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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/config.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
27#define CPUFREQ_NAME_LEN 16
28
29
30/*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
33
34int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
35int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
36
37#define CPUFREQ_TRANSITION_NOTIFIER (0)
38#define CPUFREQ_POLICY_NOTIFIER (1)
39
40
41/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
42 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
43 * two generic policies are available:
44 */
45
46#define CPUFREQ_POLICY_POWERSAVE (1)
47#define CPUFREQ_POLICY_PERFORMANCE (2)
48
49/* Frequency values here are CPU kHz so that hardware which doesn't run
50 * with some frequencies can complain without having to guess what per
51 * cent / per mille means.
52 * Maximum transition latency is in microseconds - if it's unknown,
53 * CPUFREQ_ETERNAL shall be used.
54 */
55
56struct cpufreq_governor;
57
58#define CPUFREQ_ETERNAL (-1)
59struct cpufreq_cpuinfo {
60 unsigned int max_freq;
61 unsigned int min_freq;
62 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
63};
64
65struct cpufreq_real_policy {
66 unsigned int min; /* in kHz */
67 unsigned int max; /* in kHz */
68 unsigned int policy; /* see above */
69 struct cpufreq_governor *governor; /* see below */
70};
71
72struct cpufreq_policy {
73 cpumask_t cpus; /* affected CPUs */
74 unsigned int cpu; /* cpu nr of registered CPU */
75 struct cpufreq_cpuinfo cpuinfo;/* see above */
76
77 unsigned int min; /* in kHz */
78 unsigned int max; /* in kHz */
79 unsigned int cur; /* in kHz, only needed if cpufreq
80 * governors are used */
81 unsigned int policy; /* see above */
82 struct cpufreq_governor *governor; /* see below */
83
84 struct semaphore lock; /* CPU ->setpolicy or ->target may
85 only be called once a time */
86
87 struct work_struct update; /* if update_policy() needs to be
88 * called, but you're in IRQ context */
89
90 struct cpufreq_real_policy user_policy;
91
92 struct kobject kobj;
93 struct completion kobj_unregister;
94};
95
96#define CPUFREQ_ADJUST (0)
97#define CPUFREQ_INCOMPATIBLE (1)
98#define CPUFREQ_NOTIFY (2)
99
100
101/******************** cpufreq transition notifiers *******************/
102
103#define CPUFREQ_PRECHANGE (0)
104#define CPUFREQ_POSTCHANGE (1)
105#define CPUFREQ_RESUMECHANGE (8)
106
107struct cpufreq_freqs {
108 unsigned int cpu; /* cpu nr */
109 unsigned int old;
110 unsigned int new;
111 u8 flags; /* flags of cpufreq_driver, see below. */
112};
113
114
115/**
116 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
117 * @old: old value
118 * @div: divisor
119 * @mult: multiplier
120 *
121 *
122 * new = old * mult / div
123 */
124static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
125{
126#if BITS_PER_LONG == 32
127
128 u64 result = ((u64) old) * ((u64) mult);
129 do_div(result, div);
130 return (unsigned long) result;
131
132#elif BITS_PER_LONG == 64
133
134 unsigned long result = old * ((u64) mult);
135 result /= div;
136 return result;
137
138#endif
139};
140
141/*********************************************************************
142 * CPUFREQ GOVERNORS *
143 *********************************************************************/
144
145#define CPUFREQ_GOV_START 1
146#define CPUFREQ_GOV_STOP 2
147#define CPUFREQ_GOV_LIMITS 3
148
149struct cpufreq_governor {
150 char name[CPUFREQ_NAME_LEN];
151 int (*governor) (struct cpufreq_policy *policy,
152 unsigned int event);
153 struct list_head governor_list;
154 struct module *owner;
155};
156
157/* pass a target to the cpufreq driver
158 */
159extern int cpufreq_driver_target(struct cpufreq_policy *policy,
160 unsigned int target_freq,
161 unsigned int relation);
162extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
163 unsigned int target_freq,
164 unsigned int relation);
165
166
167/* pass an event to the cpufreq governor */
168int cpufreq_governor(unsigned int cpu, unsigned int event);
169
170int cpufreq_register_governor(struct cpufreq_governor *governor);
171void cpufreq_unregister_governor(struct cpufreq_governor *governor);
172
173
174/*********************************************************************
175 * CPUFREQ DRIVER INTERFACE *
176 *********************************************************************/
177
178#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
179#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
180
181struct freq_attr;
182
183struct cpufreq_driver {
184 struct module *owner;
