2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
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.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
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>
22 /*********************************************************************
24 *********************************************************************/
26 * Frequency values here are CPU kHz
28 * Maximum transition latency is in nanoseconds - if it's unknown,
29 * CPUFREQ_ETERNAL shall be used.
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)
37 struct cpufreq_governor;
39 struct cpufreq_freqs {
40 unsigned int cpu; /* cpu nr */
43 u8 flags; /* flags of cpufreq_driver, see below. */
46 struct cpufreq_cpuinfo {
47 unsigned int max_freq;
48 unsigned int min_freq;
50 /* in 10^(-9) s = nanoseconds */
51 unsigned int transition_latency;
54 struct cpufreq_user_policy {
55 unsigned int min; /* in kHz */
56 unsigned int max; /* in kHz */
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 */
65 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
67 unsigned int cpu; /* cpu managing this policy, must be online */
70 struct cpufreq_cpuinfo cpuinfo;/* see above */
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 */
79 unsigned int policy; /* see above */
80 unsigned int last_policy; /* policy before unplug */
81 struct cpufreq_governor *governor; /* see below */
83 char last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
85 struct work_struct update; /* if update_policy() needs to be
86 * called, but you're in IRQ context */
88 struct cpufreq_user_policy user_policy;
89 struct cpufreq_frequency_table *freq_table;
91 struct list_head policy_list;
93 struct completion kobj_unregister;
96 * The rules for this semaphore:
97 * - Any routine that wants to read from the policy structure will
98 * do a down_read on this semaphore.
99 * - Any routine that will write to the policy structure and/or may take away
100 * the policy altogether (eg. CPU hotplug), will hold this lock in write
101 * mode before doing so.
103 struct rw_semaphore rwsem;
107 * - fast_switch_possible should be set by the driver if it can
108 * guarantee that frequency can be changed on any CPU sharing the
109 * policy and that the change will affect all of the policy CPUs then.
110 * - fast_switch_enabled is to be set by governors that support fast
111 * freqnency switching with the help of cpufreq_enable_fast_switch().
113 bool fast_switch_possible;
114 bool fast_switch_enabled;
116 /* Synchronization for frequency transitions */
117 bool transition_ongoing; /* Tracks transition status */
118 spinlock_t transition_lock;
119 wait_queue_head_t transition_wait;
120 struct task_struct *transition_task; /* Task which is doing the transition */
123 struct cpufreq_stats *stats;
125 /* For cpufreq driver's internal use */
130 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
131 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
132 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
133 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
135 #ifdef CONFIG_CPU_FREQ
136 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
137 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
138 void cpufreq_cpu_put(struct cpufreq_policy *policy);
140 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
144 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
148 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
151 static inline bool policy_is_shared(struct cpufreq_policy *policy)
153 return cpumask_weight(policy->cpus) > 1;
156 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
157 extern struct kobject *cpufreq_global_kobject;
159 #ifdef CONFIG_CPU_FREQ
160 unsigned int cpufreq_get(unsigned int cpu);
161 unsigned int cpufreq_quick_get(unsigned int cpu);
162 unsigned int cpufreq_quick_get_max(unsigned int cpu);
163 void disable_cpufreq(void);
165 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
166 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
167 int cpufreq_update_policy(unsigned int cpu);
168 bool have_governor_per_policy(void);
169 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
170 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy);
171 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy);
173 static inline unsigned int cpufreq_get(unsigned int cpu)
177 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
181 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
185 static inline void disable_cpufreq(void) { }
188 #ifdef CONFIG_CPU_FREQ_STAT
