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 #define CPUFREQ_ETERNAL                 (-1)
  69 struct cpufreq_cpuinfo {
  70         unsigned int            max_freq;
  71         unsigned int            min_freq;
  72         unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  73 };
  74
  75 struct cpufreq_real_policy {
  76         unsigned int            min;    /* in kHz */
  77         unsigned int            max;    /* in kHz */
  78         unsigned int            policy; /* see above */
  79         struct cpufreq_governor *governor; /* see below */
  80 };
  81
  82 struct cpufreq_policy {
  83         cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  84         cpumask_var_t           related_cpus; /* CPUs with any coordination */
  85         unsigned int            shared_type; /* ANY or ALL affected CPUs
  86                                                 should set cpufreq */
  87         unsigned int            cpu;    /* cpu nr of registered CPU */
  88         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  89
  90         unsigned int            min;    /* in kHz */
  91         unsigned int            max;    /* in kHz */
  92         unsigned int            cur;    /* in kHz, only needed if cpufreq
  93                                          * governors are used */
  94         unsigned int            policy; /* see above */
  95         struct cpufreq_governor *governor; /* see below */
  96
  97         struct work_struct      update; /* if update_policy() needs to be
  98                                          * called, but you're in IRQ context */
  99
 100         struct cpufreq_real_policy      user_policy;
 101
 102         struct kobject          kobj;
 103         struct completion       kobj_unregister;
 104 };
 105
 106 #define CPUFREQ_ADJUST          (0)
 107 #define CPUFREQ_INCOMPATIBLE    (1)
 108 #define CPUFREQ_NOTIFY          (2)
 109 #define CPUFREQ_START           (3)
 110
 111 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 112 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 113 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 114 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 115
 116 /******************** cpufreq transition notifiers *******************/
 117
 118 #define CPUFREQ_PRECHANGE       (0)
 119 #define CPUFREQ_POSTCHANGE      (1)
 120 #define CPUFREQ_RESUMECHANGE    (8)
 121 #define CPUFREQ_SUSPENDCHANGE   (9)
 122
 123 struct cpufreq_freqs {
 124         unsigned int cpu;       /* cpu nr */
 125         unsigned int old;
 126         unsigned int new;
 127         u8 flags;               /* flags of cpufreq_driver, see below. */
 128 };
 129
 130
 131 /**
 132  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 133  * @old:   old value
 134  * @div:   divisor
 135  * @mult:  multiplier
 136  *
 137  *
 138  *    new = old * mult / div
 139  */
 140 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 141 {
 142 #if BITS_PER_LONG == 32
 143
 144         u64 result = ((u64) old) * ((u64) mult);
 145         do_div(result, div);
 146         return (unsigned long) result;
 147
 148 #elif BITS_PER_LONG == 64
 149
 150         unsigned long result = old * ((u64) mult);
 151         result /= div;
 152         return result;
 153
 154 #endif
 155 };
 156
 157 /*********************************************************************
 158  *                          CPUFREQ GOVERNORS                        *
 159  *********************************************************************/
 160
 161 #define CPUFREQ_GOV_START  1
 162 #define CPUFREQ_GOV_STOP   2
 163 #define CPUFREQ_GOV_LIMITS 3
 164
 165 struct cpufreq_governor {
 166         char    name[CPUFREQ_NAME_LEN];
 167         int     (*governor)     (struct cpufreq_policy *policy,
 168                                  unsigned int event);
 169         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 170                                          char *buf);
 171         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 172                                          unsigned int freq);
 173         unsigned int max_transition_latency; /* HW must be able to switch to
 174                         next freq faster than this value in nano secs or we
 175                         will fallback to performance governor */
 176         struct list_head        governor_list;
 177         struct module           *owner;
 178 };
 179
 180 /* pass a target to the cpufreq driver
 181  */
 182 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 183                                  unsigned int target_freq,
 184                                  unsigned int relation);
 185 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 186                                    unsigned int target_freq,
 187                                    unsigned int relation);
 188
 189
 190 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 191                                    unsigned int cpu);
 192
 193 int cpufreq_register_governor(struct cpufreq_governor *governor);
 194 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 195
 196 int lock_policy_rwsem_read(int cpu);
 197 int lock_policy_rwsem_write(int cpu);
 198 void unlock_policy_rwsem_read(int cpu);
 199 void unlock_policy_rwsem_write(int cpu);
 200
 201
 202 /*********************************************************************
 203  *                      CPUFREQ DRIVER INTERFACE                     *
 204  *********************************************************************/
 205
 206 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 207 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 208
 209 struct freq_attr;
 210
 211 struct cpufreq_driver {
 212         struct module           *owner;
 213         char                    name[CPUFREQ_NAME_LEN];
 214         u8                      flags;
 215
 216         /* needed by all drivers */
 217         int     (*init)         (struct cpufreq_policy *policy);
 218         int     (*verify)       (struct cpufreq_policy *policy);
 219
 220         /* define one out of two */
 221         int     (*setpolicy)    (struct cpufreq_policy *policy);
 222         int     (*target)       (struct cpufreq_policy *policy,
 223                                  unsigned int target_freq,
 224                                  unsigned int relation);
