1 /* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <[email protected]> 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/device.h> 18 #include <linux/kobject.h> 19 #include <linux/sysfs.h> 20 #include <linux/completion.h> 21 #include <linux/workqueue.h> 22 #include <linux/cpumask.h> 23 #include <asm/div64.h> 24 25 #define CPUFREQ_NAME_LEN 16 26 27 28 /********************************************************************* 29 * CPUFREQ NOTIFIER INTERFACE * 30 *********************************************************************/ 31 32 #define CPUFREQ_TRANSITION_NOTIFIER (0) 33 #define CPUFREQ_POLICY_NOTIFIER (1) 34 35 #ifdef CONFIG_CPU_FREQ 36 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 37 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 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 #endif /* CONFIG_CPU_FREQ */ 50 51 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 52 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 53 * two generic policies are available: 54 */ 55 56 #define CPUFREQ_POLICY_POWERSAVE (1) 57 #define CPUFREQ_POLICY_PERFORMANCE (2) 58 59 /* Frequency values here are CPU kHz so that hardware which doesn't run 60 * with some frequencies can complain without having to guess what per 61 * cent / per mille means. 62 * Maximum transition latency is in nanoseconds - if it's unknown, 63 * CPUFREQ_ETERNAL shall be used. 64 */ 65 66 struct cpufreq_governor; 67 68 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ 69 extern struct kobject *cpufreq_global_kobject; 70 71 #define CPUFREQ_ETERNAL (-1) 72 struct cpufreq_cpuinfo { 73 unsigned int max_freq; 74 unsigned int min_freq; 75 76 /* in 10^(-9) s = nanoseconds */ 77 unsigned int transition_latency; 78 }; 79 80 struct cpufreq_real_policy { 81 unsigned int min; /* in kHz */ 82 unsigned int max; /* in kHz */ 83 unsigned int policy; /* see above */ 84 struct cpufreq_governor *governor; /* see below */ 85 }; 86 87 struct cpufreq_policy { 88 cpumask_var_t cpus; /* CPUs requiring sw coordination */ 89 cpumask_var_t related_cpus; /* CPUs with any coordination */ 90 unsigned int shared_type; /* ANY or ALL affected CPUs 91 should set cpufreq */ 92 unsigned int cpu; /* cpu nr of registered CPU */ 93 struct cpufreq_cpuinfo cpuinfo;/* see above */ 94 95 unsigned int min; /* in kHz */ 96 unsigned int max; /* in kHz */ 97 unsigned int cur; /* in kHz, only needed if cpufreq 98 * governors are used */ 99 unsigned int policy; /* see above */ 100 struct cpufreq_governor *governor; /* see below */ 101 102 struct work_struct update; /* if update_policy() needs to be 103 * called, but you're in IRQ context */ 104 105 struct cpufreq_real_policy user_policy; 106 107 struct kobject kobj; 108 struct completion kobj_unregister; 109 }; 110 111 #define CPUFREQ_ADJUST (0) 112 #define CPUFREQ_INCOMPATIBLE (1) 113 #define CPUFREQ_NOTIFY (2) 114 #define CPUFREQ_START (3) 115 116 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 117 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 118 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 119 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 120 121 /******************** cpufreq transition notifiers *******************/ 122 123 #define CPUFREQ_PRECHANGE (0) 124 #define CPUFREQ_POSTCHANGE (1) 125 #define CPUFREQ_RESUMECHANGE (8) 126 #define CPUFREQ_SUSPENDCHANGE (9) 127 128 struct cpufreq_freqs { 129 unsigned int cpu; /* cpu nr */ 130 unsigned int old; 131 unsigned int new; 132 u8 flags; /* flags of cpufreq_driver, see below. */ 133 }; 134 135 136 /** 137 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 138 * @old: old value 139 * @div: divisor 140 * @mult: multiplier 141 * 142 * 143 * new = old * mult / div 144 */ 145 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 146 { 147 #if BITS_PER_LONG == 32 148 149 u64 result = ((u64) old) * ((u64) mult); 150 do_div(result, div); 151 return (unsigned long) result; 152 153 #elif BITS_PER_LONG == 64 154 155 unsigned long result = old * ((u64) mult); 156 result /= div; 157 return result; 158 159 #endif 160 }; 161 162 /********************************************************************* 163 * CPUFREQ GOVERNORS * 164 *********************************************************************/ 165 166 #define CPUFREQ_GOV_START 1 167 #define CPUFREQ_GOV_STOP 2 168 #define CPUFREQ_GOV_LIMITS 3 169 170 struct cpufreq_governor { 171 char name[CPUFREQ_NAME_LEN]; 172 int (*governor) (struct cpufreq_policy *policy, 173 unsigned int event); 174 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 175 char *buf); 176 int (*store_setspeed) (struct cpufreq_policy *policy, 177 unsigned int freq); 178 unsigned int max_transition_latency; /* HW must be able to switch to 179 next freq faster than this value in nano secs or we 180 will fallback to performance governor */ 181 struct list_head governor_list; 182 struct module *owner; 183 }; 184 185 /* 186 * Pass a target to the cpufreq driver. 