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/module.h>
17 #include <linux/kobject.h>
18 #include <linux/completion.h>
20 #define CPUIDLE_STATE_MAX 8
21 #define CPUIDLE_NAME_LEN 16
22 #define CPUIDLE_DESC_LEN 32
24 struct cpuidle_device;
27 /****************************
28 * CPUIDLE DEVICE INTERFACE *
29 ****************************/
31 struct cpuidle_state {
32 char name[CPUIDLE_NAME_LEN];
33 char desc[CPUIDLE_DESC_LEN];
37 unsigned int exit_latency; /* in US */
38 unsigned int power_usage; /* in mW */
39 unsigned int target_residency; /* in US */
41 unsigned long long usage;
42 unsigned long long time; /* in US */
44 int (*enter) (struct cpuidle_device *dev,
48 /* Idle State Flags */
49 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
50 #define CPUIDLE_FLAG_IGNORE (0x100) /* ignore during this idle period */
52 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
55 * cpuidle_get_statedata - retrieves private driver state data
58 static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
60 return state->driver_data;
64 * cpuidle_set_statedata - stores private driver state data
66 * @data: the private data
69 cpuidle_set_statedata(struct cpuidle_state *state, void *data)
71 state->driver_data = data;
74 struct cpuidle_state_kobj {
75 struct cpuidle_state *state;
76 struct completion kobj_unregister;
80 struct cpuidle_device {
81 unsigned int registered:1;
82 unsigned int enabled:1;
83 unsigned int power_specified:1;
88 struct cpuidle_state states[CPUIDLE_STATE_MAX];
89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
91 struct list_head device_list;
93 struct completion kobj_unregister;
97 int (*prepare) (struct cpuidle_device *dev);
100 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
103 * cpuidle_get_last_residency - retrieves the last state's residency time
104 * @dev: the target CPU
106 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
108 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
110 return dev->last_residency;
114 /****************************
115 * CPUIDLE DRIVER INTERFACE *
116 ****************************/
118 struct cpuidle_driver {
119 char name[CPUIDLE_NAME_LEN];
120 struct module *owner;
123 #ifdef CONFIG_CPU_IDLE
124 extern void disable_cpuidle(void);
125 extern int cpuidle_idle_call(void);
127 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
128 struct cpuidle_driver *cpuidle_get_driver(void);
129 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
130 extern int cpuidle_register_device(struct cpuidle_device *dev);
131 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
133 extern void cpuidle_pause_and_lock(void);
134 extern void cpuidle_resume_and_unlock(void);
135 extern int cpuidle_enable_device(struct cpuidle_device *dev);
136 extern void cpuidle_disable_device(struct cpuidle_device *dev);
139 static inline void disable_cpuidle(void) { }
140 static inline int cpuidle_idle_call(void) { return -ENODEV; }
142 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
144 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
145 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
146 static inline int cpuidle_register_device(struct cpuidle_device *dev)
148 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
150 static inline void cpuidle_pause_and_lock(void) { }
151 static inline void cpuidle_resume_and_unlock(void) { }
152 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
154 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
158 /******************************
159 * CPUIDLE GOVERNOR INTERFACE *
160 ******************************/
162 struct cpuidle_governor {
163 char name[CPUIDLE_NAME_LEN];
164 struct list_head governor_list;
167 int (*enable) (struct cpuidle_device *dev);
168 void (*disable) (struct cpuidle_device *dev);
170 int (*select) (struct cpuidle_device *dev);
171 void (*reflect) (struct cpuidle_device *dev, int index);
173 struct module *owner;
176 #ifdef CONFIG_CPU_IDLE
178 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
179 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
183 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
185 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
189 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
190 #define CPUIDLE_DRIVER_STATE_START 1
192 #define CPUIDLE_DRIVER_STATE_START 0
195 #endif /* _LINUX_CPUIDLE_H */