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 */
65 cpumask_var_t real_cpus
; /* Related and present */
67 unsigned int shared_type
; /* ACPI: ANY or ALL affected CPUs
69 unsigned int cpu
; /* cpu managing this policy, must be online */
70 unsigned int kobj_cpu
; /* cpu managing sysfs files, can be offline */
73 struct cpufreq_cpuinfo cpuinfo
;/* see above */
75 unsigned int min
; /* in kHz */
76 unsigned int max
; /* in kHz */
77 unsigned int cur
; /* in kHz, only needed if cpufreq
78 * governors are used */
79 unsigned int restore_freq
; /* = policy->cur before transition */
80 unsigned int suspend_freq
; /* freq to set during suspend */
82 unsigned int policy
; /* see above */
83 struct cpufreq_governor
*governor
; /* see below */
85 bool governor_enabled
; /* governor start/stop flag */
86 char last_governor
[CPUFREQ_NAME_LEN
]; /* last governor used */
88 struct work_struct update
; /* if update_policy() needs to be
89 * called, but you're in IRQ context */
91 struct cpufreq_real_policy user_policy
;
92 struct cpufreq_frequency_table
*freq_table
;
94 struct list_head policy_list
;
96 struct completion kobj_unregister
;
99 * The rules for this semaphore:
100 * - Any routine that wants to read from the policy structure will
101 * do a down_read on this semaphore.
102 * - Any routine that will write to the policy structure and/or may take away
103 * the policy altogether (eg. CPU hotplug), will hold this lock in write
104 * mode before doing so.
107 * - Lock should not be held across
108 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
110 struct rw_semaphore rwsem
;
112 /* Synchronization for frequency transitions */
113 bool transition_ongoing
; /* Tracks transition status */
114 spinlock_t transition_lock
;
115 wait_queue_head_t transition_wait
;
116 struct task_struct
*transition_task
; /* Task which is doing the transition */
119 struct cpufreq_stats
*stats
;
121 /* For cpufreq driver's internal use */
126 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
127 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
128 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
129 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
131 #ifdef CONFIG_CPU_FREQ
132 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
133 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
135 static inline struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
139 static inline void cpufreq_cpu_put(struct cpufreq_policy
*policy
) { }
142 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
144 return cpumask_weight(policy
->cpus
) > 1;
147 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
148 extern struct kobject
*cpufreq_global_kobject
;
149 int cpufreq_get_global_kobject(void);
150 void cpufreq_put_global_kobject(void);
151 int cpufreq_sysfs_create_file(const struct attribute
*attr
);
152 void cpufreq_sysfs_remove_file(const struct attribute
*attr
);
154 #ifdef CONFIG_CPU_FREQ
155 unsigned int cpufreq_get(unsigned int cpu
);
156 unsigned int cpufreq_quick_get(unsigned int cpu
);
157 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
158 void disable_cpufreq(void);
160 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
161 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
162 int cpufreq_update_policy(unsigned int cpu
);
163 bool have_governor_per_policy(void);
164 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
166 static inline unsigned int cpufreq_get(unsigned int cpu
)
170 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
174 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
178 static inline void disable_cpufreq(void) { }
181 /*********************************************************************
182 * CPUFREQ DRIVER INTERFACE *
183 *********************************************************************/
185 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
186 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
187 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
190 struct attribute attr
;
191 ssize_t (*show
)(struct cpufreq_policy
*, char *);
192 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
195 #define cpufreq_freq_attr_ro(_name) \
196 static struct freq_attr _name = \
197 __ATTR(_name, 0444, show_##_name, NULL)
199 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
200 static struct freq_attr _name = \
201 __ATTR(_name, _perm, show_##_name, NULL)
203 #define cpufreq_freq_attr_rw(_name) \
204 static struct freq_attr _name = \
205 __ATTR(_name, 0644, show_##_name, store_##_name)
208 struct attribute attr
;
209 ssize_t (*show
)(struct kobject
*kobj
,
210 struct attribute
*attr
, char *buf
);
211 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
212 const char *c
, size_t count
);
215 #define define_one_global_ro(_name) \
216 static struct global_attr _name = \
217 __ATTR(_name, 0444, show_##_name, NULL)
219 #define define_one_global_rw(_name) \
220 static struct global_attr _name = \
221 __ATTR(_name, 0644, show_##_name, store_##_name)
224 struct cpufreq_driver
{
225 char name
[CPUFREQ_NAME_LEN
];
229 /* needed by all drivers */
230 int (*init
)(struct cpufreq_policy
*policy
);
231 int (*verify
)(struct cpufreq_policy
*policy
);
233 /* define one out of two */
234 int (*setpolicy
)(struct cpufreq_policy
*policy
);
237 * On failure, should always restore frequency to policy->restore_freq
240 int (*target
)(struct cpufreq_policy
*policy
,
241 unsigned int target_freq
,
242 unsigned int relation
); /* Deprecated */
243 int (*target_index
)(struct cpufreq_policy
*policy
,
246 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
249 * get_intermediate should return a stable intermediate frequency
250 * platform wants to switch to and target_intermediate() should set CPU
251 * to to that frequency, before jumping to the frequency corresponding
252 * to 'index'. Core will take care of sending notifications and driver
253 * doesn't have to handle them in target_intermediate() or
256 * Drivers can return '0' from get_intermediate() in case they don't
257 * wish to switch to intermediate frequency for some target frequency.
