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/clk.h>
  15#include <linux/cpumask.h>
  16#include <linux/completion.h>
  17#include <linux/kobject.h>
  18#include <linux/notifier.h>
  19#include <linux/spinlock.h>
  20#include <linux/sysfs.h>
  21
  22/*********************************************************************
  23 *                        CPUFREQ INTERFACE                          *
  24 *********************************************************************/
  25/*
  26 * Frequency values here are CPU kHz
  27 *
  28 * Maximum transition latency is in nanoseconds - if it's unknown,
  29 * CPUFREQ_ETERNAL shall be used.
  30 */
  31
  32#define CPUFREQ_ETERNAL                 (-1)
  33#define CPUFREQ_NAME_LEN                16
  34/* Print length for names. Extra 1 space for accomodating '\n' in prints */
  35#define CPUFREQ_NAME_PLEN               (CPUFREQ_NAME_LEN + 1)
  36
  37struct cpufreq_governor;
  38
  39struct cpufreq_freqs {
  40        unsigned int cpu;       /* cpu nr */
  41        unsigned int old;
  42        unsigned int new;
  43        u8 flags;               /* flags of cpufreq_driver, see below. */
  44};
  45
  46struct cpufreq_cpuinfo {
  47        unsigned int            max_freq;
  48        unsigned int            min_freq;
  49
  50        /* in 10^(-9) s = nanoseconds */
  51        unsigned int            transition_latency;
  52};
  53
  54struct cpufreq_real_policy {
  55        unsigned int            min;    /* in kHz */
  56        unsigned int            max;    /* in kHz */
  57        unsigned int            policy; /* see above */
  58        struct cpufreq_governor *governor; /* see below */
  59};
  60
  61struct cpufreq_policy {
  62        /* CPUs sharing clock, require sw coordination */
  63        cpumask_var_t           cpus;   /* Online CPUs only */
  64        cpumask_var_t           related_cpus; /* Online + Offline CPUs */
  65        cpumask_var_t           real_cpus; /* Related and present */
  66
  67        unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
  68                                                should set cpufreq */
  69        unsigned int            cpu;    /* cpu managing this policy, must be online */
  70        unsigned int            kobj_cpu; /* cpu managing sysfs files, can be offline */
  71
  72        struct clk              *clk;
  73        struct cpufreq_cpuinfo  cpuinfo;/* see above */
  74
  75        unsigned int            min;    /* in kHz */
  76        unsigned int            max;    /* in kHz */
  77        unsigned int            cur;    /* in kHz, only needed if cpufreq
  78                                         * governors are used */
  79        unsigned int            restore_freq; /* = policy->cur before transition */
  80        unsigned int            suspend_freq; /* freq to set during suspend */
  81
  82        unsigned int            policy; /* see above */
  83        struct cpufreq_governor *governor; /* see below */
  84        void                    *governor_data;
  85        bool                    governor_enabled; /* governor start/stop flag */
  86        char                    last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
  87
  88        struct work_struct      update; /* if update_policy() needs to be
  89                                         * called, but you're in IRQ context */
  90
  91        struct cpufreq_real_policy      user_policy;
  92        struct cpufreq_frequency_table  *freq_table;
  93
  94        struct list_head        policy_list;
  95        struct kobject          kobj;
  96        struct completion       kobj_unregister;
  97
  98        /*
  99         * The rules for this semaphore:
 100         * - Any routine that wants to read from the policy structure will
 101         *   do a down_read on this semaphore.
 102         * - Any routine that will write to the policy structure and/or may take away
 103         *   the policy altogether (eg. CPU hotplug), will hold this lock in write
 104         *   mode before doing so.
