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
  37 struct cpufreq_governor;
  38
  39 struct 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
  46 struct 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
  54 struct 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
  61 struct 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
  66         unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
  67                                                 should set cpufreq */
  68         unsigned int            cpu;    /* cpu nr of CPU managing this policy */
  69         unsigned int            last_cpu; /* cpu nr of previous CPU that managed
  70                                            * this policy */
  71         struct clk              *clk;
  72         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  73
  74         unsigned int            min;    /* in kHz */
  75         unsigned int            max;    /* in kHz */
  76         unsigned int            cur;    /* in kHz, only needed if cpufreq
  77                                          * governors are used */
  78         unsigned int            restore_freq; /* = policy->cur before transition */
  79         unsigned int            suspend_freq; /* freq to set during suspend */
  80
  81         unsigned int            policy; /* see above */
  82         struct cpufreq_governor *governor; /* see below */
  83         void                    *governor_data;
  84         bool                    governor_enabled; /* governor start/stop flag */
  85
  86         struct work_struct      update; /* if update_policy() needs to be
  87                                          * called, but you're in IRQ context */
  88
  89         struct cpufreq_real_policy      user_policy;
  90         struct cpufreq_frequency_table  *freq_table;
  91
  92         struct list_head        policy_list;
  93         struct kobject          kobj;
  94         struct completion       kobj_unregister;
  95
  96         /*
  97          * The rules for this semaphore:
  98          * - Any routine that wants to read from the policy structure will
  99          *   do a down_read on this semaphore.
 100          * - Any routine that will write to the policy structure and/or may take away
 101          *   the policy altogether (eg. CPU hotplug), will hold this lock in write
 102          *   mode before doing so.
 103          *
 104          * Additional rules:
 105          * - Lock should not be held across
 106          *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
 107          */
 108         struct rw_semaphore     rwsem;
 109
 110         /* Synchronization for frequency transitions */
 111         bool                    transition_ongoing; /* Tracks transition status */
 112         spinlock_t              transition_lock;
 113         wait_queue_head_t       transition_wait;
 114         struct task_struct      *transition_task; /* Task which is doing the transition */
 115 };
 116
 117 /* Only for ACPI */
 118 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 119 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 120 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 121 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 122
 123 #ifdef CONFIG_CPU_FREQ
 124 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 125 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 126 #else
 127 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 128 {
 129         return NULL;
 130 }
 131 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 132 #endif
 133
 134 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 135 {
 136         return cpumask_weight(policy->cpus) > 1;
 137 }
 138
 139 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 140 extern struct kobject *cpufreq_global_kobject;
 141 int cpufreq_get_global_kobject(void);
 142 void cpufreq_put_global_kobject(void);
 143 int cpufreq_sysfs_create_file(const struct attribute *attr);
 144 void cpufreq_sysfs_remove_file(const struct attribute *attr);
 145
 146 #ifdef CONFIG_CPU_FREQ
 147 unsigned int cpufreq_get(unsigned int cpu);
 148 unsigned int cpufreq_quick_get(unsigned int cpu);
 149 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 150 void disable_cpufreq(void);
 151
 152 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 153 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 154 int cpufreq_update_policy(unsigned int cpu);
 155 bool have_governor_per_policy(void);
 156 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 157 #else
 158 static inline unsigned int cpufreq_get(unsigned int cpu)
 159 {
 160         return 0;
 161 }
 162 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 163 {
 164         return 0;
 165 }
 166 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 167 {
 168         return 0;
 169 }
 170 static inline void disable_cpufreq(void) { }
 171 #endif
 172
 173 /*********************************************************************
 174  *                      CPUFREQ DRIVER INTERFACE                     *
 175  *********************************************************************/
 176
 177 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 178 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 179
 180 struct freq_attr {
 181         struct attribute attr;
 182         ssize_t (*show)(struct cpufreq_policy *, char *);
 183         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 184 };
 185
 186 #define cpufreq_freq_attr_ro(_name)             \
 187 static struct freq_attr _name =                 \
 188 __ATTR(_name, 0444, show_##_name, NULL)
 189
 190 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 191 static struct freq_attr _name =                 \
 192 __ATTR(_name, _perm, show_##_name, NULL)
 193
 194 #define cpufreq_freq_attr_rw(_name)             \
 195 static struct freq_attr _name =                 \
 196 __ATTR(_name, 0644, show_##_name, store_##_name)
 197
 198 struct global_attr {
 199         struct attribute attr;
 200         ssize_t (*show)(struct kobject *kobj,
 201                         struct attribute *attr, char *buf);
 202         ssize_t (*store)(struct kobject *a, struct attribute *b,
 203                          const char *c, size_t count);
 204 };
 205
 206 #define define_one_global_ro(_name)             \
 207 static struct global_attr _name =               \
 208 __ATTR(_name, 0444, show_##_name, NULL)
 209
 210 #define define_one_global_rw(_name)             \
 211 static struct global_attr _name =               \
 212 __ATTR(_name, 0644, show_##_name, store_##_name)
 213
 214
 215 struct cpufreq_driver {
 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
 226         /*
 227          * On failure, should always restore frequency to policy->restore_freq
 228          * (i.e. old freq).