185 char name[CPUFREQ_NAME_LEN];
186 u8 flags;
187
188 /* needed by all drivers */
189 int (*init) (struct cpufreq_policy *policy);
190 int (*verify) (struct cpufreq_policy *policy);
191
192 /* define one out of two */
193 int (*setpolicy) (struct cpufreq_policy *policy);
194 int (*target) (struct cpufreq_policy *policy,
195 unsigned int target_freq,
196 unsigned int relation);
197
198 /* should be defined, if possible */
199 unsigned int (*get) (unsigned int cpu);
200
201 /* optional */
202 int (*exit) (struct cpufreq_policy *policy);
203 int (*resume) (struct cpufreq_policy *policy);
204 struct freq_attr **attr;
205};
206
207/* flags */
208
209#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
210 * all ->init() calls failed */
211#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
212 * "constants" aren't affected by
213 * frequency transitions */
214
215
216int cpufreq_register_driver(struct cpufreq_driver *driver_data);
217int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
218
219
220void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
221
222
223static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
224{
225 if (policy->min < min)
226 policy->min = min;
227 if (policy->max < min)
228 policy->max = min;
229 if (policy->min > max)
230 policy->min = max;
231 if (policy->max > max)
232 policy->max = max;
233 if (policy->min > policy->max)
234 policy->min = policy->max;
235 return;
236}
237
238struct freq_attr {
239 struct attribute attr;
240 ssize_t (*show)(struct cpufreq_policy *, char *);
241 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
242};
243
244
245/*********************************************************************
246 * CPUFREQ 2.6. INTERFACE *
247 *********************************************************************/
248int cpufreq_set_policy(struct cpufreq_policy *policy);
249int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
250int cpufreq_update_policy(unsigned int cpu);
251
252/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
253unsigned int cpufreq_get(unsigned int cpu);
254
255
256/*********************************************************************
257 * CPUFREQ DEFAULT GOVERNOR *
258 *********************************************************************/
259
260
261#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
262extern struct cpufreq_governor cpufreq_gov_performance;
263#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
264#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
265extern struct cpufreq_governor cpufreq_gov_userspace;
266#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
267#endif
268
269
270/*********************************************************************
271 * FREQUENCY TABLE HELPERS *
272 *********************************************************************/
273
274#define CPUFREQ_ENTRY_INVALID ~0
275#define CPUFREQ_TABLE_END ~1
276
277struct cpufreq_frequency_table {
278 unsigned int index; /* any */
279 unsigned int frequency; /* kHz - doesn't need to be in ascending
280 * order */
281};
282
283int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
284 struct cpufreq_frequency_table *table);
285
286int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
287 struct cpufreq_frequency_table *table);
288
289int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
290 struct cpufreq_frequency_table *table,
291 unsigned int target_freq,
292 unsigned int relation,
293 unsigned int *index);
294
295/* the following 3 funtions are for cpufreq core use only */
296struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
297struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
298void cpufreq_cpu_put (struct cpufreq_policy *data);
299
300/* the following are really really optional */
301extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
302
303void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
304 unsigned int cpu);
305
306void cpufreq_frequency_table_put_attr(unsigned int cpu);
307
308
309/*********************************************************************
310 * UNIFIED DEBUG HELPERS *
311 *********************************************************************/
312
313#define CPUFREQ_DEBUG_CORE 1
314#define CPUFREQ_DEBUG_DRIVER 2
315#define CPUFREQ_DEBUG_GOVERNOR 4
316
317#ifdef CONFIG_CPU_FREQ_DEBUG
318
319extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
320 const char *fmt, ...);
321
322#else
323
324#define cpufreq_debug_printk(msg...) do { } while(0)
325
326#endif /* CONFIG_CPU_FREQ_DEBUG */
327
328#endif /* _LINUX_CPUFREQ_H */
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