drivers/devfreq/governor_performance.c

   1 /*
   2  *  linux/drivers/devfreq/governor_performance.c
   3  *
   4  *  Copyright (C) 2011 Samsung Electronics
   5  *      MyungJoo Ham <myungjoo.ham@samsung.com>
   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 #include <linux/devfreq.h>
  13 #include <linux/module.h>
  14 #include "governor.h"
  15
  16 static int devfreq_performance_func(struct devfreq *df,
  17                                     unsigned long *freq)
  18 {
  19         /*
  20          * target callback should be able to get floor value as
  21          * said in devfreq.h
  22          */
  23         if (!df->max_freq)
  24                 *freq = UINT_MAX;
  25         else
  26                 *freq = df->max_freq;
  27         return 0;
  28 }
  29
  30 static int devfreq_performance_handler(struct devfreq *devfreq,
  31                                 unsigned int event, void *data)
  32 {
  33         int ret = 0;
  34
  35         if (event == DEVFREQ_GOV_START) {
  36                 mutex_lock(&devfreq->lock);
  37                 ret = update_devfreq(devfreq);
  38                 mutex_unlock(&devfreq->lock);
  39         }
  40
  41         return ret;
  42 }
  43
  44 static struct devfreq_governor devfreq_performance = {
  45         .name = DEVFREQ_GOV_PERFORMANCE,
  46         .get_target_freq = devfreq_performance_func,
  47         .event_handler = devfreq_performance_handler,
  48 };
  49
  50 static int __init devfreq_performance_init(void)
  51 {
  52         return devfreq_add_governor(&devfreq_performance);
  53 }
  54 subsys_initcall(devfreq_performance_init);
  55
  56 static void __exit devfreq_performance_exit(void)
  57 {
  58         int ret;
  59
  60         ret = devfreq_remove_governor(&devfreq_performance);
  61         if (ret)
  62                 pr_err("%s: failed remove governor %d\n", __func__, ret);
  63
  64         return;
  65 }
  66 module_exit(devfreq_performance_exit);
  67 MODULE_LICENSE("GPL");