 229          */
 230         int     (*target)       (struct cpufreq_policy *policy, /* Deprecated */
 231                                  unsigned int target_freq,
 232                                  unsigned int relation);
 233         int     (*target_index) (struct cpufreq_policy *policy,
 234                                  unsigned int index);
 235         /*
 236          * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
 237          * unset.
 238          *
 239          * get_intermediate should return a stable intermediate frequency
 240          * platform wants to switch to and target_intermediate() should set CPU
 241          * to to that frequency, before jumping to the frequency corresponding
 242          * to 'index'. Core will take care of sending notifications and driver
 243          * doesn't have to handle them in target_intermediate() or
 244          * target_index().
 245          *
 246          * Drivers can return '0' from get_intermediate() in case they don't
 247          * wish to switch to intermediate frequency for some target frequency.
 248          * In that case core will directly call ->target_index().
 249          */
 250         unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
 251                                          unsigned int index);
 252         int     (*target_intermediate)(struct cpufreq_policy *policy,
 253                                        unsigned int index);
 254
 255         /* should be defined, if possible */
 256         unsigned int    (*get)  (unsigned int cpu);
 257
 258         /* optional */
 259         int     (*bios_limit)   (int cpu, unsigned int *limit);
 260
 261         int     (*exit)         (struct cpufreq_policy *policy);
 262         void    (*stop_cpu)     (struct cpufreq_policy *policy);
 263         int     (*suspend)      (struct cpufreq_policy *policy);
 264         int     (*resume)       (struct cpufreq_policy *policy);
 265         struct freq_attr        **attr;
 266
 267         /* platform specific boost support code */
 268         bool                    boost_supported;
 269         bool                    boost_enabled;
 270         int     (*set_boost)    (int state);
 271 };
 272
 273 /* flags */
 274 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 275                                                    all ->init() calls failed */
 276 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 277                                                    kernel "constants" aren't
 278                                                    affected by frequency
 279                                                    transitions */
 280 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 281                                                    speed mismatches */
 282
 283 /*
 284  * This should be set by platforms having multiple clock-domains, i.e.
 285  * supporting multiple policies. With this sysfs directories of governor would
 286  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 287  * governor with different tunables for different clusters.
 288  */
 289 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 290
 291 /*
 292  * Driver will do POSTCHANGE notifications from outside of their ->target()
 293  * routine and so must set cpufreq_driver->flags with this flag, so that core
 294  * can handle them specially.
 295  */
 296 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 297
 298 /*
 299  * Set by drivers which want cpufreq core to check if CPU is running at a
 300  * frequency present in freq-table exposed by the driver. For these drivers if
 301  * CPU is found running at an out of table freq, we will try to set it to a freq
 302  * from the table. And if that fails, we will stop further boot process by
 303  * issuing a BUG_ON().
