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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 * 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 /* cpufreq-stats */
117 struct cpufreq_stats *stats;
118
119 /* For cpufreq driver's internal use */
120 void *driver_data;
121 };
122
123 /* Only for ACPI */
124 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
125 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
126 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
127 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
128
129 #ifdef CONFIG_CPU_FREQ
130 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
131 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
132 void cpufreq_cpu_put(struct cpufreq_policy *policy);
133 #else
134 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
135 {
136 return NULL;
137 }
138 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
139 {
140 return NULL;
141 }
142 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
143 #endif
144
145 static inline bool policy_is_shared(struct cpufreq_policy *policy)
146 {
147 return cpumask_weight(policy->cpus) > 1;
148 }
149
150 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
151 extern struct kobject *cpufreq_global_kobject;
152
153 #ifdef CONFIG_CPU_FREQ
154 unsigned int cpufreq_get(unsigned int cpu);
155 unsigned int cpufreq_quick_get(unsigned int cpu);
156 unsigned int cpufreq_quick_get_max(unsigned int cpu);
157 void disable_cpufreq(void);
158
159 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
160 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
161 int cpufreq_update_policy(unsigned int cpu);
162 bool have_governor_per_policy(void);
163 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
164 #else
165 static inline unsigned int cpufreq_get(unsigned int cpu)
166 {
167 return 0;
168 }
169 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
170 {
171 return 0;
172 }
173 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
174 {
175 return 0;
176 }
177 static inline void disable_cpufreq(void) { }
178 #endif
179
180 /*********************************************************************
181 * CPUFREQ DRIVER INTERFACE *
182 *********************************************************************/
183
184 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
185 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
186 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
187
188 struct freq_attr {
189 struct attribute attr;
190 ssize_t (*show)(struct cpufreq_policy *, char *);
191 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
192 };
193
194 #define cpufreq_freq_attr_ro(_name) \
195 static struct freq_attr _name = \
196 __ATTR(_name, 0444, show_##_name, NULL)
197
198 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
199 static struct freq_attr _name = \
200 __ATTR(_name, _perm, show_##_name, NULL)
201
202 #define cpufreq_freq_attr_rw(_name) \
203 static struct freq_attr _name = \
204 __ATTR(_name, 0644, show_##_name, store_##_name)
205
206 struct global_attr {
207 struct attribute attr;
208 ssize_t (*show)(struct kobject *kobj,
209 struct attribute *attr, char *buf);
210 ssize_t (*store)(struct kobject *a, struct attribute *b,
211 const char *c, size_t count);
212 };
213
214 #define define_one_global_ro(_name) \
215 static struct global_attr _name = \
216 __ATTR(_name, 0444, show_##_name, NULL)
217
218 #define define_one_global_rw(_name) \
219 static struct global_attr _name = \
220 __ATTR(_name, 0644, show_##_name, store_##_name)
221
222
223 struct cpufreq_driver {
224 char name[CPUFREQ_NAME_LEN];
225 u8 flags;
226 void *driver_data;
227
228 /* needed by all drivers */
229 int (*init)(struct cpufreq_policy *policy);
230 int (*verify)(struct cpufreq_policy *policy);
231
232 /* define one out of two */
233 int (*setpolicy)(struct cpufreq_policy *policy);
234
235 /*
236 * On failure, should always restore frequency to policy->restore_freq
237 * (i.e. old freq).
238 */
239 int (*target)(struct cpufreq_policy *policy,
240 unsigned int target_freq,
241 unsigned int relation); /* Deprecated */
242 int (*target_index)(struct cpufreq_policy *policy,
243 unsigned int index);
244 /*
245 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
246 * unset.
247 *
248 * get_intermediate should return a stable intermediate frequency
249 * platform wants to switch to and target_intermediate() should set CPU
250 * to to that frequency, before jumping to the frequency corresponding
251 * to 'index'. Core will take care of sending notifications and driver
252 * doesn't have to handle them in target_intermediate() or
253 * target_index().
254 *
255 * Drivers can return '0' from get_intermediate() in case they don't
256 * wish to switch to intermediate frequency for some target frequency.
257 * In that case core will directly call ->target_index().
258 */
259 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
260 unsigned int index);
261 int (*target_intermediate)(struct cpufreq_policy *policy,
262 unsigned int index);
263
264 /* should be defined, if possible */
265 unsigned int (*get)(unsigned int cpu);
266
267 /* optional */
268 int (*bios_limit)(int cpu, unsigned int *limit);
269
270 int (*exit)(struct cpufreq_policy *policy);
271 void (*stop_cpu)(struct cpufreq_policy *policy);
272 int (*suspend)(struct cpufreq_policy *policy);
273 int (*resume)(struct cpufreq_policy *policy);
274
275 /* Will be called after the driver is fully initialized */
276 void (*ready)(struct cpufreq_policy *policy);
277
278 struct freq_attr **attr;
279
280 /* platform specific boost support code */
281 bool boost_supported;
282 bool boost_enabled;
283 int (*set_boost)(int state);
284 };
285
286 /* flags */
287 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
288 all ->init() calls failed */
289 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
290 kernel "constants" aren't
291 affected by frequency
292 transitions */
293 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
294 speed mismatches */
295
296 /*
297 * This should be set by platforms having multiple clock-domains, i.e.
