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/sysfs.h>
21 /*********************************************************************
23 *********************************************************************/
25 * Frequency values here are CPU kHz
27 * Maximum transition latency is in nanoseconds - if it's unknown,
28 * CPUFREQ_ETERNAL shall be used.
31 #define CPUFREQ_ETERNAL (-1)
32 #define CPUFREQ_NAME_LEN 16
33 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
34 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
36 struct cpufreq_governor;
38 struct cpufreq_freqs {
39 unsigned int cpu; /* cpu nr */
42 u8 flags; /* flags of cpufreq_driver, see below. */
45 struct cpufreq_cpuinfo {
46 unsigned int max_freq;
47 unsigned int min_freq;
49 /* in 10^(-9) s = nanoseconds */
50 unsigned int transition_latency;
53 struct cpufreq_real_policy {
54 unsigned int min; /* in kHz */
55 unsigned int max; /* in kHz */
56 unsigned int policy; /* see above */
57 struct cpufreq_governor *governor; /* see below */
60 struct cpufreq_policy {
61 /* CPUs sharing clock, require sw coordination */
62 cpumask_var_t cpus; /* Online CPUs only */
63 cpumask_var_t related_cpus; /* Online + Offline CPUs */
65 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
67 unsigned int cpu; /* cpu nr of CPU managing this policy */
68 unsigned int last_cpu; /* cpu nr of previous CPU that managed
71 struct cpufreq_cpuinfo cpuinfo;/* see above */
73 unsigned int min; /* in kHz */
74 unsigned int max; /* in kHz */
75 unsigned int cur; /* in kHz, only needed if cpufreq
76 * governors are used */
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;
110 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
111 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
112 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
113 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
115 #ifdef CONFIG_CPU_FREQ
116 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
117 void cpufreq_cpu_put(struct cpufreq_policy *policy);
119 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
123 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
126 static inline bool policy_is_shared(struct cpufreq_policy *policy)
128 return cpumask_weight(policy->cpus) > 1;
131 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
132 extern struct kobject *cpufreq_global_kobject;
133 int cpufreq_get_global_kobject(void);
134 void cpufreq_put_global_kobject(void);
135 int cpufreq_sysfs_create_file(const struct attribute *attr);
136 void cpufreq_sysfs_remove_file(const struct attribute *attr);
138 #ifdef CONFIG_CPU_FREQ
139 unsigned int cpufreq_get(unsigned int cpu);
140 unsigned int cpufreq_quick_get(unsigned int cpu);
141 unsigned int cpufreq_quick_get_max(unsigned int cpu);
142 void disable_cpufreq(void);
144 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
145 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
146 int cpufreq_update_policy(unsigned int cpu);
147 bool have_governor_per_policy(void);
148 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
150 static inline unsigned int cpufreq_get(unsigned int cpu)
154 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
158 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
162 static inline void disable_cpufreq(void) { }
165 /*********************************************************************
166 * CPUFREQ DRIVER INTERFACE *
167 *********************************************************************/
169 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
170 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
173 struct attribute attr;
174 ssize_t (*show)(struct cpufreq_policy *, char *);
175 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
178 #define cpufreq_freq_attr_ro(_name) \
179 static struct freq_attr _name = \
180 __ATTR(_name, 0444, show_##_name, NULL)
182 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
183 static struct freq_attr _name = \
184 __ATTR(_name, _perm, show_##_name, NULL)
186 #define cpufreq_freq_attr_rw(_name) \
187 static struct freq_attr _name = \
188 __ATTR(_name, 0644, show_##_name, store_##_name)
191 struct attribute attr;
192 ssize_t (*show)(struct kobject *kobj,
193 struct attribute *attr, char *buf);
194 ssize_t (*store)(struct kobject *a, struct attribute *b,
195 const char *c, size_t count);
198 #define define_one_global_ro(_name) \
199 static struct global_attr _name = \
200 __ATTR(_name, 0444, show_##_name, NULL)
202 #define define_one_global_rw(_name) \
203 static struct global_attr _name = \
204 __ATTR(_name, 0644, show_##_name, store_##_name)
