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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 *
8 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14#ifndef _LINUX_CPUFREQ_H
15#define _LINUX_CPUFREQ_H
16
17#include <linux/mutex.h>
18#include <linux/notifier.h>
19#include <linux/threads.h>
20#include <linux/device.h>
21#include <linux/kobject.h>
22#include <linux/sysfs.h>
23#include <linux/completion.h>
24#include <linux/workqueue.h>
25#include <linux/cpumask.h>
26#include <asm/div64.h>
27
28#define CPUFREQ_NAME_LEN 16
29
30
31/*********************************************************************
32 * CPUFREQ NOTIFIER INTERFACE *
33 *********************************************************************/
34
35#define CPUFREQ_TRANSITION_NOTIFIER (0)
36#define CPUFREQ_POLICY_NOTIFIER (1)
37
38#ifdef CONFIG_CPU_FREQ
39int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
40int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
41#else /* CONFIG_CPU_FREQ */
42static inline int cpufreq_register_notifier(struct notifier_block *nb,
43 unsigned int list)
44{
45 return 0;
46}
47static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
48 unsigned int list)
49{
50 return 0;
51}
52#endif /* CONFIG_CPU_FREQ */
53
54/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
56 * two generic policies are available:
57 */
58
59#define CPUFREQ_POLICY_POWERSAVE (1)
60#define CPUFREQ_POLICY_PERFORMANCE (2)
61
62/* Frequency values here are CPU kHz so that hardware which doesn't run
63 * with some frequencies can complain without having to guess what per
64 * cent / per mille means.
65 * Maximum transition latency is in nanoseconds - if it's unknown,
66 * CPUFREQ_ETERNAL shall be used.
67 */
68
69struct cpufreq_governor;
70
71#define CPUFREQ_ETERNAL (-1)
72struct cpufreq_cpuinfo {
73 unsigned int max_freq;
74 unsigned int min_freq;
75 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
76};
77
78struct cpufreq_real_policy {
79 unsigned int min; /* in kHz */
80 unsigned int max; /* in kHz */
81 unsigned int policy; /* see above */
82 struct cpufreq_governor *governor; /* see below */
83};
84
85struct cpufreq_policy {
86 cpumask_t cpus; /* CPUs requiring sw coordination */
87 cpumask_t related_cpus; /* CPUs with any coordination */
88 unsigned int shared_type; /* ANY or ALL affected CPUs
89 should set cpufreq */
90 unsigned int cpu; /* cpu nr of registered CPU */
91 struct cpufreq_cpuinfo cpuinfo;/* see above */
92
93 unsigned int min; /* in kHz */
94 unsigned int max; /* in kHz */
95 unsigned int cur; /* in kHz, only needed if cpufreq
96 * governors are used */
97 unsigned int policy; /* see above */
98 struct cpufreq_governor *governor; /* see below */
99
100 struct work_struct update; /* if update_policy() needs to be
101 * called, but you're in IRQ context */
102
103 struct cpufreq_real_policy user_policy;
104
105 struct kobject kobj;
106 struct completion kobj_unregister;
107};
108
109#define CPUFREQ_ADJUST (0)
110#define CPUFREQ_INCOMPATIBLE (1)
111#define CPUFREQ_NOTIFY (2)
112
113#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
114#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
115#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
116#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
117
118/******************** cpufreq transition notifiers *******************/
119
120#define CPUFREQ_PRECHANGE (0)
121#define CPUFREQ_POSTCHANGE (1)
122#define CPUFREQ_RESUMECHANGE (8)
123#define CPUFREQ_SUSPENDCHANGE (9)
124
125struct cpufreq_freqs {
126 unsigned int cpu; /* cpu nr */
127 unsigned int old;
128 unsigned int new;
129 u8 flags; /* flags of cpufreq_driver, see below. */
130};
131
132
133/**
134 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
135 * @old: old value
136 * @div: divisor
137 * @mult: multiplier
138 *
139 *
140 * new = old * mult / div
141 */
142static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
143{
144#if BITS_PER_LONG == 32
145
146 u64 result = ((u64) old) * ((u64) mult);
147 do_div(result, div);
148 return (unsigned long) result;
149
150#elif BITS_PER_LONG == 64
151
152 unsigned long result = old * ((u64) mult);
153 result /= div;
154 return result;
155
156#endif
157};
158
159/*********************************************************************
160 * CPUFREQ GOVERNORS *
161 *********************************************************************/
162
163#define CPUFREQ_GOV_START 1
164#define CPUFREQ_GOV_STOP 2
165#define CPUFREQ_GOV_LIMITS 3
166
167struct cpufreq_governor {
168 char name[CPUFREQ_NAME_LEN];
169 int (*governor) (struct cpufreq_policy *policy,
170 unsigned int event);
171 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
172 char *buf);
173 int (*store_setspeed) (struct cpufreq_policy *policy,
174 unsigned int freq);
175 unsigned int max_transition_latency; /* HW must be able to switch to
176 next freq faster than this value in nano secs or we
177 will fallback to performance governor */
178 struct list_head governor_list;
179 struct module *owner;
180};
181
182/* pass a target to the cpufreq driver
183 */
184extern int cpufreq_driver_target(struct cpufreq_policy *policy,
185 unsigned int target_freq,
186 unsigned int relation);
187extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
188 unsigned int target_freq,
189 unsigned int relation);
190
191
192extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
193
194int cpufreq_register_governor(struct cpufreq_governor *governor);
195void cpufreq_unregister_governor(struct cpufreq_governor *governor);
196
197int lock_policy_rwsem_read(int cpu);
198int lock_policy_rwsem_write(int cpu);
199void unlock_policy_rwsem_read(int cpu);
200void unlock_policy_rwsem_write(int cpu);
201
202