187 */ 188 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 189 unsigned int target_freq, 190 unsigned int relation); 191 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 192 unsigned int target_freq, 193 unsigned int relation); 194 195 196 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy, 197 unsigned int cpu); 198 199 int cpufreq_register_governor(struct cpufreq_governor *governor); 200 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 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) (struct cpufreq_policy *policy, 232 unsigned int cpu); 233 int (*bios_limit) (int cpu, unsigned int *limit); 234 235 int (*exit) (struct cpufreq_policy *policy); 236 int (*suspend) (struct cpufreq_policy *policy); 237 int (*resume) (struct cpufreq_policy *policy); 238 struct freq_attr **attr; 239 }; 240 241 /* flags */ 242 243 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 244 * all ->init() calls failed */ 245 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 246 * "constants" aren't affected by 247 * frequency transitions */ 248 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 249 * mismatches */ 250 251 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 252 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 253 254 255 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 256 257 258 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 259 { 260 if (policy->min < min) 261 policy->min = min; 262 if (policy->max < min) 263 policy->max = min; 264 if (policy->min > max) 265 policy->min = max; 266 if (policy->max > max) 267 policy->max = max; 268 if (policy->min > policy->max) 269 policy->min = policy->max; 270 return; 271 } 272 273 struct freq_attr { 274 struct attribute attr; 275 ssize_t (*show)(struct cpufreq_policy *, char *); 276 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 277 }; 278 279 #define cpufreq_freq_attr_ro(_name) \ 280 static struct freq_attr _name = \ 281 __ATTR(_name, 0444, show_##_name, NULL) 282 283 #define cpufreq_freq_attr_ro_perm(_name, _perm) \ 284 static struct freq_attr _name = \ 285 __ATTR(_name, _perm, show_##_name, NULL) 286 287 #define cpufreq_freq_attr_rw(_name) \ 288 static struct freq_attr _name = \ 289 __ATTR(_name, 0644, show_##_name, store_##_name) 290 291 struct global_attr { 292 struct attribute attr; 293 ssize_t (*show)(struct kobject *kobj, 294 struct attribute *attr, char *buf); 295 ssize_t (*store)(struct kobject *a, struct attribute *b, 296 const char *c, size_t count); 297 }; 298 299 #define define_one_global_ro(_name) \ 300 static struct global_attr _name = \ 301 __ATTR(_name, 0444, show_##_name, NULL) 302 303 #define define_one_global_rw(_name) \ 304 static struct global_attr _name = \ 305 __ATTR(_name, 0644, show_##_name, store_##_name) 306 307 308 /********************************************************************* 309 * CPUFREQ 2.6. INTERFACE * 310 *********************************************************************/ 311 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 312 int cpufreq_update_policy(unsigned int cpu); 313 314 #ifdef CONFIG_CPU_FREQ 315 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 316 unsigned int cpufreq_get(unsigned int cpu); 317 #else 318 static inline unsigned int cpufreq_get(unsigned int cpu) 319 { 320 return 0; 321 } 322 #endif 323 324 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 325 #ifdef CONFIG_CPU_FREQ 326 unsigned int cpufreq_quick_get(unsigned int cpu); 327 unsigned int cpufreq_quick_get_max(unsigned int cpu); 328 #else 329 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 330 { 331 return 0; 332 } 333 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 334 { 335 return 0; 336 } 337 #endif 338 339 340 /********************************************************************* 341 * CPUFREQ DEFAULT GOVERNOR * 342 *********************************************************************/ 343 344 345 /* 346 Performance governor is fallback governor if any other gov failed to 347 auto load due latency restrictions 348 */ 349 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 350 extern struct cpufreq_governor cpufreq_gov_performance; 351 #endif 352 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 353 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 354 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 355 extern struct cpufreq_governor cpufreq_gov_powersave; 356 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 357 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 358 extern struct cpufreq_governor cpufreq_gov_userspace; 359 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 360 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 361 extern struct cpufreq_governor cpufreq_gov_ondemand; 362 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 364 extern struct cpufreq_governor cpufreq_gov_conservative; 365 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 366 #endif 367 368 369 /********************************************************************* 370 * FREQUENCY TABLE HELPERS * 371 *********************************************************************/ 372 373 #define CPUFREQ_ENTRY_INVALID ~0 374 #define CPUFREQ_TABLE_END ~1 375 376 struct cpufreq_frequency_table { 377 unsigned int index; /* any */ 378 unsigned int frequency; /* kHz - doesn't need to be in ascending 379 * order */ 380 }; 381 382 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 383 struct cpufreq_frequency_table *table); 384 385 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 386 struct cpufreq_frequency_table *table); 387 388 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 389 struct cpufreq_frequency_table *table, 390 unsigned int target_freq, 391 unsigned int relation, 392 unsigned int *index); 393 394 /* the following 3 funtions are for cpufreq core use only */ 395 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 396 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 397 void cpufreq_cpu_put(struct cpufreq_policy *data); 398 399 /* the following are really really optional */ 400 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 401 402 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 403 unsigned int cpu); 404 405 void cpufreq_frequency_table_put_attr(unsigned int cpu); 406 407 408 #endif /* _LINUX_CPUFREQ_H */ 409