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