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 #ifdef CONFIG_CPU_FREQ
  36 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  37 #else
  38 static inline int cpufreq_register_notifier(struct notifier_block *nb,
  39                                                 unsigned int list)
  40 {
  41         return 0;
  42 }
  43 #endif
  44 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  45
  46 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  47 #define CPUFREQ_POLICY_NOTIFIER         (1)
  48
  49
  50 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  51  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  52  * two generic policies are available:
  53  */
  54
  55 #define CPUFREQ_POLICY_POWERSAVE        (1)
  56 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  57
  58 /* Frequency values here are CPU kHz so that hardware which doesn't run
  59  * with some frequencies can complain without having to guess what per
  60  * cent / per mille means.
  61  * Maximum transition latency is in nanoseconds - if it's unknown,
  62  * CPUFREQ_ETERNAL shall be used.
  63  */
  64
  65 struct cpufreq_governor;
  66
  67 #define CPUFREQ_ETERNAL                 (-1)
  68 struct cpufreq_cpuinfo {
  69         unsigned int            max_freq;
  70         unsigned int            min_freq;
  71         unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  72 };
  73
  74 struct cpufreq_real_policy {
  75         unsigned int            min;    /* in kHz */
  76         unsigned int            max;    /* in kHz */
  77         unsigned int            policy; /* see above */
  78         struct cpufreq_governor *governor; /* see below */
  79 };
  80
  81 struct cpufreq_policy {
  82         cpumask_t               cpus;   /* affected CPUs */
  83         unsigned int            shared_type; /* ANY or ALL affected CPUs
  84                                                 should set cpufreq */
  85         unsigned int            cpu;    /* cpu nr of registered CPU */
  86         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  87
  88         unsigned int            min;    /* in kHz */
  89         unsigned int            max;    /* in kHz */
  90         unsigned int            cur;    /* in kHz, only needed if cpufreq
  91                                          * governors are used */
  92         unsigned int            policy; /* see above */
  93         struct cpufreq_governor *governor; /* see below */
  94
  95         struct work_struct      update; /* if update_policy() needs to be
  96                                          * called, but you're in IRQ context */
  97
  98         struct cpufreq_real_policy      user_policy;
  99
 100         struct kobject          kobj;
 101         struct completion       kobj_unregister;
 102 };
 103
 104 #define CPUFREQ_ADJUST          (0)
 105 #define CPUFREQ_INCOMPATIBLE    (1)
 106 #define CPUFREQ_NOTIFY          (2)
 107
 108 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 109 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 110 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 111 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 112
 113 /******************** cpufreq transition notifiers *******************/
 114
 115 #define CPUFREQ_PRECHANGE       (0)
 116 #define CPUFREQ_POSTCHANGE      (1)
 117 #define CPUFREQ_RESUMECHANGE    (8)
 118 #define CPUFREQ_SUSPENDCHANGE   (9)
 119
 120 struct cpufreq_freqs {
 121         unsigned int cpu;       /* cpu nr */
 122         unsigned int old;
 123         unsigned int new;
 124         u8 flags;               /* flags of cpufreq_driver, see below. */
 125 };
 126
 127
 128 /**
 129  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 130  * @old:   old value
 131  * @div:   divisor
 132  * @mult:  multiplier
 133  *
 134  *
 135  *    new = old * mult / div
 136  */
 137 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 138 {
 139 #if BITS_PER_LONG == 32
 140
 141         u64 result = ((u64) old) * ((u64) mult);
 142         do_div(result, div);
 143         return (unsigned long) result;
 144
 145 #elif BITS_PER_LONG == 64
 146
 147         unsigned long result = old * ((u64) mult);
 148         result /= div;
 149         return result;
 150
 151 #endif
 152 };
 153
 154 /*********************************************************************
 155  *                          CPUFREQ GOVERNORS                        *
 156  *********************************************************************/
 157
 158 #define CPUFREQ_GOV_START  1
 159 #define CPUFREQ_GOV_STOP   2
 160 #define CPUFREQ_GOV_LIMITS 3
 161
 162 struct cpufreq_governor {
 163         char    name[CPUFREQ_NAME_LEN];
 164         int     (*governor)     (struct cpufreq_policy *policy,
 165                                  unsigned int event);
 166         struct list_head        governor_list;
 167         struct module           *owner;
 168 };
 169
 170 /* pass a target to the cpufreq driver
 171  */
 172 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 173                                  unsigned int target_freq,
 174                                  unsigned int relation);
 175 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 176                                    unsigned int target_freq,
 177                                    unsigned int relation);
 178
 179
 180 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
 181
 182 int cpufreq_register_governor(struct cpufreq_governor *governor);
 183 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 184
 185 int lock_policy_rwsem_read(int cpu);
 186 int lock_policy_rwsem_write(int cpu);
 187 void unlock_policy_rwsem_read(int cpu);
 188 void unlock_policy_rwsem_write(int cpu);
 189
 190
 191 /*********************************************************************
 192  *                      CPUFREQ DRIVER INTERFACE                     *
 193  *********************************************************************/
 194
 195 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 196 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 197
 198 struct freq_attr;
 199
 200 struct cpufreq_driver {
 201         struct module           *owner;
