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
  76         /* in 10^(-9) s = nanoseconds */
  77         unsigned int            transition_latency;
  78 };
  79
  80 struct cpufreq_real_policy {
  81         unsigned int            min;    /* in kHz */
  82         unsigned int            max;    /* in kHz */
  83         unsigned int            policy; /* see above */
  84         struct cpufreq_governor *governor; /* see below */
  85 };
  86
  87 struct cpufreq_policy {
  88         cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  89         cpumask_var_t           related_cpus; /* CPUs with any coordination */
  90         unsigned int            shared_type; /* ANY or ALL affected CPUs
  91                                                 should set cpufreq */
  92         unsigned int            cpu;    /* cpu nr of registered CPU */
  93         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  94
  95         unsigned int            min;    /* in kHz */
  96         unsigned int            max;    /* in kHz */
  97         unsigned int            cur;    /* in kHz, only needed if cpufreq
  98                                          * governors are used */
  99         unsigned int            policy; /* see above */
 100         struct cpufreq_governor *governor; /* see below */
 101
 102         struct work_struct      update; /* if update_policy() needs to be
 103                                          * called, but you're in IRQ context */
 104
 105         struct cpufreq_real_policy      user_policy;
 106
 107         struct kobject          kobj;
 108         struct completion       kobj_unregister;
 109 };
 110
 111 #define CPUFREQ_ADJUST          (0)
 112 #define CPUFREQ_INCOMPATIBLE    (1)
 113 #define CPUFREQ_NOTIFY          (2)
 114 #define CPUFREQ_START           (3)
 115
 116 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 117 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 118 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 119 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 120
 121 /******************** cpufreq transition notifiers *******************/
 122
 123 #define CPUFREQ_PRECHANGE       (0)
 124 #define CPUFREQ_POSTCHANGE      (1)
 125 #define CPUFREQ_RESUMECHANGE    (8)
 126 #define CPUFREQ_SUSPENDCHANGE   (9)
 127
 128 struct cpufreq_freqs {
 129         unsigned int cpu;       /* cpu nr */
 130         unsigned int old;
 131         unsigned int new;
 132         u8 flags;               /* flags of cpufreq_driver, see below. */
 133 };
 134
 135
 136 /**
 137  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 138  * @old:   old value
 139  * @div:   divisor
 140  * @mult:  multiplier
 141  *
 142  *
 143  *    new = old * mult / div
 144  */
 145 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 146 {
 147 #if BITS_PER_LONG == 32
 148
 149         u64 result = ((u64) old) * ((u64) mult);
 150         do_div(result, div);
 151         return (unsigned long) result;
 152
 153 #elif BITS_PER_LONG == 64
 154
 155         unsigned long result = old * ((u64) mult);
 156         result /= div;
 157         return result;
 158
 159 #endif
 160 };
 161
 162 /*********************************************************************
 163  *                          CPUFREQ GOVERNORS                        *
 164  *********************************************************************/
 165
 166 #define CPUFREQ_GOV_START  1
 167 #define CPUFREQ_GOV_STOP   2
 168 #define CPUFREQ_GOV_LIMITS 3
 169
 170 struct cpufreq_governor {
 171         char    name[CPUFREQ_NAME_LEN];
 172         int     (*governor)     (struct cpufreq_policy *policy,
 173                                  unsigned int event);
 174         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 175                                          char *buf);
 176         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 177                                          unsigned int freq);
 178         unsigned int max_transition_latency; /* HW must be able to switch to
 179                         next freq faster than this value in nano secs or we
 180                         will fallback to performance governor */
 181         struct list_head        governor_list;
 182         struct module           *owner;
 183 };
 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);
 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_rw(_name)             \
 288 static struct freq_attr _name =                 \
 289 __ATTR(_name, 0644, show_##_name, store_##_name)
 290
 291 struct global_attr {
 292         struct attribute attr;
 293         ssize_t (*show)(struct kobject *kobj,
 294                         struct attribute *attr, char *buf);
 295         ssize_t (*store)(struct kobject *a, struct attribute *b,
 296                          const char *c, size_t count);
 297 };
 298
 299 #define define_one_global_ro(_name)             \
 300 static struct global_attr _name =               \
 301 __ATTR(_name, 0444, show_##_name, NULL)
 302
 303 #define define_one_global_rw(_name)             \
 304 static struct global_attr _name =               \
 305 __ATTR(_name, 0644, show_##_name, store_##_name)
 306
 307
 308 /*********************************************************************
 309  *                        CPUFREQ 2.6. INTERFACE                     *
 310  *********************************************************************/
 311 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 312 int cpufreq_update_policy(unsigned int cpu);
 313
 314 #ifdef CONFIG_CPU_FREQ
 315 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 316 unsigned int cpufreq_get(unsigned int cpu);
 317 #else
 318 static inline unsigned int cpufreq_get(unsigned int cpu)
 319 {
 320         return 0;
 321 }
 322 #endif
 323
 324 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 325 #ifdef CONFIG_CPU_FREQ
 326 unsigned int cpufreq_quick_get(unsigned int cpu);
 327 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 328 #else
 329 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 330 {
 331         return 0;
 332 }
 333 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 334 {
 335         return 0;
 336 }
 337 #endif
 338
 339
 340 /*********************************************************************
 341  *                       CPUFREQ DEFAULT GOVERNOR                    *
 342  *********************************************************************/
 343
 344
 345 /*
 346   Performance governor is fallback governor if any other gov failed to
 347   auto load due latency restrictions
 348 */
 349 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 350 extern struct cpufreq_governor cpufreq_gov_performance;
 351 #endif
 352 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 353 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 354 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 355 extern struct cpufreq_governor cpufreq_gov_powersave;
 356 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 357 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 358 extern struct cpufreq_governor cpufreq_gov_userspace;
 359 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 360 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 361 extern struct cpufreq_governor cpufreq_gov_ondemand;
 362 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 364 extern struct cpufreq_governor cpufreq_gov_conservative;
 365 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 366 #endif
 367
 368
 369 /*********************************************************************
 370  *                     FREQUENCY TABLE HELPERS                       *
 371  *********************************************************************/
 372
 373 #define CPUFREQ_ENTRY_INVALID ~0
 374 #define CPUFREQ_TABLE_END     ~1
 375
 376 struct cpufreq_frequency_table {
 377         unsigned int    index;     /* any */
 378         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 379                                     * order */
 380 };
 381
 382 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 383                                     struct cpufreq_frequency_table *table);
 384
 385 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 386                                    struct cpufreq_frequency_table *table);
 387
 388 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 389                                    struct cpufreq_frequency_table *table,
 390                                    unsigned int target_freq,
 391                                    unsigned int relation,
 392                                    unsigned int *index);
 393
 394 /* the following 3 funtions are for cpufreq core use only */
 395 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 396 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 397 void   cpufreq_cpu_put(struct cpufreq_policy *data);
 398
 399 /* the following are really really optional */
 400 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 401
 402 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 403                                       unsigned int cpu);
 404
 405 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 406
 407
 408 #endif /* _LINUX_CPUFREQ_H */