GNU Linux-libre 4.4.285-gnu1
[releases.git] / 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_user_policy {
55         unsigned int            min;    /* in kHz */
56         unsigned int            max;    /* in kHz */
57 };
58
59 struct cpufreq_policy {
60         /* CPUs sharing clock, require sw coordination */
61         cpumask_var_t           cpus;   /* Online CPUs only */
62         cpumask_var_t           related_cpus; /* Online + Offline CPUs */
63         cpumask_var_t           real_cpus; /* Related and present */
64
65         unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
66                                                 should set cpufreq */
67         unsigned int            cpu;    /* cpu managing this policy, must be online */
68
69         struct clk              *clk;
70         struct cpufreq_cpuinfo  cpuinfo;/* see above */
71
72         unsigned int            min;    /* in kHz */
73         unsigned int            max;    /* in kHz */
74         unsigned int            cur;    /* in kHz, only needed if cpufreq
75                                          * governors are used */
76         unsigned int            restore_freq; /* = policy->cur before transition */
77         unsigned int            suspend_freq; /* freq to set during suspend */
78
79         unsigned int            policy; /* see above */
80         unsigned int            last_policy; /* policy before unplug */
81         struct cpufreq_governor *governor; /* see below */
82         void                    *governor_data;
83         bool                    governor_enabled; /* governor start/stop flag */
84         char                    last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
85
86         struct work_struct      update; /* if update_policy() needs to be
87                                          * called, but you're in IRQ context */
88
89         struct cpufreq_user_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         struct rw_semaphore     rwsem;
105
106         /* Synchronization for frequency transitions */
107         bool                    transition_ongoing; /* Tracks transition status */
108         spinlock_t              transition_lock;
109         wait_queue_head_t       transition_wait;
110         struct task_struct      *transition_task; /* Task which is doing the transition */
111
112         /* cpufreq-stats */
113         struct cpufreq_stats    *stats;
114
115         /* For cpufreq driver's internal use */
116         void                    *driver_data;
117 };
118
119 /* Only for ACPI */
120 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
121 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
122 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
123 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
124
125 #ifdef CONFIG_CPU_FREQ
126 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
127 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
128 void cpufreq_cpu_put(struct cpufreq_policy *policy);
129 #else
130 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
131 {
132         return NULL;
133 }
134 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
135 {
136         return NULL;
137 }
138 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
139 #endif
140
141 static inline bool policy_is_shared(struct cpufreq_policy *policy)
142 {
143         return cpumask_weight(policy->cpus) > 1;
144 }
145
146 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
147 extern struct kobject *cpufreq_global_kobject;
148
149 #ifdef CONFIG_CPU_FREQ
150 unsigned int cpufreq_get(unsigned int cpu);
151 unsigned int cpufreq_quick_get(unsigned int cpu);
152 unsigned int cpufreq_quick_get_max(unsigned int cpu);
153 void disable_cpufreq(void);
154
155 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
156 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
157 int cpufreq_update_policy(unsigned int cpu);
158 bool have_governor_per_policy(void);
159 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
160 #else
161 static inline unsigned int cpufreq_get(unsigned int cpu)
162 {
163         return 0;
164 }
165 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
166 {
167         return 0;
168 }
169 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
170 {
171         return 0;
172 }
173 static inline void disable_cpufreq(void) { }
174 #endif
175
176 /*********************************************************************
177  *                      CPUFREQ DRIVER INTERFACE                     *
178  *********************************************************************/
179
180 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
181 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
182 #define CPUFREQ_RELATION_C 2  /* closest frequency to target */
183
184 struct freq_attr {
185         struct attribute attr;
186         ssize_t (*show)(struct cpufreq_policy *, char *);
187         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
188 };
189
190 #define cpufreq_freq_attr_ro(_name)             \
191 static struct freq_attr _name =                 \
192 __ATTR(_name, 0444, show_##_name, NULL)
193
194 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
195 static struct freq_attr _name =                 \
196 __ATTR(_name, _perm, show_##_name, NULL)
197
198 #define cpufreq_freq_attr_rw(_name)             \
199 static struct freq_attr _name =                 \
200 __ATTR(_name, 0644, show_##_name, store_##_name)
201
202 #define define_one_global_ro(_name)             \
203 static struct kobj_attribute _name =            \
204 __ATTR(_name, 0444, show_##_name, NULL)
205
206 #define define_one_global_rw(_name)             \
207 static struct kobj_attribute _name =            \
208 __ATTR(_name, 0644, show_##_name, store_##_name)
209
210
211 struct cpufreq_driver {
212         char            name[CPUFREQ_NAME_LEN];
213         u8              flags;
214         void            *driver_data;
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
223         /*
224          * On failure, should always restore frequency to policy->restore_freq
225          * (i.e. old freq).
226          */
227         int             (*target)(struct cpufreq_policy *policy,
228                                   unsigned int target_freq,
229                                   unsigned int relation);       /* Deprecated */
230         int             (*target_index)(struct cpufreq_policy *policy,
231                                         unsigned int index);
232         /*
233          * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
234          * unset.
