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 usage;
38 unsigned long long time; /* in US */
41 struct cpuidle_state {
42 char name[CPUIDLE_NAME_LEN];
43 char desc[CPUIDLE_DESC_LEN];
46 unsigned int exit_latency; /* in US */
47 int power_usage; /* in mW */
48 unsigned int target_residency; /* in US */
51 int (*enter) (struct cpuidle_device *dev,
52 struct cpuidle_driver *drv,
55 int (*enter_dead) (struct cpuidle_device *dev, int index);
58 /* Idle State Flags */
59 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
60 #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
62 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
65 * cpuidle_get_statedata - retrieves private driver state data
66 * @st_usage: the state usage statistics
68 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
70 return st_usage->driver_data;
74 * cpuidle_set_statedata - stores private driver state data
75 * @st_usage: the state usage statistics
76 * @data: the private data
79 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
81 st_usage->driver_data = data;
84 struct cpuidle_state_kobj {
85 struct cpuidle_state *state;
86 struct cpuidle_state_usage *state_usage;
87 struct completion kobj_unregister;
91 struct cpuidle_device {
92 unsigned int registered:1;
93 unsigned int enabled:1;
98 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
99 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
101 struct list_head device_list;
103 struct completion kobj_unregister;
105 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
106 int safe_state_index;
107 cpumask_t coupled_cpus;
108 struct cpuidle_coupled *coupled;
112 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
115 * cpuidle_get_last_residency - retrieves the last state's residency time
116 * @dev: the target CPU
118 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
120 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
122 return dev->last_residency;
126 /****************************
127 * CPUIDLE DRIVER INTERFACE *
128 ****************************/
130 struct cpuidle_driver {
132 struct module *owner;
134 unsigned int power_specified:1;
135 /* set to 1 to use the core cpuidle time keeping (for all states). */
136 unsigned int en_core_tk_irqen:1;
137 struct cpuidle_state states[CPUIDLE_STATE_MAX];
139 int safe_state_index;
142 #ifdef CONFIG_CPU_IDLE
143 extern void disable_cpuidle(void);
144 extern int cpuidle_idle_call(void);
145 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
146 struct cpuidle_driver *cpuidle_get_driver(void);
147 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
148 extern int cpuidle_register_device(struct cpuidle_device *dev);
149 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
151 extern void cpuidle_pause_and_lock(void);
152 extern void cpuidle_resume_and_unlock(void);
153 extern int cpuidle_enable_device(struct cpuidle_device *dev);
154 extern void cpuidle_disable_device(struct cpuidle_device *dev);
155 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
156 struct cpuidle_driver *drv, int index,
157 int (*enter)(struct cpuidle_device *dev,
158 struct cpuidle_driver *drv, int index));
159 extern int cpuidle_play_dead(void);
162 static inline void disable_cpuidle(void) { }
163 static inline int cpuidle_idle_call(void) { return -ENODEV; }
164 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
166 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
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 int cpuidle_enable_device(struct cpuidle_device *dev)
176 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
177 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
178 struct cpuidle_driver *drv, int index,
179 int (*enter)(struct cpuidle_device *dev,
180 struct cpuidle_driver *drv, int index))
182 static inline int cpuidle_play_dead(void) {return -ENODEV; }
186 /******************************
187 * CPUIDLE GOVERNOR INTERFACE *
188 ******************************/
190 struct cpuidle_governor {
191 char name[CPUIDLE_NAME_LEN];
192 struct list_head governor_list;
195 int (*enable) (struct cpuidle_driver *drv,
196 struct cpuidle_device *dev);
197 void (*disable) (struct cpuidle_driver *drv,
198 struct cpuidle_device *dev);
200 int (*select) (struct cpuidle_driver *drv,
201 struct cpuidle_device *dev);
202 void (*reflect) (struct cpuidle_device *dev, int index);
204 struct module *owner;
207 #ifdef CONFIG_CPU_IDLE
209 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
210 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
212 #ifdef CONFIG_INTEL_IDLE
213 extern int intel_idle_cpu_init(int cpu);
215 static inline int intel_idle_cpu_init(int cpu) { return -1; }
219 static inline int intel_idle_cpu_init(int cpu) { return -1; }
221 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
223 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
227 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
228 #define CPUIDLE_DRIVER_STATE_START 1
230 #define CPUIDLE_DRIVER_STATE_START 0
233 #endif /* _LINUX_CPUIDLE_H */