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 */
69 unsigned int last_cpu; /* cpu nr of previous CPU that managed
72 struct cpufreq_cpuinfo cpuinfo;/* see above */
74 unsigned int min; /* in kHz */
75 unsigned int max; /* in kHz */
76 unsigned int cur; /* in kHz, only needed if cpufreq
77 * governors are used */
78 unsigned int restore_freq; /* = policy->cur before transition */
79 unsigned int suspend_freq; /* freq to set during suspend */
81 unsigned int policy; /* see above */
82 struct cpufreq_governor *governor; /* see below */
84 bool governor_enabled; /* governor start/stop flag */
86 struct work_struct update; /* if update_policy() needs to be
87 * called, but you're in IRQ context */
89 struct cpufreq_real_policy user_policy;
90 struct cpufreq_frequency_table *freq_table;
92 struct list_head policy_list;
94 struct completion kobj_unregister;
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.
105 * - Lock should not be held across
106 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
108 struct rw_semaphore rwsem;
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 */
116 /* For cpufreq driver's internal use */
121 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
122 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
123 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
124 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
126 #ifdef CONFIG_CPU_FREQ
127 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
128 void cpufreq_cpu_put(struct cpufreq_policy *policy);
130 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
134 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
137 static inline bool policy_is_shared(struct cpufreq_policy *policy)
139 return cpumask_weight(policy->cpus) > 1;
142 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
143 extern struct kobject *cpufreq_global_kobject;
144 int cpufreq_get_global_kobject(void);
145 void cpufreq_put_global_kobject(void);
146 int cpufreq_sysfs_create_file(const struct attribute *attr);
147 void cpufreq_sysfs_remove_file(const struct attribute *attr);
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);
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);
161 static inline unsigned int cpufreq_get(unsigned int cpu)
165 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
169 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
173 static inline void disable_cpufreq(void) { }
176 /*********************************************************************
177 * CPUFREQ DRIVER INTERFACE *
178 *********************************************************************/
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 */
185 struct attribute attr;
186 ssize_t (*show)(struct cpufreq_policy *, char *);
187 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
190 #define cpufreq_freq_attr_ro(_name) \
191 static struct freq_attr _name = \
192 __ATTR(_name, 0444, show_##_name, NULL)
194 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
195 static struct freq_attr _name = \
196 __ATTR(_name, _perm, show_##_name, NULL)
198 #define cpufreq_freq_attr_rw(_name) \
199 static struct freq_attr _name = \
200 __ATTR(_name, 0644, show_##_name, store_##_name)
203 struct attribute attr;
204 ssize_t (*show)(struct kobject *kobj,
205 struct attribute *attr, char *buf);
206 ssize_t (*store)(struct kobject *a, struct attribute *b,
207 const char *c, size_t count);
210 #define define_one_global_ro(_name) \
211 static struct global_attr _name = \
212 __ATTR(_name, 0444, show_##_name, NULL)
214 #define define_one_global_rw(_name) \
215 static struct global_attr _name = \
216 __ATTR(_name, 0644, show_##_name, store_##_name)
219 struct cpufreq_driver {
220 char name[CPUFREQ_NAME_LEN];
224 /* needed by all drivers */
225 int (*init)(struct cpufreq_policy *policy);
226 int (*verify)(struct cpufreq_policy *policy);
228 /* define one out of two */
229 int (*setpolicy)(struct cpufreq_policy *policy);
232 * On failure, should always restore frequency to policy->restore_freq
235 int (*target)(struct cpufreq_policy *policy,
236 unsigned int target_freq,
237 unsigned int relation); /* Deprecated */
238 int (*target_index)(struct cpufreq_policy *policy,
241 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
244 * get_intermediate should return a stable intermediate frequency
245 * platform wants to switch to and target_intermediate() should set CPU
246 * to to that frequency, before jumping to the frequency corresponding
247 * to 'index'. Core will take care of sending notifications and driver
248 * doesn't have to handle them in target_intermediate() or
251 * Drivers can return '0' from get_intermediate() in case they don't
252 * wish to switch to intermediate frequency for some target frequency.
253 * In that case core will directly call ->target_index().
255 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
257 int (*target_intermediate)(struct cpufreq_policy *policy,
260 /* should be defined, if possible */
261 unsigned int (*get)(unsigned int cpu);
264 int (*bios_limit)(int cpu, unsigned int *limit);
266 int (*exit)(struct cpufreq_policy *policy);
267 void (*stop_cpu)(struct cpufreq_policy *policy);
268 int (*suspend)(struct cpufreq_policy *policy);
269 int (*resume)(struct cpufreq_policy *policy);
271 /* Will be called after the driver is fully initialized */
272 void (*ready)(struct cpufreq_policy *policy);
274 struct freq_attr **attr;
276 /* platform specific boost support code */
277 bool boost_supported;
279 int (*set_boost)(int state);
283 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
284 all ->init() calls failed */
285 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
286 kernel "constants" aren't
287 affected by frequency
289 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
293 * This should be set by platforms having multiple clock-domains, i.e.