258 * In that case core will directly call ->target_index().
260 unsigned int (*get_intermediate
)(struct cpufreq_policy
*policy
,
262 int (*target_intermediate
)(struct cpufreq_policy
*policy
,
265 /* should be defined, if possible */
266 unsigned int (*get
)(unsigned int cpu
);
269 int (*bios_limit
)(int cpu
, unsigned int *limit
);
271 int (*exit
)(struct cpufreq_policy
*policy
);
272 void (*stop_cpu
)(struct cpufreq_policy
*policy
);
273 int (*suspend
)(struct cpufreq_policy
*policy
);
274 int (*resume
)(struct cpufreq_policy
*policy
);
276 /* Will be called after the driver is fully initialized */
277 void (*ready
)(struct cpufreq_policy
*policy
);
279 struct freq_attr
**attr
;
281 /* platform specific boost support code */
282 bool boost_supported
;
284 int (*set_boost
)(int state
);
288 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
289 all ->init() calls failed */
290 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
291 kernel "constants" aren't
292 affected by frequency
294 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
298 * This should be set by platforms having multiple clock-domains, i.e.
299 * supporting multiple policies. With this sysfs directories of governor would
300 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
301 * governor with different tunables for different clusters.
303 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
306 * Driver will do POSTCHANGE notifications from outside of their ->target()
307 * routine and so must set cpufreq_driver->flags with this flag, so that core
308 * can handle them specially.
310 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
313 * Set by drivers which want cpufreq core to check if CPU is running at a
314 * frequency present in freq-table exposed by the driver. For these drivers if
315 * CPU is found running at an out of table freq, we will try to set it to a freq
316 * from the table. And if that fails, we will stop further boot process by
317 * issuing a BUG_ON().
319 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
321 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
322 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
324 const char *cpufreq_get_current_driver(void);
325 void *cpufreq_get_driver_data(void);
327 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
328 unsigned int min
, unsigned int max
)
330 if (policy
->min
< min
)
332 if (policy
->max
< min
)
334 if (policy
->min
> max
)
336 if (policy
->max
> max
)
338 if (policy
->min
> policy
->max
)
339 policy
->min
= policy
->max
;
344 cpufreq_verify_within_cpu_limits(struct cpufreq_policy
*policy
)
346 cpufreq_verify_within_limits(policy
, policy
->cpuinfo
.min_freq
,
347 policy
->cpuinfo
.max_freq
);
350 #ifdef CONFIG_CPU_FREQ
351 void cpufreq_suspend(void);
352 void cpufreq_resume(void);
353 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
);
355 static inline void cpufreq_suspend(void) {}
356 static inline void cpufreq_resume(void) {}
359 /*********************************************************************
360 * CPUFREQ NOTIFIER INTERFACE *
361 *********************************************************************/
363 #define CPUFREQ_TRANSITION_NOTIFIER (0)
364 #define CPUFREQ_POLICY_NOTIFIER (1)
366 /* Transition notifiers */
367 #define CPUFREQ_PRECHANGE (0)
368 #define CPUFREQ_POSTCHANGE (1)
370 /* Policy Notifiers */
371 #define CPUFREQ_ADJUST (0)
372 #define CPUFREQ_INCOMPATIBLE (1)
373 #define CPUFREQ_NOTIFY (2)
374 #define CPUFREQ_START (3)
375 #define CPUFREQ_CREATE_POLICY (4)
376 #define CPUFREQ_REMOVE_POLICY (5)
378 #ifdef CONFIG_CPU_FREQ
379 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
380 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
382 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
383 struct cpufreq_freqs
*freqs
);
384 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
385 struct cpufreq_freqs
*freqs
, int transition_failed
);
387 #else /* CONFIG_CPU_FREQ */
388 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
393 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
398 #endif /* !CONFIG_CPU_FREQ */
401 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
408 * new = old * mult / div
410 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
413 #if BITS_PER_LONG == 32
414 u64 result
= ((u64
) old
) * ((u64
) mult
);
416 return (unsigned long) result
;
418 #elif BITS_PER_LONG == 64
419 unsigned long result
= old
* ((u64
) mult
);
425 /*********************************************************************
426 * CPUFREQ GOVERNORS *
427 *********************************************************************/
430 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
431 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
432 * two generic policies are available:
434 #define CPUFREQ_POLICY_POWERSAVE (1)
435 #define CPUFREQ_POLICY_PERFORMANCE (2)
437 /* Governor Events */
438 #define CPUFREQ_GOV_START 1
439 #define CPUFREQ_GOV_STOP 2
440 #define CPUFREQ_GOV_LIMITS 3
441 #define CPUFREQ_GOV_POLICY_INIT 4
442 #define CPUFREQ_GOV_POLICY_EXIT 5
444 struct cpufreq_governor
{
445 char name
[CPUFREQ_NAME_LEN
];
447 int (*governor
