include/linux/cpufreq.h

   1 /*
   2  *  linux/include/linux/cpufreq.h
   3  *
   4  *  Copyright (C) 2001 Russell King
   5  *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
   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 #ifdef CONFIG_CPU_FREQ_TICKLE
 108         bool                    tickle_enabled;
 109 #endif
 110 };
 111
 112 #define CPUFREQ_ADJUST          (0)
 113 #define CPUFREQ_INCOMPATIBLE    (1)
 114 #define CPUFREQ_NOTIFY          (2)
 115 #define CPUFREQ_START           (3)
 116
 117 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 118 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 119 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 120 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 121
 122 /******************** cpufreq transition notifiers *******************/
 123
 124 #define CPUFREQ_PRECHANGE       (0)
 125 #define CPUFREQ_POSTCHANGE      (1)
 126 #define CPUFREQ_RESUMECHANGE    (8)
 127 #define CPUFREQ_SUSPENDCHANGE   (9)
 128
 129 struct cpufreq_freqs {
 130         unsigned int cpu;       /* cpu nr */
 131         unsigned int old;
 132         unsigned int new;
 133         u8 flags;               /* flags of cpufreq_driver, see below. */
 134 };
 135
 136
 137 /**
 138  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 139  * @old:   old value
 140  * @div:   divisor
 141  * @mult:  multiplier
 142  *
 143  *
 144  *    new = old * mult / div
 145  */
 146 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 147 {
 148 #if BITS_PER_LONG == 32
 149
 150         u64 result = ((u64) old) * ((u64) mult);
 151         do_div(result, div);
 152         return (unsigned long) result;
 153
 154 #elif BITS_PER_LONG == 64
 155
 156         unsigned long result = old * ((u64) mult);
 157         result /= div;
 158         return result;
 159
 160 #endif
 161 };
 162
 163 /*********************************************************************
 164  *                          CPUFREQ GOVERNORS                        *
 165  *********************************************************************/
 166
 167 #define CPUFREQ_GOV_START  1
 168 #define CPUFREQ_GOV_STOP   2
 169 #define CPUFREQ_GOV_LIMITS 3
 170
 171 struct cpufreq_governor {
 172         char    name[CPUFREQ_NAME_LEN];
 173         int     (*governor)     (struct cpufreq_policy *policy,
 174                                  unsigned int event);
 175         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 176                                          char *buf);
 177         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 178                                          unsigned int freq);
 179         unsigned int max_transition_latency; /* HW must be able to switch to
 180                         next freq faster than this value in nano secs or we
 181                         will fallback to performance governor */
 182         struct list_head        governor_list;
 183         struct module           *owner;
 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, pm_message_t pmsg);
 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_ro_old(_name)         \
 288 static struct freq_attr _name##_old =           \
 289 __ATTR(_name, 0444, show_##_name##_old, NULL)
 290
 291 #define cpufreq_freq_attr_rw(_name)             \
 292 static struct freq_attr _name =                 \
 293 __ATTR(_name, 0644, show_##_name, store_##_name)
 294
 295 #define cpufreq_freq_attr_rw_old(_name)         \
 296 static struct freq_attr _name##_old =           \
 297 __ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
 298
 299
 300 struct global_attr {
 301         struct attribute attr;
 302         ssize_t (*show)(struct kobject *kobj,
 303                         struct attribute *attr, char *buf);
 304         ssize_t (*store)(struct kobject *a, struct attribute *b,
 305                          const char *c, size_t count);
 306 };
 307
 308 #define define_one_global_ro(_name)             \
 309 static struct global_attr _name =               \
 310 __ATTR(_name, 0444, show_##_name, NULL)
 311
 312 #define define_one_global_rw(_name)             \
 313 static struct global_attr _name =               \
 314 __ATTR(_name, 0644, show_##_name, store_##_name)
 315
 316
 317 /*********************************************************************
 318  *                        CPUFREQ 2.6. INTERFACE                     *
 319  *********************************************************************/
 320 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 321 int cpufreq_update_policy(unsigned int cpu);
 322
 323 #ifdef CONFIG_CPU_FREQ
 324 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 325 unsigned int cpufreq_get(unsigned int cpu);
 326 #else
 327 static inline unsigned int cpufreq_get(unsigned int cpu)
 328 {
 329         return 0;
 330 }
 331 #endif
 332
