gpio: gpiolib: Support for open source/emitter gpios
[linux-2.6.git] / include / linux / cpufreq.h
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/mutex.h>
15 #include <linux/notifier.h>
16 #include <linux/threads.h>
17 #include <linux/device.h>
18 #include <linux/kobject.h>
19 #include <linux/sysfs.h>
20 #include <linux/completion.h>
21 #include <linux/workqueue.h>
22 #include <linux/cpumask.h>
23 #include <asm/div64.h>
24
25 #define CPUFREQ_NAME_LEN 16
26
27
28 /*********************************************************************
29  *                     CPUFREQ NOTIFIER INTERFACE                    *
30  *********************************************************************/
31
32 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
33 #define CPUFREQ_POLICY_NOTIFIER         (1)
34
35 #ifdef CONFIG_CPU_FREQ
36 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
37 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
38 #else           /* CONFIG_CPU_FREQ */
39 static inline int cpufreq_register_notifier(struct notifier_block *nb,
40                                                 unsigned int list)
41 {
42         return 0;
43 }
44 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
45                                                 unsigned int list)
46 {
47         return 0;
48 }
49 #endif          /* CONFIG_CPU_FREQ */
50
51 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
52  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
53  * two generic policies are available:
54  */
55
56 #define CPUFREQ_POLICY_POWERSAVE        (1)
57 #define CPUFREQ_POLICY_PERFORMANCE      (2)
58
59 /* Frequency values here are CPU kHz so that hardware which doesn't run
60  * with some frequencies can complain without having to guess what per
61  * cent / per mille means.
62  * Maximum transition latency is in nanoseconds - if it's unknown,
63  * CPUFREQ_ETERNAL shall be used.
64  */
65
66 struct cpufreq_governor;
67
68 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
69 extern struct kobject *cpufreq_global_kobject;
70
71 #define CPUFREQ_ETERNAL                 (-1)
72 struct cpufreq_cpuinfo {
73         unsigned int            max_freq;
74         unsigned int            min_freq;
75
76         /* in 10^(-9) s = nanoseconds */
77         unsigned int            transition_latency;
78 };
79
80 struct cpufreq_real_policy {
81         unsigned int            min;    /* in kHz */
82         unsigned int            max;    /* in kHz */
83         unsigned int            policy; /* see above */
84         struct cpufreq_governor *governor; /* see below */
85 };
86
87 struct cpufreq_policy {
88         cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
89         cpumask_var_t           related_cpus; /* CPUs with any coordination */
90         unsigned int            shared_type; /* ANY or ALL affected CPUs
91                                                 should set cpufreq */
92         unsigned int            cpu;    /* cpu nr of registered CPU */
93         struct cpufreq_cpuinfo  cpuinfo;/* see above */
94
95         unsigned int            min;    /* in kHz */
96         unsigned int            max;    /* in kHz */
97         unsigned int            cur;    /* in kHz, only needed if cpufreq
98                                          * governors are used */
99         unsigned int            policy; /* see above */
100         struct cpufreq_governor *governor; /* see below */
101
102         struct work_struct      update; /* if update_policy() needs to be
103                                          * called, but you're in IRQ context */
104
105         struct cpufreq_real_policy      user_policy;
106
107         struct kobject          kobj;
108         struct completion       kobj_unregister;
109 };
110
111 #define CPUFREQ_ADJUST          (0)
112 #define CPUFREQ_INCOMPATIBLE    (1)
113 #define CPUFREQ_NOTIFY          (2)
114 #define CPUFREQ_START           (3)
115
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 /******************** cpufreq transition notifiers *******************/
122
123 #define CPUFREQ_PRECHANGE       (0)
124 #define CPUFREQ_POSTCHANGE      (1)
125 #define CPUFREQ_RESUMECHANGE    (8)
126 #define CPUFREQ_SUSPENDCHANGE   (9)
127
128 struct cpufreq_freqs {
129         unsigned int cpu;       /* cpu nr */
130         unsigned int old;
131         unsigned int new;
132         u8 flags;               /* flags of cpufreq_driver, see below. */
133 };
134
135
136 /**
137  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
138  * @old:   old value
139  * @div:   divisor
140  * @mult:  multiplier
141  *
142  *
143  *    new = old * mult / div
144  */
145 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
146 {
147 #if BITS_PER_LONG == 32
148
149         u64 result = ((u64) old) * ((u64) mult);
150         do_div(result, div);
151         return (unsigned long) result;
152
153 #elif BITS_PER_LONG == 64
154
155         unsigned long result = old * ((u64) mult);
156         result /= div;
157         return result;
158
159 #endif
160 };
161
162 /*********************************************************************
163  *                          CPUFREQ GOVERNORS                        *
164  *********************************************************************/
165
166 #define CPUFREQ_GOV_START  1
167 #define CPUFREQ_GOV_STOP   2
168 #define CPUFREQ_GOV_LIMITS 3
169
170 struct cpufreq_governor {
171         char    name[CPUFREQ_NAME_LEN];
172         int     (*governor)     (struct cpufreq_policy *policy,
173                                  unsigned int event);
174         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
175                                          char *buf);
176         int     (*store_setspeed)       (struct cpufreq_policy *policy,
177                                          unsigned int freq);
178         unsigned int max_transition_latency; /* HW must be able to switch to
179                         next freq faster than this value in nano secs or we
180                         will fallback to performance governor */
181         struct list_head        governor_list;
182         struct module           *owner;
183 };
184
185 /*
186  * Pass a target to the cpufreq driver.
