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/config.h>
  19 #include <linux/notifier.h>
  20 #include <linux/threads.h>
  21 #include <linux/device.h>
  22 #include <linux/kobject.h>
  23 #include <linux/sysfs.h>
  24 #include <linux/completion.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/cpumask.h>
  27 #include <asm/div64.h>
  28
  29 #define CPUFREQ_NAME_LEN 16
  30
  31
  32 /*********************************************************************
  33  *                     CPUFREQ NOTIFIER INTERFACE                    *
  34  *********************************************************************/
  35
  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
  39 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  40 #define CPUFREQ_POLICY_NOTIFIER         (1)
  41
  42
  43 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  44  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  45  * two generic policies are available:
  46  */
  47
  48 #define CPUFREQ_POLICY_POWERSAVE        (1)
  49 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  50
  51 /* Frequency values here are CPU kHz so that hardware which doesn't run
  52  * with some frequencies can complain without having to guess what per
  53  * cent / per mille means.
  54  * Maximum transition latency is in nanoseconds - if it's unknown,
  55  * CPUFREQ_ETERNAL shall be used.
  56  */
  57
  58 struct cpufreq_governor;
  59
  60 #define CPUFREQ_ETERNAL                 (-1)
  61 struct cpufreq_cpuinfo {
  62         unsigned int            max_freq;
  63         unsigned int            min_freq;
  64         unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  65 };
  66
  67 struct cpufreq_real_policy {
  68         unsigned int            min;    /* in kHz */
  69         unsigned int            max;    /* in kHz */
  70         unsigned int            policy; /* see above */
  71         struct cpufreq_governor *governor; /* see below */
  72 };
  73
  74 struct cpufreq_policy {
  75         cpumask_t               cpus;   /* affected CPUs */
  76         unsigned int            cpu;    /* cpu nr of registered CPU */
  77         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  78
  79         unsigned int            min;    /* in kHz */
  80         unsigned int            max;    /* in kHz */
  81         unsigned int            cur;    /* in kHz, only needed if cpufreq
  82                                          * governors are used */
  83         unsigned int            policy; /* see above */
  84         struct cpufreq_governor *governor; /* see below */
  85
  86         struct mutex            lock;   /* CPU ->setpolicy or ->target may
  87                                            only be called once a time */
  88
  89         struct work_struct      update; /* if update_policy() needs to be
  90                                          * called, but you're in IRQ context */
  91
  92         struct cpufreq_real_policy      user_policy;
  93
  94         struct kobject          kobj;
  95         struct completion       kobj_unregister;
  96 };
  97
  98 #define CPUFREQ_ADJUST          (0)
  99 #define CPUFREQ_INCOMPATIBLE    (1)
 100 #define CPUFREQ_NOTIFY          (2)
 101
 102
 103 /******************** cpufreq transition notifiers *******************/
 104
 105 #define CPUFREQ_PRECHANGE       (0)
 106 #define CPUFREQ_POSTCHANGE      (1)
 107 #define CPUFREQ_RESUMECHANGE    (8)
 108 #define CPUFREQ_SUSPENDCHANGE   (9)
 109
 110 struct cpufreq_freqs {
 111         unsigned int cpu;       /* cpu nr */
 112         unsigned int old;
 113         unsigned int new;
 114         u8 flags;               /* flags of cpufreq_driver, see below. */
 115 };
 116
 117
 118 /**
 119  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 120  * @old:   old value
 121  * @div:   divisor
 122  * @mult:  multiplier
 123  *
 124  *
 125  *    new = old * mult / div
 126  */
 127 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 128 {
 129 #if BITS_PER_LONG == 32
 130
 131         u64 result = ((u64) old) * ((u64) mult);
 132         do_div(result, div);
 133         return (unsigned long) result;
 134
 135 #elif BITS_PER_LONG == 64
 136
 137         unsigned long result = old * ((u64) mult);
 138         result /= div;
 139         return result;
 140
 141 #endif
 142 };
 143
 144 /*********************************************************************
 145  *                          CPUFREQ GOVERNORS                        *
 146  *********************************************************************/
 147
 148 #define CPUFREQ_GOV_START  1
 149 #define CPUFREQ_GOV_STOP   2
 150 #define CPUFREQ_GOV_LIMITS 3
 151
 152 struct cpufreq_governor {
 153         char    name[CPUFREQ_NAME_LEN];
 154         int     (*governor)     (struct cpufreq_policy *policy,
 155                                  unsigned int event);
 156         struct list_head        governor_list;
 157         struct module           *owner;
 158 };
 159
 160 /* pass a target to the cpufreq driver
 161  */
 162 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 163                                  unsigned int target_freq,
 164                                  unsigned int relation);
 165 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 166                                    unsigned int target_freq,
 167                                    unsigned int relation);
 168
 169
 170 /* pass an event to the cpufreq governor */
 171 int cpufreq_governor(unsigned int cpu, unsigned int event);
 172
 173 int cpufreq_register_governor(struct cpufreq_governor *governor);
 174 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 175
 176
 177 /*********************************************************************
 178  *                      CPUFREQ DRIVER INTERFACE                     *
 179  *********************************************************************/
 180
 181 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 182 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 183
 184 struct freq_attr;
 185
 186 struct cpufreq_driver {
 187         struct module           *owner;