 105         *
 106         * Additional rules:
 107         * - Lock should not be held across
 108         *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
 109         */
 110        struct rw_semaphore     rwsem;
 111
 112        /* Synchronization for frequency transitions */
 113        bool                    transition_ongoing; /* Tracks transition status */
 114        spinlock_t              transition_lock;
 115        wait_queue_head_t       transition_wait;
 116        struct task_struct      *transition_task; /* Task which is doing the transition */
 117
 118        /* cpufreq-stats */
 119        struct cpufreq_stats    *stats;
 120
 121        /* For cpufreq driver's internal use */
 122        void                    *driver_data;
 123};
 124
 125/* Only for ACPI */
 126#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 127#define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 128#define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 129#define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 130
 131#ifdef CONFIG_CPU_FREQ
 132struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 133void cpufreq_cpu_put(struct cpufreq_policy *policy);
 134#else
 135static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 136{
 137        return NULL;
 138}
 139static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 140#endif
 141
 142static inline bool policy_is_shared(struct cpufreq_policy *policy)
 143{
 144        return cpumask_weight(policy->cpus) > 1;
 145}
 146
 147/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 148extern struct kobject *cpufreq_global_kobject;
 149int cpufreq_get_global_kobject(void);
 150void cpufreq_put_global_kobject(void);
 151int cpufreq_sysfs_create_file(const struct attribute *attr);
 152void cpufreq_sysfs_remove_file(const struct attribute *attr);
 153
 154#ifdef CONFIG_CPU_FREQ
 155unsigned int cpufreq_get(unsigned int cpu);
 156unsigned int cpufreq_quick_get(unsigned int cpu);
 157unsigned int cpufreq_quick_get_max(unsigned int cpu);
 158void disable_cpufreq(void);
 159
 160u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 161int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 162int cpufreq_update_policy(unsigned int cpu);
 163bool have_governor_per_policy(void);
 164struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 165#else
 166static inline unsigned int cpufreq_get(unsigned int cpu)
 167{
 168        return 0;
 169}
 170static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 171{
 172        return 0;
 173}
 174static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 175{
 176        return 0;
 177}
 178static inline void disable_cpufreq(void) { }
 179#endif
 180
 181/*********************************************************************
 182 *                      CPUFREQ DRIVER INTERFACE                     *
 183 *********************************************************************/
 184
 185#define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 186#define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 187#define CPUFREQ_RELATION_C 2  /* closest frequency to target */
 188
 189struct freq_attr {
 190        struct attribute attr;
 191        ssize_t (*show)(struct cpufreq_policy *, char *);
 192        ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 193};
 194
 195#define cpufreq_freq_attr_ro(_name)             \
 196static struct freq_attr _name =                 \
 197__ATTR(_name, 0444, show_##_name, NULL)
 198
 199#define cpufreq_freq_attr_ro_perm(_name, _perm) \
 200static struct freq_attr _name =                 \
 201__ATTR(_name, _perm, show_##_name, NULL)
 202
 203#define cpufreq_freq_attr_rw(_name)             \
 204static struct freq_attr _name =                 \
 205__ATTR(_name, 0644, show_##_name, store_##_name)
 206
 207struct global_attr {
 208        struct attribute attr;
 209        ssize_t (*show)(struct kobject *kobj,
 210                        struct attribute *attr, char *buf);
 211        ssize_t (*store)(struct kobject *a, struct attribute *b,
 212                         const char *c, size_t count);
 213};
 214
 215#define define_one_global_ro(_name)             \
 216static struct global_attr _name =               \
 217__ATTR(_name, 0444, show_##_name, NULL)
 218
 219#define define_one_global_rw(_name)             \
 220static struct global_attr _name =               \
 221__ATTR(_name, 0644, show_##_name, store_##_name)
 222
 223
 224struct cpufreq_driver {
 225        char            name[CPUFREQ_NAME_LEN];
 226        u8              flags;
 227        void            *driver_data;
 228
 229        /* needed by all drivers */
 230        int             (*init)(struct cpufreq_policy *policy);
 231        int             (*verify)(struct cpufreq_policy *policy);
 232
 233        /* define one out of two */
 234        int             (*setpolicy)(struct cpufreq_policy *policy);
 235
 236        /*
 237         * On failure, should always restore frequency to policy->restore_freq
 238         * (i.e. old freq).