235          *
236          * get_intermediate should return a stable intermediate frequency
237          * platform wants to switch to and target_intermediate() should set CPU
238          * to to that frequency, before jumping to the frequency corresponding
239          * to 'index'. Core will take care of sending notifications and driver
240          * doesn't have to handle them in target_intermediate() or
241          * target_index().
242          *
243          * Drivers can return '0' from get_intermediate() in case they don't
244          * wish to switch to intermediate frequency for some target frequency.
245          * In that case core will directly call ->target_index().
246          */
247         unsigned int    (*get_intermediate)(struct cpufreq_policy *policy,
248                                             unsigned int index);
249         int             (*target_intermediate)(struct cpufreq_policy *policy,
250                                                unsigned int index);
251
252         /* should be defined, if possible */
253         unsigned int    (*get)(unsigned int cpu);
254
255         /* optional */
256         int             (*bios_limit)(int cpu, unsigned int *limit);
257
258         int             (*exit)(struct cpufreq_policy *policy);
259         void            (*stop_cpu)(struct cpufreq_policy *policy);
260         int             (*suspend)(struct cpufreq_policy *policy);
261         int             (*resume)(struct cpufreq_policy *policy);
262
263         /* Will be called after the driver is fully initialized */
264         void            (*ready)(struct cpufreq_policy *policy);
265
266         struct freq_attr **attr;
267
268         /* platform specific boost support code */
269         bool            boost_supported;
270         bool            boost_enabled;
271         int             (*set_boost)(int state);
272 };
273
274 /* flags */
275 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
276                                                    all ->init() calls failed */
277 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
278                                                    kernel "constants" aren't
279                                                    affected by frequency
280                                                    transitions */
281 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
282                                                    speed mismatches */
283
284 /*
285  * This should be set by platforms having multiple clock-domains, i.e.
286  * supporting multiple policies. With this sysfs directories of governor would
287  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
288  * governor with different tunables for different clusters.
289  */
290 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
291
292 /*
293  * Driver will do POSTCHANGE notifications from outside of their ->target()
294  * routine and so must set cpufreq_driver->flags with this flag, so that core
295  * can handle them specially.
296  */
297 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
298
299 /*
300  * Set by drivers which want cpufreq core to check if CPU is running at a
301  * frequency present in freq-table exposed by the driver. For these drivers if
302  * CPU is found running at an out of table freq, we will try to set it to a freq
303  * from the table. And if that fails, we will stop further boot process by
304  * issuing a BUG_ON().
305  */
306 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
307
308 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
309 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
310
311 const char *cpufreq_get_current_driver(void);
312 void *cpufreq_get_driver_data(void);
313
314 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
315                 unsigned int min, unsigned int max)
316 {
317         if (policy->min < min)
318                 policy->min = min;
319         if (policy->max < min)
320                 policy->max = min;
321         if (policy->min > max)
322                 policy->min = max;
323         if (policy->max > max)
324                 policy->max = max;
325         if (policy->min > policy->max)
326                 policy->min = policy->max;
327         return;
328 }
329
330 static inline void
331 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
332 {
333         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
334                         policy->cpuinfo.max_freq);
335 }
336
337 #ifdef CONFIG_CPU_FREQ
338 void cpufreq_suspend(void);
339 void cpufreq_resume(void);
340 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
341 #else
342 static inline void cpufreq_suspend(void) {}
343 static inline void cpufreq_resume(void) {}
344 #endif
345
346 /*********************************************************************
347  *                     CPUFREQ NOTIFIER INTERFACE                    *
348  *********************************************************************/
349
350 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
351 #define CPUFREQ_POLICY_NOTIFIER         (1)
352
353 /* Transition notifiers */
354 #define CPUFREQ_PRECHANGE               (0)
355 #define CPUFREQ_POSTCHANGE              (1)
356
357 /* Policy Notifiers  */
358 #define CPUFREQ_ADJUST                  (0)
359 #define CPUFREQ_NOTIFY                  (1)
360 #define CPUFREQ_START                   (2)
361 #define CPUFREQ_CREATE_POLICY           (3)
362 #define CPUFREQ_REMOVE_POLICY           (4)
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 int cpufreq_enable_boost_support(void);
568 bool policy_has_boost_freq(struct cpufreq_policy *policy);
569 #else
570 static inline int cpufreq_boost_trigger_state(int state)
571 {
572         return 0;
573 }
574 static inline int cpufreq_boost_supported(void)
575 {
576         return 0;
577 }
578 static inline int cpufreq_boost_enabled(void)
579 {
580         return 0;
581 }
582
583 static inline int cpufreq_enable_boost_support(void)
584 {
585         return -EINVAL;
586 }
587
588 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
589 {
590         return false;
591 }
592 #endif
593 /* the following funtion is for cpufreq core use only */
594 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
595
596 /* the following are really really optional */
597 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
598 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
599 extern struct freq_attr *cpufreq_generic_attr[];
600 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
601                                       struct cpufreq_frequency_table *table);
602
603 unsigned int cpufreq_generic_get(unsigned int cpu);
604 int cpufreq_generic_init(struct cpufreq_policy *policy,
605                 struct cpufreq_frequency_table *table,
606                 unsigned int transition_latency);
607 #endif /* _LINUX_CPUFREQ_H */