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_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 */
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 */
66 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
68 unsigned int cpu; /* cpu nr of CPU managing this policy */
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 struct cpufreq_governor *governor; /* see below */
82 bool governor_enabled; /* governor start/stop flag */
84 struct work_struct update; /* if update_policy() needs to be
85 * called, but you're in IRQ context */
87 struct cpufreq_real_policy user_policy;
88 struct cpufreq_frequency_table *freq_table;
90 struct list_head policy_list;
92 struct completion kobj_unregister;
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.
103 * - Lock should not be held across
104 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
106 struct rw_semaphore rwsem;
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 */
115 struct cpufreq_stats *stats;
117 /* For cpufreq driver's internal use */
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*/
127 #ifdef CONFIG_CPU_FREQ
128 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
129 void cpufreq_cpu_put(struct cpufreq_policy *policy);
131 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
135 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
138 static inline bool policy_is_shared(struct cpufreq_policy *policy)
140 return cpumask_weight(policy->cpus) > 1;
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);
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);
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);
162 static inline unsigned int cpufreq_get(unsigned int cpu)
166 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
170 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
174 static inline void disable_cpufreq(void) { }
177 /*********************************************************************
178 * CPUFREQ DRIVER INTERFACE *
179 *********************************************************************/
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 */
186 struct attribute attr;
187 ssize_t (*show)(struct cpufreq_policy *, char *);
188 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
191 #define cpufreq_freq_attr_ro(_name) \
192 static struct freq_attr _name = \
193 __ATTR(_name, 0444, show_##_name, NULL)
195 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
196 static struct freq_attr _name = \
197 __ATTR(_name, _perm, show_##_name, NULL)
199 #define cpufreq_freq_attr_rw(_name) \
200 static struct freq_attr _name = \
201 __ATTR(_name, 0644, show_##_name, store_##_name)
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);
211 #define define_one_global_ro(_name) \
212 static struct global_attr _name = \
213 __ATTR(_name, 0444, show_##_name, NULL)
215 #define define_one_global_rw(_name) \
216 static struct global_attr _name = \
217 __ATTR(_name, 0644, show_##_name, store_##_name)
220 struct cpufreq_driver {
221 char name[CPUFREQ_NAME_LEN];
225 /* needed by all drivers */
226 int (*init)(struct cpufreq_policy *policy);
227 int (*verify)(struct cpufreq_policy *policy);
229 /* define one out of two */
230 int (*setpolicy)(struct cpufreq_policy *policy);
233 * On failure, should always restore frequency to policy->restore_freq
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,
242 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
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
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().
256 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
258 int (*target_intermediate)(struct cpufreq_policy *policy,
261 /* should be defined, if possible */
262 unsigned int (*get)(unsigned int cpu);
265 int (*bios_limit)(int cpu, unsigned int *limit);
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);
272 /* Will be called after the driver is fully initialized */
273 void (*ready)(struct cpufreq_policy *policy);
275 struct freq_attr **attr;
277 /* platform specific boost support code */
278 bool boost_supported;
280 int (*set_boost)(int state);
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
290 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
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.
299 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
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.
306 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
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().
315 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
317 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
318 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
320 const char *cpufreq_get_current_driver(void);
321 void *cpufreq_get_driver_data(void);
323 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
324 unsigned int min, unsigned int max)
326 if (policy->min < min)
328 if (policy->max < min)
330 if (policy->min > max)
332 if (policy->max > max)
334 if (policy->min > policy->max)
335 policy->min = policy->max;
340 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
342 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
343 policy->cpuinfo.max_freq);
346 #ifdef CONFIG_CPU_FREQ
347 void cpufreq_suspend(void);
348 void cpufreq_resume(void);
349 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
351 static inline void cpufreq_suspend(void) {}
352 static inline void cpufreq_resume(void) {}
355 /*********************************************************************
356 * CPUFREQ NOTIFIER INTERFACE *
357 *********************************************************************/
359 #define CPUFREQ_TRANSITION_NOTIFIER (0)
360 #define CPUFREQ_POLICY_NOTIFIER (1)
362 /* Transition notifiers */
363 #define CPUFREQ_PRECHANGE (0)
364 #define CPUFREQ_POSTCHANGE (1)
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_UPDATE_POLICY_CPU (4)
372 #define CPUFREQ_CREATE_POLICY (5)
373 #define CPUFREQ_REMOVE_POLICY (6)
375 #ifdef CONFIG_CPU_FREQ
376 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
377 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
379 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
380 struct cpufreq_freqs *freqs);
381 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
382 struct cpufreq_freqs *freqs, int transition_failed);
384 #else /* CONFIG_CPU_FREQ */
