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 unsigned int power_usage; /* in mW */
48 unsigned int target_residency; /* in US */
51 int (*enter) (struct cpuidle_device *dev,
52 struct cpuidle_driver *drv,
56 /* Idle State Flags */
57 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
59 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62 * cpuidle_get_statedata - retrieves private driver state data
63 * @st_usage: the state usage statistics
65 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
67 return st_usage->driver_data;
71 * cpuidle_set_statedata - stores private driver state data
72 * @st_usage: the state usage statistics
73 * @data: the private data
76 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
78 st_usage->driver_data = data;
81 struct cpuidle_state_kobj {
82 struct cpuidle_state *state;
83 struct cpuidle_state_usage *state_usage;
84 struct completion kobj_unregister;
88 struct cpuidle_device {
89 unsigned int registered:1;
90 unsigned int enabled:1;
95 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
96 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
98 struct list_head device_list;
100 struct completion kobj_unregister;
103 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
106 * cpuidle_get_last_residency - retrieves the last state's residency time
107 * @dev: the target CPU
109 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
111 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
113 return dev->last_residency;
117 /****************************
118 * CPUIDLE DRIVER INTERFACE *
119 ****************************/
121 struct cpuidle_driver {
123 struct module *owner;
125 unsigned int power_specified:1;
126 /* set to 1 to use the core cpuidle time keeping (for all states). */
127 unsigned int en_core_tk_irqen:1;
128 struct cpuidle_state states[CPUIDLE_STATE_MAX];
130 int safe_state_index;
133 #ifdef CONFIG_CPU_IDLE
134 extern void disable_cpuidle(void);
135 extern int cpuidle_idle_call(void);
136 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
137 struct cpuidle_driver *cpuidle_get_driver(void);
138 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
139 extern int cpuidle_register_device(struct cpuidle_device *dev);
140 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
142 extern void cpuidle_pause_and_lock(void);
143 extern void cpuidle_resume_and_unlock(void);
144 extern int cpuidle_enable_device(struct cpuidle_device *dev);
145 extern void cpuidle_disable_device(struct cpuidle_device *dev);
146 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
147 struct cpuidle_driver *drv, int index,
148 int (*enter)(struct cpuidle_device *dev,
149 struct cpuidle_driver *drv, int index));
151 static inline void disable_cpuidle(void) { }
152 static inline int cpuidle_idle_call(void) { return -ENODEV; }
153 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
155 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
156 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
157 static inline int cpuidle_register_device(struct cpuidle_device *dev)
159 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
161 static inline void cpuidle_pause_and_lock(void) { }
162 static inline void cpuidle_resume_and_unlock(void) { }
163 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
165 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
166 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
167 struct cpuidle_driver *drv, int index,
168 int (*enter)(struct cpuidle_device *dev,
169 struct cpuidle_driver *drv, int index))
174 /******************************
175 * CPUIDLE GOVERNOR INTERFACE *
176 ******************************/
178 struct cpuidle_governor {
179 char name[CPUIDLE_NAME_LEN];
180 struct list_head governor_list;
183 int (*enable) (struct cpuidle_driver *drv,
184 struct cpuidle_device *dev);
185 void (*disable) (struct cpuidle_driver *drv,
186 struct cpuidle_device *dev);
188 int (*select) (struct cpuidle_driver *drv,
189 struct cpuidle_device *dev);
190 void (*reflect) (struct cpuidle_device *dev, int index);
192 struct module *owner;
195 #ifdef CONFIG_CPU_IDLE
197 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
198 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
200 #ifdef CONFIG_INTEL_IDLE
201 extern int intel_idle_cpu_init(int cpu);
203 static inline int intel_idle_cpu_init(int cpu) { return -1; }
207 static inline int intel_idle_cpu_init(int cpu) { return -1; }
209 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
211 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
215 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
216 #define CPUIDLE_DRIVER_STATE_START 1
218 #define CPUIDLE_DRIVER_STATE_START 0
221 #endif /* _LINUX_CPUIDLE_H */