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 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 #ifndef _LINUX_CPUFREQ_H 12 #define _LINUX_CPUFREQ_H 13 14 #include <linux/mutex.h> 15 #include <linux/notifier.h> 16 #include <linux/threads.h> 17 #include <linux/kobject.h> 18 #include <linux/sysfs.h> 19 #include <linux/completion.h> 20 #include <linux/workqueue.h> 21 #include <linux/cpumask.h> 22 #include <asm/div64.h> 23 24 #define CPUFREQ_NAME_LEN 16 25 26 27 /********************************************************************* 28 * CPUFREQ NOTIFIER INTERFACE * 29 *********************************************************************/ 30 31 #define CPUFREQ_TRANSITION_NOTIFIER (0) 32 #define CPUFREQ_POLICY_NOTIFIER (1) 33 34 #ifdef CONFIG_CPU_FREQ 35 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 36 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 37 extern void disable_cpufreq(void); 38 #else /* CONFIG_CPU_FREQ */ 39 static inline int cpufreq_register_notifier(struct notifier_block *nb, 40 unsigned int list) 41 { 42 return 0; 43 } 44 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 45 unsigned int list) 46 { 47 return 0; 48 } 49 static inline void disable_cpufreq(void) { } 50 #endif /* CONFIG_CPU_FREQ */ 51 52 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 53 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 54 * two generic policies are available: 55 */ 56 57 #define CPUFREQ_POLICY_POWERSAVE (1) 58 #define CPUFREQ_POLICY_PERFORMANCE (2) 59 60 /* Frequency values here are CPU kHz so that hardware which doesn't run 61 * with some frequencies can complain without having to guess what per 62 * cent / per mille means. 63 * Maximum transition latency is in nanoseconds - if it's unknown, 64 * CPUFREQ_ETERNAL shall be used. 65 */ 66 67 struct cpufreq_governor; 68 69 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ 70 extern struct kobject *cpufreq_global_kobject; 71 72 #define CPUFREQ_ETERNAL (-1) 73 struct cpufreq_cpuinfo { 74 unsigned int max_freq; 75 unsigned int min_freq; 76 77 /* in 10^(-9) s = nanoseconds */ 78 unsigned int transition_latency; 79 }; 80 81 struct cpufreq_real_policy { 82 unsigned int min; /* in kHz */ 83 unsigned int max; /* in kHz */ 84 unsigned int policy; /* see above */ 85 struct cpufreq_governor *governor; /* see below */ 86 }; 87 88 struct cpufreq_policy { 89 cpumask_var_t cpus; /* CPUs requiring sw coordination */ 90 cpumask_var_t related_cpus; /* CPUs with any coordination */ 91 unsigned int shared_type; /* ANY or ALL affected CPUs 92 should set cpufreq */ 93 unsigned int cpu; /* cpu nr of registered CPU */ 94 struct cpufreq_cpuinfo cpuinfo;/* see above */ 95 96 unsigned int min; /* in kHz */ 97 unsigned int max; /* in kHz */ 98 unsigned int cur; /* in kHz, only needed if cpufreq 99 * governors are used */ 100 unsigned int policy; /* see above */ 101 struct cpufreq_governor *governor; /* see below */ 102 103 struct work_struct update; /* if update_policy() needs to be 104 * called, but you're in IRQ context */ 105 106 struct cpufreq_real_policy user_policy; 107 108 struct kobject kobj; 109 struct completion kobj_unregister; 110 }; 111 112 #define CPUFREQ_ADJUST (0) 113 #define CPUFREQ_INCOMPATIBLE (1) 114 #define CPUFREQ_NOTIFY (2) 115 #define CPUFREQ_START (3) 116 117 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 118 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 119 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 120 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 121 122 /******************** cpufreq transition notifiers *******************/ 123 124 #define CPUFREQ_PRECHANGE (0) 125 #define CPUFREQ_POSTCHANGE (1) 126 #define CPUFREQ_RESUMECHANGE (8) 127 #define CPUFREQ_SUSPENDCHANGE (9) 128 129 struct cpufreq_freqs { 130 unsigned int cpu; /* cpu nr */ 131 unsigned int old; 132 unsigned int new; 133 u8 flags; /* flags of cpufreq_driver, see below. */ 134 }; 135 136 137 /** 138 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 139 * @old: old value 140 * @div: divisor 141 * @mult: multiplier 142 * 143 * 144 * new = old * mult / div 145 */ 146 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 