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/kobject.h>
  18 #include <linux/sysfs.h>
  19 #include <linux/completion.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/cpumask.h>
  22 #include <asm/div64.h>
  23
  24 #define CPUFREQ_NAME_LEN 16
  25
  26
  27 /*********************************************************************
  28  *                     CPUFREQ NOTIFIER INTERFACE                    *
  29  *********************************************************************/
  30
  31 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  32 #define CPUFREQ_POLICY_NOTIFIER         (1)
  33
  34 #ifdef CONFIG_CPU_FREQ
  35 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  36 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  37 extern void disable_cpufreq(void);
  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 static inline void disable_cpufreq(void) { }
  50 #endif          /* CONFIG_CPU_FREQ */
  51
  52 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  53  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  54  * two generic policies are available:
  55  */
  56
  57 #define CPUFREQ_POLICY_POWERSAVE        (1)
  58 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  59
  60 /* Frequency values here are CPU kHz so that hardware which doesn't run
  61  * with some frequencies can complain without having to guess what per
  62  * cent / per mille means.
  63  * Maximum transition latency is in nanoseconds - if it's unknown,
  64  * CPUFREQ_ETERNAL shall be used.
  65  */
  66
  67 struct cpufreq_governor;
  68
  69 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
  70 extern struct kobject *cpufreq_global_kobject;
  71
  72 #define CPUFREQ_ETERNAL                 (-1)
  73 struct cpufreq_cpuinfo {
  74         unsigned int            max_freq;
  75         unsigned int            min_freq;
  76
  77         /* in 10^(-9) s = nanoseconds */
  78         unsigned int            transition_latency;
  79 };
  80
  81 struct cpufreq_real_policy {
  82         unsigned int            min;    /* in kHz */
  83         unsigned int            max;    /* in kHz */
  84         unsigned int            policy; /* see above */
  85         struct cpufreq_governor *governor; /* see below */
  86 };
  87
  88 struct cpufreq_policy {
  89         cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  90         cpumask_var_t           related_cpus; /* CPUs with any coordination */
  91         unsigned int            shared_type; /* ANY or ALL affected CPUs
  92                                                 should set cpufreq */
  93         unsigned int            cpu;    /* cpu nr of registered CPU */
  94         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  95
  96         unsigned int            min;    /* in kHz */
  97         unsigned int            max;    /* in kHz */
  98         unsigned int            cur;    /* in kHz, only needed if cpufreq
  99                                          * governors are used */
 100         unsigned int            policy; /* see above */
 101         struct cpufreq_governor *governor; /* see below */
 102
 103         struct work_struct      update; /* if update_policy() needs to be
 104                                          * called, but you're in IRQ context */
 105
 106         struct cpufreq_real_policy      user_policy;
 107
 108         struct kobject          kobj;
 109         struct completion       kobj_unregister;
 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 /*
 187  * Pass a target to the cpufreq driver.
 188  */
 189 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 190                                  unsigned int target_freq,
 191                                  unsigned int relation);
 192 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 193                                    unsigned int target_freq,
 194                                    unsigned int relation);
 195
 196
 197 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 198                                    unsigned int cpu);
 199
 200 int cpufreq_register_governor(struct cpufreq_governor *governor);
 201 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 202
 203
 204 /*********************************************************************
 205  *                      CPUFREQ DRIVER INTERFACE                     *
 206  *********************************************************************/
 207
 208 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 209 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 210
 211 struct freq_attr;
 212
 213 struct cpufreq_driver {
 214         struct module           *owner;
 215         char                    name[CPUFREQ_NAME_LEN];
 216         u8                      flags;
 217
 218         /* needed by all drivers */
 219         int     (*init)         (struct cpufreq_policy *policy);
 220         int     (*verify)       (struct cpufreq_policy *policy);
 221
 222         /* define one out of two */
 223         int     (*setpolicy)    (struct cpufreq_policy *policy);
 224         int     (*target)       (struct cpufreq_policy *policy,
 225                                  unsigned int target_freq,
 226                                  unsigned int relation);
 227
 228         /* should be defined, if possible */
 229         unsigned int    (*get)  (unsigned int cpu);
 230
 231         /* optional */
 232         unsigned int (*getavg)  (struct cpufreq_policy *policy,
 233                                  unsigned int cpu);
 234         int     (*bios_limit)   (int cpu, unsigned int *limit);
 235
 236         int     (*exit)         (struct cpufreq_policy *policy);
 237         int     (*suspend)      (struct cpufreq_policy *policy);
 238         int     (*resume)       (struct cpufreq_policy *policy);
 239         struct freq_attr        **attr;
 240 };
 241
 242 /* flags */
 243
 244 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 245                                          * all ->init() calls failed */
 246 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 247                                          * "constants" aren't affected by
 248                                          * frequency transitions */
 249 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 250                                          * mismatches */
 251
 252 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 253 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 254
 255
 256 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 257
 258
 259 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 260 {
 261         if (policy->min < min)
 262                 policy->min = min;
 263         if (policy->max < min)
 264                 policy->max = min;
 265         if (policy->min > max)
 266                 policy->min = max;
 267         if (policy->max > max)
 268                 policy->max = max;
 269         if (policy->min > policy->max)
 270                 policy->min = policy->max;
 271         return;
 272 }
 273
 274 struct freq_attr {
 275         struct attribute attr;
 276         ssize_t (*show)(struct cpufreq_policy *, char *);
 277         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 278 };
 279
 280 #define cpufreq_freq_attr_ro(_name)             \
 281 static struct freq_attr _name =                 \
 282 __ATTR(_name, 0444, show_##_name, NULL)
 283
 284 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 285 static struct freq_attr _name =                 \
 286 __ATTR(_name, _perm, show_##_name, 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 struct global_attr {
 293         struct attribute attr;
 294         ssize_t (*show)(struct kobject *kobj,
 295                         struct attribute *attr, char *buf);
 296         ssize_t (*store)(struct kobject *a, struct attribute *b,
 297                          const char *c, size_t count);
 298 };
 299
 300 #define define_one_global_ro(_name)             \
 301 static struct global_attr _name =               \
 302 __ATTR(_name, 0444, show_##_name, NULL)
 303
 304 #define define_one_global_rw(_name)             \
 305 static struct global_attr _name =               \
 306 __ATTR(_name, 0644, show_##_name, store_##_name)
 307
 308
 309 /*********************************************************************
 310  *                        CPUFREQ 2.6. INTERFACE                     *
 311  *********************************************************************/
 312 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 313 int cpufreq_update_policy(unsigned int cpu);
 314
 315 #ifdef CONFIG_CPU_FREQ
 316 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 317 unsigned int cpufreq_get(unsigned int cpu);
 318 #else
 319 static inline unsigned int cpufreq_get(unsigned int cpu)
 320 {
 321         return 0;
 322 }
 323 #endif
 324
 325 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 326 #ifdef CONFIG_CPU_FREQ
 327 unsigned int cpufreq_quick_get(unsigned int cpu);
 328 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 329 #else
 330 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 331 {
 332         return 0;
 333 }
 334 static inline unsigned int cpufreq_quick_get_max(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 #endif /* _LINUX_CPUFREQ_H */