LXR linux/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
  36int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  37int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  38#else           /* CONFIG_CPU_FREQ */
  39static inline int cpufreq_register_notifier(struct notifier_block *nb,
  40                                                unsigned int list)
  41{
  42        return 0;
  43}
  44static 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
  66struct cpufreq_governor;
  67
  68/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
  69extern struct kobject *cpufreq_global_kobject;
  70
  71#define CPUFREQ_ETERNAL                 (-1)
  72struct cpufreq_cpuinfo {
  73        unsigned int            max_freq;
  74        unsigned int            min_freq;
  75        unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  76};
  77
  78struct 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
  85struct cpufreq_policy {
  86        cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  87        cpumask_var_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#define CPUFREQ_START           (3)
 113
 114#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 115#define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 116#define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 117#define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 118
 119/******************** cpufreq transition notifiers *******************/
 120
 121#define CPUFREQ_PRECHANGE       (0)
 122#define CPUFREQ_POSTCHANGE      (1)
 123#define CPUFREQ_RESUMECHANGE    (8)
 124#define CPUFREQ_SUSPENDCHANGE   (9)
 125
 126struct cpufreq_freqs {
 127        unsigned int cpu;       /* cpu nr */
 128        unsigned int old;
 129        unsigned int new;
 130        u8 flags;               /* flags of cpufreq_driver, see below. */
 131};
 132
 133
 134/**
 135 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 136 * @old:   old value
 137 * @div:   divisor
 138 * @mult:  multiplier
 139 *
 140 *
 141 *    new = old * mult / div
 142 */
 143static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 144{
 145#if BITS_PER_LONG == 32
 146
 147        u64 result = ((u64) old) * ((u64) mult);
 148        do_div(result, div);
 149        return (unsigned long) result;
 150
 151#elif BITS_PER_LONG == 64
 152
 153        unsigned long result = old * ((u64) mult);
 154        result /= div;
 155        return result;
 156
 157#endif
 158};
 159
 160/*********************************************************************
 161 *                          CPUFREQ GOVERNORS                        *
 162 *********************************************************************/
 163
 164#define CPUFREQ_GOV_START  1
 165#define CPUFREQ_GOV_STOP   2
 166#define CPUFREQ_GOV_LIMITS 3
 167
 168struct cpufreq_governor {
 169        char    name[CPUFREQ_NAME_LEN];
 170        int     (*governor)     (struct cpufreq_policy *policy,
 171                                 unsigned int event);
 172        ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 173                                         char *buf);
 174        int     (*store_setspeed)       (struct cpufreq_policy *policy,
 175                                         unsigned int freq);
 176        unsigned int max_transition_latency; /* HW must be able to switch to
 177                        next freq faster than this value in nano secs or we
 178                        will fallback to performance governor */
 179        struct list_head        governor_list;
 180        struct module           *owner;
 181};
 182
 183/* pass a target to the cpufreq driver 
 184 */
 185extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 186                                 unsigned int target_freq,
 187                                 unsigned int relation);
 188extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 189                                   unsigned int target_freq,
 190                                   unsigned int relation);
 191
 192
 193extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 194                                   unsigned int cpu);
 195
 196int cpufreq_register_governor(struct cpufreq_governor *governor);
 197void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 198
 199int lock_policy_rwsem_read(int cpu);
 200int lock_policy_rwsem_write(int cpu);
 201void unlock_policy_rwsem_read(int cpu);
 202void unlock_policy_rwsem_write(int cpu);
 203
 204
 205/*********************************************************************
 206 *                      CPUFREQ DRIVER INTERFACE                     *
 207 *********************************************************************/
 208
 209#define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 210#define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 211
 212struct freq_attr;
 213
 214struct cpufreq_driver {
 215        struct module           *owner;
 216        char                    name[CPUFREQ_NAME_LEN];
 217        u8                      flags;
 218
 219        /* needed by all drivers */
 220        int     (*init)         (struct cpufreq_policy *policy);
 221        int     (*verify)       (struct cpufreq_policy *policy);
 222
 223        /* define one out of two */
 224        int     (*setpolicy)    (struct cpufreq_policy *policy);
 225        int     (*target)       (struct cpufreq_policy *policy,
 226                                 unsigned int target_freq,
 227                                 unsigned int relation);
 228
 229        /* should be defined, if possible */
 230        unsigned int    (*get)  (unsigned int cpu);
 231
 232        /* optional */
 233        unsigned int (*getavg)  (struct cpufreq_policy *policy,
 234                                 unsigned int cpu);
 235
 236        int     (*exit)         (struct cpufreq_policy *policy);
 237        int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 238        int     (*resume)       (struct cpufreq_policy *policy);
 239        struct freq_attr        **attr;
 240};
 241
 242/* flags */
 243
 244#define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if 
