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