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1/*
2 * linux/include/linux/cpufreq.h
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 *
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.
10 */
11#ifndef _LINUX_CPUFREQ_H
12#define _LINUX_CPUFREQ_H
13
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>
21
22/*********************************************************************
23 * CPUFREQ INTERFACE *
24 *********************************************************************/
25/*
26 * Frequency values here are CPU kHz
27 *
28 * Maximum transition latency is in nanoseconds - if it's unknown,
29 * CPUFREQ_ETERNAL shall be used.
30 */
31
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)
36
37struct cpufreq_governor;
38
39struct cpufreq_freqs {
40 unsigned int cpu; /* cpu nr */
41 unsigned int old;
42 unsigned int new;
43 u8 flags; /* flags of cpufreq_driver, see below. */
44};
45
46struct cpufreq_cpuinfo {
47 unsigned int max_freq;
48 unsigned int min_freq;
49
50 /* in 10^(-9) s = nanoseconds */
51 unsigned int transition_latency;
52};
53
54struct 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 */
59};
60
61struct 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
66 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
67 should set cpufreq */
68 unsigned int cpu; /* cpu nr of CPU managing this policy */
69 unsigned int last_cpu; /* cpu nr of previous CPU that managed
70 * this policy */
71 struct clk *clk;
72 struct cpufreq_cpuinfo cpuinfo;/* see above */
73
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 suspend_freq; /* freq to set during suspend */
79
80 unsigned int policy; /* see above */
81 struct cpufreq_governor *governor; /* see below */
82 void *governor_data;
83 bool governor_enabled; /* governor start/stop flag */
84
85 struct work_struct update; /* if update_policy() needs to be
86 * called, but you're in IRQ context */
87
88 struct cpufreq_real_policy user_policy;
89 struct cpufreq_frequency_table *freq_table;
90
91 struct list_head policy_list;
92 struct kobject kobj;
93 struct completion kobj_unregister;
94
95 /*
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.
102 *
103 * Additional rules:
104 * - Lock should not be held across
105 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
106 */
107 struct rw_semaphore rwsem;
108
109 /* Synchronization for frequency transitions */
110 bool transition_ongoing; /* Tracks transition status */
111 spinlock_t transition_lock;
112 wait_queue_head_t transition_wait;
113};
114
115/* Only for ACPI */
116#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
117#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
118#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
119#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
120
121#ifdef CONFIG_CPU_FREQ
122struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
123void cpufreq_cpu_put(struct cpufreq_policy *policy);
124#else
125static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
126{
127 return NULL;
128}
129static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
130#endif
131
132static inline bool policy_is_shared(struct cpufreq_policy *policy)
133{
134 return cpumask_weight(policy->cpus) > 1;
135}
136
137/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
138extern struct kobject *cpufreq_global_kobject;
139int cpufreq_get_global_kobject(void);
140void cpufreq_put_global_kobject(void);
141int cpufreq_sysfs_create_file(const struct attribute *attr);
142void cpufreq_sysfs_remove_file(const struct attribute *attr);
143
144#ifdef CONFIG_CPU_FREQ
145unsigned int cpufreq_get(unsigned int cpu);
146unsigned int cpufreq_quick_get(unsigned int cpu);
147unsigned int cpufreq_quick_get_max(unsigned int cpu);
148void disable_cpufreq(void);
149
150u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
151int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
152int cpufreq_update_policy(unsigned int cpu);
153bool have_governor_per_policy(void);
154struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
155#else
156static inline unsigned int cpufreq_get(unsigned int cpu)
157{
158 return 0;
159}
160static inline unsigned int cpufreq_quick_get(unsigned int cpu)
161{
162 return 0;
163}
164static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
165{
166 return 0;
167}
168static inline void disable_cpufreq(void) { }
169#endif
170
171/*********************************************************************
172 * CPUFREQ DRIVER INTERFACE *
173 *********************************************************************/
174
175#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
176#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
177
178struct freq_attr {
179 struct attribute attr;
180 ssize_t (*show)(struct cpufreq_policy *, char *);
181 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
182};
183
184#define cpufreq_freq_attr_ro(_name) \
185static struct freq_attr _name = \
186__ATTR(_name, 0444, show_##_name, NULL)
187
188#define cpufreq_freq_attr_ro_perm(_name, _perm) \
189static struct freq_attr _name = \
190__ATTR(_name, _perm, show_##_name, NULL)
191
192#define cpufreq_freq_attr_rw(_name) \
193static struct freq_attr _name = \
194__ATTR(_name, 0644, show_##_name, store_##_name)
195
196struct global_attr {
197 struct attribute attr;
198 ssize_t (*show)(struct kobject *kobj,
199 struct attribute *attr, char *buf);