189 void cpufreq_stats_create_table(struct cpufreq_policy *policy);
190 void cpufreq_stats_free_table(struct cpufreq_policy *policy);
191 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
192 unsigned int new_freq);
194 static inline void cpufreq_stats_create_table(struct cpufreq_policy *policy) { }
195 static inline void cpufreq_stats_free_table(struct cpufreq_policy *policy) { }
196 static inline void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
197 unsigned int new_freq) { }
198 #endif /* CONFIG_CPU_FREQ_STAT */
200 /*********************************************************************
201 * CPUFREQ DRIVER INTERFACE *
202 *********************************************************************/
204 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
205 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
206 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
209 struct attribute attr;
210 ssize_t (*show)(struct cpufreq_policy *, char *);
211 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
214 #define cpufreq_freq_attr_ro(_name) \
215 static struct freq_attr _name = \
216 __ATTR(_name, 0444, show_##_name, NULL)
218 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
219 static struct freq_attr _name = \
220 __ATTR(_name, _perm, show_##_name, NULL)
222 #define cpufreq_freq_attr_rw(_name) \
223 static struct freq_attr _name = \
224 __ATTR(_name, 0644, show_##_name, store_##_name)
227 struct attribute attr;
228 ssize_t (*show)(struct kobject *kobj,
229 struct attribute *attr, char *buf);
230 ssize_t (*store)(struct kobject *a, struct attribute *b,
231 const char *c, size_t count);
234 #define define_one_global_ro(_name) \
235 static struct global_attr _name = \
236 __ATTR(_name, 0444, show_##_name, NULL)
238 #define define_one_global_rw(_name) \
239 static struct global_attr _name = \
240 __ATTR(_name, 0644, show_##_name, store_##_name)
243 struct cpufreq_driver {
244 char name[CPUFREQ_NAME_LEN];
248 /* needed by all drivers */
249 int (*init)(struct cpufreq_policy *policy);
250 int (*verify)(struct cpufreq_policy *policy);
252 /* define one out of two */
253 int (*setpolicy)(struct cpufreq_policy *policy);
256 * On failure, should always restore frequency to policy->restore_freq
259 int (*target)(struct cpufreq_policy *policy,
260 unsigned int target_freq,
261 unsigned int relation); /* Deprecated */
262 int (*target_index)(struct cpufreq_policy *policy,
264 unsigned int (*fast_switch)(struct cpufreq_policy *policy,
265 unsigned int target_freq);
267 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
270 * get_intermediate should return a stable intermediate frequency
271 * platform wants to switch to and target_intermediate() should set CPU
272 * to to that frequency, before jumping to the frequency corresponding
273 * to 'index'. Core will take care of sending notifications and driver
274 * doesn't have to handle them in target_intermediate() or
277 * Drivers can return '0' from get_intermediate() in case they don't
278 * wish to switch to intermediate frequency for some target frequency.
279 * In that case core will directly call ->target_index().
281 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
283 int (*target_intermediate)(struct cpufreq_policy *policy,
286 /* should be defined, if possible */
287 unsigned int (*get)(unsigned int cpu);
290 int (*bios_limit)(int cpu, unsigned int *limit);
292 int (*exit)(struct cpufreq_policy *policy);
293 void (*stop_cpu)(struct cpufreq_policy *policy);
294 int (*suspend)(struct cpufreq_policy *policy);
295 int (*resume)(struct cpufreq_policy *policy);
297 /* Will be called after the driver is fully initialized */
298 void (*ready)(struct cpufreq_policy *policy);
300 struct freq_attr **attr;
302 /* platform specific boost support code */
304 int (*set_boost)(int state);
308 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
309 all ->init() calls failed */
310 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
311 kernel "constants" aren't
312 affected by frequency
314 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
318 * This should be set by platforms having multiple clock-domains, i.e.
319 * supporting multiple policies. With this sysfs directories of governor would
320 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
321 * governor with different tunables for different clusters.
323 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
326 * Driver will do POSTCHANGE notifications from outside of their ->target()
327 * routine and so must set cpufreq_driver->flags with this flag, so that core
328 * can handle them specially.
