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_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 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 */
47struct 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
57extern void devfreq_monitor_start(struct devfreq *devfreq);
58extern void devfreq_monitor_stop(struct devfreq *devfreq);
59extern void devfreq_monitor_suspend(struct devfreq *devfreq);
60extern void devfreq_monitor_resume(struct devfreq *devfreq);
61extern void devfreq_interval_update(struct devfreq *devfreq,
62					unsigned int *delay);
63
64extern int devfreq_add_governor(struct devfreq_governor *governor);
65extern int devfreq_remove_governor(struct devfreq_governor *governor);
66
67extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
68
69static inline int devfreq_update_stats(struct devfreq *df)
70{
71	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
72}
73#endif /* _GOVERNOR_H */