1/* 2 * cpuidle.h - a generic framework for CPU idle power management 3 * 4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 5 * Shaohua Li <shaohua.li@intel.com> 6 * Adam Belay <abelay@novell.com> 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/kobject.h> 17#include <linux/completion.h> 18 19#define CPUIDLE_STATE_MAX 8 20#define CPUIDLE_NAME_LEN 16 21#define CPUIDLE_DESC_LEN 32 22 23struct module; 24 25struct cpuidle_device; 26struct cpuidle_driver; 27 28 29/**************************** 30 * CPUIDLE DEVICE INTERFACE * 31 ****************************/ 32 33struct cpuidle_state_usage { 34 void *driver_data; 35 36 unsigned long long usage; 37 unsigned long long time; /* in US */ 38}; 39 40struct cpuidle_state { 41 char name[CPUIDLE_NAME_LEN]; 42 char desc[CPUIDLE_DESC_LEN]; 43 44 unsigned int flags; 45 unsigned int exit_latency; /* in US */ 46 unsigned int power_usage; /* in mW */ 47 unsigned int target_residency; /* in US */ 48 49 int (*enter) (struct cpuidle_device *dev, 50 struct cpuidle_driver *drv, 51 int index); 52}; 53 54/* Idle State Flags */ 55#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ 56 57#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) 58 59/** 60 * cpuidle_get_statedata - retrieves private driver state data 61 * @st_usage: the state usage statistics 62 */ 63static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage) 64{ 65 return st_usage->driver_data; 66} 67 68/** 69 * cpuidle_set_statedata - stores private driver state data 70 * @st_usage: the state usage statistics 71 * @data: the private data 72 */ 73static inline void 74cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data) 75{ 76 st_usage->driver_data = data; 77} 78 79struct cpuidle_state_kobj { 80 struct cpuidle_state *state; 81 struct cpuidle_state_usage *state_usage; 82 struct completion kobj_unregister; 83 struct kobject kobj; 84}; 85 86struct cpuidle_device { 87 unsigned int registered:1; 88 unsigned int enabled:1; 89 unsigned int cpu; 90 91 int last_residency; 92 int state_count; 93 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; 94 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; 95 96 struct list_head device_list; 97 struct kobject kobj; 98 struct completion kobj_unregister; 99 void *governor_data; 100}; 101 102DECLARE_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 */ 110static 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 120struct cpuidle_driver { 121 char name[CPUIDLE_NAME_LEN]; 122 struct module *owner; 123 124 unsigned int power_specified:1; 125 struct cpuidle_state states[CPUIDLE_STATE_MAX]; 126 int state_count; 127 int safe_state_index; 128}; 129 130#ifdef CONFIG_CPU_IDLE 131extern void disable_cpuidle(void); 132extern int cpuidle_idle_call(void); 133 134extern int cpuidle_register_driver(struct cpuidle_driver *drv); 135struct cpuidle_driver *cpuidle_get_driver(void); 136extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); 137extern int cpuidle_register_device(struct cpuidle_device *dev); 138extern void cpuidle_unregister_device(struct cpuidle_device *dev); 139 140extern void cpuidle_pause_and_lock(void); 141extern void cpuidle_resume_and_unlock(void); 142extern int cpuidle_enable_device(struct cpuidle_device *dev); 143extern void cpuidle_disable_device(struct cpuidle_device *dev); 144 145#else 146static inline void disable_cpuidle(void) { } 147static inline int cpuidle_idle_call(void) { return -ENODEV; } 148 149static inline int cpuidle_register_driver(struct cpuidle_driver *drv) 150{return -ENODEV; } 151static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } 152static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } 153static inline int cpuidle_register_device(struct cpuidle_device *dev) 154{return -ENODEV; } 155static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } 156 157static inline void cpuidle_pause_and_lock(void) { } 158static inline void cpuidle_resume_and_unlock(void) { } 159static inline int cpuidle_enable_device(struct cpuidle_device *dev) 160{return -ENODEV; } 161static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } 162 163#endif 164 165/****************************** 166 * CPUIDLE GOVERNOR INTERFACE * 167 ******************************/ 168 169struct cpuidle_governor { 170 char name[CPUIDLE_NAME_LEN]; 171 struct list_head governor_list; 172 unsigned int rating; 173 174 int (*enable) (struct cpuidle_driver *drv, 175 struct cpuidle_device *dev); 176 void (*disable) (struct cpuidle_driver *drv, 177 struct cpuidle_device *dev); 178 179 int (*select) (struct cpuidle_driver *drv, 180 struct cpuidle_device *dev); 181 void (*reflect) (struct cpuidle_device *dev, int index); 182 183 struct module *owner; 184}; 185 186#ifdef CONFIG_CPU_IDLE 187 188extern int cpuidle_register_governor(struct cpuidle_governor *gov); 189extern void cpuidle_unregister_governor(struct cpuidle_governor *gov); 190 191#else 192 193static inline int cpuidle_register_governor(struct cpuidle_governor *gov) 194{return 0;} 195static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } 196 197#endif 198 199#ifdef CONFIG_ARCH_HAS_CPU_RELAX 200#define CPUIDLE_DRIVER_STATE_START 1 201#else 202#define CPUIDLE_DRIVER_STATE_START 0 203#endif 204 205#endif /* _LINUX_CPUIDLE_H */ 206