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