1 /* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <[email protected]> 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 */ 344