 239         */
 240        int             (*target)(struct cpufreq_policy *policy,
 241                                  unsigned int target_freq,
 242                                  unsigned int relation);       /* Deprecated */
 243        int             (*target_index)(struct cpufreq_policy *policy,
 244                                        unsigned int index);
 245        /*
 246         * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
 247         * unset.
 248         *
 249         * get_intermediate should return a stable intermediate frequency
 250         * platform wants to switch to and target_intermediate() should set CPU
 251         * to to that frequency, before jumping to the frequency corresponding
 252         * to 'index'. Core will take care of sending notifications and driver
 253         * doesn't have to handle them in target_intermediate() or
 254         * target_index().
 255         *
 256         * Drivers can return '0' from get_intermediate() in case they don't
 257         * wish to switch to intermediate frequency for some target frequency.
 258         * In that case core will directly call ->target_index().
 259         */
 260        unsigned int    (*get_intermediate)(struct cpufreq_policy *policy,
 261                                            unsigned int index);
 262        int             (*target_intermediate)(struct cpufreq_policy *policy,
 263                                               unsigned int index);
 264
 265        /* should be defined, if possible */
 266        unsigned int    (*get)(unsigned int cpu);
 267
 268        /* optional */
 269        int             (*bios_limit)(int cpu, unsigned int *limit);
 270
 271        int             (*exit)(struct cpufreq_policy *policy);
 272        void            (*stop_cpu)(struct cpufreq_policy *policy);
 273        int             (*suspend)(struct cpufreq_policy *policy);
 274        int             (*resume)(struct cpufreq_policy *policy);
 275
 276        /* Will be called after the driver is fully initialized */
 277        void            (*ready)(struct cpufreq_policy *policy);
 278
 279        struct freq_attr **attr;
 280
 281        /* platform specific boost support code */
 282        bool            boost_supported;
 283        bool            boost_enabled;
 284        int             (*set_boost)(int state);
 285};
 286
 287/* flags */
 288#define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 289                                                   all ->init() calls failed */
 290#define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 291                                                   kernel "constants" aren't
 292                                                   affected by frequency
 293                                                   transitions */
 294#define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 295                                                   speed mismatches */
 296
 297/*
 298 * This should be set by platforms having multiple clock-domains, i.e.
 299 * supporting multiple policies. With this sysfs directories of governor would
 300 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 301 * governor with different tunables for different clusters.
 302 */
 303#define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 304
 305/*
 306 * Driver will do POSTCHANGE notifications from outside of their ->target()
 307 * routine and so must set cpufreq_driver->flags with this flag, so that core
 308 * can handle them specially.
 309 */
 310#define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 311
 312/*
 313 * Set by drivers which want cpufreq core to check if CPU is running at a
 314 * frequency present in freq-table exposed by the driver. For these drivers if
 315 * CPU is found running at an out of table freq, we will try to set it to a freq
 316 * from the table. And if that fails, we will stop further boot process by
 317 * issuing a BUG_ON().
