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#define CPUFREQ_ETERNAL                 (-1)
  69struct cpufreq_cpuinfo {
  70        unsigned int            max_freq;
  71        unsigned int            min_freq;
  72        unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  73};
  74
  75struct 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
  82struct 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
 123struct 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 */
 140static 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
 165struct 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 */
 182extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 183                                 unsigned int target_freq,
 184                                 unsigned int relation);
 185extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 186                                   unsigned int target_freq,
 187                                   unsigned int relation);
 188
 189
 190extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 191                                   unsigned int cpu);
 192
 193int cpufreq_register_governor(struct cpufreq_governor *governor);
 194void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 195
 196int lock_policy_rwsem_read(int cpu);
 197int lock_policy_rwsem_write(int cpu);
 198void unlock_policy_rwsem_read(int cpu);
 199void 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
 209struct freq_attr;
 210
 211struct 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
 249int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 250int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 251
 252
 253void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 254
 255
 256static 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
 271struct 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 *********************************************************************/
 281int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 282int cpufreq_update_policy(unsigned int cpu);
 283
 284/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 285unsigned 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
 289unsigned int cpufreq_quick_get(unsigned int cpu);
 290#else
 291static 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
 308extern 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)
 313extern struct cpufreq_governor cpufreq_gov_powersave;
 314#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 315#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 316extern struct cpufreq_governor cpufreq_gov_userspace;
 317#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 318#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 319extern struct cpufreq_governor cpufreq_gov_ondemand;
 320#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 321#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 322extern 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
 334struct cpufreq_frequency_table {
 335        unsigned int    index;     /* any */
 336        unsigned int    frequency; /* kHz - doesn't need to be in ascending
 337                                    * order */
 338};
 339
 340int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 341                                    struct cpufreq_frequency_table *table);
 342
 343int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 344                                   struct cpufreq_frequency_table *table);
 345
 346int 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 */
 353struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 354struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 355void   cpufreq_cpu_put (struct cpufreq_policy *data);
 356
 357/* the following are really really optional */
 358extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 359
 360void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 
 361                                      unsigned int cpu);
 362
 363void 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
 376extern 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 */
 386