1 /* 2 * cpuidle.h - a generic framework for CPU idle power management 3 * 4 * (C) 2007 Venkatesh Pallipadi <[email protected]> 5 * Shaohua Li <[email protected]> 6 * Adam Belay <[email protected]> 7 * 8 * This code is licenced under the GPL. 9 */ 10 11 #ifndef _LINUX_CPUIDLE_H 12 #define _LINUX_CPUIDLE_H 13 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> 19 20 #define CPUIDLE_STATE_MAX 8 21 #define CPUIDLE_NAME_LEN 16 22 #define CPUIDLE_DESC_LEN 32 23 24 struct cpuidle_device; 25 26 27 /**************************** 28 * CPUIDLE DEVICE INTERFACE * 29 ****************************/ 30 31 struct cpuidle_state { 32 char name[CPUIDLE_NAME_LEN]; 33 char desc[CPUIDLE_DESC_LEN]; 34 void *driver_data; 35 36 unsigned int flags; 37 unsigned int exit_latency; /* in US */ 38 unsigned int power_usage; /* in mW */ 39 unsigned int target_residency; /* in US */ 40 41 unsigned long long usage; 42 unsigned long long time; /* in US */ 43 44 int (*enter) (struct cpuidle_device *dev, 45 struct cpuidle_state *state); 46 }; 47 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_POLL (0x10) /* no latency, no savings */ 52 #define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */ 53 #define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */ 54 #define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */ 55 56 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 57 58 /** 59 * cpuidle_get_statedata - retrieves private driver state data 60 * @state: the state 61 */ 62 static inline void * cpuidle_get_statedata(struct cpuidle_state *state) 63 { 64 return state->driver_data; 65 } 66 67 /** 68 * cpuidle_set_statedata - stores private driver state data 69 * @state: the state 70 * @data: the private data 71 */ 72 static inline void 73 cpuidle_set_statedata(struct cpuidle_state *state, void *data) 74 { 75 state->driver_data = data; 76 } 77 78 struct cpuidle_state_kobj { 79 struct cpuidle_state *state; 80 struct completion kobj_unregister; 81 struct kobject kobj; 82 }; 83 84 struct cpuidle_device { 85 unsigned int registered:1; 86 unsigned int enabled:1; 87 unsigned int cpu; 88 89 int last_residency; 90 int state_count; 91 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 92 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 93 struct cpuidle_state *last_state; 94 95 struct list_head device_list; 96 struct kobject kobj; 97 struct completion kobj_unregister; 98 void *governor_data; 99 struct cpuidle_state *safe_state; 100 }; 101 102 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 103 104 /** 105 * cpuidle_get_last_residency - retrieves the last state's residency time 106 * @dev: the target CPU 107 * 108 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 109 */ 110 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 111 { 112 return dev->last_residency; 113 } 114 115 116 /**************************** 117 * CPUIDLE DRIVER INTERFACE * 118 ****************************/ 119 120 struct cpuidle_driver { 121 char name[CPUIDLE_NAME_LEN]; 122 struct module *owner; 123 }; 124 125 #ifdef CONFIG_CPU_IDLE 126 127 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); 132 133 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); 137 138 #else 139 140 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 141 {return -ENODEV; } 142 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 143 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 144 static inline int cpuidle_register_device(struct cpuidle_device *dev) 145 {return -ENODEV; } 146 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 147 148 static inline void cpuidle_pause_and_lock(void) { } 149 static inline void cpuidle_resume_and_unlock(void) { } 150 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 151 {return -ENODEV; } 152 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 153 154 #endif 155 156 /****************************** 157 * CPUIDLE GOVERNOR INTERFACE * 158 ******************************/ 159 160 struct cpuidle_governor { 161 char name[CPUIDLE_NAME_LEN]; 162 struct list_head governor_list; 163 unsigned int rating; 164 165 int (*enable) (struct cpuidle_device *dev); 166 void (*disable) (struct cpuidle_device *dev); 167 168 int (*select) (struct cpuidle_device *dev); 169 void (*reflect) (struct cpuidle_device *dev); 170 171 struct module *owner; 172 }; 173 174 #ifdef CONFIG_CPU_IDLE 175 176 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 177 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 178 179 #else 180 181 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 182 {return 0;} 183 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 184 185 #endif 186 187 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 188 #define CPUIDLE_DRIVER_STATE_START 1 189 #else 190 #define CPUIDLE_DRIVER_STATE_START 0 191 #endif 192 193 #endif /* _LINUX_CPUIDLE_H */ 194