 202         char                    name[CPUFREQ_NAME_LEN];
 203         u8                      flags;
 204
 205         /* needed by all drivers */
 206         int     (*init)         (struct cpufreq_policy *policy);
 207         int     (*verify)       (struct cpufreq_policy *policy);
 208
 209         /* define one out of two */
 210         int     (*setpolicy)    (struct cpufreq_policy *policy);
 211         int     (*target)       (struct cpufreq_policy *policy,
 212                                  unsigned int target_freq,
 213                                  unsigned int relation);
 214
 215         /* should be defined, if possible */
 216         unsigned int    (*get)  (unsigned int cpu);
 217
 218         /* optional */
 219         unsigned int (*getavg)  (unsigned int cpu);
 220         int     (*exit)         (struct cpufreq_policy *policy);
 221         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 222         int     (*resume)       (struct cpufreq_policy *policy);
 223         struct freq_attr        **attr;
 224 };
 225
 226 /* flags */
 227
 228 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 229                                          * all ->init() calls failed */
 230 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 231                                          * "constants" aren't affected by
 232                                          * frequency transitions */
 233 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 234                                          * mismatches */
 235
 236 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 237 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 238
 239
 240 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 241
 242
 243 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 244 {
 245         if (policy->min < min)
 246                 policy->min = min;
 247         if (policy->max < min)
 248                 policy->max = min;
 249         if (policy->min > max)
 250                 policy->min = max;
 251         if (policy->max > max)
 252                 policy->max = max;
 253         if (policy->min > policy->max)
 254                 policy->min = policy->max;
 255         return;
 256 }
 257
 258 struct freq_attr {
 259         struct attribute attr;
 260         ssize_t (*show)(struct cpufreq_policy *, char *);
 261         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 262 };
 263
 264
 265 /*********************************************************************
 266  *                        CPUFREQ 2.6. INTERFACE                     *
 267  *********************************************************************/
 268 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 269 int cpufreq_update_policy(unsigned int cpu);
 270
 271
 272 /*
 273  * query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it
 274  */
 275 #ifdef CONFIG_CPU_FREQ
 276 unsigned int cpufreq_quick_get(unsigned int cpu);
 277 unsigned int cpufreq_get(unsigned int cpu);
 278 #else
 279 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 280 {
 281         return 0;
 282 }
 283 static inline unsigned int cpufreq_get(unsigned int cpu)
 284 {
 285         return 0;
 286 }
 287 #endif
 288
 289
 290 /*********************************************************************
 291  *                       CPUFREQ DEFAULT GOVERNOR                    *
 292  *********************************************************************/
 293
 294
 295 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 296 extern struct cpufreq_governor cpufreq_gov_performance;
 297 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_performance
 298 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 299 extern struct cpufreq_governor cpufreq_gov_userspace;
 300 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_userspace
 301 #endif
 302
 303
 304 /*********************************************************************
 305  *                     FREQUENCY TABLE HELPERS                       *
 306  *********************************************************************/
 307
 308 #define CPUFREQ_ENTRY_INVALID ~0
 309 #define CPUFREQ_TABLE_END     ~1
 310
 311 struct cpufreq_frequency_table {
 312         unsigned int    index;     /* any */
 313         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 314                                     * order */
 315 };
 316
 317 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 318                                     struct cpufreq_frequency_table *table);
 319
 320 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 321                                    struct cpufreq_frequency_table *table);
 322
 323 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 324                                    struct cpufreq_frequency_table *table,
 325                                    unsigned int target_freq,
 326                                    unsigned int relation,
 327                                    unsigned int *index);
 328
 329 /* the following 3 funtions are for cpufreq core use only */
 330 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 331 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 332 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 333
 334 /* the following are really really optional */
 335 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 336
 337 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 338                                       unsigned int cpu);
 339
 340 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 341
 342
 343 /*********************************************************************
 344  *                     UNIFIED DEBUG HELPERS                         *
 345  *********************************************************************/
 346
 347 #define CPUFREQ_DEBUG_CORE      1
 348 #define CPUFREQ_DEBUG_DRIVER    2
 349 #define CPUFREQ_DEBUG_GOVERNOR  4
 350
 351 #ifdef CONFIG_CPU_FREQ_DEBUG
 352
 353 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 354                                  const char *fmt, ...);
 355
 356 #else
 357
 358 #define cpufreq_debug_printk(msg...) do { } while(0)
 359
 360 #endif /* CONFIG_CPU_FREQ_DEBUG */
 361
 362 #endif /* _LINUX_CPUFREQ_H */