1/* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> 6 * 7 * 8 * $Id: cpufreq.h,v 1.1.1.1 2007/08/03 18:53:40 Exp $ 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14#ifndef _LINUX_CPUFREQ_H 15#define _LINUX_CPUFREQ_H 16 17#include <linux/mutex.h> 18#include <linux/notifier.h> 19#include <linux/threads.h> 20#include <linux/device.h> 21#include <linux/kobject.h> 22#include <linux/sysfs.h> 23#include <linux/completion.h> 24#include <linux/workqueue.h> 25#include <linux/cpumask.h> 26#include <asm/div64.h> 27 28#define CPUFREQ_NAME_LEN 16 29 30 31/********************************************************************* 32 * CPUFREQ NOTIFIER INTERFACE * 33 *********************************************************************/ 34 35#ifdef CONFIG_CPU_FREQ 36int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 37#else 38static inline int cpufreq_register_notifier(struct notifier_block *nb, 39 unsigned int list) 40{ 41 return 0; 42} 43#endif 44int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 45 46#define CPUFREQ_TRANSITION_NOTIFIER (0) 47#define CPUFREQ_POLICY_NOTIFIER (1) 48 49 50/* if (cpufreq_driver->target) exists, the ->governor decides what frequency 51 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 52 * two generic policies are available: 53 */ 54 55#define CPUFREQ_POLICY_POWERSAVE (1) 56#define CPUFREQ_POLICY_PERFORMANCE (2) 57 58/* Frequency values here are CPU kHz so that hardware which doesn't run 59 * with some frequencies can complain without having to guess what per 60 * cent / per mille means. 61 * Maximum transition latency is in nanoseconds - if it's unknown, 62 * CPUFREQ_ETERNAL shall be used. 63 */ 64 65struct cpufreq_governor; 66 67#define CPUFREQ_ETERNAL (-1) 68struct cpufreq_cpuinfo { 69 unsigned int max_freq; 70 unsigned int min_freq; 71 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ 72}; 73 74struct cpufreq_real_policy { 75 unsigned int min; /* in kHz */ 76 unsigned int max; /* in kHz */ 77 unsigned int policy; /* see above */ 78 struct cpufreq_governor *governor; /* see below */ 79}; 80 81struct cpufreq_policy { 82 cpumask_t cpus; /* affected CPUs */ 83 unsigned int shared_type; /* ANY or ALL affected CPUs 84 should set cpufreq */ 85 unsigned int cpu; /* cpu nr of registered CPU */ 86 struct cpufreq_cpuinfo cpuinfo;/* see above */ 87 88 unsigned int min; /* in kHz */ 89 unsigned int max; /* in kHz */ 90 unsigned int cur; /* in kHz, only needed if cpufreq 91 * governors are used */ 92 unsigned int policy; /* see above */ 93 struct cpufreq_governor *governor; /* see below */ 94 95 struct work_struct update; /* if update_policy() needs to be 96 * called, but you're in IRQ context */ 97 98 struct cpufreq_real_policy user_policy; 99 100 struct kobject kobj; 101 struct completion kobj_unregister; 102}; 103 104#define CPUFREQ_ADJUST (0) 105#define CPUFREQ_INCOMPATIBLE (1) 106#define CPUFREQ_NOTIFY (2) 107 108#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 109#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 110#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 111#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 112 113/******************** cpufreq transition notifiers *******************/ 114 115#define CPUFREQ_PRECHANGE (0) 116#define CPUFREQ_POSTCHANGE (1) 117#define CPUFREQ_RESUMECHANGE (8) 118#define CPUFREQ_SUSPENDCHANGE (9) 119 120struct cpufreq_freqs { 121 unsigned int cpu; /* cpu nr */ 122 unsigned int old; 123 unsigned int new; 124 u8 flags; /* flags of cpufreq_driver, see below. */ 125}; 126 127 128/** 129 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 130 * @old: old value 131 * @div: divisor 132 * @mult: multiplier 133 * 134 * 135 * new = old * mult / div 136 */ 137static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 138{ 139#if BITS_PER_LONG == 32 140 141 u64 result = ((u64) old) * ((u64) mult); 142 do_div(result, div); 143 return (unsigned long) result; 144 145#elif BITS_PER_LONG == 64 146 147 unsigned long result = old * ((u64) mult); 148 result /= div; 149 return result; 150 151#endif 152}; 153 154/********************************************************************* 155 * CPUFREQ GOVERNORS * 156 *********************************************************************/ 157 158#define CPUFREQ_GOV_START 1 159#define CPUFREQ_GOV_STOP 2 160#define CPUFREQ_GOV_LIMITS 3 161 162struct cpufreq_governor { 163 char name[CPUFREQ_NAME_LEN]; 164 int (*governor) (struct cpufreq_policy *policy, 165 unsigned int event); 166 struct list_head governor_list; 167 struct module *owner; 168}; 169 170/* pass a target to the cpufreq driver 171 */ 172extern int cpufreq_driver_target(struct cpufreq_policy *policy, 173 unsigned int target_freq, 174 unsigned int relation); 175extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 176 unsigned int target_freq, 177 unsigned int relation); 178 179 180extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy); 181 182int cpufreq_register_governor(struct cpufreq_governor *governor); 183void cpufreq_unregister_governor(struct cpufreq_governor *governor); 184 185int lock_policy_rwsem_read(int cpu); 186int lock_policy_rwsem_write(int cpu); 187void unlock_policy_rwsem_read(int cpu); 188void unlock_policy_rwsem_write(int cpu); 189 190 191/********************************************************************* 