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_device {
86 unsigned int registered:1;
87 unsigned int enabled:1;
92 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
93 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
95 struct list_head device_list;
97 struct completion kobj_unregister;
99 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
100 int safe_state_index;
101 cpumask_t coupled_cpus;
102 struct cpuidle_coupled *coupled;
106 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
109 * cpuidle_get_last_residency - retrieves the last state's residency time
110 * @dev: the target CPU
112 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
114 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
116 return dev->last_residency;
120 /****************************
121 * CPUIDLE DRIVER INTERFACE *
122 ****************************/
124 struct cpuidle_driver {
126 struct module *owner;
128 unsigned int power_specified:1;
129 /* set to 1 to use the core cpuidle time keeping (for all states). */
130 unsigned int en_core_tk_irqen:1;
131 struct cpuidle_state states[CPUIDLE_STATE_MAX];
133 int safe_state_index;
136 #ifdef CONFIG_CPU_IDLE
137 extern void disable_cpuidle(void);
138 extern int cpuidle_idle_call(void);
139 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
140 extern struct cpuidle_driver *cpuidle_get_driver(void);
141 extern struct cpuidle_driver *cpuidle_driver_ref(void);
142 extern void cpuidle_driver_unref(void);
143 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
144 extern int cpuidle_register_device(struct cpuidle_device *dev);
145 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
147 extern void cpuidle_pause_and_lock(void);
148 extern void cpuidle_resume_and_unlock(void);
149 extern void cpuidle_pause(void);
150 extern void cpuidle_resume(void);
151 extern int cpuidle_enable_device(struct cpuidle_device *dev);
152 extern void cpuidle_disable_device(struct cpuidle_device *dev);
153 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
154 struct cpuidle_driver *drv, int index,
155 int (*enter)(struct cpuidle_device *dev,
156 struct cpuidle_driver *drv, int index));
157 extern int cpuidle_play_dead(void);
160 static inline void disable_cpuidle(void) { }
161 static inline int cpuidle_idle_call(void) { return -ENODEV; }
162 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
164 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
165 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
166 static inline void cpuidle_driver_unref(void) {}
167 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
168 static inline int cpuidle_register_device(struct cpuidle_device *dev)
170 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
172 static inline void cpuidle_pause_and_lock(void) { }
173 static inline void cpuidle_resume_and_unlock(void) { }
174 static inline void cpuidle_pause(void) { }
175 static inline void cpuidle_resume(void) { }
176 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
178 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
179 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
180 struct cpuidle_driver *drv, int index,
181 int (*enter)(struct cpuidle_device *dev,
182 struct cpuidle_driver *drv, int index))
184 static inline int cpuidle_play_dead(void) {return -ENODEV; }
188 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
189 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
191 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
196 /******************************
197 * CPUIDLE GOVERNOR INTERFACE *
198 ******************************/
200 struct cpuidle_governor {
201 char name[CPUIDLE_NAME_LEN];
202 struct list_head governor_list;
205 int (*enable) (struct cpuidle_driver *drv,
206 struct cpuidle_device *dev);
207 void (*disable) (struct cpuidle_driver *drv,
208 struct cpuidle_device *dev);
210 int (*select) (struct cpuidle_driver *drv,
211 struct cpuidle_device *dev);
212 void (*reflect) (struct cpuidle_device *dev, int index);
214 struct module *owner;
217 #ifdef CONFIG_CPU_IDLE
219 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
220 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
224 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
226 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
230 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
231 #define CPUIDLE_DRIVER_STATE_START 1
233 #define CPUIDLE_DRIVER_STATE_START 0
236 #endif /* _LINUX_CPUIDLE_H */