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  *
   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 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  36 int 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
  57 struct cpufreq_governor;
  58
  59 #define CPUFREQ_ETERNAL                 (-1)
  60 struct cpufreq_cpuinfo {
  61         unsigned int            max_freq;
  62         unsigned int            min_freq;
  63         unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  64 };
  65
  66 struct 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
  73 struct 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_ALL (0) /* All dependent CPUs should set freq */
 104 #define CPUFREQ_SHARED_TYPE_ANY (1) /* Freq can be set from any dependent CPU */
 105
 106 /******************** cpufreq transition notifiers *******************/
 107
 108 #define CPUFREQ_PRECHANGE       (0)
 109 #define CPUFREQ_POSTCHANGE      (1)
 110 #define CPUFREQ_RESUMECHANGE    (8)
 111 #define CPUFREQ_SUSPENDCHANGE   (9)
 112
 113 struct cpufreq_freqs {
 114         unsigned int cpu;       /* cpu nr */
 115         unsigned int old;
 116         unsigned int new;
 117         u8 flags;               /* flags of cpufreq_driver, see below. */
 118 };
 119
 120
 121 /**
 122  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 123  * @old:   old value
 124  * @div:   divisor
 125  * @mult:  multiplier
 126  *
 127  *
 128  *    new = old * mult / div
 129  */
 130 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 131 {
 132 #if BITS_PER_LONG == 32
 133
 134         u64 result = ((u64) old) * ((u64) mult);
 135         do_div(result, div);
 136         return (unsigned long) result;
 137
 138 #elif BITS_PER_LONG == 64
 139
 140         unsigned long result = old * ((u64) mult);
 141         result /= div;
 142         return result;
 143
 144 #endif
 145 };
 146
 147 /*********************************************************************
 148  *                          CPUFREQ GOVERNORS                        *
 149  *********************************************************************/
 150
 151 #define CPUFREQ_GOV_START  1
 152 #define CPUFREQ_GOV_STOP   2
 153 #define CPUFREQ_GOV_LIMITS 3
 154
 155 struct cpufreq_governor {
 156         char    name[CPUFREQ_NAME_LEN];
 157         int     (*governor)     (struct cpufreq_policy *policy,
 158                                  unsigned int event);
 159         struct list_head        governor_list;
 160         struct module           *owner;
 161 };
 162
 163 /* pass a target to the cpufreq driver
 164  */
 165 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 166                                  unsigned int target_freq,
 167                                  unsigned int relation);
 168 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 169                                    unsigned int target_freq,
 170                                    unsigned int relation);
 171
 172
 173 /* pass an event to the cpufreq governor */
 174 int cpufreq_governor(unsigned int cpu, unsigned int event);
 175
 176 int cpufreq_register_governor(struct cpufreq_governor *governor);
 177 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 178
 179
 180 /*********************************************************************
 181  *                      CPUFREQ DRIVER INTERFACE                     *
 182  *********************************************************************/
 183
 184 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 185 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 186
 187 struct freq_attr;
 188
 189 struct cpufreq_driver {
 190         struct module           *owner;
 191         char                    name[CPUFREQ_NAME_LEN];
 192         u8                      flags;
 193
 194         /* needed by all drivers */
 195         int     (*init)         (struct cpufreq_policy *policy);
 196         int     (*verify)       (struct cpufreq_policy *policy);
 197
 198         /* define one out of two */
 199         int     (*setpolicy)    (struct cpufreq_policy *policy);
 200         int     (*target)       (struct cpufreq_policy *policy,
 201                                  unsigned int target_freq,
 202                                  unsigned int relation);
 203
 204         /* should be defined, if possible */
 205         unsigned int    (*get)  (unsigned int cpu);
 206
 207         /* optional */
 208         int     (*exit)         (struct cpufreq_policy *policy);
 209         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 210         int     (*resume)       (struct cpufreq_policy *policy);
 211         struct freq_attr        **attr;
 212 };
 213
 214 /* flags */
 215
 216 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 217                                          * all ->init() calls failed */
 218 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 219                                          * "constants" aren't affected by
 220                                          * frequency transitions */
 221 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 222                                          * mismatches */
 223
 224 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 225 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 226
 227
 228 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 229
 230
 231 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 232 {
 233         if (policy->min < min)
 234                 policy->min = min;
 235         if (policy->max < min)
 236                 policy->max = min;
 237         if (policy->min > max)
 238                 policy->min = max;
 239         if (policy->max > max)
 240                 policy->max = max;
 241         if (policy->min > policy->max)
 242                 policy->min = policy->max;
 243         return;
 244 }
 245
 246 struct freq_attr {
 247         struct attribute attr;
 248         ssize_t (*show)(struct cpufreq_policy *, char *);
 249         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 250 };
 251
 252
 253 /*********************************************************************
 254  *                        CPUFREQ 2.6. INTERFACE                     *
 255  *********************************************************************/
 256 int cpufreq_set_policy(struct cpufreq_policy *policy);
 257 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 258 int cpufreq_update_policy(unsigned int cpu);
 259
 260 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 261 unsigned int cpufreq_get(unsigned int cpu);
 262
 263 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 264 #ifdef CONFIG_CPU_FREQ
 265 unsigned int cpufreq_quick_get(unsigned int cpu);
 266 #else
 267 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 268 {
 269         return 0;
 270 }
 271 #endif
 272
 273
 274 /*********************************************************************
 275  *                       CPUFREQ DEFAULT GOVERNOR                    *
 276  *********************************************************************/
 277
 278
 279 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 280 extern struct cpufreq_governor cpufreq_gov_performance;
 281 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_performance
 282 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 283 extern struct cpufreq_governor cpufreq_gov_userspace;
 284 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_userspace
 285 #endif
 286
 287
 288 /*********************************************************************
 289  *                     FREQUENCY TABLE HELPERS                       *
 290  *********************************************************************/
 291
 292 #define CPUFREQ_ENTRY_INVALID ~0
 293 #define CPUFREQ_TABLE_END     ~1
 294
 295 struct cpufreq_frequency_table {
 296         unsigned int    index;     /* any */
 297         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 298                                     * order */
 299 };
 300
 301 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 302                                     struct cpufreq_frequency_table *table);
 303
 304 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 305                                    struct cpufreq_frequency_table *table);
 306
 307 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 308                                    struct cpufreq_frequency_table *table,
 309                                    unsigned int target_freq,
 310                                    unsigned int relation,
 311                                    unsigned int *index);
 312
 313 /* the following 3 funtions are for cpufreq core use only */
 314 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 315 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 316 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 317
 318 /* the following are really really optional */
 319 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 320
 321 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 322                                       unsigned int cpu);
 323
 324 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 325
 326
 327 /*********************************************************************
 328  *                     UNIFIED DEBUG HELPERS                         *
 329  *********************************************************************/
 330
 331 #define CPUFREQ_DEBUG_CORE      1
 332 #define CPUFREQ_DEBUG_DRIVER    2
 333 #define CPUFREQ_DEBUG_GOVERNOR  4
 334
 335 #ifdef CONFIG_CPU_FREQ_DEBUG
 336
 337 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 338                                  const char *fmt, ...);
 339
 340 #else
 341
 342 #define cpufreq_debug_printk(msg...) do { } while(0)
 343
 344 #endif /* CONFIG_CPU_FREQ_DEBUG */
 345
 346 #endif /* _LINUX_CPUFREQ_H */