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>
18 #include <linux/hrtimer.h>
20 #define CPUIDLE_STATE_MAX 8
21 #define CPUIDLE_NAME_LEN 16
22 #define CPUIDLE_DESC_LEN 32
26 struct cpuidle_device;
27 struct cpuidle_driver;
30 /****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
34 struct cpuidle_state_usage {
37 unsigned long long usage;
38 unsigned long long time; /* in US */
41 struct cpuidle_state {
42 char name[CPUIDLE_NAME_LEN];
43 char desc[CPUIDLE_DESC_LEN];
46 unsigned int exit_latency; /* in US */
47 unsigned int power_usage; /* in mW */
48 unsigned int target_residency; /* in US */
51 int (*enter) (struct cpuidle_device *dev,
52 struct cpuidle_driver *drv,
56 /* Idle State Flags */
57 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
59 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62 * cpuidle_get_statedata - retrieves private driver state data
63 * @st_usage: the state usage statistics
65 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
67 return st_usage->driver_data;
71 * cpuidle_set_statedata - stores private driver state data
72 * @st_usage: the state usage statistics
73 * @data: the private data
76 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
78 st_usage->driver_data = data;
81 struct cpuidle_state_kobj {
82 struct cpuidle_state *state;
83 struct cpuidle_state_usage *state_usage;
84 struct completion kobj_unregister;
88 struct cpuidle_device {
89 unsigned int registered:1;
90 unsigned int enabled:1;
95 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
96 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
98 struct list_head device_list;
100 struct completion kobj_unregister;
104 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
107 * cpuidle_get_last_residency - retrieves the last state's residency time
108 * @dev: the target CPU
110 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
112 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
114 return dev->last_residency;
118 /****************************
119 * CPUIDLE DRIVER INTERFACE *
120 ****************************/
122 struct cpuidle_driver {
123 char name[CPUIDLE_NAME_LEN];
124 struct module *owner;
126 unsigned int power_specified:1;
127 /* set to 1 to use the core cpuidle time keeping (for all states). */
128 unsigned int en_core_tk_irqen:1;
129 struct cpuidle_state states[CPUIDLE_STATE_MAX];
131 int safe_state_index;
134 #ifdef CONFIG_CPU_IDLE
135 extern void disable_cpuidle(void);
136 extern int cpuidle_idle_call(void);
137 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
138 struct cpuidle_driver *cpuidle_get_driver(void);
139 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
140 extern int cpuidle_register_device(struct cpuidle_device *dev);
141 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
143 extern void cpuidle_pause_and_lock(void);
144 extern void cpuidle_resume_and_unlock(void);
145 extern int cpuidle_enable_device(struct cpuidle_device *dev);
146 extern void cpuidle_disable_device(struct cpuidle_device *dev);
147 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
148 struct cpuidle_driver *drv, int index,
149 int (*enter)(struct cpuidle_device *dev,
150 struct cpuidle_driver *drv, int index));
152 static inline void disable_cpuidle(void) { }
153 static inline int cpuidle_idle_call(void) { return -ENODEV; }
154 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
156 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
157 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
158 static inline int cpuidle_register_device(struct cpuidle_device *dev)
160 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
162 static inline void cpuidle_pause_and_lock(void) { }
163 static inline void cpuidle_resume_and_unlock(void) { }
164 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
166 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
167 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
168 struct cpuidle_driver *drv, int index,
169 int (*enter)(struct cpuidle_device *dev,
170 struct cpuidle_driver *drv, int index))
175 /******************************
176 * CPUIDLE GOVERNOR INTERFACE *
177 ******************************/
179 struct cpuidle_governor {
180 char name[CPUIDLE_NAME_LEN];
181 struct list_head governor_list;
184 int (*enable) (struct cpuidle_driver *drv,
185 struct cpuidle_device *dev);
186 void (*disable) (struct cpuidle_driver *drv,
187 struct cpuidle_device *dev);
189 int (*select) (struct cpuidle_driver *drv,
190 struct cpuidle_device *dev);
191 void (*reflect) (struct cpuidle_device *dev, int index);
193 struct module *owner;
196 #ifdef CONFIG_CPU_IDLE
198 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
199 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
201 #ifdef CONFIG_INTEL_IDLE
202 extern int intel_idle_cpu_init(int cpu);
204 static inline int intel_idle_cpu_init(int cpu) { return -1; }
208 static inline int intel_idle_cpu_init(int cpu) { return -1; }
210 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
212 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
216 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
217 #define CPUIDLE_DRIVER_STATE_START 1
219 #define CPUIDLE_DRIVER_STATE_START 0
222 #endif /* _LINUX_CPUIDLE_H */