 245                                         * all ->init() calls failed */
 246#define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 247                                         * "constants" aren't affected by
 248                                         * frequency transitions */
 249#define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 250                                         * mismatches */
 251
 252int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 253int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 254
 255
 256void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 257
 258
 259static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 
 260{
 261        if (policy->min < min)
 262                policy->min = min;
 263        if (policy->max < min)
 264                policy->max = min;
 265        if (policy->min > max)
 266                policy->min = max;
 267        if (policy->max > max)
 268                policy->max = max;
 269        if (policy->min > policy->max)
 270                policy->min = policy->max;
 271        return;
 272}
 273
 274struct freq_attr {
 275        struct attribute attr;
 276        ssize_t (*show)(struct cpufreq_policy *, char *);
 277        ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 278};
 279
 280struct global_attr {
 281        struct attribute attr;
 282        ssize_t (*show)(struct kobject *kobj,
 283                        struct attribute *attr, char *buf);
 284        ssize_t (*store)(struct kobject *a, struct attribute *b,
 285                         const char *c, size_t count);
 286};
 287
 288/*********************************************************************
 289 *                        CPUFREQ 2.6. INTERFACE                     *
 290 *********************************************************************/
 291int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 292int cpufreq_update_policy(unsigned int cpu);
 293
 294#ifdef CONFIG_CPU_FREQ
 295/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 296unsigned int cpufreq_get(unsigned int cpu);
 297#else
 298static inline unsigned int cpufreq_get(unsigned int cpu)
 299{
 300        return 0;
 301}
 302#endif
 303
 304/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 305#ifdef CONFIG_CPU_FREQ
 306unsigned int cpufreq_quick_get(unsigned int cpu);
 307#else
 308static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 309{
 310        return 0;
 311}
 312#endif
 313
 314
 315/*********************************************************************
 316 *                       CPUFREQ DEFAULT GOVERNOR                    *
 317 *********************************************************************/
 318
 319
 320/*
 321  Performance governor is fallback governor if any other gov failed to
 322  auto load due latency restrictions
 323*/
 324#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 325extern struct cpufreq_governor cpufreq_gov_performance;
 326#endif
 327#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 328#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 329#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 330extern struct cpufreq_governor cpufreq_gov_powersave;
 331#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 332#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 333extern struct cpufreq_governor cpufreq_gov_userspace;
 334#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 335#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 336extern struct cpufreq_governor cpufreq_gov_ondemand;
 337#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 338#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 339extern struct cpufreq_governor cpufreq_gov_conservative;
 340#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 341#endif
 342
 343
 344/*********************************************************************
 345 *                     FREQUENCY TABLE HELPERS                       *
 346 *********************************************************************/
 347
 348#define CPUFREQ_ENTRY_INVALID ~0
 349#define CPUFREQ_TABLE_END     ~1
 350
 351struct cpufreq_frequency_table {
 352        unsigned int    index;     /* any */
 353        unsigned int    frequency; /* kHz - doesn't need to be in ascending
 354                                    * order */
 355};
 356
 357int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 358                                    struct cpufreq_frequency_table *table);
 359
 360int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 361                                   struct cpufreq_frequency_table *table);
 362
 363int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 364                                   struct cpufreq_frequency_table *table,
 365                                   unsigned int target_freq,
 366                                   unsigned int relation,
 367                                   unsigned int *index);
 368
 369/* the following 3 funtions are for cpufreq core use only */
 370struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 371struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 372void   cpufreq_cpu_put (struct cpufreq_policy *data);
 373
 374/* the following are really really optional */
 375extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 376
 377void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 
 378                                      unsigned int cpu);
 379
 380void cpufreq_frequency_table_put_attr(unsigned int cpu);
 381
 382
 383/*********************************************************************
 384 *                     UNIFIED DEBUG HELPERS                         *
 385 *********************************************************************/
 386
 387#define CPUFREQ_DEBUG_CORE      1
 388#define CPUFREQ_DEBUG_DRIVER    2
 389#define CPUFREQ_DEBUG_GOVERNOR  4
 390
 391#ifdef CONFIG_CPU_FREQ_DEBUG
 392
 393extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 
 394                                 const char *fmt, ...);
 395
 396#else
 397
 398#define cpufreq_debug_printk(msg...) do { } while(0)
 399
 400#endif /* CONFIG_CPU_FREQ_DEBUG */
 401
 402#endif /* _LINUX_CPUFREQ_H */
 403