drivers/devfreq/governor.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * governor.h - internal header for devfreq governors.
   4  *
   5  * Copyright (C) 2011 Samsung Electronics
   6  *      MyungJoo Ham <myungjoo.ham@samsung.com>
   7  *
   8  * This header is for devfreq governors in drivers/devfreq/
   9  */
  10
  11 #ifndef _GOVERNOR_H
  12 #define _GOVERNOR_H
  13
  14 #include <linux/devfreq.h>
  15
  16 #define DEVFREQ_NAME_LEN                        16
  17
  18 #define to_devfreq(DEV) container_of((DEV), struct devfreq, dev)
  19
  20 /* Devfreq events */
  21 #define DEVFREQ_GOV_START                       0x1
  22 #define DEVFREQ_GOV_STOP                        0x2
  23 #define DEVFREQ_GOV_UPDATE_INTERVAL             0x3
  24 #define DEVFREQ_GOV_SUSPEND                     0x4
  25 #define DEVFREQ_GOV_RESUME                      0x5
  26
  27 #define DEVFREQ_MIN_FREQ                        0
  28 #define DEVFREQ_MAX_FREQ                        ULONG_MAX
  29
  30 /*
  31  * Definition of the governor feature flags
  32  * - DEVFREQ_GOV_FLAG_IMMUTABLE
  33  *   : This governor is never changeable to other governors.
  34  * - DEVFREQ_GOV_FLAG_IRQ_DRIVEN
  35  *   : The devfreq won't schedule the work for this governor.
  36  */
  37 #define DEVFREQ_GOV_FLAG_IMMUTABLE                      BIT(0)
  38 #define DEVFREQ_GOV_FLAG_IRQ_DRIVEN                     BIT(1)
  39
  40 /*
  41  * Definition of governor attribute flags except for common sysfs attributes
  42  * - DEVFREQ_GOV_ATTR_POLLING_INTERVAL
  43  *   : Indicate polling_interval sysfs attribute
  44  * - DEVFREQ_GOV_ATTR_TIMER
  45  *   : Indicate timer sysfs attribute
  46  */
  47 #define DEVFREQ_GOV_ATTR_POLLING_INTERVAL               BIT(0)
  48 #define DEVFREQ_GOV_ATTR_TIMER                          BIT(1)
  49
  50 /**
  51  * struct devfreq_governor - Devfreq policy governor
  52  * @node:               list node - contains registered devfreq governors
  53  * @name:               Governor's name
  54  * @attrs:              Governor's sysfs attribute flags
  55  * @flags:              Governor's feature flags
  56  * @get_target_freq:    Returns desired operating frequency for the device.
  57  *                      Basically, get_target_freq will run
  58  *                      devfreq_dev_profile.get_dev_status() to get the
  59  *                      status of the device (load = busy_time / total_time).
  60  *                      If no_central_polling is set, this callback is called
  61  *                      only with update_devfreq() notified by OPP.
  62  * @event_handler:      Callback for devfreq core framework to notify events
  63  *                      to governors. Events include per device governor
  64  *                      init and exit, opp changes out of devfreq, suspend
  65  *                      and resume of per device devfreq during device idle.
  66  *
  67  * Note that the callbacks are called with devfreq->lock locked by devfreq.
  68  */
  69 struct devfreq_governor {
  70         struct list_head node;
  71
  72         const char name[DEVFREQ_NAME_LEN];
  73         const u64 attrs;
  74         const u64 flags;
  75         int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
  76         int (*event_handler)(struct devfreq *devfreq,
  77                                 unsigned int event, void *data);
  78 };
  79
  80 void devfreq_monitor_start(struct devfreq *devfreq);
  81 void devfreq_monitor_stop(struct devfreq *devfreq);
  82 void devfreq_monitor_suspend(struct devfreq *devfreq);
  83 void devfreq_monitor_resume(struct devfreq *devfreq);
  84 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
  85
  86 int devfreq_add_governor(struct devfreq_governor *governor);
  87 int devfreq_remove_governor(struct devfreq_governor *governor);
  88
  89 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
  90 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
  91
  92 static inline int devfreq_update_stats(struct devfreq *df)
  93 {
  94         return df->profile->get_dev_status(df->dev.parent, &df->last_status);
  95 }
  96 #endif /* _GOVERNOR_H */