xref: /linux/drivers/cpufreq/cpufreq_powersave.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/cpufreq.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 
19 static int cpufreq_governor_powersave(struct cpufreq_policy *policy,
20 					unsigned int event)
21 {
22 	switch (event) {
23 	case CPUFREQ_GOV_START:
24 	case CPUFREQ_GOV_LIMITS:
25 		pr_debug("setting to %u kHz because of event %u\n",
26 							policy->min, event);
27 		__cpufreq_driver_target(policy, policy->min,
28 						CPUFREQ_RELATION_L);
29 		break;
30 	default:
31 		break;
32 	}
33 	return 0;
34 }
35 
36 static struct cpufreq_governor cpufreq_gov_powersave = {
37 	.name		= "powersave",
38 	.governor	= cpufreq_governor_powersave,
39 	.owner		= THIS_MODULE,
40 };
41 
42 static int __init cpufreq_gov_powersave_init(void)
43 {
44 	return cpufreq_register_governor(&cpufreq_gov_powersave);
45 }
46 
47 static void __exit cpufreq_gov_powersave_exit(void)
48 {
49 	cpufreq_unregister_governor(&cpufreq_gov_powersave);
50 }
51 
52 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
53 MODULE_DESCRIPTION("CPUfreq policy governor 'powersave'");
54 MODULE_LICENSE("GPL");
55 
56 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
57 struct cpufreq_governor *cpufreq_default_governor(void)
58 {
59 	return &cpufreq_gov_powersave;
60 }
61 
62 fs_initcall(cpufreq_gov_powersave_init);
63 #else
64 module_init(cpufreq_gov_powersave_init);
65 #endif
66 module_exit(cpufreq_gov_powersave_exit);
67