drivers/devfreq/governor.h

   1 /*
   2  * governor.h - internal header for devfreq governors.
   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  * This header is for devfreq governors in drivers/devfreq/
  12  */
  13
  14 #ifndef _GOVERNOR_H
  15 #define _GOVERNOR_H
  16
  17 #include <linux/devfreq.h>
  18
  19 #define to_devfreq(DEV) container_of((DEV), struct devfreq, dev)
  20
  21 /* Devfreq events */
  22 #define DEVFREQ_GOV_START                       0x1
  23 #define DEVFREQ_GOV_STOP                        0x2
  24 #define DEVFREQ_GOV_INTERVAL                    0x3
  25 #define DEVFREQ_GOV_SUSPEND                     0x4
  26 #define DEVFREQ_GOV_RESUME                      0x5
  27
  28 /**
  29  * struct devfreq_governor - Devfreq policy governor
  30  * @node:               list node - contains registered devfreq governors
  31  * @name:               Governor's name
  32  * @immutable:          Immutable flag for governor. If the value is 1,
  33  *                      this govenror is never changeable to other governor.
  34  * @get_target_freq:    Returns desired operating frequency for the device.
  35  *                      Basically, get_target_freq will run
  36  *                      devfreq_dev_profile.get_dev_status() to get the
  37  *                      status of the device (load = busy_time / total_time).
  38  *                      If no_central_polling is set, this callback is called
  39  *                      only with update_devfreq() notified by OPP.
  40  * @event_handler:      Callback for devfreq core framework to notify events
  41  *                      to governors. Events include per device governor
  42  *                      init and exit, opp changes out of devfreq, suspend
  43  *                      and resume of per device devfreq during device idle.
  44  *
  45  * Note that the callbacks are called with devfreq->lock locked by devfreq.
  46  */
  47 struct devfreq_governor {
  48         struct list_head node;
  49
  50         const char name[DEVFREQ_NAME_LEN];
  51         const unsigned int immutable;
  52         int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
  53         int (*event_handler)(struct devfreq *devfreq,
  54                                 unsigned int event, void *data);
  55 };
  56
  57 /* Caution: devfreq->lock must be locked before calling update_devfreq */
  58 extern int update_devfreq(struct devfreq *devfreq);
  59
  60 extern void devfreq_monitor_start(struct devfreq *devfreq);
  61 extern void devfreq_monitor_stop(struct devfreq *devfreq);
  62 extern void devfreq_monitor_suspend(struct devfreq *devfreq);
  63 extern void devfreq_monitor_resume(struct devfreq *devfreq);
  64 extern void devfreq_interval_update(struct devfreq *devfreq,
  65                                         unsigned int *delay);
  66
  67 extern int devfreq_add_governor(struct devfreq_governor *governor);
  68 extern int devfreq_remove_governor(struct devfreq_governor *governor);
  69
  70 extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
  71
  72 static inline int devfreq_update_stats(struct devfreq *df)
  73 {
  74         return df->profile->get_dev_status(df->dev.parent, &df->last_status);
  75 }
  76 #endif /* _GOVERNOR_H */