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/config.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 27 #define CPUFREQ_NAME_LEN 16 28 29 30 /********************************************************************* 31 * CPUFREQ NOTIFIER INTERFACE * 32 *********************************************************************/ 33 34 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 35 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 36 37 #define CPUFREQ_TRANSITION_NOTIFIER (0) 38 #define CPUFREQ_POLICY_NOTIFIER (1) 39 40 41 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 42 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 43 * two generic policies are available: 44 */ 45 46 #define CPUFREQ_POLICY_POWERSAVE (1) 47 #define CPUFREQ_POLICY_PERFORMANCE (2) 48 49 /* Frequency values here are CPU kHz so that hardware which doesn't run 50 * with some frequencies can complain without having to guess what per 51 * cent / per mille means. 52 * Maximum transition latency is in nanoseconds - if it's unknown, 53 * CPUFREQ_ETERNAL shall be used. 54 */ 55 56 struct cpufreq_governor; 57 58 #define CPUFREQ_ETERNAL (-1) 59 struct cpufreq_cpuinfo { 60 unsigned int max_freq; 61 unsigned int min_freq; 62 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ 63 }; 64 65 struct cpufreq_real_policy { 66 unsigned int min; /* in kHz */ 67 unsigned int max; /* in kHz */ 68 unsigned int policy; /* see above */ 69 struct cpufreq_governor *governor; /* see below */ 70 }; 71 72 struct cpufreq_policy { 73 cpumask_t cpus; /* affected CPUs */ 74 unsigned int cpu; /* cpu nr of registered CPU */ 75 struct cpufreq_cpuinfo cpuinfo;/* see above */ 76 77 unsigned int min; /* in kHz */ 78 unsigned int max; /* in kHz */ 79 unsigned int cur; /* in kHz, only needed if cpufreq 80 * governors are used */ 81 unsigned int policy; /* see above */ 82 struct cpufreq_governor *governor; /* see below */ 83 84 struct semaphore lock; /* CPU ->setpolicy or ->target may 85 only be called once a time */ 86 87 struct work_struct update; /* if update_policy() needs to be 88 * called, but you're in IRQ context */ 89 90 struct cpufreq_real_policy user_policy; 91 92 struct kobject kobj; 93 struct completion kobj_unregister; 94 }; 95 96 #define CPUFREQ_ADJUST (0) 97 #define CPUFREQ_INCOMPATIBLE (1) 98 #define CPUFREQ_NOTIFY (2) 99 100 101 /******************** cpufreq transition notifiers *******************/ 102 103 #define CPUFREQ_PRECHANGE (0) 104 #define CPUFREQ_POSTCHANGE (1) 105 #define CPUFREQ_RESUMECHANGE (8) 106 #define CPUFREQ_SUSPENDCHANGE (9) 107 108 struct cpufreq_freqs { 109 unsigned int cpu; /* cpu nr */ 110 unsigned int old; 111 unsigned int new; 112 u8 flags; /* flags of cpufreq_driver, see below. */ 113 }; 114 115 116 /** 117 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 118 * @old: old value 119 * @div: divisor 120 * @mult: multiplier 121 * 122 * 123 * new = old * mult / div 124 */ 125 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 126 { 127 #if BITS_PER_LONG == 32 128 129 u64 result = ((u64) old) * ((u64) mult); 130 do_div(result, div); 131 return (unsigned long) result; 132 133 #elif BITS_PER_LONG == 64 134 135 unsigned long result = old * ((u64) mult); 136 result /= div; 137 return result; 138 139 #endif 140 }; 141 142 /********************************************************************* 143 * CPUFREQ GOVERNORS * 144 *********************************************************************/ 145 146 #define CPUFREQ_GOV_START 1 147 #define CPUFREQ_GOV_STOP 2 148 #define CPUFREQ_GOV_LIMITS 3 149 150 struct cpufreq_governor { 151 char name[CPUFREQ_NAME_LEN]; 152 int (*governor) (struct cpufreq_policy *policy, 153 unsigned int event); 154 struct list_head governor_list; 155 struct module *owner; 156 }; 157 158 /* pass a target to the cpufreq driver 159 */ 160 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 161 unsigned int target_freq, 162 unsigned int relation); 163 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 164 unsigned int target_freq, 165 unsigned int relation); 166 167 168 /* pass an event to the cpufreq governor */ 169 int cpufreq_governor(unsigned int cpu, unsigned int event); 170 171 int cpufreq_register_governor(struct cpufreq_governor *governor); 172 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 173 174 175 /********************************************************************* 176 * CPUFREQ DRIVER INTERFACE * 177 *********************************************************************/ 178 179 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 180 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 181 182 struct freq_attr; 183 184 struct cpufreq_driver { 185 struct