 318 */
 319#define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 320
 321int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 322int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 323
 324const char *cpufreq_get_current_driver(void);
 325void *cpufreq_get_driver_data(void);
 326
 327static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 328                unsigned int min, unsigned int max)
 329{
 330        if (policy->min < min)
 331                policy->min = min;
 332        if (policy->max < min)
 333                policy->max = min;
 334        if (policy->min > max)
 335                policy->min = max;
 336        if (policy->max > max)
 337                policy->max = max;
 338        if (policy->min > policy->max)
 339                policy->min = policy->max;
 340        return;
 341}
 342
 343static inline void
 344cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 345{
 346        cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 347                        policy->cpuinfo.max_freq);
 348}
 349
 350#ifdef CONFIG_CPU_FREQ
 351void cpufreq_suspend(void);
 352void cpufreq_resume(void);
 353int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 354#else
 355static inline void cpufreq_suspend(void) {}
 356static inline void cpufreq_resume(void) {}
 357#endif
 358
 359/*********************************************************************
 360 *                     CPUFREQ NOTIFIER INTERFACE                    *
 361 *********************************************************************/
 362
 363#define CPUFREQ_TRANSITION_NOTIFIER     (0)
 364#define CPUFREQ_POLICY_NOTIFIER         (1)
 365
 366/* Transition notifiers */
 367#define CPUFREQ_PRECHANGE               (0)
 368#define CPUFREQ_POSTCHANGE              (1)
 369
 370/* Policy Notifiers  */
 371#define CPUFREQ_ADJUST                  (0)
 372#define CPUFREQ_INCOMPATIBLE            (1)
 373#define CPUFREQ_NOTIFY                  (2)
 374#define CPUFREQ_START                   (3)
 375#define CPUFREQ_CREATE_POLICY           (4)
 376#define CPUFREQ_REMOVE_POLICY           (5)
 377
 378#ifdef CONFIG_CPU_FREQ
 379int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 380int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 381
 382void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 383                struct cpufreq_freqs *freqs);
 384void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 385                struct cpufreq_freqs *freqs, int transition_failed);
 386
 387#else /* CONFIG_CPU_FREQ */
 388static inline int cpufreq_register_notifier(struct notifier_block *nb,
 389                                                unsigned int list)
 390{
 391        return 0;
 392}
 393static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 394                                                unsigned int list)
 395{
 396        return 0;
 397}
 398#endif /* !CONFIG_CPU_FREQ */
 399
 400/**
 401 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 402 * safe)
 403 * @old:   old value
 404 * @div:   divisor
 405 * @mult:  multiplier
 406 *
 407 *
 408 * new = old * mult / div
 409 */
 410static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 411                u_int mult)
 412{
 413#if BITS_PER_LONG == 32
 414        u64 result = ((u64) old) * ((u64) mult);
 415        do_div(result, div);
 416        return (unsigned long) result;
 417
 418#elif BITS_PER_LONG == 64
 419        unsigned long result = old * ((u64) mult);
 420        result /= div;
 421        return result;
 422#endif
 423}
 424
 425/*********************************************************************
 426 *                          CPUFREQ GOVERNORS                        *
 427 *********************************************************************/
 428
 429/*
 430 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 431 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 432 * two generic policies are available:
 433 */
 434#define CPUFREQ_POLICY_POWERSAVE        (1)
 435#define CPUFREQ_POLICY_PERFORMANCE      (2)
 436
 437/* Governor Events */
 438#define CPUFREQ_GOV_START       1
 439#define CPUFREQ_GOV_STOP        2
 440#define CPUFREQ_GOV_LIMITS      3
 441#define CPUFREQ_GOV_POLICY_INIT 4
 442#define CPUFREQ_GOV_POLICY_EXIT 5
 443
 444struct cpufreq_governor {
 445        char    name[CPUFREQ_NAME_LEN];
 446        int     initialized;
 447        int     (*governor)     (struct cpufreq_policy *policy,
 448                                 unsigned int event);
 449        ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 450                                         char *buf);
 451        int     (*store_setspeed)       (struct cpufreq_policy *policy,
 452                                         unsigned int freq);
 453        unsigned int max_transition_latency; /* HW must be able to switch to
 454                        next freq faster than this value in nano secs or we
 455                        will fallback to performance governor */
 456        struct list_head        governor_list;
 457        struct module           *owner;
 458};
 459
 460/* Pass a target to the cpufreq driver */
 461int cpufreq_driver_target(struct cpufreq_policy *policy,
 462                                 unsigned int target_freq,
 463                                 unsigned int relation);
 464int __cpufreq_driver_target(struct cpufreq_policy *policy,
 465                                   unsigned int target_freq,
 466                                   unsigned int relation);
 467int cpufreq_register_governor(struct cpufreq_governor *governor);
 468void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 469
 470/* CPUFREQ DEFAULT GOVERNOR */
 471/*