192 * CPUFREQ DRIVER INTERFACE * 193 *********************************************************************/ 194 195#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 196#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 197 198struct freq_attr; 199 200struct cpufreq_driver { 201 struct module *owner; 202 char name[CPUFREQ_NAME_LEN]; 203 u8 flags; 204 205 /* needed by all drivers */ 206 int (*init) (struct cpufreq_policy *policy); 207 int (*verify) (struct cpufreq_policy *policy); 208 209 /* define one out of two */ 210 int (*setpolicy) (struct cpufreq_policy *policy); 211 int (*target) (struct cpufreq_policy *policy, 212 unsigned int target_freq, 213 unsigned int relation); 214 215 /* should be defined, if possible */ 216 unsigned int (*get) (unsigned int cpu); 217 218 /* optional */ 219 unsigned int (*getavg) (unsigned int cpu); 220 int (*exit) (struct cpufreq_policy *policy); 221 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 222 int (*resume) (struct cpufreq_policy *policy); 223 struct freq_attr **attr; 224}; 225 226/* flags */ 227 228#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 229 * all ->init() calls failed */ 230#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 231 * "constants" aren't affected by 232 * frequency transitions */ 233#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 234 * mismatches */ 235 236int cpufreq_register_driver(struct cpufreq_driver *driver_data); 237int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 238 239 240void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 241 242 243static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 244{ 245 if (policy->min < min) 246 policy->min = min; 247 if (policy->max < min) 248 policy->max = min; 249 if (policy->min > max) 250 policy->min = max; 251 if (policy->max > max) 252 policy->max = max; 253 if (policy->min > policy->max) 254 policy->min = policy->max; 255 return; 256} 257 258struct freq_attr { 259 struct attribute attr; 260 ssize_t (*show)(struct cpufreq_policy *, char *); 261 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 262}; 263 264 265/********************************************************************* 266 * CPUFREQ 2.6. INTERFACE * 267 *********************************************************************/ 268int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 269int cpufreq_update_policy(unsigned int cpu); 270 271 272/* 273 * query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it 274 */ 275#ifdef CONFIG_CPU_FREQ 276unsigned int cpufreq_quick_get(unsigned int cpu); 277unsigned int cpufreq_get(unsigned int cpu); 278#else 279static inline unsigned int cpufreq_quick_get(unsigned int cpu) 280{ 281 return 0; 282} 283static inline unsigned int cpufreq_get(unsigned int cpu) 284{ 285 return 0; 286} 287#endif 288 289 290/********************************************************************* 291 * CPUFREQ DEFAULT GOVERNOR * 292 *********************************************************************/ 293 294 295#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 296extern struct cpufreq_governor cpufreq_gov_performance; 297#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 298#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 299extern struct cpufreq_governor cpufreq_gov_userspace; 300#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 301#endif 302 303 304/********************************************************************* 305 * FREQUENCY TABLE HELPERS * 306 *********************************************************************/ 307 308#define CPUFREQ_ENTRY_INVALID ~0 309#define CPUFREQ_TABLE_END ~1 310 311struct cpufreq_frequency_table { 312 unsigned int index; /* any */ 313 unsigned int frequency; /* kHz - doesn't need to be in ascending 314 * order */ 315}; 316 317int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 318 struct cpufreq_frequency_table *table); 319 320int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 321 struct cpufreq_frequency_table *table); 322 323int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 324 struct cpufreq_frequency_table *table, 325 unsigned int target_freq, 326 unsigned int relation, 327 unsigned int *index); 328 329/* the following 3 funtions are for cpufreq core use only */ 330struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 331struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 332void cpufreq_cpu_put (struct cpufreq_policy *data); 333 334/* the following are really really optional */ 335extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 336 337void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 338 unsigned int cpu); 339 340void cpufreq_frequency_table_put_attr(unsigned int cpu); 341 342 343/********************************************************************* 344 * UNIFIED DEBUG HELPERS * 345 *********************************************************************/ 346 347#define CPUFREQ_DEBUG_CORE 1 348#define CPUFREQ_DEBUG_DRIVER 2 349#define CPUFREQ_DEBUG_GOVERNOR 4 350 351#ifdef CONFIG_CPU_FREQ_DEBUG 352 353extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 354 const char *fmt, ...); 355 356#else 357 358#define cpufreq_debug_printk(msg...) do { } while(0) 359 360#endif /* CONFIG_CPU_FREQ_DEBUG */ 361 362#endif /* _LINUX_CPUFREQ_H */ 363