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 */
49 struct 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
60 void devfreq_monitor_start(struct devfreq *devfreq);
61 void devfreq_monitor_stop(struct devfreq *devfreq);
62 void devfreq_monitor_suspend(struct devfreq *devfreq);
63 void devfreq_monitor_resume(struct devfreq *devfreq);
64 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
65
66 int devfreq_add_governor(struct devfreq_governor *governor);
67 int devfreq_remove_governor(struct devfreq_governor *governor);
68
69 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
70
devfreq_update_stats(struct devfreq * df)71 static 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