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 */