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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/kobject.h>
17#include <linux/completion.h>
18#include <linux/hrtimer.h>
19
20#define CPUIDLE_STATE_MAX 8
21#define CPUIDLE_NAME_LEN 16
22#define CPUIDLE_DESC_LEN 32
23
24struct module;
25
26struct cpuidle_device;
27struct cpuidle_driver;
28
29
30/****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
33
34struct cpuidle_state_usage {
35 void *driver_data;
36
37 unsigned long long usage;
38 unsigned long long time; /* in US */
39};
40
41struct cpuidle_state {
42 char name[CPUIDLE_NAME_LEN];
43 char desc[CPUIDLE_DESC_LEN];
44
45 unsigned int flags;
46 unsigned int exit_latency; /* in US */
47 int power_usage; /* in mW */
48 unsigned int target_residency; /* in US */
49 unsigned int disable;
50
51 int (*enter) (struct cpuidle_device *dev,
52 struct cpuidle_driver *drv,
53 int index);
54
55 int (*enter_dead) (struct cpuidle_device *dev, int index);
56};
57
58/* Idle State Flags */
59#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
60
61#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62
63/**
64 * cpuidle_get_statedata - retrieves private driver state data
65 * @st_usage: the state usage statistics
66 */
67static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
68{
69 return st_usage->driver_data;
70}
71
72/**
73 * cpuidle_set_statedata - stores private driver state data
74 * @st_usage: the state usage statistics
75 * @data: the private data
76 */
77static inline void
78cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
79{
80 st_usage->driver_data = data;
81}
82
83struct cpuidle_state_kobj {
84 struct cpuidle_state *state;
85 struct cpuidle_state_usage *state_usage;
86 struct completion kobj_unregister;
87 struct kobject kobj;
88};
89
90struct cpuidle_device {
91 unsigned int registered:1;
92 unsigned int enabled:1;
93 unsigned int cpu;
94
95 int last_residency;
96 int state_count;
97 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
98 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
99
100 struct list_head device_list;
101 struct kobject kobj;
102 struct completion kobj_unregister;
103};
104
105DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
106
107/**
108 * cpuidle_get_last_residency - retrieves the last state's residency time
109 * @dev: the target CPU
110 *
111 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
112 */
113static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
114{
115 return dev->last_residency;
116}
117
118
119/****************************
120 * CPUIDLE DRIVER INTERFACE *
121 ****************************/
122
123struct cpuidle_driver {
124 const char *name;
125 struct module *owner;
126
127 unsigned int power_specified:1;
128 /* set to 1 to use the core cpuidle time keeping (for all states). */
129 unsigned int en_core_tk_irqen:1;
130 struct cpuidle_state states[CPUIDLE_STATE_MAX];
131 int state_count;
132 int safe_state_index;
133};
134
135#ifdef CONFIG_CPU_IDLE
136extern void disable_cpuidle(void);
137extern int cpuidle_idle_call(void);
138extern int cpuidle_register_driver(struct cpuidle_driver *drv);
139struct cpuidle_driver *cpuidle_get_driver(void);
140extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
141extern int cpuidle_register_device(struct cpuidle_device *dev);
142extern void cpuidle_unregister_device(struct cpuidle_device *dev);
143
144extern void cpuidle_pause_and_lock(void);
145extern void cpuidle_resume_and_unlock(void);
146extern int cpuidle_enable_device(struct cpuidle_device *dev);
147extern void cpuidle_disable_device(struct cpuidle_device *dev);
148extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
149 struct cpuidle_driver *drv, int index,
150 int (*enter)(struct cpuidle_device *dev,
151 struct cpuidle_driver *drv, int index));
152extern int cpuidle_play_dead(void);
153
154#else
155static inline void disable_cpuidle(void) { }
156static inline int cpuidle_idle_call(void) { return -ENODEV; }
157static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
158{return -ENODEV; }
159static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
160static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
161static inline int cpuidle_register_device(struct cpuidle_device *dev)
162{return -ENODEV; }
163static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
164
165static inline void cpuidle_pause_and_lock(void) { }
166static inline void cpuidle_resume_and_unlock(void) { }
167static inline int cpuidle_enable_device(struct cpuidle_device *dev)
168{return -ENODEV; }
169static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
170static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
171 struct cpuidle_driver *drv, int index,
172 int (*enter)(struct cpuidle_device *dev,
173 struct cpuidle_driver *drv, int index))
174{ return -ENODEV; }
175static inline int cpuidle_play_dead(void) {return -ENODEV; }
176
177#endif
178
179/******************************
180 * CPUIDLE GOVERNOR INTERFACE *
181 ******************************/
182
183struct cpuidle_governor {
184 char name[CPUIDLE_NAME_LEN];
185 struct list_head governor_list;
186 unsigned int rating;
187
188 int (*enable) (struct cpuidle_driver *drv,
189 struct cpuidle_device *dev);
190 void (*disable) (struct cpuidle_driver *drv,
191 struct cpuidle_device *dev);
192
193 int (*select) (struct cpuidle_driver *drv,
194 struct cpuidle_device *dev);
195 void (*reflect) (struct cpuidle_device *dev, int index);
196
197 struct module *owner;
198};
199
200#ifdef CONFIG_CPU_IDLE
201
202extern int cpuidle_register_governor(struct cpuidle_governor *gov);
203extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
204
205#ifdef CONFIG_INTEL_IDLE
206extern int intel_idle_cpu_init(int cpu);
207#else
208static inline int intel_idle_cpu_init(int cpu) { return -1; }
209#endif
210
211#else
212static inline int intel_idle_cpu_init(int cpu) { return -1; }
213
214static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
215{return 0;}
216static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
217
218#endif
219
220#ifdef CONFIG_ARCH_HAS_CPU_RELAX
221#define CPUIDLE_DRIVER_STATE_START 1
222#else
223#define CPUIDLE_DRIVER_STATE_START 0
224#endif
225
226#endif /* _LINUX_CPUIDLE_H */