385 static inline int cpufreq_register_notifier(struct notifier_block *nb,
390 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
395 #endif /* !CONFIG_CPU_FREQ */
398 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
405 * new = old * mult / div
407 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
410 #if BITS_PER_LONG == 32
411 u64 result = ((u64) old) * ((u64) mult);
413 return (unsigned long) result;
415 #elif BITS_PER_LONG == 64
416 unsigned long result = old * ((u64) mult);
422 /*********************************************************************
423 * CPUFREQ GOVERNORS *
424 *********************************************************************/
427 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
428 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
429 * two generic policies are available:
431 #define CPUFREQ_POLICY_POWERSAVE (1)
432 #define CPUFREQ_POLICY_PERFORMANCE (2)
434 /* Governor Events */
435 #define CPUFREQ_GOV_START 1
436 #define CPUFREQ_GOV_STOP 2
437 #define CPUFREQ_GOV_LIMITS 3
438 #define CPUFREQ_GOV_POLICY_INIT 4
439 #define CPUFREQ_GOV_POLICY_EXIT 5
441 struct cpufreq_governor {
442 char name[CPUFREQ_NAME_LEN];
444 int (*governor) (struct cpufreq_policy *policy,
446 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
448 int (*store_setspeed) (struct cpufreq_policy *policy,
450 unsigned int max_transition_latency; /* HW must be able to switch to
451 next freq faster than this value in nano secs or we
452 will fallback to performance governor */
453 struct list_head governor_list;
454 struct module *owner;
457 /* Pass a target to the cpufreq driver */
458 int cpufreq_driver_target(struct cpufreq_policy *policy,
459 unsigned int target_freq,
460 unsigned int relation);
461 int __cpufreq_driver_target(struct cpufreq_policy *policy,
462 unsigned int target_freq,
463 unsigned int relation);
464 int cpufreq_register_governor(struct cpufreq_governor *governor);
465 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
467 /* CPUFREQ DEFAULT GOVERNOR */
469 * Performance governor is fallback governor if any other gov failed to auto
470 * load due latency restrictions
472 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
473 extern struct cpufreq_governor cpufreq_gov_performance;
475 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
476 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
477 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
478 extern struct cpufreq_governor cpufreq_gov_powersave;
479 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
480 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
481 extern struct cpufreq_governor cpufreq_gov_userspace;
482 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
483 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
484 extern struct cpufreq_governor cpufreq_gov_ondemand;
485 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
486 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
487 extern struct cpufreq_governor cpufreq_gov_conservative;
488 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
491 /*********************************************************************
492 * FREQUENCY TABLE HELPERS *
493 *********************************************************************/
495 /* Special Values of .frequency field */
496 #define CPUFREQ_ENTRY_INVALID ~0u
497 #define CPUFREQ_TABLE_END ~1u
498 /* Special Values of .flags field */
499 #define CPUFREQ_BOOST_FREQ (1 << 0)
501 struct cpufreq_frequency_table {
503 unsigned int driver_data; /* driver specific data, not used by core */
504 unsigned int frequency; /* kHz - doesn't need to be in ascending
508 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
509 int dev_pm_opp_init_cpufreq_table(struct device *dev,
510 struct cpufreq_frequency_table **table);
511 void dev_pm_opp_free_cpufreq_table(struct device *dev,
512 struct cpufreq_frequency_table **table);
514 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
515 struct cpufreq_frequency_table
521 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
522 struct cpufreq_frequency_table
528 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
530 while ((*pos)->frequency != CPUFREQ_TABLE_END)
531 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
539 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
540 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
541 * @table: the cpufreq_frequency_table * to iterate over.
544 #define cpufreq_for_each_entry(pos, table) \
545 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
548 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
549 * excluding CPUFREQ_ENTRY_INVALID frequencies.
550 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
551 * @table: the cpufreq_frequency_table * to iterate over.
554 #define cpufreq_for_each_valid_entry(pos, table) \
555 for (pos = table; cpufreq_next_valid(&pos); pos++)
557 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
558 struct cpufreq_frequency_table *table);
560 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
561 struct cpufreq_frequency_table *table);
562 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
564 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
565 struct cpufreq_frequency_table *table,
566 unsigned int target_freq,
567 unsigned int relation,
568 unsigned int *index);
569 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
572 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
574 #ifdef CONFIG_CPU_FREQ
575 int cpufreq_boost_trigger_state(int state);
576 int cpufreq_boost_supported(void);
577 int cpufreq_boost_enabled(void);
579 static inline int cpufreq_boost_trigger_state(int state)
583 static inline int cpufreq_boost_supported(void)
587 static inline int cpufreq_boost_enabled(void)
592 /* the following funtion is for cpufreq core use only */
593 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
595 /* the following are really really optional */
596 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
597 extern struct freq_attr *cpufreq_generic_attr[];
598 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
599 struct cpufreq_frequency_table *table);
601 unsigned int cpufreq_generic_get(unsigned int cpu);
602 int cpufreq_generic_init(struct cpufreq_policy *policy,
603 struct cpufreq_frequency_table *table,
604 unsigned int transition_latency);
605 #endif /* _LINUX_CPUFREQ_H */