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 };
 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
 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)  (struct cpufreq_policy *policy,
 229                                  unsigned int cpu);
 230         int     (*bios_limit)   (int cpu, unsigned int *limit);
 231
 232         int     (*exit)         (struct cpufreq_policy *policy);
 233         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 234         int     (*resume)       (struct cpufreq_policy *policy);
 235         struct freq_attr        **attr;
 236 };
 237
 238 /* flags */
 239
 240 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 241                                          * all ->init() calls failed */
 242 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 243                                          * "constants" aren't affected by
 244                                          * frequency transitions */
 245 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 246                                          * mismatches */
 247
 248 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 249 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 250
 251
 252 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 253
 254
 255 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 256 {
 257         if (policy->min < min)
 258                 policy->min = min;
 259         if (policy->max < min)
 260                 policy->max = min;
 261         if (policy->min > max)
 262                 policy->min = max;
 263         if (policy->max > max)
 264                 policy->max = max;
 265         if (policy->min > policy->max)
 266                 policy->min = policy->max;
 267         return;
 268 }
 269
 270 struct freq_attr {
 271         struct attribute attr;
 272         ssize_t (*show)(struct cpufreq_policy *, char *);
 273         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 274 };
 275
 276 #define cpufreq_freq_attr_ro(_name)             \
 277 static struct freq_attr _name =                 \
 278 __ATTR(_name, 0444, show_##_name, NULL)
 279
 280 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 281 static struct freq_attr _name =                 \
 282 __ATTR(_name, _perm, show_##_name, NULL)
 283
 284 #define cpufreq_freq_attr_ro_old(_name)         \
 285 static struct freq_attr _name##_old =           \
 286 __ATTR(_name, 0444, show_##_name##_old, NULL)
 287
 288 #define cpufreq_freq_attr_rw(_name)             \
 289 static struct freq_attr _name =                 \
 290 __ATTR(_name, 0644, show_##_name, store_##_name)
 291
 292 #define cpufreq_freq_attr_rw_old(_name)         \
 293 static struct freq_attr _name##_old =           \
 294 __ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
 295
 296
 297 struct global_attr {
 298         struct attribute attr;
 299         ssize_t (*show)(struct kobject *kobj,
 300                         struct attribute *attr, char *buf);
 301         ssize_t (*store)(struct kobject *a, struct attribute *b,
 302                          const char *c, size_t count);
 303 };
 304
 305 #define define_one_global_ro(_name)             \
 306 static struct global_attr _name =               \
 307 __ATTR(_name, 0444, show_##_name, NULL)
 308
 309 #define define_one_global_rw(_name)             \
 310 static struct global_attr _name =               \
 311 __ATTR(_name, 0644, show_##_name, store_##_name)
 312
 313
 314 /*********************************************************************
 315  *                        CPUFREQ 2.6. INTERFACE                     *
 316  *********************************************************************/
 317 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 318 int cpufreq_update_policy(unsigned int cpu);
 319
 320 #ifdef CONFIG_CPU_FREQ
 321 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 322 unsigned int cpufreq_get(unsigned int cpu);
 323 #else
 324 static inline unsigned int cpufreq_get(unsigned int cpu)
 325 {
 326         return 0;
 327 }
 328 #endif
 329
 330 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 331 #ifdef CONFIG_CPU_FREQ
 332 unsigned int cpufreq_quick_get(unsigned int cpu);
 333 #else
 334 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 335 {
 336         return 0;
 337 }
 338 #endif
 339
 340
 341 /*********************************************************************
 342  *                       CPUFREQ DEFAULT GOVERNOR                    *
 343  *********************************************************************/
 344
 345
 346 /*
 347   Performance governor is fallback governor if any other gov failed to
 348   auto load due latency restrictions
 349 */
 350 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 351 extern struct cpufreq_governor cpufreq_gov_performance;
 352 #endif
 353 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 354 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 355 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 356 extern struct cpufreq_governor cpufreq_gov_powersave;
 357 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 358 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 359 extern struct cpufreq_governor cpufreq_gov_userspace;
 360 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 361 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 362 extern struct cpufreq_governor cpufreq_gov_ondemand;
 363 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 365 extern struct cpufreq_governor cpufreq_gov_conservative;
 366 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 367 #endif
 368
 369
 370 /*********************************************************************
 371  *                     FREQUENCY TABLE HELPERS                       *
 372  *********************************************************************/
 373
 374 #define CPUFREQ_ENTRY_INVALID ~0
 375 #define CPUFREQ_TABLE_END     ~1
 376
 377 struct cpufreq_frequency_table {
 378         unsigned int    index;     /* any */
 379         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 380                                     * order */
 381 };
 382
 383 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 384                                     struct cpufreq_frequency_table *table);
 385
 386 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 387                                    struct cpufreq_frequency_table *table);
 388
 389 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 390                                    struct cpufreq_frequency_table *table,
 391                                    unsigned int target_freq,
 392                                    unsigned int relation,
 393                                    unsigned int *index);
 394
 395 /* the following 3 funtions are for cpufreq core use only */
 396 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 397 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 398 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 399
 400 /* the following are really really optional */
 401 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 402
 403 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 404                                       unsigned int cpu);
 405
 406 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 407
 408
 409 /*********************************************************************
 410  *                     UNIFIED DEBUG HELPERS                         *
 411  *********************************************************************/
 412
 413 #define CPUFREQ_DEBUG_CORE      1
 414 #define CPUFREQ_DEBUG_DRIVER    2
 415 #define CPUFREQ_DEBUG_GOVERNOR  4
 416
 417 #ifdef CONFIG_CPU_FREQ_DEBUG
 418
 419 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 420                                  const char *fmt, ...);
 421
 422 #else
 423
 424 #define cpufreq_debug_printk(msg...) do { } while(0)
 425
 426 #endif /* CONFIG_CPU_FREQ_DEBUG */
 427
 428 #endif /* _LINUX_CPUFREQ_H */