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 #define CPUFREQ_START (3) 110 111 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 112 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 113 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 114 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 115 116 /******************** cpufreq transition notifiers *******************/ 117 118 #define CPUFREQ_PRECHANGE (0) 119 #define CPUFREQ_POSTCHANGE (1) 120 #define CPUFREQ_RESUMECHANGE (8) 121 #define CPUFREQ_SUSPENDCHANGE (9) 122 123 struct cpufreq_freqs { 124 unsigned int cpu; /* cpu nr */ 125 unsigned int old; 126 unsigned int new; 127 u8 flags; /* flags of cpufreq_driver, see below. */ 128 }; 129 130 131 /** 132 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 133 * @old: old value 134 * @div: divisor 135 * @mult: multiplier 136 * 137 * 138 * new = old * mult / div 139 */ 140 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 141 { 142 #if BITS_PER_LONG == 32 143 144 u64 result = ((u64) old) * ((u64) mult); 145 do_div(result, div); 146 return (unsigned long) result; 147 148 #elif BITS_PER_LONG == 64 149 150 unsigned long result = old * ((u64) mult); 151 result /= div; 152 return result; 153 154 #endif 155 }; 156 157 /********************************************************************* 158 * CPUFREQ GOVERNORS * 159 *********************************************************************/ 160 161 #define CPUFREQ_GOV_START 1 162 #define CPUFREQ_GOV_STOP 2 163 #define CPUFREQ_GOV_LIMITS 3 164 165 struct cpufreq_governor { 166 char name[CPUFREQ_NAME_LEN]; 167 int (*governor) (struct cpufreq_policy *policy, 168 unsigned int event); 169 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 170 char *buf); 171 int (*store_setspeed) (struct cpufreq_policy *policy, 172 unsigned int freq); 173 unsigned int max_transition_latency; /* HW must be able to switch to 174 next freq faster than this value in nano secs or we 175 will fallback to performance governor */ 176 struct list_head governor_list; 177 struct module *owner; 178 }; 179 180 /* pass a target to the cpufreq driver 181 */ 182 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 183 unsigned int target_freq, 184 unsigned int relation); 185 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 186 unsigned int target_freq, 187 unsigned int relation); 188 189 190 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy); 191 192 int cpufreq_register_governor(struct cpufreq_governor *governor); 193 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 194 195 int lock_policy_rwsem_read(int cpu); 196 int lock_policy_rwsem_write(int cpu); 197 void unlock_policy_rwsem_read(int cpu); 198 void unlock_policy_rwsem_write(int cpu); 199 200 201 /********************************************************************* 202 * CPUFREQ DRIVER INTERFACE * 203 *********************************************************************/ 204 205 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 206 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 207 208 struct freq_attr; 209 210 struct cpufreq_driver { 211 struct module *owner; 212 char name[CPUFREQ_NAME_LEN]; 213 u8 flags; 214 215 /* needed by all drivers */ 216 int (*init) (struct cpufreq_policy *policy); 217 int (*verify) (struct cpufreq_policy *policy); 218 219 /* define one out of two */ 220 int (*setpolicy) (struct cpufreq_policy *policy); 221 int (*target) (struct cpufreq_policy *policy, 222 unsigned int target_freq, 223 unsigned int relation); 224 225 /* should be defined, if possible */ 226 unsigned int (*get) (unsigned int cpu); 227 228 /* optional */ 229 unsigned int (*getavg) (unsigned int cpu); 230 int (*exit) (struct cpufreq_policy *policy); 231 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 232 int (*resume) (struct cpufreq_policy *policy); 233 struct freq_attr **attr; 234 }; 235 236 /* flags */ 237 238 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 239 * all ->init() calls failed */ 240 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 241 * "constants" aren't affected by 242 * frequency transitions */ 243 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 244 * mismatches */ 245 246 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 247 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 248 249 250 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 251 252 253 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 254 { 255 if (policy->min < min) 256 policy->min = min; 257 if (policy->max < min) 258 policy->max = min; 259 if (policy->min > max) 260 policy->min = max; 261 if (policy->max > max) 262 policy->max = max; 263 if (policy->min > policy->max) 264 policy->min = policy->max; 265 return; 266 } 267 268 struct freq_attr { 269 struct attribute attr; 270 ssize_t (*show)(struct cpufreq_policy *, char *); 271 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 272 }; 273 274 275 /********************************************************************* 276 * CPUFREQ 2.6. INTERFACE * 277 *********************************************************************/ 278 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 279 int cpufreq_update_policy(unsigned int cpu); 280 281 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 282 unsigned int cpufreq_get(unsigned int cpu); 283 284 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 285 #ifdef CONFIG_CPU_FREQ 286 unsigned int cpufreq_quick_get(unsigned int cpu); 287 #else 288 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 289 { 290 return 0; 291 } 292 #endif 293 294 295 /********************************************************************* 296 * CPUFREQ DEFAULT GOVERNOR * 297 *********************************************************************/ 298 299 300 /* 301 Performance governor is fallback governor if any other gov failed to 302 auto load due latency restrictions 303 */ 304 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 305 extern struct cpufreq_governor cpufreq_gov_performance; 306 #endif 307 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 308 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 309 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 310 extern struct cpufreq_governor cpufreq_gov_powersave; 311 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 312 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 313 extern struct cpufreq_governor cpufreq_gov_userspace; 314 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 315 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 316 extern struct cpufreq_governor cpufreq_gov_ondemand; 317 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 318 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 319 extern struct cpufreq_governor cpufreq_gov_conservative; 320 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 321 #endif 322 323 324 /********************************************************************* 325 * FREQUENCY TABLE HELPERS * 326 *********************************************************************/ 327 328 #define CPUFREQ_ENTRY_INVALID ~0 329 #define CPUFREQ_TABLE_END ~1 330 331 struct cpufreq_frequency_table { 332 unsigned int index; /* any */ 333 unsigned int frequency; /* kHz - doesn't need to be in ascending 334 * order */ 335 }; 336 337 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 338 struct cpufreq_frequency_table *table); 339 340 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 341 struct cpufreq_frequency_table *table); 342 343 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 344 struct cpufreq_frequency_table *table, 345 unsigned int target_freq, 346 unsigned int relation, 347 unsigned int *index); 348 349 /* the following 3 funtions are for cpufreq core use only */ 350 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 351 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 352 void cpufreq_cpu_put (struct cpufreq_policy *data); 353 354 /* the following are really really optional */ 355 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 356 357 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 358 unsigned int cpu); 359 360 void cpufreq_frequency_table_put_attr(unsigned int cpu); 361 362 363 /********************************************************************* 364 * UNIFIED DEBUG HELPERS * 365 *********************************************************************/ 366 367 #define CPUFREQ_DEBUG_CORE 1 368 #define CPUFREQ_DEBUG_DRIVER 2 369 #define CPUFREQ_DEBUG_GOVERNOR 4 370 371 #ifdef CONFIG_CPU_FREQ_DEBUG 372 373 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 374 const char *fmt, ...); 375 376 #else 377 378 #define cpufreq_debug_printk(msg...) do { } while(0) 379 380 #endif /* CONFIG_CPU_FREQ_DEBUG */ 381 382 #endif /* _LINUX_CPUFREQ_H */ 383