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
;
105 /* Synchronization for frequency transitions */
106 bool transition_ongoing
; /* Tracks transition status */
107 spinlock_t transition_lock
;
108 wait_queue_head_t transition_wait
;
109 struct task_struct
*transition_task
; /* Task which is doing the transition */
112 struct cpufreq_stats
*stats
;
114 /* For cpufreq driver's internal use */
119 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
120 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
121 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
122 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
124 #ifdef CONFIG_CPU_FREQ
125 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
);
126 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
127 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
129 static inline struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
133 static inline struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
137 static inline void cpufreq_cpu_put(struct cpufreq_policy
*policy
) { }
140 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
142 return cpumask_weight(policy
->cpus
) > 1;
145 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
146 extern struct kobject
*cpufreq_global_kobject
;
148 #ifdef CONFIG_CPU_FREQ
149 unsigned int cpufreq_get(unsigned int cpu
);
150 unsigned int cpufreq_quick_get(unsigned int cpu
);
151 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
152 void disable_cpufreq(void);
154 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
155 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
156 int cpufreq_update_policy(unsigned int cpu
);
157 bool have_governor_per_policy(void);
158 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
160 static inline unsigned int cpufreq_get(unsigned int cpu
)
164 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
168 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
172 static inline void disable_cpufreq(void) { }
175 /*********************************************************************
176 * CPUFREQ DRIVER INTERFACE *
177 *********************************************************************/
179 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
180 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
181 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
184 struct attribute attr
;
185 ssize_t (*show
)(struct cpufreq_policy
*, char *);
186 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
189 #define cpufreq_freq_attr_ro(_name) \
190 static struct freq_attr _name = \
191 __ATTR(_name, 0444, show_##_name, NULL)
193 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
194 static struct freq_attr _name = \
195 __ATTR(_name, _perm, show_##_name, NULL)
197 #define cpufreq_freq_attr_rw(_name) \
198 static struct freq_attr _name = \
199 __ATTR(_name, 0644, show_##_name, store_##_name)
202 struct attribute attr
;
203 ssize_t (*show
)(struct kobject
*kobj
,
204 struct attribute
*attr
, char *buf
);
205 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
206 const char *c
, size_t count
);
209 #define define_one_global_ro(_name) \
210 static struct global_attr _name = \
211 __ATTR(_name, 0444, show_##_name, NULL)
213 #define define_one_global_rw(_name) \
214 static struct global_attr _name = \
215 __ATTR(_name, 0644, show_##_name, store_##_name)
218 struct cpufreq_driver
{
219 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
,
235 unsigned int target_freq
,
236 unsigned int relation
); /* Deprecated */
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
);
270 /* Will be called after the driver is fully initialized */
271 void (*ready
)(struct cpufreq_policy
*policy
);
273 struct freq_attr
**attr
;
275 /* platform specific boost support code */
277 int (*set_boost
)(int state
);
281 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
282 all ->init() calls failed */
283 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
284 kernel "constants" aren't
285 affected by frequency
287 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
291 * This should be set by platforms having multiple clock-domains, i.e.
292 * supporting multiple policies. With this sysfs directories of governor would
293 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
294 * governor with different tunables for different clusters.
296 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
299 * Driver will do POSTCHANGE notifications from outside of their ->target()
300 * routine and so must set cpufreq_driver->flags with this flag, so that core
301 * can handle them specially.
303 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
306 * Set by drivers which want cpufreq core to check if CPU is running at a
307 * frequency present in freq-table exposed by the driver. For these drivers if
308 * CPU is found running at an out of table freq, we will try to set it to a freq
309 * from the table. And if that fails, we will stop further boot process by
310 * issuing a BUG_ON().
