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 devm_devfreq_add_governor(struct device *dev,
88 			      struct devfreq_governor *governor);
89 
90 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
91 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
92 
devfreq_update_stats(struct devfreq * df)93 static inline int devfreq_update_stats(struct devfreq *df)
94 {
95 	if (!df->profile->get_dev_status)
96 		return -EINVAL;
97 
98 	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
99 }
100 #endif /* _GOVERNOR_H */
101