 225
 226         /* should be defined, if possible */
 227         unsigned int    (*get)  (unsigned int cpu);
 228
 229         /* optional */
 230         unsigned int (*getavg)  (struct cpufreq_policy *policy,
 231                                  unsigned int cpu);
 232
 233         int     (*exit)         (struct cpufreq_policy *policy);
 234         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 235         int     (*resume)       (struct cpufreq_policy *policy);
 236         struct freq_attr        **attr;
 237 };
 238
 239 /* flags */
 240
 241 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 242                                          * all ->init() calls failed */
 243 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 244                                          * "constants" aren't affected by
 245                                          * frequency transitions */
 246 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 247                                          * mismatches */
 248
 249 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 250 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 251
 252
 253 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 254
 255
 256 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 257 {
 258         if (policy->min < min)
 259                 policy->min = min;
 260         if (policy->max < min)
 261                 policy->max = min;
 262         if (policy->min > max)
 263                 policy->min = max;
 264         if (policy->max > max)
 265                 policy->max = max;
 266         if (policy->min > policy->max)
 267                 policy->min = policy->max;
 268         return;
 269 }
 270
 271 struct freq_attr {
 272         struct attribute attr;
 273         ssize_t (*show)(struct cpufreq_policy *, char *);
 274         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 275 };
 276
 277
 278 /*********************************************************************
 279  *                        CPUFREQ 2.6. INTERFACE                     *
 280  *********************************************************************/
 281 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 282 int cpufreq_update_policy(unsigned int cpu);
 283
 284 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 285 unsigned int cpufreq_get(unsigned int cpu);
 286
 287 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 288 #ifdef CONFIG_CPU_FREQ
 289 unsigned int cpufreq_quick_get(unsigned int cpu);
 290 #else
 291 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 292 {
 293         return 0;
 294 }
 295 #endif
 296
 297
 298 /*********************************************************************
 299  *                       CPUFREQ DEFAULT GOVERNOR                    *
 300  *********************************************************************/
 301
 302
 303 /*
 304   Performance governor is fallback governor if any other gov failed to
 305   auto load due latency restrictions
 306 */
 307 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 308 extern struct cpufreq_governor cpufreq_gov_performance;
 309 #endif
 310 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 311 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 312 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 313 extern struct cpufreq_governor cpufreq_gov_powersave;
 314 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 315 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 316 extern struct cpufreq_governor cpufreq_gov_userspace;
 317 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 318 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 319 extern struct cpufreq_governor cpufreq_gov_ondemand;
 320 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 321 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 322 extern struct cpufreq_governor cpufreq_gov_conservative;
 323 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 324 #endif
 325
 326
 327 /*********************************************************************
 328  *                     FREQUENCY TABLE HELPERS                       *
 329  *********************************************************************/
 330
 331 #define CPUFREQ_ENTRY_INVALID ~0
 332 #define CPUFREQ_TABLE_END     ~1
 333
 334 struct cpufreq_frequency_table {
 335         unsigned int    index;     /* any */
 336         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 337                                     * order */
 338 };
 339
 340 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 341                                     struct cpufreq_frequency_table *table);
 342
 343 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 344                                    struct cpufreq_frequency_table *table);
 345
 346 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 347                                    struct cpufreq_frequency_table *table,
 348                                    unsigned int target_freq,
 349                                    unsigned int relation,
 350                                    unsigned int *index);
 351
 352 /* the following 3 funtions are for cpufreq core use only */
 353 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 354 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 355 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 356
 357 /* the following are really really optional */
 358 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 359
 360 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 361                                       unsigned int cpu);
 362
 363 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 364
 365
 366 /*********************************************************************
 367  *                     UNIFIED DEBUG HELPERS                         *
 368  *********************************************************************/
 369
 370 #define CPUFREQ_DEBUG_CORE      1
 371 #define CPUFREQ_DEBUG_DRIVER    2
 372 #define CPUFREQ_DEBUG_GOVERNOR  4
 373
 374 #ifdef CONFIG_CPU_FREQ_DEBUG
 375
 376 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 377                                  const char *fmt, ...);
 378
 379 #else
 380
 381 #define cpufreq_debug_printk(msg...) do { } while(0)
 382
 383 #endif /* CONFIG_CPU_FREQ_DEBUG */
 384
 385 #endif /* _LINUX_CPUFREQ_H */