330 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
333 * Set by drivers which want cpufreq core to check if CPU is running at a
334 * frequency present in freq-table exposed by the driver. For these drivers if
335 * CPU is found running at an out of table freq, we will try to set it to a freq
336 * from the table. And if that fails, we will stop further boot process by
337 * issuing a BUG_ON().
339 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
341 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
342 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
344 const char *cpufreq_get_current_driver(void);
345 void *cpufreq_get_driver_data(void);
347 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
348 unsigned int min, unsigned int max)
350 if (policy->min < min)
352 if (policy->max < min)
354 if (policy->min > max)
356 if (policy->max > max)
358 if (policy->min > policy->max)
359 policy->min = policy->max;
364 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
366 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
367 policy->cpuinfo.max_freq);
370 #ifdef CONFIG_CPU_FREQ
371 void cpufreq_suspend(void);
372 void cpufreq_resume(void);
373 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
375 static inline void cpufreq_suspend(void) {}
376 static inline void cpufreq_resume(void) {}
379 /*********************************************************************
380 * CPUFREQ NOTIFIER INTERFACE *
381 *********************************************************************/
383 #define CPUFREQ_TRANSITION_NOTIFIER (0)
384 #define CPUFREQ_POLICY_NOTIFIER (1)
386 /* Transition notifiers */
387 #define CPUFREQ_PRECHANGE (0)
388 #define CPUFREQ_POSTCHANGE (1)
390 /* Policy Notifiers */
391 #define CPUFREQ_ADJUST (0)
392 #define CPUFREQ_NOTIFY (1)
393 #define CPUFREQ_START (2)
394 #define CPUFREQ_CREATE_POLICY (3)
395 #define CPUFREQ_REMOVE_POLICY (4)
397 #ifdef CONFIG_CPU_FREQ
398 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
399 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
401 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
402 struct cpufreq_freqs *freqs);
403 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
404 struct cpufreq_freqs *freqs, int transition_failed);
406 #else /* CONFIG_CPU_FREQ */
407 static inline int cpufreq_register_notifier(struct notifier_block *nb,
412 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
417 #endif /* !CONFIG_CPU_FREQ */
420 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
427 * new = old * mult / div
429 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
432 #if BITS_PER_LONG == 32
433 u64 result = ((u64) old) * ((u64) mult);
435 return (unsigned long) result;
437 #elif BITS_PER_LONG == 64
438 unsigned long result = old * ((u64) mult);
444 /*********************************************************************
445 * CPUFREQ GOVERNORS *
446 *********************************************************************/
449 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
450 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
451 * two generic policies are available:
453 #define CPUFREQ_POLICY_POWERSAVE (1)
454 #define CPUFREQ_POLICY_PERFORMANCE (2)
457 * The polling frequency depends on the capability of the processor. Default
458 * polling frequency is 1000 times the transition latency of the processor. The
459 * ondemand governor will work on any processor with transition latency <= 10ms,
460 * using appropriate sampling rate.
462 * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
463 * the ondemand governor will not work. All times here are in us (microseconds).
