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
];
223 /* needed by all drivers */
224 int (*init
) (struct cpufreq_policy
*policy
);
225 int (*verify
) (struct cpufreq_policy
*policy
);
227 /* define one out of two */
228 int (*setpolicy
) (struct cpufreq_policy
*policy
);
231 * On failure, should always restore frequency to policy->restore_freq
234 int (*target
) (struct cpufreq_policy
*policy
, /* Deprecated */
235 unsigned int target_freq
,
236 unsigned int relation
);
237 int (*target_index
) (struct cpufreq_policy
*policy
,
240 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
243 * get_intermediate should return a stable intermediate frequency
244 * platform wants to switch to and target_intermediate() should set CPU
245 * to to that frequency, before jumping to the frequency corresponding
246 * to 'index'. Core will take care of sending notifications and driver
247 * doesn't have to handle them in target_intermediate() or
250 * Drivers can return '0' from get_intermediate() in case they don't
251 * wish to switch to intermediate frequency for some target frequency.
252 * In that case core will directly call ->target_index().
254 unsigned int (*get_intermediate
)(struct cpufreq_policy
*policy
,
256 int (*target_intermediate
)(struct cpufreq_policy
*policy
,
259 /* should be defined, if possible */
260 unsigned int (*get
) (unsigned int cpu
);
263 int (*bios_limit
) (int cpu
, unsigned int *limit
);
265 int (*exit
) (struct cpufreq_policy
*policy
);
266 void (*stop_cpu
) (struct cpufreq_policy
*policy
);
267 int (*suspend
) (struct cpufreq_policy
*policy
);
268 int (*resume
) (struct cpufreq_policy
*policy
);
269 struct freq_attr
**attr
;
271 /* platform specific boost support code */
272 bool boost_supported
;
274 int (*set_boost
) (int state
);
278 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
279 all ->init() calls failed */
280 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
281 kernel "constants" aren't
282 affected by frequency
284 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
288 * This should be set by platforms having multiple clock-domains, i.e.
289 * supporting multiple policies. With this sysfs directories of governor would
290 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
291 * governor with different tunables for different clusters.
293 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
296 * Driver will do POSTCHANGE notifications from outside of their ->target()
297 * routine and so must set cpufreq_driver->flags with this flag, so that core
298 * can handle them specially.
300 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
303 * Set by drivers which want cpufreq core to check if CPU is running at a
304 * frequency present in freq-table exposed by the driver. For these drivers if
305 * CPU is found running at an out of table freq, we will try to set it to a freq
306 * from the table. And if that fails, we will stop further boot process by
307 * issuing a BUG_ON().
309 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
311 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
312 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
314 const char *cpufreq_get_current_driver(void);
316 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
317 unsigned int min
, unsigned int max
)
319 if (policy
->min
< min
)
321 if (policy
->max
< min
)
323 if (policy
->min
> max
)
325 if (policy
->max
> max
)
327 if (policy
->min
> policy
->max
)
328 policy
->min
= policy
->max
;
333 cpufreq_verify_within_cpu_limits(struct cpufreq_policy
*policy
)
335 cpufreq_verify_within_limits(policy
, policy
->cpuinfo
.min_freq
,
336 policy
->cpuinfo
.max_freq
);
339 #ifdef CONFIG_CPU_FREQ
340 void cpufreq_suspend(void);
341 void cpufreq_resume(void);
342 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
);
344 static inline void cpufreq_suspend(void) {}
345 static inline void cpufreq_resume(void) {}
348 /*********************************************************************
349 * CPUFREQ NOTIFIER INTERFACE *
350 *********************************************************************/
352 #define CPUFREQ_TRANSITION_NOTIFIER (0)
353 #define CPUFREQ_POLICY_NOTIFIER (1)
355 /* Transition notifiers */
356 #define CPUFREQ_PRECHANGE (0)
357 #define CPUFREQ_POSTCHANGE (1)
359 /* Policy Notifiers */
360 #define CPUFREQ_ADJUST (0)
361 #define CPUFREQ_INCOMPATIBLE (1)
362 #define CPUFREQ_NOTIFY (2)
363 #define CPUFREQ_START (3)
364 #define CPUFREQ_UPDATE_POLICY_CPU (4)
365 #define CPUFREQ_CREATE_POLICY (5)
366 #define CPUFREQ_REMOVE_POLICY (6)
368 #ifdef CONFIG_CPU_FREQ
369 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
370 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
372 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
373 struct cpufreq_freqs
*freqs
);
374 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
375 struct cpufreq_freqs
*freqs
, int transition_failed
);
377 #else /* CONFIG_CPU_FREQ */
378 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
383 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
388 #endif /* !CONFIG_CPU_FREQ */
391 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
398 * new = old * mult / div
400 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
403 #if BITS_PER_LONG == 32
404 u64 result
= ((u64
) old
) * ((u64
) mult
);
406 return (unsigned long) result
;
408 #elif BITS_PER_LONG == 64
409 unsigned long result
= old
* ((u64
) mult
);
415 /*********************************************************************
416 * CPUFREQ GOVERNORS *
417 *********************************************************************/
420 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
