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 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 * @event_handler:      Callback for devfreq core framework to notify events
  61 *                      to governors. Events include per device governor
  62 *                      init and exit, opp changes out of devfreq, suspend
  63 *                      and resume of per device devfreq during device idle.
  64 *
  65 * Note that the callbacks are called with devfreq->lock locked by devfreq.
  66 */
  67struct devfreq_governor {
  68        struct list_head node;
  69
  70        const char name[DEVFREQ_NAME_LEN];
  71        const u64 attrs;
  72        const u64 flags;
  73        int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
  74        int (*event_handler)(struct devfreq *devfreq,
  75                                unsigned int event, void *data);
  76};
  77
  78void devfreq_monitor_start(struct devfreq *devfreq);
  79void devfreq_monitor_stop(struct devfreq *devfreq);
  80void devfreq_monitor_suspend(struct devfreq *devfreq);
  81void devfreq_monitor_resume(struct devfreq *devfreq);
  82void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
  83
  84int devfreq_add_governor(struct devfreq_governor *governor);
  85int devfreq_remove_governor(struct devfreq_governor *governor);
  86
  87int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
  88int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
  89
  90static inline int devfreq_update_stats(struct devfreq *df)
  91{
  92        if (!df->profile->get_dev_status)
  93                return -EINVAL;
  94
  95        return df->profile->get_dev_status(df->dev.parent, &df->last_status);
  96}
  97#endif /* _GOVERNOR_H */
  98