465 #define MIN_SAMPLING_RATE_RATIO (2)
466 #define LATENCY_MULTIPLIER (1000)
467 #define MIN_LATENCY_MULTIPLIER (20)
468 #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
470 struct cpufreq_governor {
471 char name[CPUFREQ_NAME_LEN];
472 int (*init)(struct cpufreq_policy *policy);
473 void (*exit)(struct cpufreq_policy *policy);
474 int (*start)(struct cpufreq_policy *policy);
475 void (*stop)(struct cpufreq_policy *policy);
476 void (*limits)(struct cpufreq_policy *policy);
477 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
479 int (*store_setspeed) (struct cpufreq_policy *policy,
481 unsigned int max_transition_latency; /* HW must be able to switch to
482 next freq faster than this value in nano secs or we
483 will fallback to performance governor */
484 struct list_head governor_list;
485 struct module *owner;
488 /* Pass a target to the cpufreq driver */
489 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
490 unsigned int target_freq);
491 int cpufreq_driver_target(struct cpufreq_policy *policy,
492 unsigned int target_freq,
493 unsigned int relation);
494 int __cpufreq_driver_target(struct cpufreq_policy *policy,
495 unsigned int target_freq,
496 unsigned int relation);
497 int cpufreq_register_governor(struct cpufreq_governor *governor);
498 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
500 struct cpufreq_governor *cpufreq_default_governor(void);
501 struct cpufreq_governor *cpufreq_fallback_governor(void);
503 static inline void cpufreq_policy_apply_limits(struct cpufreq_policy *policy)
505 if (policy->max < policy->cur)
506 __cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H);
507 else if (policy->min > policy->cur)
508 __cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L);
511 /* Governor attribute set */
512 struct gov_attr_set {
514 struct list_head policy_list;
515 struct mutex update_lock;
519 /* sysfs ops for cpufreq governors */
520 extern const struct sysfs_ops governor_sysfs_ops;
522 void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node);
523 void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node);
524 unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node);
526 /* Governor sysfs attribute */
527 struct governor_attr {
528 struct attribute attr;
529 ssize_t (*show)(struct gov_attr_set *attr_set, char *buf);
530 ssize_t (*store)(struct gov_attr_set *attr_set, const char *buf,
534 /*********************************************************************
535 * FREQUENCY TABLE HELPERS *
536 *********************************************************************/
538 /* Special Values of .frequency field */
539 #define CPUFREQ_ENTRY_INVALID ~0u
540 #define CPUFREQ_TABLE_END ~1u
541 /* Special Values of .flags field */
542 #define CPUFREQ_BOOST_FREQ (1 << 0)
544 struct cpufreq_frequency_table {
546 unsigned int driver_data; /* driver specific data, not used by core */
547 unsigned int frequency; /* kHz - doesn't need to be in ascending
551 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
552 int dev_pm_opp_init_cpufreq_table(struct device *dev,
553 struct cpufreq_frequency_table **table);
554 void dev_pm_opp_free_cpufreq_table(struct device *dev,
555 struct cpufreq_frequency_table **table);
557 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
558 struct cpufreq_frequency_table
564 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
565 struct cpufreq_frequency_table
572 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
573 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
574 * @table: the cpufreq_frequency_table * to iterate over.
577 #define cpufreq_for_each_entry(pos, table) \
578 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
581 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
582 * excluding CPUFREQ_ENTRY_INVALID frequencies.
583 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
584 * @table: the cpufreq_frequency_table * to iterate over.
587 #define cpufreq_for_each_valid_entry(pos, table) \
588 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++) \
589 if (pos->frequency == CPUFREQ_ENTRY_INVALID) \
593 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
594 struct cpufreq_frequency_table *table);
596 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
597 struct cpufreq_frequency_table *table);
598 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
600 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
601 struct cpufreq_frequency_table *table,
602 unsigned int target_freq,
603 unsigned int relation,
604 unsigned int *index);
605 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
608 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
610 #ifdef CONFIG_CPU_FREQ
611 int cpufreq_boost_trigger_state(int state);
612 int cpufreq_boost_enabled(void);
613 int cpufreq_enable_boost_support(void);
614 bool policy_has_boost_freq(struct cpufreq_policy *policy);
616 static inline int cpufreq_boost_trigger_state(int state)
620 static inline int cpufreq_boost_enabled(void)
625 static inline int cpufreq_enable_boost_support(void)
630 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
635 /* the following funtion is for cpufreq core use only */
636 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
638 /* the following are really really optional */
639 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
640 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
641 extern struct freq_attr *cpufreq_generic_attr[];
642 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
643 struct cpufreq_frequency_table *table);
645 unsigned int cpufreq_generic_get(unsigned int cpu);
646 int cpufreq_generic_init(struct cpufreq_policy *policy,
647 struct cpufreq_frequency_table *table,
648 unsigned int transition_latency);
649 #endif /* _LINUX_CPUFREQ_H */