207 struct cpufreq_driver {
208 char name[CPUFREQ_NAME_LEN];
211 /* needed by all drivers */
212 int (*init) (struct cpufreq_policy *policy);
213 int (*verify) (struct cpufreq_policy *policy);
215 /* define one out of two */
216 int (*setpolicy) (struct cpufreq_policy *policy);
217 int (*target) (struct cpufreq_policy *policy, /* Deprecated */
218 unsigned int target_freq,
219 unsigned int relation);
220 int (*target_index) (struct cpufreq_policy *policy,
223 /* should be defined, if possible */
224 unsigned int (*get) (unsigned int cpu);
227 int (*bios_limit) (int cpu, unsigned int *limit);
229 int (*exit) (struct cpufreq_policy *policy);
230 void (*stop_cpu) (struct cpufreq_policy *policy);
231 int (*suspend) (struct cpufreq_policy *policy);
232 int (*resume) (struct cpufreq_policy *policy);
233 struct freq_attr **attr;
235 /* platform specific boost support code */
236 bool boost_supported;
238 int (*set_boost) (int state);
242 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
243 all ->init() calls failed */
244 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
245 kernel "constants" aren't
246 affected by frequency
248 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
252 * This should be set by platforms having multiple clock-domains, i.e.
253 * supporting multiple policies. With this sysfs directories of governor would
254 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
255 * governor with different tunables for different clusters.
257 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
260 * Driver will do POSTCHANGE notifications from outside of their ->target()
261 * routine and so must set cpufreq_driver->flags with this flag, so that core
262 * can handle them specially.
264 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
267 * Set by drivers which want cpufreq core to check if CPU is running at a
268 * frequency present in freq-table exposed by the driver. For these drivers if
269 * CPU is found running at an out of table freq, we will try to set it to a freq
270 * from the table. And if that fails, we will stop further boot process by
271 * issuing a BUG_ON().
273 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
275 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
276 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
278 const char *cpufreq_get_current_driver(void);
280 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
281 unsigned int min, unsigned int max)
283 if (policy->min < min)
285 if (policy->max < min)
287 if (policy->min > max)
289 if (policy->max > max)
291 if (policy->min > policy->max)
292 policy->min = policy->max;
297 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
299 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
300 policy->cpuinfo.max_freq);
303 #ifdef CONFIG_CPU_FREQ
304 void cpufreq_suspend(void);
305 void cpufreq_resume(void);
306 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
308 static inline void cpufreq_suspend(void) {}
309 static inline void cpufreq_resume(void) {}
312 /*********************************************************************
313 * CPUFREQ NOTIFIER INTERFACE *
314 *********************************************************************/
316 #define CPUFREQ_TRANSITION_NOTIFIER (0)
317 #define CPUFREQ_POLICY_NOTIFIER (1)
319 /* Transition notifiers */
320 #define CPUFREQ_PRECHANGE (0)
321 #define CPUFREQ_POSTCHANGE (1)
323 /* Policy Notifiers */
324 #define CPUFREQ_ADJUST (0)
325 #define CPUFREQ_INCOMPATIBLE (1)
326 #define CPUFREQ_NOTIFY (2)
327 #define CPUFREQ_START (3)
328 #define CPUFREQ_UPDATE_POLICY_CPU (4)
329 #define CPUFREQ_CREATE_POLICY (5)
330 #define CPUFREQ_REMOVE_POLICY (6)
332 #ifdef CONFIG_CPU_FREQ
333 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
334 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
336 void cpufreq_notify_transition(struct cpufreq_policy *policy,
337 struct cpufreq_freqs *freqs, unsigned int state);
338 void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
339 struct cpufreq_freqs *freqs, int transition_failed);
341 #else /* CONFIG_CPU_FREQ */
342 static inline int cpufreq_register_notifier(struct notifier_block *nb,
347 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
352 #endif /* !CONFIG_CPU_FREQ */
355 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
362 * new = old * mult / div
364 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
367 #if BITS_PER_LONG == 32
368 u64 result = ((u64) old) * ((u64) mult);
370 return (unsigned long) result;
372 #elif BITS_PER_LONG == 64