 304  */
 305 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 306
 307 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 308 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 309
 310 const char *cpufreq_get_current_driver(void);
 311
 312 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 313                 unsigned int min, unsigned int max)
 314 {
 315         if (policy->min < min)
 316                 policy->min = min;
 317         if (policy->max < min)
 318                 policy->max = min;
 319         if (policy->min > max)
 320                 policy->min = max;
 321         if (policy->max > max)
 322                 policy->max = max;
 323         if (policy->min > policy->max)
 324                 policy->min = policy->max;
 325         return;
 326 }
 327
 328 static inline void
 329 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 330 {
 331         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 332                         policy->cpuinfo.max_freq);
 333 }
 334
 335 #ifdef CONFIG_CPU_FREQ
 336 void cpufreq_suspend(void);
 337 void cpufreq_resume(void);
 338 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 339 #else
 340 static inline void cpufreq_suspend(void) {}
 341 static inline void cpufreq_resume(void) {}
 342 #endif
 343
 344 /*********************************************************************
 345  *                     CPUFREQ NOTIFIER INTERFACE                    *
 346  *********************************************************************/
 347
 348 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 349 #define CPUFREQ_POLICY_NOTIFIER         (1)
 350
 351 /* Transition notifiers */
 352 #define CPUFREQ_PRECHANGE               (0)
 353 #define CPUFREQ_POSTCHANGE              (1)
 354
 355 /* Policy Notifiers  */
 356 #define CPUFREQ_ADJUST                  (0)
 357 #define CPUFREQ_INCOMPATIBLE            (1)
 358 #define CPUFREQ_NOTIFY                  (2)
 359 #define CPUFREQ_START                   (3)
 360 #define CPUFREQ_UPDATE_POLICY_CPU       (4)
 361 #define CPUFREQ_CREATE_POLICY           (5)
 362 #define CPUFREQ_REMOVE_POLICY           (6)
 363
 364 #ifdef CONFIG_CPU_FREQ
 365 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 366 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 367
 368 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 369                 struct cpufreq_freqs *freqs);
 370 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 371                 struct cpufreq_freqs *freqs, int transition_failed);
 372
 373 #else /* CONFIG_CPU_FREQ */
 374 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 375                                                 unsigned int list)
 376 {
 377         return 0;
 378 }
 379 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 380                                                 unsigned int list)
 381 {
 382         return 0;
 383 }
 384 #endif /* !CONFIG_CPU_FREQ */
 385
 386 /**
 387  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 388  * safe)
 389  * @old:   old value
 390  * @div:   divisor
 391  * @mult:  multiplier
 392  *
 393  *
 394  * new = old * mult / div
 395  */
 396 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 397                 u_int mult)
 398 {
 399 #if BITS_PER_LONG == 32
 400         u64 result = ((u64) old) * ((u64) mult);
 401         do_div(result, div);
 402         return (unsigned long) result;
 403
 404 #elif BITS_PER_LONG == 64
 405         unsigned long result = old * ((u64) mult);
 406         result /= div;
 407         return result;
 408 #endif
 409 }
 410
 411 /*********************************************************************
 412  *                          CPUFREQ GOVERNORS                        *
 413  *********************************************************************/
 414
 415 /*
 416  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 417  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 418  * two generic policies are available:
 419  */
 420 #define CPUFREQ_POLICY_POWERSAVE        (1)
 421 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 422
 423 /* Governor Events */
 424 #define CPUFREQ_GOV_START       1
 425 #define CPUFREQ_GOV_STOP        2
 426 #define CPUFREQ_GOV_LIMITS      3
 427 #define CPUFREQ_GOV_POLICY_INIT 4
 428 #define CPUFREQ_GOV_POLICY_EXIT 5
 429
 430 struct cpufreq_governor {
 431         char    name[CPUFREQ_NAME_LEN];
 432         int     initialized;
 433         int     (*governor)     (struct cpufreq_policy *policy,
 434                                  unsigned int event);
 435         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 436                                          char *buf);
 437         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 438                                          unsigned int freq);
 439         unsigned int max_transition_latency; /* HW must be able to switch to
 440                         next freq faster than this value in nano secs or we
 441                         will fallback to performance governor */
 442         struct list_head        governor_list;
 443         struct module           *owner;
 444 };
 445
 446 /* Pass a target to the cpufreq driver */
 447 int cpufreq_driver_target(struct cpufreq_policy *policy,
 448                                  unsigned int target_freq,
 449                                  unsigned int relation);
 450 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 451                                    unsigned int target_freq,
 452                                    unsigned int relation);
 453 int cpufreq_register_governor(struct cpufreq_governor *governor);
 454 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 455
 456 /* CPUFREQ DEFAULT GOVERNOR */