module *owner; 186 char name[CPUFREQ_NAME_LEN]; 187 u8 flags; 188 189 /* needed by all drivers */ 190 int (*init) (struct cpufreq_policy *policy); 191 int (*verify) (struct cpufreq_policy *policy); 192 193 /* define one out of two */ 194 int (*setpolicy) (struct cpufreq_policy *policy); 195 int (*target) (struct cpufreq_policy *policy, 196 unsigned int target_freq, 197 unsigned int relation); 198 199 /* should be defined, if possible */ 200 unsigned int (*get) (unsigned int cpu); 201 202 /* optional */ 203 int (*exit) (struct cpufreq_policy *policy); 204 int (*suspend) (struct cpufreq_policy *policy, u32 state); 205 int (*resume) (struct cpufreq_policy *policy); 206 struct freq_attr **attr; 207 }; 208 209 /* flags */ 210 211 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 212 * all ->init() calls failed */ 213 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 214 * "constants" aren't affected by 215 * frequency transitions */ 216 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 217 * mismatches */ 218 219 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 220 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 221 222 223 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 224 225 226 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 227 { 228 if (policy->min < min) 229 policy->min = min; 230 if (policy->max < min) 231 policy->max = min; 232 if (policy->min > max) 233 policy->min = max; 234 if (policy->max > max) 235 policy->max = max; 236 if (policy->min > policy->max) 237 policy->min = policy->max; 238 return; 239 } 240 241 struct freq_attr { 242 struct attribute attr; 243 ssize_t (*show)(struct cpufreq_policy *, char *); 244 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 245 }; 246 247 248 /********************************************************************* 249 * CPUFREQ 2.6. INTERFACE * 250 *********************************************************************/ 251 int cpufreq_set_policy(struct cpufreq_policy *policy); 252 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 253 int cpufreq_update_policy(unsigned int cpu); 254 255 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 256 unsigned int cpufreq_get(unsigned int cpu); 257 258 259 /********************************************************************* 260 * CPUFREQ DEFAULT GOVERNOR * 261 *********************************************************************/ 262 263 264 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 265 extern struct cpufreq_governor cpufreq_gov_performance; 266 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 267 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 268 extern struct cpufreq_governor cpufreq_gov_userspace; 269 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 270 #endif 271 272 273 /********************************************************************* 274 * FREQUENCY TABLE HELPERS * 275 *********************************************************************/ 276 277 #define CPUFREQ_ENTRY_INVALID ~0 278 #define CPUFREQ_TABLE_END ~1 279 280 struct cpufreq_frequency_table { 281 unsigned int index; /* any */ 282 unsigned int frequency; /* kHz - doesn't need to be in ascending 283 * order */ 284 }; 285 286 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 287 struct cpufreq_frequency_table *table); 288 289 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 290 struct cpufreq_frequency_table *table); 291 292 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 293 struct cpufreq_frequency_table *table, 294 unsigned int target_freq, 295 unsigned int relation, 296 unsigned int *index); 297 298 /* the following 3 funtions are for cpufreq core use only */ 299 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 300 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 301 void cpufreq_cpu_put (struct cpufreq_policy *data); 302 303 /* the following are really really optional */ 304 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 305 306 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 307 unsigned int cpu); 308 309 void cpufreq_frequency_table_put_attr(unsigned int cpu); 310 311 312 /********************************************************************* 313 * UNIFIED DEBUG HELPERS * 314 *********************************************************************/ 315 316 #define CPUFREQ_DEBUG_CORE 1 317 #define CPUFREQ_DEBUG_DRIVER 2 318 #define CPUFREQ_DEBUG_GOVERNOR 4 319 320 #ifdef CONFIG_CPU_FREQ_DEBUG 321 322 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 323 const char *fmt, ...); 324 325 #else 326 327 #define cpufreq_debug_printk(msg...) do { } while(0) 328 329 #endif /* CONFIG_CPU_FREQ_DEBUG */ 330 331 #endif /* _LINUX_CPUFREQ_H */ 332