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>
19 #define CPUIDLE_STATE_MAX 8
20 #define CPUIDLE_NAME_LEN 16
21 #define CPUIDLE_DESC_LEN 32
25 struct cpuidle_device;
26 struct cpuidle_driver;
29 /****************************
30 * CPUIDLE DEVICE INTERFACE *
31 ****************************/
33 struct cpuidle_state_usage {
36 unsigned long long usage;
37 unsigned long long time; /* in US */
40 struct cpuidle_state {
41 char name[CPUIDLE_NAME_LEN];
42 char desc[CPUIDLE_DESC_LEN];
45 unsigned int exit_latency; /* in US */
46 unsigned int power_usage; /* in mW */
47 unsigned int target_residency; /* in US */
50 int (*enter) (struct cpuidle_device *dev,
51 struct cpuidle_driver *drv,
55 /* Idle State Flags */
56 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
58 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
61 * cpuidle_get_statedata - retrieves private driver state data
62 * @st_usage: the state usage statistics
64 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
66 return st_usage->driver_data;
70 * cpuidle_set_statedata - stores private driver state data
71 * @st_usage: the state usage statistics
72 * @data: the private data
75 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
77 st_usage->driver_data = data;
80 struct cpuidle_state_kobj {
81 struct cpuidle_state *state;
82 struct cpuidle_state_usage *state_usage;
83 struct completion kobj_unregister;
87 struct cpuidle_device {
88 unsigned int registered:1;
89 unsigned int enabled:1;
94 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
95 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
97 struct list_head device_list;
99 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 {
122 char name[CPUIDLE_NAME_LEN];
123 struct module *owner;
125 unsigned int power_specified:1;
126 struct cpuidle_state states[CPUIDLE_STATE_MAX];
128 int safe_state_index;
131 #ifdef CONFIG_CPU_IDLE
132 extern void disable_cpuidle(void);
133 extern int cpuidle_idle_call(void);
135 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
136 struct cpuidle_driver *cpuidle_get_driver(void);
137 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
138 extern int cpuidle_register_device(struct cpuidle_device *dev);
139 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
141 extern void cpuidle_pause_and_lock(void);
142 extern void cpuidle_resume_and_unlock(void);
143 extern int cpuidle_enable_device(struct cpuidle_device *dev);
144 extern void cpuidle_disable_device(struct cpuidle_device *dev);
147 static inline void disable_cpuidle(void) { }
148 static inline int cpuidle_idle_call(void) { return -ENODEV; }
150 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
152 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
153 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
154 static inline int cpuidle_register_device(struct cpuidle_device *dev)
156 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
158 static inline void cpuidle_pause_and_lock(void) { }
159 static inline void cpuidle_resume_and_unlock(void) { }
160 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
162 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
166 /******************************
167 * CPUIDLE GOVERNOR INTERFACE *
168 ******************************/
170 struct cpuidle_governor {
171 char name[CPUIDLE_NAME_LEN];
172 struct list_head governor_list;
175 int (*enable) (struct cpuidle_driver *drv,
176 struct cpuidle_device *dev);
177 void (*disable) (struct cpuidle_driver *drv,
178 struct cpuidle_device *dev);
180 int (*select) (struct cpuidle_driver *drv,
181 struct cpuidle_device *dev);
182 void (*reflect) (struct cpuidle_device *dev, int index);
184 struct module *owner;
187 #ifdef CONFIG_CPU_IDLE
189 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
190 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
194 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
196 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
200 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
201 #define CPUIDLE_DRIVER_STATE_START 1
203 #define CPUIDLE_DRIVER_STATE_START 0
206 #endif /* _LINUX_CPUIDLE_H */