200 ssize_t (*store)(struct kobject *a, struct attribute *b,
201 const char *c, size_t count);
202};
203
204#define define_one_global_ro(_name) \
205static struct global_attr _name = \
206__ATTR(_name, 0444, show_##_name, NULL)
207
208#define define_one_global_rw(_name) \
209static struct global_attr _name = \
210__ATTR(_name, 0644, show_##_name, store_##_name)
211
212
213struct cpufreq_driver {
214 char name[CPUFREQ_NAME_LEN];
215 u8 flags;
216
217 /* needed by all drivers */
218 int (*init) (struct cpufreq_policy *policy);
219 int (*verify) (struct cpufreq_policy *policy);
220
221 /* define one out of two */
222 int (*setpolicy) (struct cpufreq_policy *policy);
223 int (*target) (struct cpufreq_policy *policy, /* Deprecated */
224 unsigned int target_freq,
225 unsigned int relation);
226 int (*target_index) (struct cpufreq_policy *policy,
227 unsigned int index);
228
229 /* should be defined, if possible */
230 unsigned int (*get) (unsigned int cpu);
231
232 /* optional */
233 int (*bios_limit) (int cpu, unsigned int *limit);
234
235 int (*exit) (struct cpufreq_policy *policy);
236 void (*stop_cpu) (struct cpufreq_policy *policy);
237 int (*suspend) (struct cpufreq_policy *policy);
238 int (*resume) (struct cpufreq_policy *policy);
239 struct freq_attr **attr;
240
241 /* platform specific boost support code */
242 bool boost_supported;
243 bool boost_enabled;
244 int (*set_boost) (int state);
245};
246
247/* flags */
248#define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
249 all ->init() calls failed */
250#define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
251 kernel "constants" aren't
252 affected by frequency
253 transitions */
254#define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
255 speed mismatches */
256
257/*
258 * This should be set by platforms having multiple clock-domains, i.e.
259 * supporting multiple policies. With this sysfs directories of governor would
260 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
261 * governor with different tunables for different clusters.
262 */
263#define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
264
265/*
266 * Driver will do POSTCHANGE notifications from outside of their ->target()
267 * routine and so must set cpufreq_driver->flags with this flag, so that core
268 * can handle them specially.
269 */
270#define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
271
272/*
273 * Set by drivers which want cpufreq core to check if CPU is running at a
274 * frequency present in freq-table exposed by the driver. For these drivers if
275 * CPU is found running at an out of table freq, we will try to set it to a freq
276 * from the table. And if that fails, we will stop further boot process by
277 * issuing a BUG_ON().
278 */
279#define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
280
281int cpufreq_register_driver(struct cpufreq_driver *driver_data);
282int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
283
284const char *cpufreq_get_current_driver(void);
285
286static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
287 unsigned int min, unsigned int max)
288{
289 if (policy->min < min)
290 policy->min = min;
291 if (policy->max < min)
292 policy->max = min;
293 if (policy->min > max)
294 policy->min = max;
295 if (policy->max > max)
296 policy->max = max;
297 if (policy->min > policy->max)
298 policy->min = policy->max;
299 return;
300}
301
302static inline void
303cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
304{
305 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
306 policy->cpuinfo.max_freq);
307}
308
309#ifdef CONFIG_CPU_FREQ
310void cpufreq_suspend(void);
311void cpufreq_resume(void);
312int cpufreq_generic_suspend(struct cpufreq_policy *policy);
313#else
314static inline void cpufreq_suspend(void) {}
315static inline void cpufreq_resume(void) {}
316#endif
317
318/*********************************************************************
319 * CPUFREQ NOTIFIER INTERFACE *
320 *********************************************************************/
321
322#define CPUFREQ_TRANSITION_NOTIFIER (0)
323#define CPUFREQ_POLICY_NOTIFIER (1)
324
325/* Transition notifiers */
326#define CPUFREQ_PRECHANGE (0)
327#define CPUFREQ_POSTCHANGE (1)
328
329/* Policy Notifiers */
330#define CPUFREQ_ADJUST (0)
331#define CPUFREQ_INCOMPATIBLE (1)
332#define CPUFREQ_NOTIFY (2)
333#define CPUFREQ_START (3)
334#define CPUFREQ_UPDATE_POLICY_CPU (4)
335#define CPUFREQ_CREATE_POLICY (5)
336#define CPUFREQ_REMOVE_POLICY (6)
337
338#ifdef CONFIG_CPU_FREQ
339int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
340int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
341
342void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
343 struct cpufreq_freqs *freqs);
344void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
345 struct cpufreq_freqs *freqs, int transition_failed);
346
347#else /* CONFIG_CPU_FREQ */
348static inline int cpufreq_register_notifier(struct notifier_block *nb,
349 unsigned int list)
350{
351 return 0;
352}
353static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
354 unsigned int list)
355{
356 return 0;
357}
358#endif /* !CONFIG_CPU_FREQ */
359
360/**
361 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
362 * safe)
363 * @old: old value
364 * @div: divisor
365 * @mult: multiplier
366 *
367 *
