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  *
   8  * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #ifndef _LINUX_CPUFREQ_H
  15 #define _LINUX_CPUFREQ_H
  16
  17 #include <linux/mutex.h>
  18 #include <linux/notifier.h>
  19 #include <linux/threads.h>
  20 #include <linux/device.h>
  21 #include <linux/kobject.h>
  22 #include <linux/sysfs.h>
  23 #include <linux/completion.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/cpumask.h>
  26 #include <asm/div64.h>
  27
  28 #define CPUFREQ_NAME_LEN 16
  29
  30
  31 /*********************************************************************
  32  *                     CPUFREQ NOTIFIER INTERFACE                    *
  33  *********************************************************************/
  34
  35 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  36 #define CPUFREQ_POLICY_NOTIFIER         (1)
  37
  38 #ifdef CONFIG_CPU_FREQ
  39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  41 #else           /* CONFIG_CPU_FREQ */
  42 static inline int cpufreq_register_notifier(struct notifier_block *nb,
  43                                                 unsigned int list)
  44 {
  45         return 0;
  46 }
  47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
  48                                                 unsigned int list)
  49 {
  50         return 0;
  51 }
  52 #endif          /* CONFIG_CPU_FREQ */
  53
  54 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  55  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  56  * two generic policies are available:
  57  */
  58
  59 #define CPUFREQ_POLICY_POWERSAVE        (1)
  60 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  61
  62 /* Frequency values here are CPU kHz so that hardware which doesn't run
  63  * with some frequencies can complain without having to guess what per
  64  * cent / per mille means.
  65  * Maximum transition latency is in nanoseconds - if it's unknown,
  66  * CPUFREQ_ETERNAL shall be used.
  67  */
  68
  69 struct cpufreq_governor;
  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_t               cpus;   /* CPUs requiring sw coordination */
  87         cpumask_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
 113 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 114 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 115 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 116 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 117
 118 /******************** cpufreq transition notifiers *******************/
 119
 120 #define CPUFREQ_PRECHANGE       (0)
 121 #define CPUFREQ_POSTCHANGE      (1)
 122 #define CPUFREQ_RESUMECHANGE    (8)
 123 #define CPUFREQ_SUSPENDCHANGE   (9)
 124
 125 struct cpufreq_freqs {
 126         unsigned int cpu;       /* cpu nr */
 127         unsigned int old;
 128         unsigned int new;
 129         u8 flags;               /* flags of cpufreq_driver, see below. */
 130 };
 131
 132
 133 /**
 134  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 135  * @old:   old value
 136  * @div:   divisor
 137  * @mult:  multiplier
 138  *
 139  *
 140  *    new = old * mult / div
 141  */
 142 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 143 {
 144 #if BITS_PER_LONG == 32
 145
 146         u64 result = ((u64) old) * ((u64) mult);
 147         do_div(result, div);
 148         return (unsigned long) result;
 149
 150 #elif BITS_PER_LONG == 64
 151
 152         unsigned long result = old * ((u64) mult);
 153         result /= div;
 154         return result;
 155
 156 #endif
 157 };
 158
 159 /*********************************************************************
 160  *                          CPUFREQ GOVERNORS                        *
 161  *********************************************************************/
 162
 163 #define CPUFREQ_GOV_START  1
 164 #define CPUFREQ_GOV_STOP   2
 165 #define CPUFREQ_GOV_LIMITS 3
 166
 167 struct cpufreq_governor {
 168         char    name[CPUFREQ_NAME_LEN];
 169         int     (*governor)     (struct cpufreq_policy *policy,
 170                                  unsigned int event);
 171         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 172                                          char *buf);
 173         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 174                                          unsigned int freq);
 175         unsigned int max_transition_latency; /* HW must be able to switch to
 176                         next freq faster than this value in nano secs or we
 177                         will fallback to performance governor */
 178         struct list_head        governor_list;
 179         struct module           *owner;
 180 };
 181
 182 /* pass a target to the cpufreq driver
 183  */
 184 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 185                                  unsigned int target_freq,
 186                                  unsigned int relation);
 187 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 188                                    unsigned int target_freq,
 189                                    unsigned int relation);
 190
 191
 192 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
 193
 194 int cpufreq_register_governor(struct cpufreq_governor *governor);
 195 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 196
 197 int lock_policy_rwsem_read(int cpu);
 198 int lock_policy_rwsem_write(int cpu);
 199 void unlock_policy_rwsem_read(int cpu);
 200 void unlock_policy_rwsem_write(int cpu);
 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)  (unsigned int cpu);
 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
 277 /*********************************************************************
 278  *                        CPUFREQ 2.6. INTERFACE                     *
 279  *********************************************************************/
 280 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 281 int cpufreq_update_policy(unsigned int cpu);
 282
 283 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 284 unsigned int cpufreq_get(unsigned int cpu);
 285
 286 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 287 #ifdef CONFIG_CPU_FREQ
 288 unsigned int cpufreq_quick_get(unsigned int cpu);
 289 #else
 290 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 291 {
 292         return 0;
 293 }
 294 #endif
 295
 296
 297 /*********************************************************************
 298  *                       CPUFREQ DEFAULT GOVERNOR                    *
 299  *********************************************************************/
 300
 301
 302 /*
 303   Performance governor is fallback governor if any other gov failed to
 304   auto load due latency restrictions
 305 */
 306 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 307 extern struct cpufreq_governor cpufreq_gov_performance;
 308 #endif
 309 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 310 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 311 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 312 extern struct cpufreq_governor cpufreq_gov_powersave;
 313 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 314 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 315 extern struct cpufreq_governor cpufreq_gov_userspace;
 316 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 317 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 318 extern struct cpufreq_governor cpufreq_gov_ondemand;
 319 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 320 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 321 extern struct cpufreq_governor cpufreq_gov_conservative;
 322 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 323 #endif
 324
 325
 326 /*********************************************************************
 327  *                     FREQUENCY TABLE HELPERS                       *
 328  *********************************************************************/
 329
 330 #define CPUFREQ_ENTRY_INVALID ~0
 331 #define CPUFREQ_TABLE_END     ~1
 332
 333 struct cpufreq_frequency_table {
 334         unsigned int    index;     /* any */
 335         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 336                                     * order */
 337 };
 338
 339 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 340                                     struct cpufreq_frequency_table *table);
 341
 342 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 343                                    struct cpufreq_frequency_table *table);
 344
 345 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 346                                    struct cpufreq_frequency_table *table,
 347                                    unsigned int target_freq,
 348                                    unsigned int relation,
 349                                    unsigned int *index);
 350
 351 /* the following 3 funtions are for cpufreq core use only */
 352 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 353 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 354 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 355
 356 /* the following are really really optional */
 357 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 358
 359 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 360                                       unsigned int cpu);
 361
 362 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 363
 364
 365 /*********************************************************************
 366  *                     UNIFIED DEBUG HELPERS                         *
 367  *********************************************************************/
 368
 369 #define CPUFREQ_DEBUG_CORE      1
 370 #define CPUFREQ_DEBUG_DRIVER    2
 371 #define CPUFREQ_DEBUG_GOVERNOR  4
 372
 373 #ifdef CONFIG_CPU_FREQ_DEBUG
 374
 375 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 376                                  const char *fmt, ...);
 377
 378 #else
 379
 380 #define cpufreq_debug_printk(msg...) do { } while(0)
 381
 382 #endif /* CONFIG_CPU_FREQ_DEBUG */
 383
 384 #endif /* _LINUX_CPUFREQ_H */