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_t               cpus;   /* CPUs requiring sw coordination */
  84         cpumask_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
 192 int cpufreq_register_governor(struct cpufreq_governor *governor);
 193 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 194
 195 int lock_policy_rwsem_read(int cpu);
 196 int lock_policy_rwsem_write(int cpu);
 197 void unlock_policy_rwsem_read(int cpu);
 198 void unlock_policy_rwsem_write(int cpu);
 199
 200
 201 /*********************************************************************
 202  *                      CPUFREQ DRIVER INTERFACE                     *
 203  *********************************************************************/
 204
 205 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 206 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 207
 208 struct freq_attr;
 209
 210 struct cpufreq_driver {
 211         struct module           *owner;
 212         char                    name[CPUFREQ_NAME_LEN];
 213         u8                      flags;
 214
 215         /* needed by all drivers */
 216         int     (*init)         (struct cpufreq_policy *policy);
 217         int     (*verify)       (struct cpufreq_policy *policy);
 218
 219         /* define one out of two */
 220         int     (*setpolicy)    (struct cpufreq_policy *policy);
 221         int     (*target)       (struct cpufreq_policy *policy,
 222                                  unsigned int target_freq,
 223                                  unsigned int relation);
 224
 225         /* should be defined, if possible */
 226         unsigned int    (*get)  (unsigned int cpu);
 227
 228         /* optional */
 229         unsigned int (*getavg)  (unsigned int cpu);
 230         int     (*exit)         (struct cpufreq_policy *policy);
 231         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 232         int     (*resume)       (struct cpufreq_policy *policy);
 233         struct freq_attr        **attr;
 234 };
 235
 236 /* flags */
 237
 238 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 239                                          * all ->init() calls failed */
 240 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 241                                          * "constants" aren't affected by
 242                                          * frequency transitions */
 243 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 244                                          * mismatches */
 245
 246 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 247 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 248
 249
 250 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 251
 252
 253 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 254 {
 255         if (policy->min < min)
 256                 policy->min = min;
 257         if (policy->max < min)
 258                 policy->max = min;
 259         if (policy->min > max)
 260                 policy->min = max;
 261         if (policy->max > max)
 262                 policy->max = max;
 263         if (policy->min > policy->max)
 264                 policy->min = policy->max;
 265         return;
 266 }
 267
 268 struct freq_attr {
 269         struct attribute attr;
 270         ssize_t (*show)(struct cpufreq_policy *, char *);
 271         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 272 };
 273
 274
 275 /*********************************************************************
 276  *                        CPUFREQ 2.6. INTERFACE                     *
 277  *********************************************************************/
 278 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 279 int cpufreq_update_policy(unsigned int cpu);
 280
 281 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 282 unsigned int cpufreq_get(unsigned int cpu);
 283
 284 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 285 #ifdef CONFIG_CPU_FREQ
 286 unsigned int cpufreq_quick_get(unsigned int cpu);
 287 #else
 288 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 289 {
 290         return 0;
 291 }
 292 #endif
 293
 294
 295 /*********************************************************************
 296  *                       CPUFREQ DEFAULT GOVERNOR                    *
 297  *********************************************************************/
 298
 299
 300 /*
 301   Performance governor is fallback governor if any other gov failed to
 302   auto load due latency restrictions
 303 */
 304 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 305 extern struct cpufreq_governor cpufreq_gov_performance;
 306 #endif
 307 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 308 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 309 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 310 extern struct cpufreq_governor cpufreq_gov_powersave;
 311 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 312 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 313 extern struct cpufreq_governor cpufreq_gov_userspace;
 314 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 315 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 316 extern struct cpufreq_governor cpufreq_gov_ondemand;
 317 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 318 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 319 extern struct cpufreq_governor cpufreq_gov_conservative;
 320 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 321 #endif
 322
 323
 324 /*********************************************************************
 325  *                     FREQUENCY TABLE HELPERS                       *
 326  *********************************************************************/
 327
 328 #define CPUFREQ_ENTRY_INVALID ~0
 329 #define CPUFREQ_TABLE_END     ~1
 330
 331 struct cpufreq_frequency_table {
 332         unsigned int    index;     /* any */
 333         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 334                                     * order */
 335 };
 336
 337 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 338                                     struct cpufreq_frequency_table *table);
 339
 340 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 341                                    struct cpufreq_frequency_table *table);
 342
 343 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 344                                    struct cpufreq_frequency_table *table,
 345                                    unsigned int target_freq,
 346                                    unsigned int relation,
 347                                    unsigned int *index);
 348
 349 /* the following 3 funtions are for cpufreq core use only */
 350 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 351 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 352 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 353
 354 /* the following are really really optional */
 355 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 356
 357 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 358                                       unsigned int cpu);
 359
 360 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 361
 362
 363 /*********************************************************************
 364  *                     UNIFIED DEBUG HELPERS                         *
 365  *********************************************************************/
 366
 367 #define CPUFREQ_DEBUG_CORE      1
 368 #define CPUFREQ_DEBUG_DRIVER    2
 369 #define CPUFREQ_DEBUG_GOVERNOR  4
 370
 371 #ifdef CONFIG_CPU_FREQ_DEBUG
 372
 373 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 374                                  const char *fmt, ...);
 375
 376 #else
 377
 378 #define cpufreq_debug_printk(msg...) do { } while(0)
 379
 380 #endif /* CONFIG_CPU_FREQ_DEBUG */
 381
 382 #endif /* _LINUX_CPUFREQ_H */