drivers/cpufreq/cpufreq_powersave.c

   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 static void __exit cpufreq_gov_powersave_exit(void)
  52 {
  53         cpufreq_unregister_governor(&cpufreq_gov_powersave);
  54 }
  55
  56 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
  57 MODULE_DESCRIPTION("CPUfreq policy governor 'powersave'");
  58 MODULE_LICENSE("GPL");
  59
  60 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
  61 fs_initcall(cpufreq_gov_powersave_init);
  62 #else
  63 module_init(cpufreq_gov_powersave_init);
  64 #endif
  65 module_exit(cpufreq_gov_powersave_exit);