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
,
45 struct cpuidle_state
*state
);
48 /* Idle State Flags */
49 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
50 #define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
51 #define CPUIDLE_FLAG_IGNORE (0x100) /* ignore during this idle period */
52 #define CPUIDLE_FLAG_TLB_FLUSHED (0x200) /* tlb will be flushed */
54 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
57 * cpuidle_get_statedata - retrieves private driver state data
60 static inline void * cpuidle_get_statedata(struct cpuidle_state
*state
)
62 return state
->driver_data
;
66 * cpuidle_set_statedata - stores private driver state data
68 * @data: the private data
71 cpuidle_set_statedata(struct cpuidle_state
*state
, void *data
)
73 state
->driver_data
= data
;
76 struct cpuidle_state_kobj
{
77 struct cpuidle_state
*state
;
78 struct completion kobj_unregister
;
82 struct cpuidle_device
{
83 unsigned int registered
:1;
84 unsigned int enabled
:1;
85 unsigned int power_specified
:1;
90 struct cpuidle_state states
[CPUIDLE_STATE_MAX
];
91 struct cpuidle_state_kobj
*kobjs
[CPUIDLE_STATE_MAX
];
92 struct cpuidle_state
*last_state
;
94 struct list_head device_list
;
96 struct completion kobj_unregister
;
98 struct cpuidle_state
*safe_state
;
100 int (*prepare
) (struct cpuidle_device
*dev
);
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
;
126 #ifdef CONFIG_CPU_IDLE
128 extern int cpuidle_register_driver(struct cpuidle_driver
*drv
);
129 struct cpuidle_driver
*cpuidle_get_driver(void);
130 extern void cpuidle_unregister_driver(struct cpuidle_driver
*drv
);
131 extern int cpuidle_register_device(struct cpuidle_device
*dev
);
132 extern void cpuidle_unregister_device(struct cpuidle_device
*dev
);
134 extern void cpuidle_pause_and_lock(void);
135 extern void cpuidle_resume_and_unlock(void);
136 extern int cpuidle_enable_device(struct cpuidle_device
*dev
);
137 extern void cpuidle_disable_device(struct cpuidle_device
*dev
);
141 static inline int cpuidle_register_driver(struct cpuidle_driver
*drv
)
143 static inline struct cpuidle_driver
*cpuidle_get_driver(void) {return NULL
; }
144 static inline void cpuidle_unregister_driver(struct cpuidle_driver
*drv
) { }
145 static inline int cpuidle_register_device(struct cpuidle_device
*dev
)
147 static inline void cpuidle_unregister_device(struct cpuidle_device
*dev
) { }
149 static inline void cpuidle_pause_and_lock(void) { }
150 static inline void cpuidle_resume_and_unlock(void) { }
151 static inline int cpuidle_enable_device(struct cpuidle_device
*dev
)
153 static inline void cpuidle_disable_device(struct cpuidle_device
*dev
) { }
157 /******************************
158 * CPUIDLE GOVERNOR INTERFACE *
159 ******************************/
161 struct cpuidle_governor
{
162 char name
[CPUIDLE_NAME_LEN
];
163 struct list_head governor_list
;
166 int (*enable
) (struct cpuidle_device
*dev
);
167 void (*disable
) (struct cpuidle_device
*dev
);
169 int (*select
) (struct cpuidle_device
*dev
);
170 void (*reflect
) (struct cpuidle_device
*dev
);
172 struct module
*owner
;
175 #ifdef CONFIG_CPU_IDLE
177 extern int cpuidle_register_governor(struct cpuidle_governor
*gov
);
178 extern void cpuidle_unregister_governor(struct cpuidle_governor
*gov
);
182 static inline int cpuidle_register_governor(struct cpuidle_governor
*gov
)
184 static inline void cpuidle_unregister_governor(struct cpuidle_governor
*gov
) { }
188 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
189 #define CPUIDLE_DRIVER_STATE_START 1
191 #define CPUIDLE_DRIVER_STATE_START 0
194 #endif /* _LINUX_CPUIDLE_H */