xref: /openbmc/linux/drivers/cpufreq/cpufreq_powersave.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  *  linux/drivers/cpufreq/cpufreq_powersave.c
3  *
4  *  Copyright (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/cpufreq.h>
16 #include <linux/init.h>
17 
18 #define dprintk(msg...) \
19 	cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "powersave", msg)
20 
21 static int cpufreq_governor_powersave(struct cpufreq_policy *policy,
22 					unsigned int event)
23 {
24 	switch (event) {
25 	case CPUFREQ_GOV_START:
26 	case CPUFREQ_GOV_LIMITS:
27 		dprintk("setting to %u kHz because of event %u\n",
28 							policy->min, event);
29 		__cpufreq_driver_target(policy, policy->min,
30 						CPUFREQ_RELATION_L);
31 		break;
32 	default:
33 		break;
34 	}
35 	return 0;
36 }
37 
38 static struct cpufreq_governor cpufreq_gov_powersave = {
39 	.name		= "powersave",
40 	.governor	= cpufreq_governor_powersave,
41 	.owner		= THIS_MODULE,
42 };
43 
44 
45 static int __init cpufreq_gov_powersave_init(void)
46 {
47 	return cpufreq_register_governor(&cpufreq_gov_powersave);
48 }
49 
50 
51 static void __exit cpufreq_gov_powersave_exit(void)
52 {
53 	cpufreq_unregister_governor(&cpufreq_gov_powersave);
54 }
55 
56 
57 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
58 MODULE_DESCRIPTION("CPUfreq policy governor 'powersave'");
59 MODULE_LICENSE("GPL");
60 
61 module_init(cpufreq_gov_powersave_init);
62 module_exit(cpufreq_gov_powersave_exit);
63