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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#define CPUIDLE_DESC_LEN 32
23
24struct cpuidle_device;
25
26
27/****************************
28 * CPUIDLE DEVICE INTERFACE *
29 ****************************/
30
31struct cpuidle_state {
32 char name[CPUIDLE_NAME_LEN];
33 char desc[CPUIDLE_DESC_LEN];
34 void *driver_data;
35
36 unsigned int flags;
37 unsigned int exit_latency; /* in US */
38 unsigned int power_usage; /* in mW */
39 unsigned int target_residency; /* in US */
40
41 unsigned long long usage;
42 unsigned long long time; /* in US */
43
44 int (*enter) (struct cpuidle_device *dev,
45 struct cpuidle_state *state);
46};
47
48/* Idle State Flags */
49#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
50#define CPUIDLE_FLAG_IGNORE (0x100) /* ignore during this idle period */
51
52#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
53
54/**
55 * cpuidle_get_statedata - retrieves private driver state data
56 * @state: the state
57 */
58static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
59{
60 return state->driver_data;
61}
62
63/**
64 * cpuidle_set_statedata - stores private driver state data
65 * @state: the state
66 * @data: the private data
67 */
68static inline void
69cpuidle_set_statedata(struct cpuidle_state *state, void *data)
70{
71 state->driver_data = data;
72}
73
74struct cpuidle_state_kobj {
75 struct cpuidle_state *state;
76 struct completion kobj_unregister;
77 struct kobject kobj;
78};
79
80struct cpuidle_device {
81 unsigned int registered:1;
82 unsigned int enabled:1;
83 unsigned int power_specified:1;
84 unsigned int cpu;
85
86 int last_residency;
87 int state_count;
88 struct cpuidle_state states[CPUIDLE_STATE_MAX];
89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
90 struct cpuidle_state *last_state;
91
92 struct list_head device_list;
93 struct kobject kobj;
94 struct completion kobj_unregister;
95 void *governor_data;
96 struct cpuidle_state *safe_state;
97
98 int (*prepare) (struct cpuidle_device *dev);
99};
100
101DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
102
103/**
104 * cpuidle_get_last_residency - retrieves the last state's residency time
105 * @dev: the target CPU
106 *
107 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
108 */
109static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
110{
111 return dev->last_residency;
112}
113
114
115/****************************
116 * CPUIDLE DRIVER INTERFACE *
117 ****************************/
118
119struct cpuidle_driver {
120 char name[CPUIDLE_NAME_LEN];
121 struct module *owner;
122};
123
124#ifdef CONFIG_CPU_IDLE
125
126extern int cpuidle_register_driver(struct cpuidle_driver *drv);
127struct cpuidle_driver *cpuidle_get_driver(void);
128extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
129extern int cpuidle_register_device(struct cpuidle_device *dev);
130extern void cpuidle_unregister_device(struct cpuidle_device *dev);
131
132extern void cpuidle_pause_and_lock(void);
133extern void cpuidle_resume_and_unlock(void);
134extern int cpuidle_enable_device(struct cpuidle_device *dev);
135extern void cpuidle_disable_device(struct cpuidle_device *dev);
136
137#else
138
139static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
140{return -ENODEV; }
141static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
142static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
143static inline int cpuidle_register_device(struct cpuidle_device *dev)
144{return -ENODEV; }
145static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
146
147static inline void cpuidle_pause_and_lock(void) { }
148static inline void cpuidle_resume_and_unlock(void) { }
149static inline int cpuidle_enable_device(struct cpuidle_device *dev)
150{return -ENODEV; }
151static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
152
153#endif
154
155/******************************
156 * CPUIDLE GOVERNOR INTERFACE *
157 ******************************/
158
159struct cpuidle_governor {
160 char name[CPUIDLE_NAME_LEN];
161 struct list_head governor_list;
162 unsigned int rating;
163
164 int (*enable) (struct cpuidle_device *dev);
165 void (*disable) (struct cpuidle_device *dev);
166
167 int (*select) (struct cpuidle_device *dev);
168 void (*reflect) (struct cpuidle_device *dev);
169
170 struct module *owner;
171};
172
173#ifdef CONFIG_CPU_IDLE
174
175extern int cpuidle_register_governor(struct cpuidle_governor *gov);
176extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
177
178#else
179
180static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
181{return 0;}
182static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
183
184#endif
185
186#ifdef CONFIG_ARCH_HAS_CPU_RELAX
187#define CPUIDLE_DRIVER_STATE_START 1
188#else
189#define CPUIDLE_DRIVER_STATE_START 0
190#endif
191
192#endif /* _LINUX_CPUIDLE_H */