147 { 148 #if BITS_PER_LONG == 32 149 150 u64 result = ((u64) old) * ((u64) mult); 151 do_div(result, div); 152 return (unsigned long) result; 153 154 #elif BITS_PER_LONG == 64 155 156 unsigned long result = old * ((u64) mult); 157 result /= div; 158 return result; 159 160 #endif 161 }; 162 163 /********************************************************************* 164 * CPUFREQ GOVERNORS * 165 *********************************************************************/ 166 167 #define CPUFREQ_GOV_START 1 168 #define CPUFREQ_GOV_STOP 2 169 #define CPUFREQ_GOV_LIMITS 3 170 171 struct cpufreq_governor { 172 char name[CPUFREQ_NAME_LEN]; 173 int (*governor) (struct cpufreq_policy *policy, 174 unsigned int event); 175 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 176 char *buf); 177 int (*store_setspeed) (struct cpufreq_policy *policy, 178 unsigned int freq); 179 unsigned int max_transition_latency; /* HW must be able to switch to 180 next freq faster than this value in nano secs or we 181 will fallback to performance governor */ 182 struct list_head governor_list; 183 struct module *owner; 184 }; 185 186 /* 187 * Pass a target to the cpufreq driver. 188 */ 189 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 190 unsigned int target_freq, 191 unsigned int relation); 192 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 193 unsigned int target_freq, 194 unsigned int relation); 195 196 197 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy, 198 unsigned int cpu); 199 200 int cpufreq_register_governor(struct cpufreq_governor *governor); 201 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 202 203 204 /********************************************************************* 205 * CPUFREQ DRIVER INTERFACE * 206 *********************************************************************/ 207 208 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 209 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 210 211 struct freq_attr; 212 213 struct cpufreq_driver { 214 struct module *owner; 215 char name[CPUFREQ_NAME_LEN]; 216 u8 flags; 217 218 /* needed by all drivers */ 219 int (*init) (struct cpufreq_policy *policy); 220 int (*verify) (struct cpufreq_policy *policy); 221 222 /* define one out of two */ 223 int (*setpolicy) (struct cpufreq_policy *policy); 224 int (*target) (struct cpufreq_policy *policy, 225 unsigned int target_freq, 226 unsigned int relation); 227 228 /* should be defined, if possible */ 229 unsigned int (*get) (unsigned int cpu); 230 231 /* optional */ 232 unsigned int (*getavg) (struct cpufreq_policy *policy, 233 unsigned int cpu); 234 int (*bios_limit) (int cpu, unsigned int *limit); 235 236 int (*exit) (struct cpufreq_policy *policy); 237 int (*suspend) (struct cpufreq_policy *policy); 238 int (*resume) (struct cpufreq_policy *policy); 239 struct freq_attr **attr; 240 }; 241 242 /* flags */ 243 244 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 245 * all ->init() calls failed */ 246 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 247 * "constants" aren't affected by 248 * frequency transitions */ 249 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 250 * mismatches */ 251 252 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 253 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 254 255 256 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 257 258 259 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 260 { 261 if (policy->min < min) 262 policy->min = min; 263 if (policy->max < min) 264 policy->max = min; 265 if (policy->min > max) 266 policy->min = max; 267 if (policy->max > max) 268 policy->max = max; 269 if (policy->min > policy->max) 270 policy->min = policy->max; 271 return; 272 } 273 274 struct freq_attr { 275 struct attribute attr; 276 ssize_t (*show)(struct cpufreq_policy *, char *); 277 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 278 }; 279 280 #define cpufreq_freq_attr_ro(_name) \ 281 static struct freq_attr _name = \ 282 __ATTR(_name, 0444, show_##_name, NULL) 283 284 #define cpufreq_freq_attr_ro_perm(_name, _perm) \ 285 static struct freq_attr _name = \ 286 __ATTR(_name, _perm, show_##_name, NULL) 287 288 #define cpufreq_freq_attr_rw(_name) \ 289 static struct freq_attr _name = \ 290 __ATTR(_name, 0644, show_##_name, store_##_name) 291 292 struct global_attr { 293 struct attribute attr; 294 ssize_t (*show)(struct kobject *kobj, 295 struct attribute *attr, char *buf); 296 ssize_t (*store)(struct kobject *a, struct attribute *b, 297 const char *c, size_t count); 298 }; 299 300 #define define_one_global_ro(_name) \ 301 static struct global_attr _name = \ 302 __ATTR(_name, 0444, show_##_name, NULL) 303 304 #define define_one_global_rw(_name) \ 305 static struct global_attr _name = \ 306 __ATTR(_name, 0644, show_##_name, store_##_name) 307 308 309 /********************************************************************* 310 * CPUFREQ 2.6. INTERFACE * 311 *********************************************************************/ 312 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 313 int cpufreq_update_policy(unsigned int cpu); 314 315 #ifdef CONFIG_CPU_FREQ 316 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 317 unsigned int cpufreq_get(unsigned int cpu); 318 #else 319 static inline unsigned int cpufreq_get(unsigned int cpu) 320 { 321 return 0; 322 } 323 #endif 324 325 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 326 #ifdef CONFIG_CPU_FREQ 327 unsigned int cpufreq_quick_get(unsigned int cpu); 328 unsigned int cpufreq_quick_get_max(unsigned int cpu); 329 #else 330 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 331 { 332 return 0; 333 } 334 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 335 { 336 return 0; 337 } 338 #endif 339 340 341 /********************************************************************* 342 * CPUFREQ DEFAULT GOVERNOR * 343 *********************************************************************/ 344 345 346 /* 347 Performance governor is fallback governor if any other gov failed to 348 auto load due latency restrictions 349 */ 350 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 351 extern struct cpufreq_governor cpufreq_gov_performance; 352 #endif 353 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 354 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 355 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 356 extern struct cpufreq_governor cpufreq_gov_powersave; 357 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 358 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 359 extern struct cpufreq_governor cpufreq_gov_userspace; 360 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 361 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 362 extern struct cpufreq_governor cpufreq_gov_ondemand; 363 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 365 extern struct cpufreq_governor cpufreq_gov_conservative; 366 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 367 #endif 368 369 370 /********************************************************************* 371 * FREQUENCY TABLE HELPERS * 372 *********************************************************************/ 373 374 #define CPUFREQ_ENTRY_INVALID ~0 375 #define CPUFREQ_TABLE_END ~1 376 377 struct cpufreq_frequency_table { 378 unsigned int index; /* any */ 379 unsigned int frequency; /* kHz - doesn't need to be in ascending 380 * order */ 381 }; 382 383 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 384 struct cpufreq_frequency_table *table); 385 386 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 387 struct cpufreq_frequency_table *table); 388 389 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 390 struct cpufreq_frequency_table *table, 391 unsigned int target_freq, 392 unsigned int relation, 393 unsigned int *index); 394 395 /* the following 3 funtions are for cpufreq core use only */ 396 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 397 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 398 void cpufreq_cpu_put(struct cpufreq_policy *data); 399 400 /* the following are really really optional */ 401 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 402 403 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 404 unsigned int cpu); 405 406 void cpufreq_frequency_table_put_attr(unsigned int cpu); 407 408 409 #endif /* _LINUX_CPUFREQ_H */ 410