 472 * Performance governor is fallback governor if any other gov failed to auto
 473 * load due latency restrictions
 474 */
 475#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 476extern struct cpufreq_governor cpufreq_gov_performance;
 477#endif
 478#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 479#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 480#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 481extern struct cpufreq_governor cpufreq_gov_powersave;
 482#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 483#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 484extern struct cpufreq_governor cpufreq_gov_userspace;
 485#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 486#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 487extern struct cpufreq_governor cpufreq_gov_ondemand;
 488#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 489#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 490extern struct cpufreq_governor cpufreq_gov_conservative;
 491#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 492#endif
 493
 494/*********************************************************************
 495 *                     FREQUENCY TABLE HELPERS                       *
 496 *********************************************************************/
 497
 498/* Special Values of .frequency field */
 499#define CPUFREQ_ENTRY_INVALID   ~0u
 500#define CPUFREQ_TABLE_END       ~1u
 501/* Special Values of .flags field */
 502#define CPUFREQ_BOOST_FREQ      (1 << 0)
 503
 504struct cpufreq_frequency_table {
 505        unsigned int    flags;
 506        unsigned int    driver_data; /* driver specific data, not used by core */
 507        unsigned int    frequency; /* kHz - doesn't need to be in ascending
 508                                    * order */
 509};
 510
 511#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
 512int dev_pm_opp_init_cpufreq_table(struct device *dev,
 513                                  struct cpufreq_frequency_table **table);
 514void dev_pm_opp_free_cpufreq_table(struct device *dev,
 515                                   struct cpufreq_frequency_table **table);
 516#else
 517static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
 518                                                struct cpufreq_frequency_table
 519                                                **table)
 520{
 521        return -EINVAL;
 522}
 523
 524static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 525                                                 struct cpufreq_frequency_table
 526                                                 **table)
 527{
 528}
 529#endif
 530
 531static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
 532{
 533        while ((*pos)->frequency != CPUFREQ_TABLE_END)
 534                if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
 535                        return true;
 536                else
 537                        (*pos)++;
 538        return false;
 539}
 540
 541/*
 542 * cpufreq_for_each_entry -     iterate over a cpufreq_frequency_table
 543 * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 544 * @table:      the cpufreq_frequency_table * to iterate over.
 545 */
 546
 547#define cpufreq_for_each_entry(pos, table)      \
 548        for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
 549
 550/*
 551 * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
 552 *      excluding CPUFREQ_ENTRY_INVALID frequencies.
 553 * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 554 * @table:      the cpufreq_frequency_table * to iterate over.
 555 */
 556
 557#define cpufreq_for_each_valid_entry(pos, table)        \
 558        for (pos = table; cpufreq_next_valid(&pos); pos++)
 559
 560int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 561                                    struct cpufreq_frequency_table *table);
 562
 563int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 564                                   struct cpufreq_frequency_table *table);
 565int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 566
 567int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 568                                   struct cpufreq_frequency_table *table,
 569                                   unsigned int target_freq,
 570                                   unsigned int relation,
 571                                   unsigned int *index);
 572int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 573                unsigned int freq);
 574
 575ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 576
 577#ifdef CONFIG_CPU_FREQ
 578int cpufreq_boost_trigger_state(int state);
 579int cpufreq_boost_supported(void);
 580int cpufreq_boost_enabled(void);
 581#else
 582static inline int cpufreq_boost_trigger_state(int state)
 583{
 584        return 0;
 585}
 586static inline int cpufreq_boost_supported(void)
 587{
 588        return 0;
 589}
 590static inline int cpufreq_boost_enabled(void)
 591{
 592        return 0;
 593}
 594#endif
 595/* the following funtion is for cpufreq core use only */
 596struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 597
 598/* the following are really really optional */
 599extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 600extern struct freq_attr *cpufreq_generic_attr[];
 601int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 602                                      struct cpufreq_frequency_table *table);
 603
 604unsigned int cpufreq_generic_get(unsigned int cpu);
 605int cpufreq_generic_init(struct cpufreq_policy *policy,
 606                struct cpufreq_frequency_table *table,
 607                unsigned int transition_latency);
 608#endif /* _LINUX_CPUFREQ_H */
 609