294 * supporting multiple policies. With this sysfs directories of governor would
295 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
296 * governor with different tunables for different clusters.
298 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
301 * Driver will do POSTCHANGE notifications from outside of their ->target()
302 * routine and so must set cpufreq_driver->flags with this flag, so that core
303 * can handle them specially.
305 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
308 * Set by drivers which want cpufreq core to check if CPU is running at a
309 * frequency present in freq-table exposed by the driver. For these drivers if
310 * CPU is found running at an out of table freq, we will try to set it to a freq
311 * from the table. And if that fails, we will stop further boot process by
312 * issuing a BUG_ON().
314 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
316 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
317 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
319 const char *cpufreq_get_current_driver(void);
320 void *cpufreq_get_driver_data(void);
322 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
323 unsigned int min, unsigned int max)
325 if (policy->min < min)
327 if (policy->max < min)
329 if (policy->min > max)
331 if (policy->max > max)
333 if (policy->min > policy->max)
334 policy->min = policy->max;
339 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
341 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
342 policy->cpuinfo.max_freq);
345 #ifdef CONFIG_CPU_FREQ
346 void cpufreq_suspend(void);
347 void cpufreq_resume(void);
348 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
350 static inline void cpufreq_suspend(void) {}
351 static inline void cpufreq_resume(void) {}
354 /*********************************************************************
355 * CPUFREQ NOTIFIER INTERFACE *
356 *********************************************************************/
358 #define CPUFREQ_TRANSITION_NOTIFIER (0)
359 #define CPUFREQ_POLICY_NOTIFIER (1)
361 /* Transition notifiers */
362 #define CPUFREQ_PRECHANGE (0)
363 #define CPUFREQ_POSTCHANGE (1)
365 /* Policy Notifiers */
366 #define CPUFREQ_ADJUST (0)
367 #define CPUFREQ_INCOMPATIBLE (1)
368 #define CPUFREQ_NOTIFY (2)
369 #define CPUFREQ_START (3)
370 #define CPUFREQ_UPDATE_POLICY_CPU (4)
371 #define CPUFREQ_CREATE_POLICY (5)
372 #define CPUFREQ_REMOVE_POLICY (6)
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);
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);
383 #else /* CONFIG_CPU_FREQ */
384 static inline int cpufreq_register_notifier(struct notifier_block *nb,
389 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
394 #endif /* !CONFIG_CPU_FREQ */
397 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
404 * new = old * mult / div
406 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
409 #if BITS_PER_LONG == 32
410 u64 result = ((u64) old) * ((u64) mult);
412 return (unsigned long) result;
414 #elif BITS_PER_LONG == 64
415 unsigned long result = old * ((u64) mult);
421 /*********************************************************************
422 * CPUFREQ GOVERNORS *
423 *********************************************************************/
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:
430 #define CPUFREQ_POLICY_POWERSAVE (1)
431 #define CPUFREQ_POLICY_PERFORMANCE (2)
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
440 struct cpufreq_governor {
441 char name[CPUFREQ_NAME_LEN];
443 int (*governor) (struct cpufreq_policy *policy,
445 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
447 int (*store_setspeed) (struct cpufreq_policy *policy,
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;
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);
466 /* CPUFREQ DEFAULT GOVERNOR */
468 * Performance governor is fallback governor if any other gov failed to auto
469 * load due latency restrictions
471 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
472 extern struct cpufreq_governor cpufreq_gov_performance;
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)
490 /*********************************************************************
491 * FREQUENCY TABLE HELPERS *
492 *********************************************************************/
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)
500 struct cpufreq_frequency_table {
502 unsigned int driver_data; /* driver specific data, not used by core */
503 unsigned int frequency; /* kHz - doesn't need to be in ascending
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);
513 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
514 struct cpufreq_frequency_table
520 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
521 struct cpufreq_frequency_table
527 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
529 while ((*pos)->frequency != CPUFREQ_TABLE_END)
530 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
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.
543 #define cpufreq_for_each_entry(pos, table) \
544 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
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.
553 #define cpufreq_for_each_valid_entry(pos, table) \
554 for (pos = table; cpufreq_next_valid(&pos); pos++)
556 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
557 struct cpufreq_frequency_table *table);
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);
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,
571 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
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);
578 static inline int cpufreq_boost_trigger_state(int state)
582 static inline int cpufreq_boost_supported(void)
586 static inline int cpufreq_boost_enabled(void)
591 /* the following funtion is for cpufreq core use only */
592 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
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);
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 */