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/kernel.h>
16 #include <linux/module.h>
17 #include <linux/cpufreq.h>
18 #include <linux/init.h>
19 
20 static int cpufreq_governor_powersave(struct cpufreq_policy *policy,
21 					unsigned int event)
22 {
23 	switch (event) {
24 	case CPUFREQ_GOV_START:
25 	case CPUFREQ_GOV_LIMITS:
26 		pr_debug("setting to %u kHz because of event %u\n",
27 							policy->min, event);
28 		__cpufreq_driver_target(policy, policy->min,
29 						CPUFREQ_RELATION_L);
30 		break;
31 	default:
32 		break;
33 	}
34 	return 0;
35 }
36 
37 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
38 static
39 #endif
40 struct cpufreq_governor cpufreq_gov_powersave = {
41 	.name		= "powersave",
42 	.governor	= cpufreq_governor_powersave,
43 	.owner		= THIS_MODULE,
44 };
45 
46 static int __init cpufreq_gov_powersave_init(void)
47 {
48 	return cpufreq_register_governor(&cpufreq_gov_powersave);
49 }
50 
51 
52 static void __exit cpufreq_gov_powersave_exit(void)
53 {
54 	cpufreq_unregister_governor(&cpufreq_gov_powersave);
55 }
56 
57 
58 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
59 MODULE_DESCRIPTION("CPUfreq policy governor 'powersave'");
60 MODULE_LICENSE("GPL");
61 
62 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
63 fs_initcall(cpufreq_gov_powersave_init);
64 #else
65 module_init(cpufreq_gov_powersave_init);
66 #endif
67 module_exit(cpufreq_gov_powersave_exit);
68