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 23 struct cpuidle_device; 24 25 26 /**************************** 27 * CPUIDLE DEVICE INTERFACE * 28 ****************************/ 29 30 struct cpuidle_state { 31 char name[CPUIDLE_NAME_LEN]; 32 void *driver_data; 33 34 unsigned int flags; 35 unsigned int exit_latency; /* in US */ 36 unsigned int power_usage; /* in mW */ 37 unsigned int target_residency; /* in US */ 38 39 unsigned int usage; 40 unsigned int time; /* in US */ 41 42 int (*enter) (struct cpuidle_device *dev, 43 struct cpuidle_state *state); 44 }; 45 46 /* Idle State Flags */ 47 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 48 #define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */ 49 #define CPUIDLE_FLAG_POLL (0x10) /* no latency, no savings */ 50 #define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */ 51 #define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */ 52 #define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */ 53 54 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 55 56 /** 57 * cpuidle_get_statedata - retrieves private driver state data 58 * @state: the state 59 */ 60 static inline void * cpuidle_get_statedata(struct cpuidle_state *state) 61 { 62 return state->driver_data; 63 } 64 65 /** 66 * cpuidle_set_statedata - stores private driver state data 67 * @state: the state 68 * @data: the private data 69 */ 70 static inline void 71 cpuidle_set_statedata(struct cpuidle_state *state, void *data) 72 { 73 state->driver_data = data; 74 } 75 76 struct cpuidle_state_kobj { 77 struct cpuidle_state *state; 78 struct completion kobj_unregister; 79 struct kobject kobj; 80 }; 81 82 struct cpuidle_device { 83 unsigned int enabled:1; 84 unsigned int cpu; 85 86 int last_residency; 87 int state_count; 88 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 90 struct cpuidle_state *last_state; 91 92 struct list_head device_list; 93 struct kobject kobj; 94 struct completion kobj_unregister; 95 void *governor_data; 96 struct cpuidle_state *safe_state; 97 }; 98 99 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); 100 101 /** 102 * cpuidle_get_last_residency - retrieves the last state's residency time 103 * @dev: the target CPU 104 * 105 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set 106 */ 107 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev) 108 { 109 return dev->last_residency; 110 } 111 112 113 /**************************** 114 * CPUIDLE DRIVER INTERFACE * 115 ****************************/ 116 117 struct cpuidle_driver { 118 char name[CPUIDLE_NAME_LEN]; 119 struct module *owner; 120 }; 121 122 #ifdef CONFIG_CPU_IDLE 123 124 extern int cpuidle_register_driver(struct cpuidle_driver *drv); 125 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 126 extern int cpuidle_register_device(struct cpuidle_device *dev); 127 extern void cpuidle_unregister_device(struct cpuidle_device *dev); 128 129 extern void cpuidle_pause_and_lock(void); 130 extern void cpuidle_resume_and_unlock(void); 131 extern int cpuidle_enable_device(struct cpuidle_device *dev); 132 extern void cpuidle_disable_device(struct cpuidle_device *dev); 133 134 #else 135 136 static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 137 {return 0;} 138 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 139 static inline int cpuidle_register_device(struct cpuidle_device *dev) 140 {return 0;} 141 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 142 143 static inline void cpuidle_pause_and_lock(void) { } 144 static inline void cpuidle_resume_and_unlock(void) { } 145 static inline int cpuidle_enable_device(struct cpuidle_device *dev) 146 {return 0;} 147 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 148 149 #endif 150 151 /****************************** 152 * CPUIDLE GOVERNOR INTERFACE * 153 ******************************/ 154 155 struct cpuidle_governor { 156 char name[CPUIDLE_NAME_LEN]; 157 struct list_head governor_list; 158 unsigned int rating; 159 160 int (*enable) (struct cpuidle_device *dev); 161 void (*disable) (struct cpuidle_device *dev); 162 163 int (*select) (struct cpuidle_device *dev); 164 void (*reflect) (struct cpuidle_device *dev); 165 166 struct module *owner; 167 }; 168 169 #ifdef CONFIG_CPU_IDLE 170 171 extern int cpuidle_register_governor(struct cpuidle_governor *gov); 172 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 173 174 #else 175 176 static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 177 {return 0;} 178 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 179 180 #endif 181 182 #ifdef CONFIG_ARCH_HAS_CPU_RELAX 183 #define CPUIDLE_DRIVER_STATE_START 1 184 #else 185 #define CPUIDLE_DRIVER_STATE_START 0 186 #endif 187 188 #endif /* _LINUX_CPUIDLE_H */ 189