// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/devfreq/governor_powersave.c
 *
 *  Copyright (C) 2011 Samsung Electronics
 *      MyungJoo Ham <myungjoo.ham@samsung.com>
 */

#include <linux/devfreq.h>
#include <linux/devfreq-governor.h>
#include <linux/module.h>

static int devfreq_powersave_func(struct devfreq *df,
                                  unsigned long *freq)
{
        /*
         * target callback should be able to get ceiling value as
         * said in devfreq.h
         */
        *freq = DEVFREQ_MIN_FREQ;
        return 0;
}

static int devfreq_powersave_handler(struct devfreq *devfreq,
                                unsigned int event, void *data)
{
        int ret = 0;

        if (event == DEVFREQ_GOV_START) {
                mutex_lock(&devfreq->lock);
                ret = update_devfreq(devfreq);
                mutex_unlock(&devfreq->lock);
        }

        return ret;
}

static struct devfreq_governor devfreq_powersave = {
        .name = DEVFREQ_GOV_POWERSAVE,
        .get_target_freq = devfreq_powersave_func,
        .event_handler = devfreq_powersave_handler,
};

static int __init devfreq_powersave_init(void)
{
        return devfreq_add_governor(&devfreq_powersave);
}
subsys_initcall(devfreq_powersave_init);

static void __exit devfreq_powersave_exit(void)
{
        int ret;

        ret = devfreq_remove_governor(&devfreq_powersave);
        if (ret)
                pr_err("%s: failed remove governor %d\n", __func__, ret);

        return;
}
module_exit(devfreq_powersave_exit);
MODULE_DESCRIPTION("DEVFREQ Powersave governor");
MODULE_LICENSE("GPL");