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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
35int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
36int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
37
38#define CPUFREQ_TRANSITION_NOTIFIER (0)
39#define CPUFREQ_POLICY_NOTIFIER (1)
40
41
42/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
43 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
44 * two generic policies are available:
45 */
46
47#define CPUFREQ_POLICY_POWERSAVE (1)
48#define CPUFREQ_POLICY_PERFORMANCE (2)
49
50/* Frequency values here are CPU kHz so that hardware which doesn't run
51 * with some frequencies can complain without having to guess what per
52 * cent / per mille means.
53 * Maximum transition latency is in nanoseconds - if it's unknown,
54 * CPUFREQ_ETERNAL shall be used.
55 */
56
57struct cpufreq_governor;
58
59#define CPUFREQ_ETERNAL (-1)
60struct cpufreq_cpuinfo {
61 unsigned int max_freq;
62 unsigned int min_freq;
63 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
64};
65
66struct cpufreq_real_policy {
67 unsigned int min; /* in kHz */
68 unsigned int max; /* in kHz */
69 unsigned int policy; /* see above */
70 struct cpufreq_governor *governor; /* see below */
71};
72
73struct cpufreq_policy {
74 cpumask_t cpus; /* affected CPUs */
75 unsigned int shared_type; /* ANY or ALL affected CPUs
76 should set cpufreq */
77 unsigned int cpu; /* cpu nr of registered CPU */
78 struct cpufreq_cpuinfo cpuinfo;/* see above */
79
80 unsigned int min; /* in kHz */
81 unsigned int max; /* in kHz */
82 unsigned int cur; /* in kHz, only needed if cpufreq
83 * governors are used */
84 unsigned int policy; /* see above */
85 struct cpufreq_governor *governor; /* see below */
86
87 struct mutex lock; /* CPU ->setpolicy or ->target may
88 only be called once a time */
89
90 struct work_struct update; /* if update_policy() needs to be
91 * called, but you're in IRQ context */
92
93 struct cpufreq_real_policy user_policy;
94
95 struct kobject kobj;
96 struct completion kobj_unregister;
97};
98
99#define CPUFREQ_ADJUST (0)
100#define CPUFREQ_INCOMPATIBLE (1)
101#define CPUFREQ_NOTIFY (2)
102
103#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
104#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
105#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
106#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
107
108/******************** cpufreq transition notifiers *******************/
109
110#define CPUFREQ_PRECHANGE (0)
111#define CPUFREQ_POSTCHANGE (1)
112#define CPUFREQ_RESUMECHANGE (8)
113#define CPUFREQ_SUSPENDCHANGE (9)
114
115struct cpufreq_freqs {
116 unsigned int cpu; /* cpu nr */
117 unsigned int old;
118 unsigned int new;
119 u8 flags; /* flags of cpufreq_driver, see below. */
120};
121
122
123/**
124 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
125 * @old: old value
126 * @div: divisor
127 * @mult: multiplier
128 *
129 *
130 * new = old * mult / div
131 */
132static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
133{
134#if BITS_PER_LONG == 32
135
136 u64 result = ((u64) old) * ((u64) mult);
137 do_div(result, div);
138 return (unsigned long) result;
139
140#elif BITS_PER_LONG == 64
141
142 unsigned long result = old * ((u64) mult);
143 result /= div;
144 return result;
145
146#endif
147};
148
149/*********************************************************************
150 * CPUFREQ GOVERNORS *
151 *********************************************************************/
152
153#define CPUFREQ_GOV_START 1
154#define CPUFREQ_GOV_STOP 2
155#define CPUFREQ_GOV_LIMITS 3
156
157struct cpufreq_governor {
158 char name[CPUFREQ_NAME_LEN];
159 int (*governor) (struct cpufreq_policy *policy,
160 unsigned int event);
161 struct list_head governor_list;
162 struct module *owner;
163};
164
165/* pass a target to the cpufreq driver
166 */
167extern int cpufreq_driver_target(struct cpufreq_policy *policy,
168 unsigned int target_freq,
169 unsigned int relation);
170extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
171 unsigned int target_freq,
172 unsigned int relation);
173
174
175int cpufreq_register_governor(struct cpufreq_governor *governor);
176void cpufreq_unregister_governor(struct cpufreq_governor *governor);
177
178
179/*********************************************************************
180 * CPUFREQ DRIVER INTERFACE *
181 *********************************************************************/
182
183#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
184#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
185
186struct freq_attr;
187
188struct cpufreq_driver {
189 struct module *owner;
190 char name[CPUFREQ_NAME_LEN];
191 u8 flags;
192
193 /* needed by all drivers */
194 int (*init) (struct cpufreq_policy *policy);