187  */
188 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
189                                  unsigned int target_freq,
190                                  unsigned int relation);
191 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
192                                    unsigned int target_freq,
193                                    unsigned int relation);
194
195
196 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
197                                    unsigned int cpu);
198
199 int cpufreq_register_governor(struct cpufreq_governor *governor);
200 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
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
210 struct freq_attr;
211
212 struct 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)  (struct cpufreq_policy *policy,
232                                  unsigned int cpu);
233         int     (*bios_limit)   (int cpu, unsigned int *limit);
234
235         int     (*exit)         (struct cpufreq_policy *policy);
236         int     (*suspend)      (struct cpufreq_policy *policy);
237         int     (*resume)       (struct cpufreq_policy *policy);
238         struct freq_attr        **attr;
239 };
240
241 /* flags */
242
243 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
244                                          * all ->init() calls failed */
245 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
246                                          * "constants" aren't affected by
247                                          * frequency transitions */
248 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
249                                          * mismatches */
250
251 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
252 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
253
254
255 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
256
257
258 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
259 {
260         if (policy->min < min)
261                 policy->min = min;
262         if (policy->max < min)
263                 policy->max = min;
264         if (policy->min > max)
265                 policy->min = max;
266         if (policy->max > max)
267                 policy->max = max;
268         if (policy->min > policy->max)
269                 policy->min = policy->max;
270         return;
271 }
272
273 struct freq_attr {
274         struct attribute attr;
275         ssize_t (*show)(struct cpufreq_policy *, char *);
276         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
277 };
278
279 #define cpufreq_freq_attr_ro(_name)             \
280 static struct freq_attr _name =                 \
281 __ATTR(_name, 0444, show_##_name, NULL)
282
283 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
284 static struct freq_attr _name =                 \
285 __ATTR(_name, _perm, show_##_name, NULL)
286
287 #define cpufreq_freq_attr_rw(_name)             \
288 static struct freq_attr _name =                 \
289 __ATTR(_name, 0644, show_##_name, store_##_name)
290
291 struct global_attr {
292         struct attribute attr;
293         ssize_t (*show)(struct kobject *kobj,
294                         struct attribute *attr, char *buf);
295         ssize_t (*store)(struct kobject *a, struct attribute *b,
296                          const char *c, size_t count);
297 };
298
299 #define define_one_global_ro(_name)             \
300 static struct global_attr _name =               \
301 __ATTR(_name, 0444, show_##_name, NULL)
302
303 #define define_one_global_rw(_name)             \
304 static struct global_attr _name =               \
305 __ATTR(_name, 0644, show_##_name, store_##_name)
306
307
308 /*********************************************************************
309  *                        CPUFREQ 2.6. INTERFACE                     *
310  *********************************************************************/
311 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
312 int cpufreq_update_policy(unsigned int cpu);
313
314 #ifdef CONFIG_CPU_FREQ
315 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
316 unsigned int cpufreq_get(unsigned int cpu);
317 #else
318 static inline unsigned int cpufreq_get(unsigned int cpu)
319 {
320         return 0;
321 }
322 #endif
323
324 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
325 #ifdef CONFIG_CPU_FREQ
326 unsigned int cpufreq_quick_get(unsigned int cpu);
327 unsigned int cpufreq_quick_get_max(unsigned int cpu);
328 #else
329 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
330 {
331         return 0;
332 }
333 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
334 {
335         return 0;
336 }
337 #endif
338
339
340 /*********************************************************************
341  *                       CPUFREQ DEFAULT GOVERNOR                    *
342  *********************************************************************/
343
344
345 /*
346   Performance governor is fallback governor if any other gov failed to
347   auto load due latency restrictions
348 */
349 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
350 extern struct cpufreq_governor cpufreq_gov_performance;
351 #endif
352 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
353 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
354 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
355 extern struct cpufreq_governor cpufreq_gov_powersave;
356 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
357 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
358 extern struct cpufreq_governor cpufreq_gov_userspace;
359 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
360 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
361 extern struct cpufreq_governor cpufreq_gov_ondemand;
362 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
364 extern struct cpufreq_governor cpufreq_gov_conservative;
365 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
366 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE)
367 extern struct cpufreq_governor cpufreq_gov_interactive;
368 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_interactive)
369 #endif
370
371
372 /*********************************************************************
373  *                     FREQUENCY TABLE HELPERS                       *
374  *********************************************************************/
375
376 #define CPUFREQ_ENTRY_INVALID ~0
377 #define CPUFREQ_TABLE_END     ~1
378
379 struct cpufreq_frequency_table {
380         unsigned int    index;     /* any */
381         unsigned int    frequency; /* kHz - doesn't need to be in ascending
382                                     * order */
383 };
384
385 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
386                                     struct cpufreq_frequency_table *table);
387
388 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
389                                    struct cpufreq_frequency_table *table);
390
391 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
392                                    struct cpufreq_frequency_table *table,
393                                    unsigned int target_freq,
394                                    unsigned int relation,
395                                    unsigned int *index);
396
397 /* the following 3 funtions are for cpufreq core use only */
398 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
399 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
400 void   cpufreq_cpu_put(struct cpufreq_policy *data);
401
402 /* the following are really really optional */
403 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
404
405 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
406                                       unsigned int cpu);
407
408 void cpufreq_frequency_table_put_attr(unsigned int cpu);
409
410
411 #endif /* _LINUX_CPUFREQ_H */