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_usage {
34 unsigned long long usage;
35 unsigned long long time; /* in US */
38 struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
43 unsigned int exit_latency; /* in US */
44 unsigned int power_usage; /* in mW */
45 unsigned int target_residency; /* in US */
47 int (*enter) (struct cpuidle_device *dev,
51 /* Idle State Flags */
52 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
54 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
57 * cpuidle_get_statedata - retrieves private driver state data
58 * @st_usage: the state usage statistics
60 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
62 return st_usage->driver_data;
66 * cpuidle_set_statedata - stores private driver state data
67 * @st_usage: the state usage statistics
68 * @data: the private data
71 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
73 st_usage->driver_data = data;
76 struct cpuidle_state_kobj {
77 struct cpuidle_state *state;
78 struct cpuidle_state_usage *state_usage;
79 struct completion kobj_unregister;
83 struct cpuidle_device {
84 unsigned int registered:1;
85 unsigned int enabled:1;
86 unsigned int power_specified:1;
91 struct cpuidle_state states[CPUIDLE_STATE_MAX];
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;
102 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
105 * cpuidle_get_last_residency - retrieves the last state's residency time
106 * @dev: the target CPU
108 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
110 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
112 return dev->last_residency;
116 /****************************
117 * CPUIDLE DRIVER INTERFACE *
118 ****************************/
120 struct cpuidle_driver {
121 char name[CPUIDLE_NAME_LEN];
122 struct module *owner;
125 #ifdef CONFIG_CPU_IDLE
126 extern void disable_cpuidle(void);
127 extern int cpuidle_idle_call(void);
129 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
130 struct cpuidle_driver *cpuidle_get_driver(void);
131 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
132 extern int cpuidle_register_device(struct cpuidle_device *dev);
133 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
135 extern void cpuidle_pause_and_lock(void);
136 extern void cpuidle_resume_and_unlock(void);
137 extern int cpuidle_enable_device(struct cpuidle_device *dev);
138 extern void cpuidle_disable_device(struct cpuidle_device *dev);
141 static inline void disable_cpuidle(void) { }
142 static inline int cpuidle_idle_call(void) { return -ENODEV; }
144 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
146 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
147 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
148 static inline int cpuidle_register_device(struct cpuidle_device *dev)
150 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
152 static inline void cpuidle_pause_and_lock(void) { }
153 static inline void cpuidle_resume_and_unlock(void) { }
154 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
156 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
160 /******************************
161 * CPUIDLE GOVERNOR INTERFACE *
162 ******************************/
164 struct cpuidle_governor {
165 char name[CPUIDLE_NAME_LEN];
166 struct list_head governor_list;
169 int (*enable) (struct cpuidle_device *dev);
170 void (*disable) (struct cpuidle_device *dev);
172 int (*select) (struct cpuidle_device *dev);
173 void (*reflect) (struct cpuidle_device *dev, int index);
175 struct module *owner;
178 #ifdef CONFIG_CPU_IDLE
180 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
181 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
185 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
187 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
191 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
192 #define CPUIDLE_DRIVER_STATE_START 1
194 #define CPUIDLE_DRIVER_STATE_START 0
197 #endif /* _LINUX_CPUIDLE_H */