312 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
314 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
315 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
317 const char *cpufreq_get_current_driver(void);
318 void *cpufreq_get_driver_data(void);
320 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
321 unsigned int min
, unsigned int max
)
323 if (policy
->min
< min
)
325 if (policy
->max
< min
)
327 if (policy
->min
> max
)
329 if (policy
->max
> max
)
331 if (policy
->min
> policy
->max
)
332 policy
->min
= policy
->max
;
337 cpufreq_verify_within_cpu_limits(struct cpufreq_policy
*policy
)
339 cpufreq_verify_within_limits(policy
, policy
->cpuinfo
.min_freq
,
340 policy
->cpuinfo
.max_freq
);
343 #ifdef CONFIG_CPU_FREQ
344 void cpufreq_suspend(void);
345 void cpufreq_resume(void);
346 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
);
348 static inline void cpufreq_suspend(void) {}
349 static inline void cpufreq_resume(void) {}
352 /*********************************************************************
353 * CPUFREQ NOTIFIER INTERFACE *
354 *********************************************************************/
356 #define CPUFREQ_TRANSITION_NOTIFIER (0)
357 #define CPUFREQ_POLICY_NOTIFIER (1)
359 /* Transition notifiers */
360 #define CPUFREQ_PRECHANGE (0)
361 #define CPUFREQ_POSTCHANGE (1)
363 /* Policy Notifiers */
364 #define CPUFREQ_ADJUST (0)
365 #define CPUFREQ_NOTIFY (1)
366 #define CPUFREQ_START (2)
367 #define CPUFREQ_CREATE_POLICY (3)
368 #define CPUFREQ_REMOVE_POLICY (4)
370 #ifdef CONFIG_CPU_FREQ
371 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
372 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
374 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
375 struct cpufreq_freqs
*freqs
);
376 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
377 struct cpufreq_freqs
*freqs
, int transition_failed
);
379 #else /* CONFIG_CPU_FREQ */
380 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
385 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
390 #endif /* !CONFIG_CPU_FREQ */
393 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
400 * new = old * mult / div
402 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
405 #if BITS_PER_LONG == 32
406 u64 result
= ((u64
) old
) * ((u64
) mult
);
408 return (unsigned long) result
;
410 #elif BITS_PER_LONG == 64
411 unsigned long result
= old
* ((u64
) mult
);
417 /*********************************************************************
418 * CPUFREQ GOVERNORS *
419 *********************************************************************/
422 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
423 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
424 * two generic policies are available:
426 #define CPUFREQ_POLICY_POWERSAVE (1)
427 #define CPUFREQ_POLICY_PERFORMANCE (2)
429 /* Governor Events */
430 #define CPUFREQ_GOV_START 1
431 #define CPUFREQ_GOV_STOP 2
432 #define CPUFREQ_GOV_LIMITS 3
433 #define CPUFREQ_GOV_POLICY_INIT 4
434 #define CPUFREQ_GOV_POLICY_EXIT 5
436 struct cpufreq_governor
{
437 char name
[CPUFREQ_NAME_LEN
];
439 int (*governor
) (struct cpufreq_policy
*policy
,
441 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
443 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
445 unsigned int max_transition_latency
; /* HW must be able to switch to
446 next freq faster than this value in nano secs or we
447 will fallback to performance governor */
448 struct list_head governor_list
;
449 struct module
*owner
;
452 /* Pass a target to the cpufreq driver */
453 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
454 unsigned int target_freq
,
455 unsigned int relation
);
456 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
457 unsigned int target_freq
,
458 unsigned int relation
);
459 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
460 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
462 struct cpufreq_governor
*cpufreq_default_governor(void);
463 struct cpufreq_governor
*cpufreq_fallback_governor(void);
465 /*********************************************************************
466 * FREQUENCY TABLE HELPERS *
467 *********************************************************************/
469 /* Special Values of .frequency field */
470 #define CPUFREQ_ENTRY_INVALID ~0u
471 #define CPUFREQ_TABLE_END ~1u
472 /* Special Values of .flags field */
473 #define CPUFREQ_BOOST_FREQ (1 << 0)
475 struct cpufreq_frequency_table
{
477 unsigned int driver_data
; /* driver specific data, not used by core */
478 unsigned int frequency
; /* kHz - doesn't need to be in ascending
482 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
483 int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
484 struct cpufreq_frequency_table
**table
);
485 void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
486 struct cpufreq_frequency_table
**table
);
488 static inline int dev_pm_opp_init_cpufreq_table(struct device
*dev
,
489 struct cpufreq_frequency_table
495 static inline void dev_pm_opp_free_cpufreq_table(struct device
*dev
,
496 struct cpufreq_frequency_table
503 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
504 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
505 * @table: the cpufreq_frequency_table * to iterate over.
508 #define cpufreq_for_each_entry(pos, table) \
509 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
512 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
513 * excluding CPUFREQ_ENTRY_INVALID frequencies.
514 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
515 * @table: the cpufreq_frequency_table * to iterate over.
518 #define cpufreq_for_each_valid_entry(pos, table) \
519 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++) \
520 if (pos->frequency == CPUFREQ_ENTRY_INVALID) \
524 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
525 struct cpufreq_frequency_table
*table
);
527 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
528 struct cpufreq_frequency_table
*table
);
529 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy
*policy
);
531 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
532 struct cpufreq_frequency_table
*table
,
533 unsigned int target_freq
,
534 unsigned int relation
,
535 unsigned int *index
);
536 int cpufreq_frequency_table_get_index(struct cpufreq_policy
*policy
,
539 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
541 #ifdef CONFIG_CPU_FREQ
542 int cpufreq_boost_trigger_state(int state
);
543 int cpufreq_boost_enabled(void);
544 int cpufreq_enable_boost_support(void);
545 bool policy_has_boost_freq(struct cpufreq_policy
*policy
);
547 static inline int cpufreq_boost_trigger_state(int state
)
551 static inline int cpufreq_boost_enabled(void)
556 static inline int cpufreq_enable_boost_support(void)
561 static inline bool policy_has_boost_freq(struct cpufreq_policy
*policy
)
566 /* the following funtion is for cpufreq core use only */
567 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
569 /* the following are really really optional */
570 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
571 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs
;
572 extern struct freq_attr
*cpufreq_generic_attr
[];
573 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
574 struct cpufreq_frequency_table
*table
);
576 unsigned int cpufreq_generic_get(unsigned int cpu
);
577 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
578 struct cpufreq_frequency_table
*table
,
579 unsigned int transition_latency
);
580 #endif /* _LINUX_CPUFREQ_H */