 457 /*
 458  * Performance governor is fallback governor if any other gov failed to auto
 459  * load due latency restrictions
 460  */
 461 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 462 extern struct cpufreq_governor cpufreq_gov_performance;
 463 #endif
 464 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 465 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 466 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 467 extern struct cpufreq_governor cpufreq_gov_powersave;
 468 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 469 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 470 extern struct cpufreq_governor cpufreq_gov_userspace;
 471 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 472 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 473 extern struct cpufreq_governor cpufreq_gov_ondemand;
 474 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 475 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 476 extern struct cpufreq_governor cpufreq_gov_conservative;
 477 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 478 #endif
 479
 480 /*********************************************************************
 481  *                     FREQUENCY TABLE HELPERS                       *
 482  *********************************************************************/
 483
 484 /* Special Values of .frequency field */
 485 #define CPUFREQ_ENTRY_INVALID   ~0u
 486 #define CPUFREQ_TABLE_END       ~1u
 487 /* Special Values of .flags field */
 488 #define CPUFREQ_BOOST_FREQ      (1 << 0)
 489
 490 struct cpufreq_frequency_table {
 491         unsigned int    flags;
 492         unsigned int    driver_data; /* driver specific data, not used by core */
 493         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 494                                     * order */
 495 };
 496
 497 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
 498 int dev_pm_opp_init_cpufreq_table(struct device *dev,
 499                                   struct cpufreq_frequency_table **table);
 500 void dev_pm_opp_free_cpufreq_table(struct device *dev,
 501                                    struct cpufreq_frequency_table **table);
 502 #else
 503 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
 504                                                 struct cpufreq_frequency_table
 505                                                 **table)
 506 {
 507         return -EINVAL;
 508 }
 509
 510 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 511                                                  struct cpufreq_frequency_table
 512                                                  **table)
 513 {
 514 }
 515 #endif
 516
 517 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
 518 {
 519         while ((*pos)->frequency != CPUFREQ_TABLE_END)
 520                 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
 521                         return true;
 522                 else
 523                         (*pos)++;
 524         return false;
 525 }
 526
 527 /*
 528  * cpufreq_for_each_entry -     iterate over a cpufreq_frequency_table
 529  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 530  * @table:      the cpufreq_frequency_table * to iterate over.
 531  */
 532
 533 #define cpufreq_for_each_entry(pos, table)      \
 534         for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
 535
 536 /*
 537  * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
 538  *      excluding CPUFREQ_ENTRY_INVALID frequencies.
 539  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 540  * @table:      the cpufreq_frequency_table * to iterate over.
 541  */
 542
 543 #define cpufreq_for_each_valid_entry(pos, table)        \
 544         for (pos = table; cpufreq_next_valid(&pos); pos++)
 545
 546 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 547                                     struct cpufreq_frequency_table *table);
 548
 549 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 550                                    struct cpufreq_frequency_table *table);
 551 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 552
 553 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 554                                    struct cpufreq_frequency_table *table,
 555                                    unsigned int target_freq,
 556                                    unsigned int relation,
 557                                    unsigned int *index);
 558 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 559                 unsigned int freq);
 560
 561 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 562
 563 #ifdef CONFIG_CPU_FREQ
 564 int cpufreq_boost_trigger_state(int state);
 565 int cpufreq_boost_supported(void);
 566 int cpufreq_boost_enabled(void);
 567 #else
 568 static inline int cpufreq_boost_trigger_state(int state)
 569 {
 570         return 0;
 571 }
 572 static inline int cpufreq_boost_supported(void)
 573 {
 574         return 0;
 575 }
 576 static inline int cpufreq_boost_enabled(void)
 577 {
 578         return 0;
 579 }
 580 #endif
 581 /* the following funtion is for cpufreq core use only */
 582 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 583
 584 /* the following are really really optional */
 585 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 586 extern struct freq_attr *cpufreq_generic_attr[];
 587 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 588                                       struct cpufreq_frequency_table *table);
 589
 590 unsigned int cpufreq_generic_get(unsigned int cpu);
 591 int cpufreq_generic_init(struct cpufreq_policy *policy,
 592                 struct cpufreq_frequency_table *table,
 593                 unsigned int transition_latency);
 594 #endif /* _LINUX_CPUFREQ_H */