_instance *instance,

                enum thermal_trend trend, bool throttle)

{

    struct thermal_cooling_device *cdev = instance->cdev;

    unsigned long cur_state;

    unsigned long next_target;

​

    /*

     * We keep this instance the way it is by default.

     * Otherwise, we use the current state of the

     * cdev in use to determine the next_target.

     */

    cdev->ops->get_cur_state(cdev, &cur_state);

    next_target = instance->target;

    dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);

​

    if (!instance->initialized) {

        if (throttle) {

            next_target = (cur_state + 1) >= instance->upper ?

                    instance->upper :

                    ((cur_state + 1) < instance->lower ?

                    instance->lower : (cur_state + 1));

        } else {

            next_target = THERMAL_NO_TARGET;

        }

​

        return next_target;

    }

​

    switch (trend) {

    case THERMAL_TREND_RAISING:

        if (throttle) {

            next_target = cur_state < instance->upper ?

                    (cur_state + 1) : instance->upper;

            if (next_target < instance->lower)

                next_target = instance->lower;

        }

        break;

    case THERMAL_TREND_RAISE_FULL:

        if (throttle)

            next_target = instance->upper;

        break;

    case THERMAL_TREND_DROPPING:

        if (cur_state <= instance->lower) {