 188         char                    name[CPUFREQ_NAME_LEN];
 189         u8                      flags;
 190
 191         /* needed by all drivers */
 192         int     (*init)         (struct cpufreq_policy *policy);
 193         int     (*verify)       (struct cpufreq_policy *policy);
 194
 195         /* define one out of two */
 196         int     (*setpolicy)    (struct cpufreq_policy *policy);
 197         int     (*target)       (struct cpufreq_policy *policy,
 198                                  unsigned int target_freq,
 199                                  unsigned int relation);
 200
 201         /* should be defined, if possible */
 202         unsigned int    (*get)  (unsigned int cpu);
 203
 204         /* optional */
 205         int     (*exit)         (struct cpufreq_policy *policy);
 206         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 207         int     (*resume)       (struct cpufreq_policy *policy);
 208         struct freq_attr        **attr;
 209 };
 210
 211 /* flags */
 212
 213 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 214                                          * all ->init() calls failed */
 215 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 216                                          * "constants" aren't affected by
 217                                          * frequency transitions */
 218 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 219                                          * mismatches */
 220
 221 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 222 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 223
 224
 225 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 226
 227
 228 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 229 {
 230         if (policy->min < min)
 231                 policy->min = min;
 232         if (policy->max < min)
 233                 policy->max = min;
 234         if (policy->min > max)
 235                 policy->min = max;
 236         if (policy->max > max)
 237                 policy->max = max;
 238         if (policy->min > policy->max)
 239                 policy->min = policy->max;
 240         return;
 241 }
 242
 243 struct freq_attr {
 244         struct attribute attr;
 245         ssize_t (*show)(struct cpufreq_policy *, char *);
 246         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 247 };
 248
 249
 250 /*********************************************************************
 251  *                        CPUFREQ 2.6. INTERFACE                     *
 252  *********************************************************************/
 253 int cpufreq_set_policy(struct cpufreq_policy *policy);
 254 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 255 int cpufreq_update_policy(unsigned int cpu);
 256
 257 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 258 unsigned int cpufreq_get(unsigned int cpu);
 259
 260 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 261 #ifdef CONFIG_CPU_FREQ
 262 unsigned int cpufreq_quick_get(unsigned int cpu);
 263 #else
 264 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 265 {
 266         return 0;
 267 }
 268 #endif
 269
 270
 271 /*********************************************************************
 272  *                       CPUFREQ DEFAULT GOVERNOR                    *
 273  *********************************************************************/
 274
 275
 276 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 277 extern struct cpufreq_governor cpufreq_gov_performance;
 278 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_performance
 279 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 280 extern struct cpufreq_governor cpufreq_gov_userspace;
 281 #define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_userspace
 282 #endif
 283
 284
 285 /*********************************************************************
 286  *                     FREQUENCY TABLE HELPERS                       *
 287  *********************************************************************/
 288
 289 #define CPUFREQ_ENTRY_INVALID ~0
 290 #define CPUFREQ_TABLE_END     ~1
 291
 292 struct cpufreq_frequency_table {
 293         unsigned int    index;     /* any */
 294         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 295                                     * order */
 296 };
 297
 298 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 299                                     struct cpufreq_frequency_table *table);
 300
 301 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 302                                    struct cpufreq_frequency_table *table);
 303
 304 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 305                                    struct cpufreq_frequency_table *table,
 306                                    unsigned int target_freq,
 307                                    unsigned int relation,
 308                                    unsigned int *index);
 309
 310 /* the following 3 funtions are for cpufreq core use only */
 311 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 312 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 313 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 314
 315 /* the following are really really optional */
 316 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 317
 318 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 319                                       unsigned int cpu);
 320
 321 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 322
 323
 324 /*********************************************************************
 325  *                     UNIFIED DEBUG HELPERS                         *
 326  *********************************************************************/
 327
 328 #define CPUFREQ_DEBUG_CORE      1
 329 #define CPUFREQ_DEBUG_DRIVER    2
 330 #define CPUFREQ_DEBUG_GOVERNOR  4
 331
 332 #ifdef CONFIG_CPU_FREQ_DEBUG
 333
 334 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 335                                  const char *fmt, ...);
 336
 337 #else
 338
 339 #define cpufreq_debug_printk(msg...) do { } while(0)
 340
 341 #endif /* CONFIG_CPU_FREQ_DEBUG */
 342
 343 #endif /* _LINUX_CPUFREQ_H */