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1/*
2 * cpuidle.h - a generic framework for CPU idle power management
3 *
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
7 *
8 * This code is licenced under the GPL.
9 */
10
11#ifndef _LINUX_CPUIDLE_H
12#define _LINUX_CPUIDLE_H
13
14#include <linux/percpu.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/kobject.h>
18#include <linux/completion.h>
19
20#define CPUIDLE_STATE_MAX 8
21#define CPUIDLE_NAME_LEN 16
22
23struct cpuidle_device;
24
25
26/****************************
27 * CPUIDLE DEVICE INTERFACE *
28 ****************************/
29
30struct cpuidle_state {
31 char name[CPUIDLE_NAME_LEN];
32 void *driver_data;
33
34 unsigned int flags;
35 unsigned int exit_latency; /* in US */
36 unsigned int power_usage; /* in mW */
37 unsigned int target_residency; /* in US */
38
39 unsigned int usage;
40 unsigned int time; /* in US */
41
42 int (*enter) (struct cpuidle_device *dev,
43 struct cpuidle_state *state);
44};
45
46/* Idle State Flags */
47#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
48#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
49#define CPUIDLE_FLAG_SHALLOW (0x10) /* low latency, minimal savings */
50#define CPUIDLE_FLAG_BALANCED (0x20) /* medium latency, moderate savings */
51#define CPUIDLE_FLAG_DEEP (0x40) /* high latency, large savings */
52
53#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
54
55/**
56 * cpuidle_get_statedata - retrieves private driver state data
57 * @state: the state
58 */
59static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
60{
61 return state->driver_data;
62}
63
64/**
65 * cpuidle_set_statedata - stores private driver state data
66 * @state: the state
67 * @data: the private data
68 */
69static inline void
70cpuidle_set_statedata(struct cpuidle_state *state, void *data)
71{
72 state->driver_data = data;
73}
74
75struct cpuidle_state_kobj {
76 struct cpuidle_state *state;
77 struct completion kobj_unregister;
78 struct kobject kobj;
79};
80
81struct cpuidle_device {
82 int enabled:1;
83 unsigned int cpu;
84
85 int last_residency;
86 int state_count;
87 struct cpuidle_state states[CPUIDLE_STATE_MAX];
88 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
89 struct cpuidle_state *last_state;
90
91 struct list_head device_list;
92 struct kobject kobj;
93 struct completion kobj_unregister;
94 void *governor_data;
95 struct cpuidle_state *safe_state;
96};
97
98DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
99
100/**
101 * cpuidle_get_last_residency - retrieves the last state's residency time
102 * @dev: the target CPU
103 *
104 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
105 */
106static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
107{
108 return dev->last_residency;
109}
110
111
112/****************************
113 * CPUIDLE DRIVER INTERFACE *
114 ****************************/
115
116struct cpuidle_driver {
117 char name[CPUIDLE_NAME_LEN];
118 struct module *owner;
119};
120
121#ifdef CONFIG_CPU_IDLE
122
123extern int cpuidle_register_driver(struct cpuidle_driver *drv);
124extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
125extern int cpuidle_register_device(struct cpuidle_device *dev);
126extern void cpuidle_unregister_device(struct cpuidle_device *dev);
127
128extern void cpuidle_pause_and_lock(void);
129extern void cpuidle_resume_and_unlock(void);
130extern int cpuidle_enable_device(struct cpuidle_device *dev);
131extern void cpuidle_disable_device(struct cpuidle_device *dev);
132
133#else
134
135static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
136{return 0;}
137static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
138static inline int cpuidle_register_device(struct cpuidle_device *dev)
139{return 0;}
140static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
141
142static inline void cpuidle_pause_and_lock(void) { }
143static inline void cpuidle_resume_and_unlock(void) { }
144static inline int cpuidle_enable_device(struct cpuidle_device *dev)
145{return 0;}
146static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
147
148#endif
149
150/******************************
151 * CPUIDLE GOVERNOR INTERFACE *
152 ******************************/
153
154struct cpuidle_governor {
155 char name[CPUIDLE_NAME_LEN];
156 struct list_head governor_list;
157 unsigned int rating;
158
159 int (*enable) (struct cpuidle_device *dev);
160 void (*disable) (struct cpuidle_device *dev);
161
162 int (*select) (struct cpuidle_device *dev);
163 void (*reflect) (struct cpuidle_device *dev);
164
165 struct module *owner;
166};
167
168#ifdef CONFIG_CPU_IDLE
169
170extern int cpuidle_register_governor(struct cpuidle_governor *gov);
171extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
172
173#else
174
175static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
176{return 0;}
177static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
178
179#endif
180
181#endif /* _LINUX_CPUIDLE_H */