summaryrefslogtreecommitdiffstats
path: root/drivers/devfreq/governor_powersave.c
blob: f059e881480465b051f27d740348adaf779aebf0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
// 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/module.h>
#include "governor.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");