421 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
422 * two generic policies are available:
424 #define CPUFREQ_POLICY_POWERSAVE (1)
425 #define CPUFREQ_POLICY_PERFORMANCE (2)
427 /* Governor Events */
428 #define CPUFREQ_GOV_START 1
429 #define CPUFREQ_GOV_STOP 2
430 #define CPUFREQ_GOV_LIMITS 3
431 #define CPUFREQ_GOV_POLICY_INIT 4
432 #define CPUFREQ_GOV_POLICY_EXIT 5
434 struct cpufreq_governor
{
435 char name
[CPUFREQ_NAME_LEN
];
437 int (*governor
) (struct cpufreq_policy
*policy
,
439 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
441 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
443 unsigned int max_transition_latency
; /* HW must be able to switch to
444 next freq faster than this value in nano secs or we
445 will fallback to performance governor */
446 struct list_head governor_list
;
447 struct module
*owner
;
450 /* Pass a target to the cpufreq driver */
451 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
452 unsigned int target_freq
,
453 unsigned int relation
);
454 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
455 unsigned int target_freq
,
456 unsigned int relation
);
457 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
458 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
460 /* CPUFREQ DEFAULT GOVERNOR */
462 * Performance governor is fallback governor if any other gov failed to auto
463 * load due latency restrictions
465 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
466 extern struct cpufreq_governor cpufreq_gov_performance
;
468 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
469 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
470 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
471 extern struct cpufreq_governor cpufreq_gov_powersave
;
472 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
473 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
474 extern struct cpufreq_governor cpufreq_gov_userspace
;
475 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
476 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
477 extern struct cpufreq_governor cpufreq_gov_ondemand
;
478 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
479 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
480 extern struct cpufreq_governor cpufreq_gov_conservative
;
481 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
484 /*********************************************************************
485 * FREQUENCY TABLE HELPERS *
486 *********************************************************************/
488 /* Special Values of .frequency field */
489 #define CPUFREQ_ENTRY_INVALID ~0u
490 #define CPUFREQ_TABLE_END ~1u
491 /* Special Values of .flags field */
492 #define CPUFREQ_BOOST_FREQ (1 << 0)
494 struct cpufreq_frequency_table
{
496 unsigned int driver_data
; /* driver specific data, not used by core */
497 unsigned int frequency
; /* kHz - doesn't need to be in ascending
501 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
502 int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
503 struct cpufreq_frequency_table
**table
);
504 void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
505 struct cpufreq_frequency_table
**table
);
507 static inline int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
508 struct cpufreq_frequency_table
514 static inline void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
515 struct cpufreq_frequency_table
521 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table
**pos
)
523 while ((*pos
)->frequency
!= CPUFREQ_TABLE_END
)
524 if ((*pos
)->frequency
!= CPUFREQ_ENTRY_INVALID
)
532 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
533 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
534 * @table: the cpufreq_frequency_table * to iterate over.
537 #define cpufreq_for_each_entry(pos, table) \
538 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
541 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
542 * excluding CPUFREQ_ENTRY_INVALID frequencies.
543 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
544 * @table: the cpufreq_frequency_table * to iterate over.
547 #define cpufreq_for_each_valid_entry(pos, table) \
548 for (pos = table; cpufreq_next_valid(&pos); pos++)
550 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
551 struct cpufreq_frequency_table
*table
);
553 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
554 struct cpufreq_frequency_table
*table
);
555 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy
*policy
);
557 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
558 struct cpufreq_frequency_table
*table
,
559 unsigned int target_freq
,
560 unsigned int relation
,
561 unsigned int *index
);
562 int cpufreq_frequency_table_get_index(struct cpufreq_policy
*policy
,
565 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
567 #ifdef CONFIG_CPU_FREQ
568 int cpufreq_boost_trigger_state(int state
);
569 int cpufreq_boost_supported(void);
570 int cpufreq_boost_enabled(void);
572 static inline int cpufreq_boost_trigger_state(int state
)
576 static inline int cpufreq_boost_supported(void)
580 static inline int cpufreq_boost_enabled(void)
585 /* the following funtion is for cpufreq core use only */
586 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
588 /* the following are really really optional */
589 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
590 extern struct freq_attr
*cpufreq_generic_attr
[];
591 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
592 struct cpufreq_frequency_table
*table
);
594 unsigned int cpufreq_generic_get(unsigned int cpu
);
595 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
596 struct cpufreq_frequency_table
*table
,
597 unsigned int transition_latency
);
598 #endif /* _LINUX_CPUFREQ_H */