LXR linux/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 to_devfreq(DEV) container_of((DEV), struct devfreq, dev)
  17
  18/* Devfreq events */
  19#define DEVFREQ_GOV_START                       0x1
  20#define DEVFREQ_GOV_STOP                        0x2
  21#define DEVFREQ_GOV_UPDATE_INTERVAL             0x3
  22#define DEVFREQ_GOV_SUSPEND                     0x4
  23#define DEVFREQ_GOV_RESUME                      0x5
  24
  25#define DEVFREQ_MIN_FREQ                        0
  26#define DEVFREQ_MAX_FREQ                        ULONG_MAX
  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 governor is never changeable to other governor.
  34 * @interrupt_driven:   Devfreq core won't schedule polling work for this
  35 *                      governor if value is set to 1.
  36 * @get_target_freq:    Returns desired operating frequency for the device.
  37 *                      Basically, get_target_freq will run
  38 *                      devfreq_dev_profile.get_dev_status() to get the
  39 *                      status of the device (load = busy_time / total_time).
  40 *                      If no_central_polling is set, this callback is called
  41 *                      only with update_devfreq() notified by OPP.
  42 * @event_handler:      Callback for devfreq core framework to notify events
  43 *                      to governors. Events include per device governor
  44 *                      init and exit, opp changes out of devfreq, suspend
  45 *                      and resume of per device devfreq during device idle.
  46 *
  47 * Note that the callbacks are called with devfreq->lock locked by devfreq.
  48 */
  49struct devfreq_governor {
  50        struct list_head node;
  51
  52        const char name[DEVFREQ_NAME_LEN];
  53        const unsigned int immutable;
  54        const unsigned int interrupt_driven;
  55        int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
  56        int (*event_handler)(struct devfreq *devfreq,
  57                                unsigned int event, void *data);
  58};
  59
  60void devfreq_monitor_start(struct devfreq *devfreq);
  61void devfreq_monitor_stop(struct devfreq *devfreq);
  62void devfreq_monitor_suspend(struct devfreq *devfreq);
  63void devfreq_monitor_resume(struct devfreq *devfreq);
  64void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
  65
  66int devfreq_add_governor(struct devfreq_governor *governor);
  67int devfreq_remove_governor(struct devfreq_governor *governor);
  68
  69int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
  70
  71static inline int devfreq_update_stats(struct devfreq *df)
  72{
  73        return df->profile->get_dev_status(df->dev.parent, &df->last_status);
  74}
  75#endif /* _GOVERNOR_H */
  76