) (struct cpufreq_policy
*policy
,
449 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
451 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
453 unsigned int max_transition_latency
; /* HW must be able to switch to
454 next freq faster than this value in nano secs or we
455 will fallback to performance governor */
456 struct list_head governor_list
;
457 struct module
*owner
;
460 /* Pass a target to the cpufreq driver */
461 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
462 unsigned int target_freq
,
463 unsigned int relation
);
464 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
465 unsigned int target_freq
,
466 unsigned int relation
);
467 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
468 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
470 /* CPUFREQ DEFAULT GOVERNOR */
472 * Performance governor is fallback governor if any other gov failed to auto
473 * load due latency restrictions
475 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
476 extern struct cpufreq_governor cpufreq_gov_performance
;
478 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
479 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
480 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
481 extern struct cpufreq_governor cpufreq_gov_powersave
;
482 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
483 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
484 extern struct cpufreq_governor cpufreq_gov_userspace
;
485 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
486 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
487 extern struct cpufreq_governor cpufreq_gov_ondemand
;
488 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
489 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
490 extern struct cpufreq_governor cpufreq_gov_conservative
;
491 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
494 /*********************************************************************
495 * FREQUENCY TABLE HELPERS *
496 *********************************************************************/
498 /* Special Values of .frequency field */
499 #define CPUFREQ_ENTRY_INVALID ~0u
500 #define CPUFREQ_TABLE_END ~1u
501 /* Special Values of .flags field */
502 #define CPUFREQ_BOOST_FREQ (1 << 0)
504 struct cpufreq_frequency_table
{
506 unsigned int driver_data
; /* driver specific data, not used by core */
507 unsigned int frequency
; /* kHz - doesn't need to be in ascending
511 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
512 int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
513 struct cpufreq_frequency_table
**table
);
514 void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
515 struct cpufreq_frequency_table
**table
);
517 static inline int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
518 struct cpufreq_frequency_table
524 static inline void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
525 struct cpufreq_frequency_table
531 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table
**pos
)
533 while ((*pos
)->frequency
!= CPUFREQ_TABLE_END
)
534 if ((*pos
)->frequency
!= CPUFREQ_ENTRY_INVALID
)
542 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
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_entry(pos, table) \
548 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
551 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
552 * excluding CPUFREQ_ENTRY_INVALID frequencies.
553 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
554 * @table: the cpufreq_frequency_table * to iterate over.
557 #define cpufreq_for_each_valid_entry(pos, table) \
558 for (pos = table; cpufreq_next_valid(&pos); pos++)
560 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
561 struct cpufreq_frequency_table
*table
);
563 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
564 struct cpufreq_frequency_table
*table
);
565 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy
*policy
);
567 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
568 struct cpufreq_frequency_table
*table
,
569 unsigned int target_freq
,
570 unsigned int relation
,
571 unsigned int *index
);
572 int cpufreq_frequency_table_get_index(struct cpufreq_policy
*policy
,
575 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
577 #ifdef CONFIG_CPU_FREQ
578 int cpufreq_boost_trigger_state(int state
);
579 int cpufreq_boost_supported(void);
580 int cpufreq_boost_enabled(void);
582 static inline int cpufreq_boost_trigger_state(int state
)
586 static inline int cpufreq_boost_supported(void)
590 static inline int cpufreq_boost_enabled(void)
595 /* the following funtion is for cpufreq core use only */
596 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
598 /* the following are really really optional */
599 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
600 extern struct freq_attr
*cpufreq_generic_attr
[];
601 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
602 struct cpufreq_frequency_table
*table
);
604 unsigned int cpufreq_generic_get(unsigned int cpu
);
605 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
606 struct cpufreq_frequency_table
*table
,
607 unsigned int transition_latency
);
608 #endif /* _LINUX_CPUFREQ_H */