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 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_var_t cpus; /* CPUs requiring sw coordination */ 87 cpumask_var_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 #define CPUFREQ_START (3) 113 114 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 115 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 116 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 117 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 118 119 /******************** cpufreq transition notifiers *******************/ 120 121 #define CPUFREQ_PRECHANGE (0) 122 #define CPUFREQ_POSTCHANGE (1) 123 #define CPUFREQ_RESUMECHANGE (8) 124 #define CPUFREQ_SUSPENDCHANGE (9) 125 126 struct cpufreq_freqs { 127 unsigned int cpu; /* cpu nr */ 128 unsigned int old; 129 unsigned int new; 130 u8 flags; /* flags of cpufreq_driver, see below. */ 131 }; 132 133 134 /** 135 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 136 * @old: old value 137 * @div: divisor 138 * @mult: multiplier 139 * 140 * 141 * new = old * mult / div 142 */ 143 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 144 { 145 #if BITS_PER_LONG == 32 146 147 u64 result = ((u64) old) * ((u64) mult); 148 do_div(result, div); 149 return (unsigned long) result; 150 151 #elif BITS_PER_LONG == 64 152 153 unsigned long result = old * ((u64) mult); 154 result /= div; 155 return result; 156 157 #endif 158 }; 159 160 /********************************************************************* 161 * CPUFREQ GOVERNORS * 162 *********************************************************************/ 163 164 #define CPUFREQ_GOV_START 1 165 #define CPUFREQ_GOV_STOP 2 166 #define CPUFREQ_GOV_LIMITS 3 167 168 struct cpufreq_governor { 169 char name[CPUFREQ_NAME_LEN]; 170 int (*governor) (struct cpufreq_policy *policy, 171 unsigned int event); 172 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 173 char *buf); 174 int (*store_setspeed) (struct cpufreq_policy *policy, 175 unsigned int freq); 176 unsigned int max_transition_latency; /* HW must be able to switch to 177 next freq faster than this value in nano secs or we 178 will fallback to performance governor */ 179 struct list_head governor_list; 180 struct module *owner; 181 }; 182 183 /* pass a target to the cpufreq driver 184 */ 185 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 186 unsigned int target_freq, 187 unsigned int relation); 188 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 189 unsigned int target_freq, 190 unsigned int relation); 191 192 193 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy, 194 unsigned int cpu); 195 196 int cpufreq_register_governor(struct cpufreq_governor *governor); 197 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 198 199 int lock_policy_rwsem_read(int cpu); 200 int lock_policy_rwsem_write(int cpu); 201 void unlock_policy_rwsem_read(int cpu); 202 void unlock_policy_rwsem_write(int cpu); 203 204 205 /********************************************************************* 206 * CPUFREQ DRIVER INTERFACE * 207 *********************************************************************/ 208 209 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 210 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 211 212 struct freq_attr; 213 214 struct cpufreq_driver { 215 struct module *owner; 216 char name[CPUFREQ_NAME_LEN]; 217 u8 flags; 218 219 /* needed by all drivers */ 220 int (*init) (struct cpufreq_policy *policy); 221 int (*verify) (struct cpufreq_policy *policy); 222 223 /* define one out of two */ 224 int (*setpolicy) (struct cpufreq_policy *policy); 225 int (*target) (struct cpufreq_policy *policy, 226 unsigned int target_freq, 227 unsigned int relation); 228 229 /* should be defined, if possible */ 230 unsigned int (*get) (unsigned int cpu); 231 232 /* optional */ 233 unsigned int (*getavg) (struct cpufreq_policy *policy, 234 unsigned int cpu); 235 236 int (*exit) (struct cpufreq_policy *policy); 237 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 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 struct global_attr { 281 struct attribute attr; 282 ssize_t (*show)(struct kobject *kobj, 283 struct attribute *attr, char *buf); 284 ssize_t (*store)(struct kobject *a, struct attribute *b, 285 const char *c, size_t count); 286 }; 287 288 /********************************************************************* 289 * CPUFREQ 2.6. INTERFACE * 290 *********************************************************************/ 291 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 292 int cpufreq_update_policy(unsigned int cpu); 293 294 #ifdef CONFIG_CPU_FREQ 295 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 296 unsigned int cpufreq_get(unsigned int cpu); 297 #else 298 static inline unsigned int cpufreq_get(unsigned int cpu) 299 { 300 return 0; 301 } 302 #endif 303 304 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 305 #ifdef CONFIG_CPU_FREQ 306 unsigned int cpufreq_quick_get(unsigned int cpu); 307 #else 308 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 309 { 310 return 0; 311 } 312 #endif 313 314 315 /********************************************************************* 316 * CPUFREQ DEFAULT GOVERNOR * 317 *********************************************************************/ 318 319 320 /* 321 Performance governor is fallback governor if any other gov failed to 322 auto load due latency restrictions 323 */ 324 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 325 extern struct cpufreq_governor cpufreq_gov_performance; 326 #endif 327 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 328 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 329 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 330 extern struct cpufreq_governor cpufreq_gov_powersave; 331 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 332 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 333 extern struct cpufreq_governor cpufreq_gov_userspace; 334 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 335 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 336 extern struct cpufreq_governor cpufreq_gov_ondemand; 337 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 338 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 339 extern struct cpufreq_governor cpufreq_gov_conservative; 340 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 341 #endif 342 343 344 /********************************************************************* 345 * FREQUENCY TABLE HELPERS * 346 *********************************************************************/ 347 348 #define CPUFREQ_ENTRY_INVALID ~0 349 #define CPUFREQ_TABLE_END ~1 350 351 struct cpufreq_frequency_table { 352 unsigned int index; /* any */ 353 unsigned int frequency; /* kHz - doesn't need to be in ascending 354 * order */ 355 }; 356 357 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 358 struct cpufreq_frequency_table *table); 359 360 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 361 struct cpufreq_frequency_table *table); 362 363 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 364 struct cpufreq_frequency_table *table, 365 unsigned int target_freq, 366 unsigned int relation, 367 unsigned int *index); 368 369 /* the following 3 funtions are for cpufreq core use only */ 370 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 371 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 372 void cpufreq_cpu_put (struct cpufreq_policy *data); 373 374 /* the following are really really optional */ 375 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 376 377 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 378 unsigned int cpu); 379 380 void cpufreq_frequency_table_put_attr(unsigned int cpu); 381 382 383 /********************************************************************* 384 * UNIFIED DEBUG HELPERS * 385 *********************************************************************/ 386 387 #define CPUFREQ_DEBUG_CORE 1 388 #define CPUFREQ_DEBUG_DRIVER 2 389 #define CPUFREQ_DEBUG_GOVERNOR 4 390 391 #ifdef CONFIG_CPU_FREQ_DEBUG 392 393 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 394 const char *fmt, ...); 395 396 #else 397 398 #define cpufreq_debug_printk(msg...) do { } while(0) 399 400 #endif /* CONFIG_CPU_FREQ_DEBUG */ 401 402 #endif /* _LINUX_CPUFREQ_H */ 403