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 */
67 struct 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
78 void devfreq_monitor_start(struct devfreq *devfreq);
79 void devfreq_monitor_stop(struct devfreq *devfreq);
80 void devfreq_monitor_suspend(struct devfreq *devfreq);
81 void devfreq_monitor_resume(struct devfreq *devfreq);
82 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
83
84 int devfreq_add_governor(struct devfreq_governor *governor);
85 int devfreq_remove_governor(struct devfreq_governor *governor);
86
87 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
88 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
89
devfreq_update_stats(struct devfreq * df)90 static 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