298 * supporting multiple policies. With this sysfs directories of governor would
299 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
300 * governor with different tunables for different clusters.
301 */
302 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
303
304 /*
305 * Driver will do POSTCHANGE notifications from outside of their ->target()
306 * routine and so must set cpufreq_driver->flags with this flag, so that core
307 * can handle them specially.
308 */
309 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
310
311 /*
312 * Set by drivers which want cpufreq core to check if CPU is running at a
313 * frequency present in freq-table exposed by the driver. For these drivers if
314 * CPU is found running at an out of table freq, we will try to set it to a freq
315 * from the table. And if that fails, we will stop further boot process by
316 * issuing a BUG_ON().
317 */
318 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
319
320 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
321 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
322
323 const char *cpufreq_get_current_driver(void);
324 void *cpufreq_get_driver_data(void);
325
326 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
327 unsigned int min, unsigned int max)
328 {
329 if (policy->min < min)
330 policy->min = min;
331 if (policy->max < min)
332 policy->max = min;
333 if (policy->min > max)
334 policy->min = max;
335 if (policy->max > max)
336 policy->max = max;
337 if (policy->min > policy->max)
338 policy->min = policy->max;
339 return;
340 }
341
342 static inline void
343 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
344 {
345 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
346 policy->cpuinfo.max_freq);
347 }
348
349 #ifdef CONFIG_CPU_FREQ
350 void cpufreq_suspend(void);
351 void cpufreq_resume(void);
352 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
353 #else
354 static inline void cpufreq_suspend(void) {}
355 static inline void cpufreq_resume(void) {}
356 #endif
357
358 /*********************************************************************
359 * CPUFREQ NOTIFIER INTERFACE *
360 *********************************************************************/
361
362 #define CPUFREQ_TRANSITION_NOTIFIER (0)
363 #define CPUFREQ_POLICY_NOTIFIER (1)
364
365 /* Transition notifiers */
366 #define CPUFREQ_PRECHANGE (0)
367 #define CPUFREQ_POSTCHANGE (1)
368
369 /* Policy Notifiers */
370 #define CPUFREQ_ADJUST (0)
371 #define CPUFREQ_NOTIFY (1)
372 #define CPUFREQ_START (2)
373 #define CPUFREQ_CREATE_POLICY (3)
374 #define CPUFREQ_REMOVE_POLICY (4)
375
376 #ifdef CONFIG_CPU_FREQ
377 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
378 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
379
380 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
381 struct cpufreq_freqs *freqs);
382 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
383 struct cpufreq_freqs *freqs, int transition_failed);
384
385 #else /* CONFIG_CPU_FREQ */
386 static inline int cpufreq_register_notifier(struct notifier_block *nb,
387 unsigned int list)
388 {
389 return 0;
390 }
391 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
392 unsigned int list)
393 {
394 return 0;
395 }
396 #endif /* !CONFIG_CPU_FREQ */
397
398 /**
399 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
400 * safe)
401 * @old: old value
402 * @div: divisor
403 * @mult: multiplier
404 *
405 *
406 * new = old * mult / div
407 */
408 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
409 u_int mult)
410 {
411 #if BITS_PER_LONG == 32
412 u64 result = ((u64) old) * ((u64) mult);
413 do_div(result, div);
414 return (unsigned long) result;
415
416 #elif BITS_PER_LONG == 64
417 unsigned long result = old * ((u64) mult);
418 result /= div;
419 return result;
420 #endif
421 }
422
423 /*********************************************************************
424 * CPUFREQ GOVERNORS *
425 *********************************************************************/
426
427 /*
428 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
429 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
430 * two generic policies are available:
431 */
432 #define CPUFREQ_POLICY_POWERSAVE (1)
433 #define CPUFREQ_POLICY_PERFORMANCE (2)
434
435 /* Governor Events */
436 #define CPUFREQ_GOV_START 1
437 #define CPUFREQ_GOV_STOP 2
438 #define CPUFREQ_GOV_LIMITS 3
439 #define CPUFREQ_GOV_POLICY_INIT 4
440 #define CPUFREQ_GOV_POLICY_EXIT 5
441
442 struct cpufreq_governor {
443 char name[CPUFREQ_NAME_LEN];
444 int initialized;
445 int (*governor) (struct cpufreq_policy *policy,
446 unsigned int event);
447 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
448 char *buf);
449 int (*store_setspeed) (struct cpufreq_policy *policy,
450 unsigned int freq);
451 unsigned int max_transition_latency; /* HW must be able to switch to
452 next freq faster than this value in nano secs or we
453 will fallback to performance governor */
454 struct list_head governor_list;
455 struct module *owner;
456 };
457
458 /* Pass a target to the cpufreq driver */
459 int cpufreq_driver_target(struct cpufreq_policy *policy,
460 unsigned int target_freq,
461 unsigned int relation);
462 int __cpufreq_driver_target(struct cpufreq_policy *policy,
463 unsigned int target_freq,
464 unsigned int relation);