 333 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 334 #ifdef CONFIG_CPU_FREQ
 335 unsigned int cpufreq_quick_get(unsigned int cpu);
 336 #else
 337 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 338 {
 339         return 0;
 340 }
 341 #endif
 342
 343 /*
 344  * tickle the cpu to enforce higher frequency for a short period;
 345  * e.g., between a user input and cpufreq's response
 346  */
 347 #ifdef CONFIG_CPU_FREQ_TICKLE
 348 extern int cpufreq_tickle_cpu(int ratio, int cpu);
 349 extern unsigned int cpufreq_tickle_cpu_frequency;
 350 #else
 351 static inline int cpufreq_tickle_cpu(int ratio, int cpu)
 352 {
 353         return ;
 354 }
 355 static unsigned int cpufreq_tickle_cpu_frequency;
 356 #endif
 357 #ifdef CONFIG_CPU_FREQ_GOV_ONDEMAND_FLEXRATE
 358 extern int cpufreq_ondemand_flexrate_request(unsigned int rate_ms,
 359                                              unsigned int duration);
 360 #else
 361 static inline int cpufreq_ondemand_flexrate_request(unsigned int rate_ms,
 362                                                     unsigned int duration)
 363 {
 364         return 0;
 365 }
 366 #endif
 367
 368
 369 /*********************************************************************
 370  *                       CPUFREQ DEFAULT GOVERNOR                    *
 371  *********************************************************************/
 372
 373
 374 /*
 375   Performance governor is fallback governor if any other gov failed to
 376   auto load due latency restrictions
 377 */
 378 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 379 extern struct cpufreq_governor cpufreq_gov_performance;
 380 #endif
 381 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 382 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 383 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 384 extern struct cpufreq_governor cpufreq_gov_powersave;
 385 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 386 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 387 extern struct cpufreq_governor cpufreq_gov_userspace;
 388 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 389 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 390 extern struct cpufreq_governor cpufreq_gov_ondemand;
 391 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 392 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 393 extern struct cpufreq_governor cpufreq_gov_conservative;
 394 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 395 #endif
 396
 397
 398 /*********************************************************************
 399  *                     FREQUENCY TABLE HELPERS                       *
 400  *********************************************************************/
 401
 402 #define CPUFREQ_ENTRY_INVALID ~0
 403 #define CPUFREQ_TABLE_END     ~1
 404
 405 struct cpufreq_frequency_table {
 406         unsigned int    index;     /* any */
 407         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 408                                     * order */
 409 };
 410
 411 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 412                                     struct cpufreq_frequency_table *table);
 413
 414 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 415                                    struct cpufreq_frequency_table *table);
 416
 417 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 418                                    struct cpufreq_frequency_table *table,
 419                                    unsigned int target_freq,
 420                                    unsigned int relation,
 421                                    unsigned int *index);
 422
 423 /* the following 3 funtions are for cpufreq core use only */
 424 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 425 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 426 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 427
 428 /* the following are really really optional */
 429 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 430
 431 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 432                                       unsigned int cpu);
 433
 434 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 435
 436
 437 /*********************************************************************
 438  *                     UNIFIED DEBUG HELPERS                         *
 439  *********************************************************************/
 440
 441 #define CPUFREQ_DEBUG_CORE      1
 442 #define CPUFREQ_DEBUG_DRIVER    2
 443 #define CPUFREQ_DEBUG_GOVERNOR  4
 444
 445 #ifdef CONFIG_CPU_FREQ_DEBUG
 446
 447 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 448                                  const char *fmt, ...);
 449
 450 #else
 451
 452 #define cpufreq_debug_printk(msg...) do { } while(0)
 453
 454 #endif /* CONFIG_CPU_FREQ_DEBUG */
 455
 456 #endif /* _LINUX_CPUFREQ_H */