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/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 extern int cpufreq_driver_getavg(struct cpufreq_policy *policy); 176 177 int cpufreq_register_governor(struct cpufreq_governor *governor); 178 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 179 180 181 /********************************************************************* 182 * CPUFREQ DRIVER INTERFACE * 183 *********************************************************************/ 184 185 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 186 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 187 188 struct freq_attr; 189 190 struct cpufreq_driver { 191 struct module *owner; 192 char name[CPUFREQ_NAME_LEN]; 193 u8 flags; 194 195 /* needed by all drivers */ 196 int (*init) (struct cpufreq_policy *policy); 197 int (*verify) (struct cpufreq_policy *policy); 198 199 /* define one out of two */ 200 int (*setpolicy) (struct cpufreq_policy *policy); 201 int (*target) (struct cpufreq_policy *policy, 202 unsigned int target_freq, 203 unsigned int relation); 204 205 /* should be defined, if possible */ 206 unsigned int (*get) (unsigned int cpu); 207 208 /* optional */ 209 unsigned int (*getavg) (unsigned int cpu); 210 int (*exit) (struct cpufreq_policy *policy); 211 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 212 int (*resume) (struct cpufreq_policy *policy); 213 struct freq_attr **attr; 214 }; 215 216 /* flags */ 217 218 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 219 * all ->init() calls failed */ 220 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 221 * "constants" aren't affected by 222 * frequency transitions */ 223 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 224 * mismatches */ 225 226 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 227 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 228 229 230 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 231 232 233 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 234 { 235 if (policy->min < min) 236 policy->min = min; 237 if (policy->max < min) 238 policy->max = min; 239 if (policy->min > max) 240 policy->min = max; 241 if (policy->max > max) 242 policy->max = max; 243 if (policy->min > policy->max) 244 policy->min = policy->max; 245 return; 246 } 247 248 struct freq_attr { 249 struct attribute attr; 250 ssize_t (*show)(struct cpufreq_policy *, char *); 251 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 252 }; 253 254 255 /********************************************************************* 256 * CPUFREQ 2.6. INTERFACE * 257 *********************************************************************/ 258 int cpufreq_set_policy(struct cpufreq_policy *policy); 259 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 260 int cpufreq_update_policy(unsigned int cpu); 261 262 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 263 unsigned int cpufreq_get(unsigned int cpu); 264 265 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 266 #ifdef CONFIG_CPU_FREQ 267 unsigned int cpufreq_quick_get(unsigned int cpu); 268 #else 269 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 270 { 271 return 0; 272 } 273 #endif 274 275 276 /********************************************************************* 277 * CPUFREQ DEFAULT GOVERNOR * 278 *********************************************************************/ 279 280 281 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 282 extern struct cpufreq_governor cpufreq_gov_performance; 283 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 284 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 285 extern struct cpufreq_governor cpufreq_gov_userspace; 286 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 287 #endif 288 289 290 /********************************************************************* 291 * FREQUENCY TABLE HELPERS * 292 *********************************************************************/ 293 294 #define CPUFREQ_ENTRY_INVALID ~0 295 #define CPUFREQ_TABLE_END ~1 296 297 struct cpufreq_frequency_table { 298 unsigned int index; /* any */ 299 unsigned int frequency; /* kHz - doesn't need to be in ascending 300 * order */ 301 }; 302 303 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 304 struct cpufreq_frequency_table *table); 305 306 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 307 struct cpufreq_frequency_table *table); 308 309 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 310 struct cpufreq_frequency_table *table, 311 unsigned int target_freq, 312 unsigned int relation, 313 unsigned int *index); 314 315 /* the following 3 funtions are for cpufreq core use only */ 316 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 317 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 318 void cpufreq_cpu_put (struct cpufreq_policy *data); 319 320 /* the following are really really optional */ 321 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 322 323 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 324 unsigned int cpu); 325 326 void cpufreq_frequency_table_put_attr(unsigned int cpu); 327 328 329 /********************************************************************* 330 * UNIFIED DEBUG HELPERS * 331 *********************************************************************/ 332 333 #define CPUFREQ_DEBUG_CORE 1 334 #define CPUFREQ_DEBUG_DRIVER 2 335 #define CPUFREQ_DEBUG_GOVERNOR 4 336 337 #ifdef CONFIG_CPU_FREQ_DEBUG 338 339 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 340 const char *fmt, ...); 341 342 #else 343 344 #define cpufreq_debug_printk(msg...) do { } while(0) 345 346 #endif /* CONFIG_CPU_FREQ_DEBUG */ 347 348 #endif /* _LINUX_CPUFREQ_H */ 349