465 int cpufreq_register_governor(struct cpufreq_governor *governor);
466 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
467
468 /* CPUFREQ DEFAULT GOVERNOR */
469 /*
470 * Performance governor is fallback governor if any other gov failed to auto
471 * load due latency restrictions
472 */
473 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
474 extern struct cpufreq_governor cpufreq_gov_performance;
475 #endif
476 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
477 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
478 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
479 extern struct cpufreq_governor cpufreq_gov_powersave;
480 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
481 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
482 extern struct cpufreq_governor cpufreq_gov_userspace;
483 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
484 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
485 extern struct cpufreq_governor cpufreq_gov_ondemand;
486 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
487 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
488 extern struct cpufreq_governor cpufreq_gov_conservative;
489 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
490 #endif
491
492 /*********************************************************************
493 * FREQUENCY TABLE HELPERS *
494 *********************************************************************/
495
496 /* Special Values of .frequency field */
497 #define CPUFREQ_ENTRY_INVALID ~0u
498 #define CPUFREQ_TABLE_END ~1u
499 /* Special Values of .flags field */
500 #define CPUFREQ_BOOST_FREQ (1 << 0)
501
502 struct cpufreq_frequency_table {
503 unsigned int flags;
504 unsigned int driver_data; /* driver specific data, not used by core */
505 unsigned int frequency; /* kHz - doesn't need to be in ascending
506 * order */
507 };
508
509 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
510 int dev_pm_opp_init_cpufreq_table(struct device *dev,
511 struct cpufreq_frequency_table **table);
512 void dev_pm_opp_free_cpufreq_table(struct device *dev,
513 struct cpufreq_frequency_table **table);
514 #else
515 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
516 struct cpufreq_frequency_table
517 **table)
518 {
519 return -EINVAL;
520 }
521
522 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
523 struct cpufreq_frequency_table
524 **table)
525 {
526 }
527 #endif
528
529 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
530 {
531 while ((*pos)->frequency != CPUFREQ_TABLE_END)
532 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
533 return true;
534 else
535 (*pos)++;
536 return false;
537 }
538
539 /*
540 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
541 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
542 * @table: the cpufreq_frequency_table * to iterate over.
543 */
544
545 #define cpufreq_for_each_entry(pos, table) \
546 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
547
548 /*
549 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
550 * excluding CPUFREQ_ENTRY_INVALID frequencies.
551 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
552 * @table: the cpufreq_frequency_table * to iterate over.
553 */
554
555 #define cpufreq_for_each_valid_entry(pos, table) \
556 for (pos = table; cpufreq_next_valid(&pos); pos++)
557
558 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
559 struct cpufreq_frequency_table *table);
560
561 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
562 struct cpufreq_frequency_table *table);
563 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
564
565 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
566 struct cpufreq_frequency_table *table,
567 unsigned int target_freq,
568 unsigned int relation,
569 unsigned int *index);
570 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
571 unsigned int freq);
572
573 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
574
575 #ifdef CONFIG_CPU_FREQ
576 int cpufreq_boost_trigger_state(int state);
577 int cpufreq_boost_supported(void);
578 int cpufreq_boost_enabled(void);
579 int cpufreq_enable_boost_support(void);
580 bool policy_has_boost_freq(struct cpufreq_policy *policy);
581 #else
582 static inline int cpufreq_boost_trigger_state(int state)
583 {
584 return 0;
585 }
586 static inline int cpufreq_boost_supported(void)
587 {
588 return 0;
589 }
590 static inline int cpufreq_boost_enabled(void)
591 {
592 return 0;
593 }
594
595 static inline int cpufreq_enable_boost_support(void)
596 {
597 return -EINVAL;
598 }
599
600 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
601 {
602 return false;
603 }
604 #endif
605 /* the following funtion is for cpufreq core use only */
606 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
607
608 /* the following are really really optional */
609 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
610 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
611 extern struct freq_attr *cpufreq_generic_attr[];
612 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
613 struct cpufreq_frequency_table *table);
614
615 unsigned int cpufreq_generic_get(unsigned int cpu);
616 int cpufreq_generic_init(struct cpufreq_policy *policy,
617 struct cpufreq_frequency_table *table,
618 unsigned int transition_latency);
619 #endif /* _LINUX_CPUFREQ_H */