1 /* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <[email protected]> 6 * 7 * 8 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db 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 #define CPUFREQ_TRANSITION_NOTIFIER (0) 36 #define CPUFREQ_POLICY_NOTIFIER (1) 37 38 #ifdef CONFIG_CPU_FREQ 39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 41 #else /* CONFIG_CPU_FREQ */ 42 static inline int cpufreq_register_notifier(struct notifier_block *nb, 43 unsigned int list) 44 { 45 return 0; 46 } 47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 48 unsigned int list) 49 { 50 return 0; 51 } 52 #endif /* CONFIG_CPU_FREQ */ 53 54 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 56 * two generic policies are available: 57 */ 58 59 #define CPUFREQ_POLICY_POWERSAVE (1) 60 #define CPUFREQ_POLICY_PERFORMANCE (2) 61 62 /* Frequency values here are CPU kHz so that hardware which doesn't run 63 * with some frequencies can complain without having to guess what per 64 * cent / per mille means. 65 * Maximum transition latency is in nanoseconds - if it's unknown, 66 * CPUFREQ_ETERNAL shall be used. 67 */ 68 69 struct cpufreq_governor; 70 71 #define CPUFREQ_ETERNAL (-1) 72 struct cpufreq_cpuinfo { 73 unsigned int max_freq; 74 unsigned int min_freq; 75 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ 76 }; 77 78 struct cpufreq_real_policy { 79 unsigned int min; /* in kHz */ 80 unsigned int max; /* in kHz */ 81 unsigned int policy; /* see above */ 82 struct cpufreq_governor *governor; /* see below */ 83 }; 84 85 struct cpufreq_policy { 86 cpumask_t cpus; /* CPUs requiring sw coordination */ 87 cpumask_t related_cpus; /* CPUs with any coordination */ 88 unsigned int shared_type; /* ANY or ALL affected CPUs 89 should set cpufreq */ 90 unsigned int cpu; /* cpu nr of registered CPU */ 91 struct cpufreq_cpuinfo cpuinfo;/* see above */ 92 93 unsigned int min; /* in kHz */ 94 unsigned int max; /* in kHz */ 95 unsigned int cur; /* in kHz, only needed if cpufreq 96 * governors are used */ 97 unsigned int policy; /* see above */ 98 struct cpufreq_governor *governor; /* see below */ 99 100 struct work_struct update; /* if update_policy() needs to be 101 * called, but you're in IRQ context */ 102 103 struct cpufreq_real_policy user_policy; 104 105 struct kobject kobj; 106 struct completion kobj_unregister; 107 }; 108 109 #define CPUFREQ_ADJUST (0) 110 #define CPUFREQ_INCOMPATIBLE (1) 111 #define CPUFREQ_NOTIFY (2) 112 113 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 114 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 115 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 116 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 117 118 /******************** cpufreq transition notifiers *******************/ 119 120 #define CPUFREQ_PRECHANGE (0) 121 #define CPUFREQ_POSTCHANGE (1) 122 #define CPUFREQ_RESUMECHANGE (8) 123 #define CPUFREQ_SUSPENDCHANGE (9) 124 125 struct cpufreq_freqs { 126 unsigned int cpu; /* cpu nr */ 127 unsigned int old; 128 unsigned int new; 129 u8 flags; /* flags of cpufreq_driver, see below. */ 130 }; 131 132 133 /** 134 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 135 * @old: old value 136 * @div: divisor 137 * @mult: multiplier 138 * 139 * 140 * new = old * mult / div 141 */ 142 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 143 { 144 #if BITS_PER_LONG == 32 145 146 u64 result = ((u64) old) * ((u64) mult); 147 do_div(result, div); 148 return (unsigned long) result; 149 150 #elif BITS_PER_LONG == 64 151 152 unsigned long result = old * ((u64) mult); 153 result /= div; 154 return result; 155 156 #endif 157 }; 158 159 /********************************************************************* 160 * CPUFREQ GOVERNORS * 161 *********************************************************************/ 162 163 #define CPUFREQ_GOV_START 1 164 #define CPUFREQ_GOV_STOP 2 165 #define CPUFREQ_GOV_LIMITS 3 166 167 struct cpufreq_governor { 168 char name[CPUFREQ_NAME_LEN]; 169 int (*governor) (struct cpufreq_policy *policy, 170 unsigned int event); 171 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 172 char *buf); 173 int (*store_setspeed) (struct cpufreq_policy *policy, 174 unsigned int freq); 175 unsigned int max_transition_latency; /* HW must be able to switch to 176 next freq faster than this value in nano secs or we 177 will fallback to performance governor */ 178 struct list_head governor_list; 179 struct module *owner; 180 }; 181 182 /* pass a target to the cpufreq driver 183 */ 184 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 185 unsigned int target_freq, 186 unsigned int relation); 187 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 188 unsigned int target_freq, 189 unsigned int relation); 190 191 192 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy); 193 194 int cpufreq_register_governor(struct cpufreq_governor *governor); 195 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 196 197 int lock_policy_rwsem_read(int cpu); 198 int lock_policy_rwsem_write(int cpu); 199 void unlock_policy_rwsem_read(int cpu); 200 void unlock_policy_rwsem_write(int cpu); 201 202 203 /********************************************************************* 204 * CPUFREQ DRIVER INTERFACE * 205 *********************************************************************/ 206 207 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 208 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 209 210 struct freq_attr; 211 212 struct cpufreq_driver { 213 struct module *owner; 214 char name[CPUFREQ_NAME_LEN]; 215 u8 flags; 216 217 /* needed by all drivers */ 218 int (*init) (struct cpufreq_policy *policy); 219 int (*verify) (struct cpufreq_policy *policy); 220 221 /* define one out of two */ 222 int (*setpolicy) (struct cpufreq_policy *policy); 223 int (*target) (struct cpufreq_policy *policy, 224 unsigned int target_freq, 225 unsigned int relation); 226 227 /* should be defined, if possible */ 228 unsigned int (*get) (unsigned int cpu); 229 230 /* optional */ 231 unsigned int (*getavg) (unsigned int cpu); 232 int (*exit) (struct cpufreq_policy *policy); 233 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 234 int (*resume) (struct cpufreq_policy *policy); 235 struct freq_attr **attr; 236 }; 237 238 /* flags */ 239 240 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 241 * all ->init() calls failed */ 242 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 243 * "constants" aren't affected by 244 * frequency transitions */ 245 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 246 * mismatches */ 247 248 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 249 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 250 251 252 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 253 254 255 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 256 { 257 if (policy->min < min) 258 policy->min = min; 259 if (policy->max < min) 260 policy->max = min; 261 if (policy->min > max) 262 policy->min = max; 263 if (policy->max > max) 264 policy->max = max; 265 if (policy->min > policy->max) 266 policy->min = policy->max; 267 return; 268 } 269 270 struct freq_attr { 271 struct attribute attr; 272 ssize_t (*show)(struct cpufreq_policy *, char *); 273 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 274 }; 275 276 277 /********************************************************************* 278 * CPUFREQ 2.6. INTERFACE * 279 *********************************************************************/ 280 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 281 int cpufreq_update_policy(unsigned int cpu); 282 283 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 284 unsigned int cpufreq_get(unsigned int cpu); 285 286 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 287 #ifdef CONFIG_CPU_FREQ 288 unsigned int cpufreq_quick_get(unsigned int cpu); 289 #else 290 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 291 { 292 return 0; 293 } 294 #endif 295 296 297 /********************************************************************* 298 * CPUFREQ DEFAULT GOVERNOR * 299 *********************************************************************/ 300 301 302 /* 303 Performance governor is fallback governor if any other gov failed to 304 auto load due latency restrictions 305 */ 306 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 307 extern struct cpufreq_governor cpufreq_gov_performance; 308 #endif 309 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 310 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 311 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 312 extern struct cpufreq_governor cpufreq_gov_powersave; 313 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 314 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 315 extern struct cpufreq_governor cpufreq_gov_userspace; 316 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 317 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 318 extern struct cpufreq_governor cpufreq_gov_ondemand; 319 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 320 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 321 extern struct cpufreq_governor cpufreq_gov_conservative; 322 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 323 #endif 324 325 326 /********************************************************************* 327 * FREQUENCY TABLE HELPERS * 328 *********************************************************************/ 329 330 #define CPUFREQ_ENTRY_INVALID ~0 331 #define CPUFREQ_TABLE_END ~1 332 333 struct cpufreq_frequency_table { 334 unsigned int index; /* any */ 335 unsigned int frequency; /* kHz - doesn't need to be in ascending 336 * order */ 337 }; 338 339 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 340 struct cpufreq_frequency_table *table); 341 342 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 343 struct cpufreq_frequency_table *table); 344 345 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 346 struct cpufreq_frequency_table *table, 347 unsigned int target_freq, 348 unsigned int relation, 349 unsigned int *index); 350 351 /* the following 3 funtions are for cpufreq core use only */ 352 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 353 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 354 void cpufreq_cpu_put (struct cpufreq_policy *data); 355 356 /* the following are really really optional */ 357 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 358 359 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 360 unsigned int cpu); 361 362 void cpufreq_frequency_table_put_attr(unsigned int cpu); 363 364 365 /********************************************************************* 366 * UNIFIED DEBUG HELPERS * 367 *********************************************************************/ 368 369 #define CPUFREQ_DEBUG_CORE 1 370 #define CPUFREQ_DEBUG_DRIVER 2 371 #define CPUFREQ_DEBUG_GOVERNOR 4 372 373 #ifdef CONFIG_CPU_FREQ_DEBUG 374 375 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 376 const char *fmt, ...); 377 378 #else 379 380 #define cpufreq_debug_printk(msg...) do { } while(0) 381 382 #endif /* CONFIG_CPU_FREQ_DEBUG */ 383 384 #endif /* _LINUX_CPUFREQ_H */ 385