203/*********************************************************************
204 * CPUFREQ DRIVER INTERFACE *
205 *********************************************************************/
206
207#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
208#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
209
210struct freq_attr;
211
212struct cpufreq_driver {
213 struct module *owner;
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,
224 unsigned int target_freq,
225 unsigned int relation);
226
227 /* should be defined, if possible */
228 unsigned int (*get) (unsigned int cpu);
229
230 /* optional */
231 unsigned int (*getavg) (unsigned int cpu);
232 int (*exit) (struct cpufreq_policy *policy);
233 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
234 int (*resume) (struct cpufreq_policy *policy);
235 struct freq_attr **attr;
236};
237
238/* flags */
239
240#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
241 * all ->init() calls failed */
242#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
243 * "constants" aren't affected by
244 * frequency transitions */
245#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
246 * mismatches */
247
248int cpufreq_register_driver(struct cpufreq_driver *driver_data);
249int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
250
251
252void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
253
254
255static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
256{
257 if (policy->min < min)
258 policy->min = min;
259 if (policy->max < min)
260 policy->max = min;
261 if (policy->min > max)
262 policy->min = max;
263 if (policy->max > max)
264 policy->max = max;
265 if (policy->min > policy->max)
266 policy->min = policy->max;
267 return;
268}
269
270struct freq_attr {
271 struct attribute attr;
272 ssize_t (*show)(struct cpufreq_policy *, char *);
273 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
274};
275
276
277/*********************************************************************
278 * CPUFREQ 2.6. INTERFACE *
279 *********************************************************************/
280int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
281int cpufreq_update_policy(unsigned int cpu);
282
283/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
284unsigned int cpufreq_get(unsigned int cpu);
285
286/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
287#ifdef CONFIG_CPU_FREQ
288unsigned int cpufreq_quick_get(unsigned int cpu);
289#else
290static inline unsigned int cpufreq_quick_get(unsigned int cpu)
291{
292 return 0;
293}
294#endif
295
296
297/*********************************************************************
298 * CPUFREQ DEFAULT GOVERNOR *
299 *********************************************************************/
300
301
302/*
303 Performance governor is fallback governor if any other gov failed to
304 auto load due latency restrictions
305*/
306#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
307extern struct cpufreq_governor cpufreq_gov_performance;
308#endif
309#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
310#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
311#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
312extern struct cpufreq_governor cpufreq_gov_powersave;
313#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
314#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
315extern struct cpufreq_governor cpufreq_gov_userspace;
316#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
317#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
318extern struct cpufreq_governor cpufreq_gov_ondemand;
319#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
320#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
321extern struct cpufreq_governor cpufreq_gov_conservative;
322#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
323#endif
324
325
326/*********************************************************************
327 * FREQUENCY TABLE HELPERS *
328 *********************************************************************/
329
330#define CPUFREQ_ENTRY_INVALID ~0
331#define CPUFREQ_TABLE_END ~1
332
333struct cpufreq_frequency_table {
334 unsigned int index; /* any */
335 unsigned int frequency; /* kHz - doesn't need to be in ascending
336 * order */
337};
338
339int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
340 struct cpufreq_frequency_table *table);
341
342int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
343 struct cpufreq_frequency_table *table);
344
345int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
346 struct cpufreq_frequency_table *table,
347 unsigned int target_freq,
348 unsigned int relation,
349 unsigned int *index);
350
351/* the following 3 funtions are for cpufreq core use only */
352struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
353struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
354void cpufreq_cpu_put (struct cpufreq_policy *data);
355
356/* the following are really really optional */
357extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
358
359void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
360 unsigned int cpu);
361
362void cpufreq_frequency_table_put_attr(unsigned int cpu);
363
364
365/*********************************************************************
366 * UNIFIED DEBUG HELPERS *
367 *********************************************************************/
368
369#define CPUFREQ_DEBUG_CORE 1
370#define CPUFREQ_DEBUG_DRIVER 2
371#define CPUFREQ_DEBUG_GOVERNOR 4
372
373#ifdef CONFIG_CPU_FREQ_DEBUG
374
375extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
376 const char *fmt, ...);
377
378#else
379
380#define cpufreq_debug_printk(msg...) do { } while(0)
381
382#endif /* CONFIG_CPU_FREQ_DEBUG */
383
384#endif /* _LINUX_CPUFREQ_H */