195 int (*verify) (struct cpufreq_policy *policy);
196
197 /* define one out of two */
198 int (*setpolicy) (struct cpufreq_policy *policy);
199 int (*target) (struct cpufreq_policy *policy,
200 unsigned int target_freq,
201 unsigned int relation);
202
203 /* should be defined, if possible */
204 unsigned int (*get) (unsigned int cpu);
205
206 /* optional */
207 int (*exit) (struct cpufreq_policy *policy);
208 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
209 int (*resume) (struct cpufreq_policy *policy);
210 struct freq_attr **attr;
211};
212
213/* flags */
214
215#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
216 * all ->init() calls failed */
217#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
218 * "constants" aren't affected by
219 * frequency transitions */
220#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
221 * mismatches */
222
223int cpufreq_register_driver(struct cpufreq_driver *driver_data);
224int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
225
226
227void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
228
229
230static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
231{
232 if (policy->min < min)
233 policy->min = min;
234 if (policy->max < min)
235 policy->max = min;
236 if (policy->min > max)
237 policy->min = max;
238 if (policy->max > max)
239 policy->max = max;
240 if (policy->min > policy->max)
241 policy->min = policy->max;
242 return;
243}
244
245struct freq_attr {
246 struct attribute attr;
247 ssize_t (*show)(struct cpufreq_policy *, char *);
248 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
249};
250
251
252/*********************************************************************
253 * CPUFREQ 2.6. INTERFACE *
254 *********************************************************************/
255int cpufreq_set_policy(struct cpufreq_policy *policy);
256int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
257int cpufreq_update_policy(unsigned int cpu);
258
259/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
260unsigned int cpufreq_get(unsigned int cpu);
261
262/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
263#ifdef CONFIG_CPU_FREQ
264unsigned int cpufreq_quick_get(unsigned int cpu);
265#else
266static inline unsigned int cpufreq_quick_get(unsigned int cpu)
267{
268 return 0;
269}
270#endif
271
272
273/*********************************************************************
274 * CPUFREQ DEFAULT GOVERNOR *
275 *********************************************************************/
276
277
278#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
279extern struct cpufreq_governor cpufreq_gov_performance;
280#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
281#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
282extern struct cpufreq_governor cpufreq_gov_userspace;
283#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
284#endif
285
286
287/*********************************************************************
288 * FREQUENCY TABLE HELPERS *
289 *********************************************************************/
290
291#define CPUFREQ_ENTRY_INVALID ~0
292#define CPUFREQ_TABLE_END ~1
293
294struct cpufreq_frequency_table {
295 unsigned int index; /* any */
296 unsigned int frequency; /* kHz - doesn't need to be in ascending
297 * order */
298};
299
300int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
301 struct cpufreq_frequency_table *table);
302
303int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
304 struct cpufreq_frequency_table *table);
305
306int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
307 struct cpufreq_frequency_table *table,
308 unsigned int target_freq,
309 unsigned int relation,
310 unsigned int *index);
311
312/* the following 3 funtions are for cpufreq core use only */
313struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
314struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
315void cpufreq_cpu_put (struct cpufreq_policy *data);
316
317/* the following are really really optional */
318extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
319
320void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
321 unsigned int cpu);
322
323void cpufreq_frequency_table_put_attr(unsigned int cpu);
324
325
326/*********************************************************************
327 * UNIFIED DEBUG HELPERS *
328 *********************************************************************/
329
330#define CPUFREQ_DEBUG_CORE 1
331#define CPUFREQ_DEBUG_DRIVER 2
332#define CPUFREQ_DEBUG_GOVERNOR 4
333
334#ifdef CONFIG_CPU_FREQ_DEBUG
335
336extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
337 const char *fmt, ...);
338
339#else
340
341#define cpufreq_debug_printk(msg...) do { } while(0)
342
343#endif /* CONFIG_CPU_FREQ_DEBUG */
344
345#endif /* _LINUX_CPUFREQ_H */