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 */
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 extern void devfreq_monitor_start(struct devfreq *devfreq);
58 extern void devfreq_monitor_stop(struct devfreq *devfreq);
59 extern void devfreq_monitor_suspend(struct devfreq *devfreq);
60 extern void devfreq_monitor_resume(struct devfreq *devfreq);
61 extern void devfreq_interval_update(struct devfreq *devfreq,
62 unsigned int *delay);
63
64 extern int devfreq_add_governor(struct devfreq_governor *governor);
65 extern int devfreq_remove_governor(struct devfreq_governor *governor);
66
67 extern int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
68
69 static 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 */