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_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
 115 struct 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  */
 132 static 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
 157 struct 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  */
 167 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 168                                  unsigned int target_freq,
 169                                  unsigned int relation);
 170 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 171                                    unsigned int target_freq,
 172                                    unsigned int relation);
 173
 174
 175 int cpufreq_register_governor(struct cpufreq_governor *governor);
 176 void 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
 186 struct freq_attr;
 187
 188 struct 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
 223 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 224 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 225
 226
 227 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 228
 229
 230 static 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
 245 struct 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  *********************************************************************/
 255 int cpufreq_set_policy(struct cpufreq_policy *policy);
 256 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 257 int cpufreq_update_policy(unsigned int cpu);
 258
 259 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 260 unsigned 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
 264 unsigned int cpufreq_quick_get(unsigned int cpu);
 265 #else
 266 static 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
 279 extern struct cpufreq_governor cpufreq_gov_performance;
 280 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_performance
 281 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 282 extern 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
 294 struct cpufreq_frequency_table {
 295         unsigned int    index;     /* any */
 296         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 297                                     * order */
 298 };
 299
 300 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 301                                     struct cpufreq_frequency_table *table);
 302
 303 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 304                                    struct cpufreq_frequency_table *table);
 305
 306 int 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 */
 313 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 314 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 315 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 316
 317 /* the following are really really optional */
 318 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 319
 320 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 321                                       unsigned int cpu);
 322
 323 void 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
 336 extern 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 */