373 unsigned long result = old * ((u64) mult);
379 /*********************************************************************
380 * CPUFREQ GOVERNORS *
381 *********************************************************************/
384 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
385 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
386 * two generic policies are available:
388 #define CPUFREQ_POLICY_POWERSAVE (1)
389 #define CPUFREQ_POLICY_PERFORMANCE (2)
391 /* Governor Events */
392 #define CPUFREQ_GOV_START 1
393 #define CPUFREQ_GOV_STOP 2
394 #define CPUFREQ_GOV_LIMITS 3
395 #define CPUFREQ_GOV_POLICY_INIT 4
396 #define CPUFREQ_GOV_POLICY_EXIT 5
398 struct cpufreq_governor {
399 char name[CPUFREQ_NAME_LEN];
401 int (*governor) (struct cpufreq_policy *policy,
403 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
405 int (*store_setspeed) (struct cpufreq_policy *policy,
407 unsigned int max_transition_latency; /* HW must be able to switch to
408 next freq faster than this value in nano secs or we
409 will fallback to performance governor */
410 struct list_head governor_list;
411 struct module *owner;
414 /* Pass a target to the cpufreq driver */
415 int cpufreq_driver_target(struct cpufreq_policy *policy,
416 unsigned int target_freq,
417 unsigned int relation);
418 int __cpufreq_driver_target(struct cpufreq_policy *policy,
419 unsigned int target_freq,
420 unsigned int relation);
421 int cpufreq_register_governor(struct cpufreq_governor *governor);
422 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
424 /* CPUFREQ DEFAULT GOVERNOR */
426 * Performance governor is fallback governor if any other gov failed to auto
427 * load due latency restrictions
429 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
430 extern struct cpufreq_governor cpufreq_gov_performance;
432 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
433 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
434 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
435 extern struct cpufreq_governor cpufreq_gov_powersave;
436 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
437 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
438 extern struct cpufreq_governor cpufreq_gov_userspace;
439 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
440 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
441 extern struct cpufreq_governor cpufreq_gov_ondemand;
442 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
443 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
444 extern struct cpufreq_governor cpufreq_gov_conservative;
445 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
448 /*********************************************************************
449 * FREQUENCY TABLE HELPERS *
450 *********************************************************************/
452 #define CPUFREQ_ENTRY_INVALID ~0
453 #define CPUFREQ_TABLE_END ~1
454 #define CPUFREQ_BOOST_FREQ ~2
456 struct cpufreq_frequency_table {
457 unsigned int driver_data; /* driver specific data, not used by core */
458 unsigned int frequency; /* kHz - doesn't need to be in ascending
462 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
463 struct cpufreq_frequency_table *table);
465 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
466 struct cpufreq_frequency_table *table);
467 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
469 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
470 struct cpufreq_frequency_table *table,
471 unsigned int target_freq,
472 unsigned int relation,
473 unsigned int *index);
474 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
477 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
479 #ifdef CONFIG_CPU_FREQ
480 int cpufreq_boost_trigger_state(int state);
481 int cpufreq_boost_supported(void);
482 int cpufreq_boost_enabled(void);
484 static inline int cpufreq_boost_trigger_state(int state)
488 static inline int cpufreq_boost_supported(void)
492 static inline int cpufreq_boost_enabled(void)
497 /* the following funtion is for cpufreq core use only */
498 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
500 /* the following are really really optional */
501 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
502 extern struct freq_attr *cpufreq_generic_attr[];
503 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
504 struct cpufreq_frequency_table *table);
506 unsigned int cpufreq_generic_get(unsigned int cpu);
507 int cpufreq_generic_init(struct cpufreq_policy *policy,
508 struct cpufreq_frequency_table *table,
509 unsigned int transition_latency);
510 #endif /* _LINUX_CPUFREQ_H */