368 * new = old * mult / div
369 */
370static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
371 u_int mult)
372{
373#if BITS_PER_LONG == 32
374 u64 result = ((u64) old) * ((u64) mult);
375 do_div(result, div);
376 return (unsigned long) result;
377
378#elif BITS_PER_LONG == 64
379 unsigned long result = old * ((u64) mult);
380 result /= div;
381 return result;
382#endif
383}
384
385/*********************************************************************
386 * CPUFREQ GOVERNORS *
387 *********************************************************************/
388
389/*
390 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
391 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
392 * two generic policies are available:
393 */
394#define CPUFREQ_POLICY_POWERSAVE (1)
395#define CPUFREQ_POLICY_PERFORMANCE (2)
396
397/* Governor Events */
398#define CPUFREQ_GOV_START 1
399#define CPUFREQ_GOV_STOP 2
400#define CPUFREQ_GOV_LIMITS 3
401#define CPUFREQ_GOV_POLICY_INIT 4
402#define CPUFREQ_GOV_POLICY_EXIT 5
403
404struct cpufreq_governor {
405 char name[CPUFREQ_NAME_LEN];
406 int initialized;
407 int (*governor) (struct cpufreq_policy *policy,
408 unsigned int event);
409 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
410 char *buf);
411 int (*store_setspeed) (struct cpufreq_policy *policy,
412 unsigned int freq);
413 unsigned int max_transition_latency; /* HW must be able to switch to
414 next freq faster than this value in nano secs or we
415 will fallback to performance governor */
416 struct list_head governor_list;
417 struct module *owner;
418};
419
420/* Pass a target to the cpufreq driver */
421int cpufreq_driver_target(struct cpufreq_policy *policy,
422 unsigned int target_freq,
423 unsigned int relation);
424int __cpufreq_driver_target(struct cpufreq_policy *policy,
425 unsigned int target_freq,
426 unsigned int relation);
427int cpufreq_register_governor(struct cpufreq_governor *governor);
428void cpufreq_unregister_governor(struct cpufreq_governor *governor);
429
430/* CPUFREQ DEFAULT GOVERNOR */
431/*
432 * Performance governor is fallback governor if any other gov failed to auto
433 * load due latency restrictions
434 */
435#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
436extern struct cpufreq_governor cpufreq_gov_performance;
437#endif
438#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
439#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
440#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
441extern struct cpufreq_governor cpufreq_gov_powersave;
442#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
443#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
444extern struct cpufreq_governor cpufreq_gov_userspace;
445#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
446#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
447extern struct cpufreq_governor cpufreq_gov_ondemand;
448#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
449#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
450extern struct cpufreq_governor cpufreq_gov_conservative;
451#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
452#endif
453
454/*********************************************************************
455 * FREQUENCY TABLE HELPERS *
456 *********************************************************************/
457
458/* Special Values of .frequency field */
459#define CPUFREQ_ENTRY_INVALID ~0
460#define CPUFREQ_TABLE_END ~1
461/* Special Values of .flags field */
462#define CPUFREQ_BOOST_FREQ (1 << 0)
463
464struct cpufreq_frequency_table {
465 unsigned int flags;
466 unsigned int driver_data; /* driver specific data, not used by core */
467 unsigned int frequency; /* kHz - doesn't need to be in ascending
468 * order */
469};
470
471int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
472 struct cpufreq_frequency_table *table);
473
474int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
475 struct cpufreq_frequency_table *table);
476int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
477
478int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
479 struct cpufreq_frequency_table *table,
480 unsigned int target_freq,
481 unsigned int relation,
482 unsigned int *index);
483int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
484 unsigned int freq);
485
486ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
487
488#ifdef CONFIG_CPU_FREQ
489int cpufreq_boost_trigger_state(int state);
490int cpufreq_boost_supported(void);
491int cpufreq_boost_enabled(void);
492#else
493static inline int cpufreq_boost_trigger_state(int state)
494{
495 return 0;
496}
497static inline int cpufreq_boost_supported(void)
498{
499 return 0;
500}
501static inline int cpufreq_boost_enabled(void)
502{
503 return 0;
504}
505#endif
506/* the following funtion is for cpufreq core use only */
507struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
508
509/* the following are really really optional */
510extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
511extern struct freq_attr *cpufreq_generic_attr[];
512int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
513 struct cpufreq_frequency_table *table);
514
515unsigned int cpufreq_generic_get(unsigned int cpu);
516int cpufreq_generic_init(struct cpufreq_policy *policy,
517 struct cpufreq_frequency_table *table,
518 unsigned int transition_latency);
519#endif /* _LINUX_CPUFREQ_H */