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_var_t cpus; /* CPUs requiring sw coordination */ 84 cpumask_var_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 unsigned int cpu); 192 193 int cpufreq_register_governor(struct cpufreq_governor *governor); 194 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 195 196 int lock_policy_rwsem_read(int cpu); 197 int lock_policy_rwsem_write(int cpu); 198 void unlock_policy_rwsem_read(int cpu); 199 void unlock_policy_rwsem_write(int cpu); 200 201 202 /********************************************************************* 203 * CPUFREQ DRIVER INTERFACE * 204 *********************************************************************/ 205 206 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 207 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 208 209 struct freq_attr; 210 211 struct cpufreq_driver { 212 struct module *owner; 213 char name[CPUFREQ_NAME_LEN]; 214 u8 flags; 215 216 /* needed by all drivers */ 217 int (*init) (struct cpufreq_policy *policy); 218 int (*verify) (struct cpufreq_policy *policy); 219 220 /* define one out of two */ 221 int (*setpolicy) (struct cpufreq_policy *policy); 222 int (*target) (struct cpufreq_policy *policy, 223 unsigned int target_freq, 224 unsigned int relation); 225 226 /* should be defined, if possible */ 227 unsigned int (*get) (unsigned int cpu); 228 229 /* optional */ 230 unsigned int (*getavg) (struct cpufreq_policy *policy, 231 unsigned int cpu); 232 233 int (*exit) (struct cpufreq_policy *policy); 234 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 235 int (*resume) (struct cpufreq_policy *policy); 236 struct freq_attr **attr; 237 bool hide_interface; 238 }; 239 240 /* flags */ 241 242 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 243 * all ->init() calls failed */ 244 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 245 * "constants" aren't affected by 246 * frequency transitions */ 247 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 248 * mismatches */ 249 250 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 251 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 252 253 254 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 255 256 257 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 258 { 259 if (policy->min < min) 260 policy->min = min; 261 if (policy->max < min) 262 policy->max = min; 263 if (policy->min > max) 264 policy->min = max; 265 if (policy->max > max) 266 policy->max = max; 267 if (policy->min > policy->max) 268 policy->min = policy->max; 269 return; 270 } 271 272 struct freq_attr { 273 struct attribute attr; 274 ssize_t (*show)(struct cpufreq_policy *, char *); 275 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 276 }; 277 278 279 /********************************************************************* 280 * CPUFREQ 2.6. INTERFACE * 281 *********************************************************************/ 282 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 283 int cpufreq_update_policy(unsigned int cpu); 284 285 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 286 unsigned int cpufreq_get(unsigned int cpu); 287 288 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 289 #ifdef CONFIG_CPU_FREQ 290 unsigned int cpufreq_quick_get(unsigned int cpu); 291 #else 292 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 293 { 294 return 0; 295 } 296 #endif 297 298 299 /********************************************************************* 300 * CPUFREQ DEFAULT GOVERNOR * 301 *********************************************************************/ 302 303 304 /* 305 Performance governor is fallback governor if any other gov failed to 306 auto load due latency restrictions 307 */ 308 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 309 extern struct cpufreq_governor cpufreq_gov_performance; 310 #endif 311 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 312 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 313 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 314 extern struct cpufreq_governor cpufreq_gov_powersave; 315 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 316 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 317 extern struct cpufreq_governor cpufreq_gov_userspace; 318 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 319 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 320 extern struct cpufreq_governor cpufreq_gov_ondemand; 321 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 322 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 323 extern struct cpufreq_governor cpufreq_gov_conservative; 324 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 325 #endif 326 327 328 /********************************************************************* 329 * FREQUENCY TABLE HELPERS * 330 *********************************************************************/ 331 332 #define CPUFREQ_ENTRY_INVALID ~0 333 #define CPUFREQ_TABLE_END ~1 334 335 struct cpufreq_frequency_table { 336 unsigned int index; /* any */ 337 unsigned int frequency; /* kHz - doesn't need to be in ascending 338 * order */ 339 }; 340 341 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 342 struct cpufreq_frequency_table *table); 343 344 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 345 struct cpufreq_frequency_table *table); 346 347 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 348 struct cpufreq_frequency_table *table, 349 unsigned int target_freq, 350 unsigned int relation, 351 unsigned int *index); 352 353 /* the following 3 funtions are for cpufreq core use only */ 354 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 355 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 356 void cpufreq_cpu_put (struct cpufreq_policy *data); 357 358 /* the following are really really optional */ 359 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 360 361 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 362 unsigned int cpu); 363 364 void cpufreq_frequency_table_put_attr(unsigned int cpu); 365 366 367 /********************************************************************* 368 * UNIFIED DEBUG HELPERS * 369 *********************************************************************/ 370 371 #define CPUFREQ_DEBUG_CORE 1 372 #define CPUFREQ_DEBUG_DRIVER 2 373 #define CPUFREQ_DEBUG_GOVERNOR 4 374 375 #ifdef CONFIG_CPU_FREQ_DEBUG 376 377 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 378 const char *fmt, ...); 379 380 #else 381 382 #define cpufreq_debug_printk(msg...) do { } while(0) 383 384 #endif /* CONFIG_CPU_FREQ_DEBUG */ 385 386 #endif /* _LINUX_CPUFREQ_H */ 387