2 * cpuidle.h - a generic framework for CPU idle power management
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
8 * This code is licenced under the GPL.
11 #ifndef _LINUX_CPUIDLE_H
12 #define _LINUX_CPUIDLE_H
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>
20 #define CPUIDLE_STATE_MAX 8
21 #define CPUIDLE_NAME_LEN 16
22 #define CPUIDLE_DESC_LEN 32
26 struct cpuidle_device;
27 struct cpuidle_driver;
30 /****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
34 struct cpuidle_state_usage {
37 unsigned long long disable;
38 unsigned long long usage;
39 unsigned long long time; /* in US */
42 struct cpuidle_state {
43 char name[CPUIDLE_NAME_LEN];
44 char desc[CPUIDLE_DESC_LEN];
47 unsigned int exit_latency; /* in US */
48 int power_usage; /* in mW */
49 unsigned int target_residency; /* in US */
50 bool disabled; /* disabled on all CPUs */
52 int (*enter) (struct cpuidle_device *dev,
53 struct cpuidle_driver *drv,
56 int (*enter_dead) (struct cpuidle_device *dev, int index);
59 /* Idle State Flags */
60 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
61 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
63 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
66 * cpuidle_get_statedata - retrieves private driver state data
67 * @st_usage: the state usage statistics
69 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
71 return st_usage->driver_data;
75 * cpuidle_set_statedata - stores private driver state data
76 * @st_usage: the state usage statistics
77 * @data: the private data
80 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
82 st_usage->driver_data = data;
85 struct cpuidle_state_kobj {
86 struct cpuidle_state *state;
87 struct cpuidle_state_usage *state_usage;
88 struct completion kobj_unregister;
92 struct cpuidle_device {
93 unsigned int registered:1;
94 unsigned int enabled:1;
99 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
100 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
102 struct list_head device_list;
104 struct completion kobj_unregister;
106 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
107 int safe_state_index;
108 cpumask_t coupled_cpus;
109 struct cpuidle_coupled *coupled;
113 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
116 * cpuidle_get_last_residency - retrieves the last state's residency time
117 * @dev: the target CPU
119 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
121 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
123 return dev->last_residency;
127 /****************************
128 * CPUIDLE DRIVER INTERFACE *
129 ****************************/
131 struct cpuidle_driver {
133 struct module *owner;
135 unsigned int power_specified:1;
136 /* set to 1 to use the core cpuidle time keeping (for all states). */
137 unsigned int en_core_tk_irqen:1;
138 struct cpuidle_state states[CPUIDLE_STATE_MAX];
140 int safe_state_index;
143 #ifdef CONFIG_CPU_IDLE
144 extern void disable_cpuidle(void);
145 extern int cpuidle_idle_call(void);
146 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
147 extern struct cpuidle_driver *cpuidle_get_driver(void);
148 extern struct cpuidle_driver *cpuidle_driver_ref(void);
149 extern void cpuidle_driver_unref(void);
150 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
151 extern int cpuidle_register_device(struct cpuidle_device *dev);
152 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
154 extern void cpuidle_pause_and_lock(void);
155 extern void cpuidle_resume_and_unlock(void);
156 extern void cpuidle_pause(void);
157 extern void cpuidle_resume(void);
158 extern int cpuidle_enable_device(struct cpuidle_device *dev);
159 extern void cpuidle_disable_device(struct cpuidle_device *dev);
160 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
161 struct cpuidle_driver *drv, int index,
162 int (*enter)(struct cpuidle_device *dev,
163 struct cpuidle_driver *drv, int index));
164 extern int cpuidle_play_dead(void);
167 static inline void disable_cpuidle(void) { }
168 static inline int cpuidle_idle_call(void) { return -ENODEV; }
169 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
171 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
172 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
173 static inline void cpuidle_driver_unref(void) {}
174 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
175 static inline int cpuidle_register_device(struct cpuidle_device *dev)
177 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
179 static inline void cpuidle_pause_and_lock(void) { }
180 static inline void cpuidle_resume_and_unlock(void) { }
181 static inline void cpuidle_pause(void) { }
182 static inline void cpuidle_resume(void) { }
183 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
185 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
186 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
187 struct cpuidle_driver *drv, int index,
188 int (*enter)(struct cpuidle_device *dev,
189 struct cpuidle_driver *drv, int index))
191 static inline int cpuidle_play_dead(void) {return -ENODEV; }
195 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
196 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
198 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
203 /******************************
204 * CPUIDLE GOVERNOR INTERFACE *
205 ******************************/
207 struct cpuidle_governor {
208 char name[CPUIDLE_NAME_LEN];
209 struct list_head governor_list;
212 int (*enable) (struct cpuidle_driver *drv,
213 struct cpuidle_device *dev);
214 void (*disable) (struct cpuidle_driver *drv,
215 struct cpuidle_device *dev);
217 int (*select) (struct cpuidle_driver *drv,
218 struct cpuidle_device *dev);
219 void (*reflect) (struct cpuidle_device *dev, int index);
221 struct module *owner;
224 #ifdef CONFIG_CPU_IDLE
226 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
227 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
231 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
233 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
237 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
238 #define CPUIDLE_DRIVER_STATE_START 1
240 #define CPUIDLE_DRIVER_STATE_START 0
243 #endif /* _LINUX_CPUIDLE_H */