xref: /linux/drivers/devfreq/governor.h (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
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_cpu_data - Hold the per-cpu data
52  * @node:	list node
53  * @dev:	reference to cpu device.
54  * @first_cpu:	the cpumask of the first cpu of a policy.
55  * @opp_table:	reference to cpu opp table.
56  * @cur_freq:	the current frequency of the cpu.
57  * @min_freq:	the min frequency of the cpu.
58  * @max_freq:	the max frequency of the cpu.
59  *
60  * This structure stores the required cpu_data of a cpu.
61  * This is auto-populated by the governor.
62  */
63 struct devfreq_cpu_data {
64 	struct list_head node;
65 
66 	struct device *dev;
67 	unsigned int first_cpu;
68 
69 	struct opp_table *opp_table;
70 	unsigned int cur_freq;
71 	unsigned int min_freq;
72 	unsigned int max_freq;
73 };
74 
75 /**
76  * struct devfreq_governor - Devfreq policy governor
77  * @node:		list node - contains registered devfreq governors
78  * @name:		Governor's name
79  * @attrs:		Governor's sysfs attribute flags
80  * @flags:		Governor's feature flags
81  * @get_target_freq:	Returns desired operating frequency for the device.
82  *			Basically, get_target_freq will run
83  *			devfreq_dev_profile.get_dev_status() to get the
84  *			status of the device (load = busy_time / total_time).
85  * @event_handler:      Callback for devfreq core framework to notify events
86  *                      to governors. Events include per device governor
87  *                      init and exit, opp changes out of devfreq, suspend
88  *                      and resume of per device devfreq during device idle.
89  *
90  * Note that the callbacks are called with devfreq->lock locked by devfreq.
91  */
92 struct devfreq_governor {
93 	struct list_head node;
94 
95 	const char name[DEVFREQ_NAME_LEN];
96 	const u64 attrs;
97 	const u64 flags;
98 	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
99 	int (*event_handler)(struct devfreq *devfreq,
100 				unsigned int event, void *data);
101 };
102 
103 void devfreq_monitor_start(struct devfreq *devfreq);
104 void devfreq_monitor_stop(struct devfreq *devfreq);
105 void devfreq_monitor_suspend(struct devfreq *devfreq);
106 void devfreq_monitor_resume(struct devfreq *devfreq);
107 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
108 
109 int devfreq_add_governor(struct devfreq_governor *governor);
110 int devfreq_remove_governor(struct devfreq_governor *governor);
111 
112 int devm_devfreq_add_governor(struct device *dev,
113 			      struct devfreq_governor *governor);
114 
115 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
116 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
117 void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq,
118 			    unsigned long *max_freq);
119 
devfreq_update_stats(struct devfreq * df)120 static inline int devfreq_update_stats(struct devfreq *df)
121 {
122 	if (!df->profile->get_dev_status)
123 		return -EINVAL;
124 
125 	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
126 }
127 #endif /* _GOVERNOR_H */
128