drivers/cpufreq/freq_table.c

   1 /*
   2  * linux/drivers/cpufreq/freq_table.c
   3  *
   4  * Copyright (C) 2002 - 2003 Dominik Brodowski
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/cpufreq.h>
  15 #include <linux/module.h>
  16
  17 /*********************************************************************
  18  *                     FREQUENCY TABLE HELPERS                       *
  19  *********************************************************************/
  20
  21 bool policy_has_boost_freq(struct cpufreq_policy *policy)
  22 {
  23         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
  24
  25         if (!table)
  26                 return false;
  27
  28         cpufreq_for_each_valid_entry(pos, table)
  29                 if (pos->flags & CPUFREQ_BOOST_FREQ)
  30                         return true;
  31
  32         return false;
  33 }
  34 EXPORT_SYMBOL_GPL(policy_has_boost_freq);
  35
  36 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
  37                                     struct cpufreq_frequency_table *table)
  38 {
  39         struct cpufreq_frequency_table *pos;
  40         unsigned int min_freq = ~0;
  41         unsigned int max_freq = 0;
  42         unsigned int freq;
  43
  44         cpufreq_for_each_valid_entry(pos, table) {
  45                 freq = pos->frequency;
  46
  47                 if (!cpufreq_boost_enabled()
  48                     && (pos->flags & CPUFREQ_BOOST_FREQ))
  49                         continue;
  50
  51                 pr_debug("table entry %u: %u kHz\n", (int)(pos - table), freq);
  52                 if (freq < min_freq)
  53                         min_freq = freq;
  54                 if (freq > max_freq)
  55                         max_freq = freq;
  56         }
  57
  58         policy->min = policy->cpuinfo.min_freq = min_freq;
  59         policy->max = policy->cpuinfo.max_freq = max_freq;
  60
  61         if (policy->min == ~0)
  62                 return -EINVAL;
  63         else
  64                 return 0;
  65 }
  66 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
  67
  68
  69 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
  70                                    struct cpufreq_frequency_table *table)
  71 {
  72         struct cpufreq_frequency_table *pos;
  73         unsigned int freq, next_larger = ~0;
  74         bool found = false;
  75
  76         pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
  77                                         policy->min, policy->max, policy->cpu);
  78
  79         cpufreq_verify_within_cpu_limits(policy);
  80
  81         cpufreq_for_each_valid_entry(pos, table) {
  82                 freq = pos->frequency;
  83
  84                 if ((freq >= policy->min) && (freq <= policy->max)) {
  85                         found = true;
  86                         break;
  87                 }
  88
  89                 if ((next_larger > freq) && (freq > policy->max))
  90                         next_larger = freq;
  91         }
  92
  93         if (!found) {
  94                 policy->max = next_larger;
  95                 cpufreq_verify_within_cpu_limits(policy);
  96         }
  97
  98         pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
  99                                 policy->min, policy->max, policy->cpu);
 100
 101         return 0;
 102 }
 103 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
 104
 105 /*
 106  * Generic routine to verify policy & frequency table, requires driver to set
 107  * policy->freq_table prior to it.
 108  */
 109 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy)
 110 {
 111         struct cpufreq_frequency_table *table =
 112                 cpufreq_frequency_get_table(policy->cpu);
 113         if (!table)
 114                 return -ENODEV;
 115
 116         return cpufreq_frequency_table_verify(policy, table);
 117 }
 118 EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
 119
 120 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 121                                    struct cpufreq_frequency_table *table,
 122                                    unsigned int target_freq,
 123                                    unsigned int relation,
 124                                    unsigned int *index)
 125 {
 126         struct cpufreq_frequency_table optimal = {
 127                 .driver_data = ~0,
 128                 .frequency = 0,
 129         };
 130         struct cpufreq_frequency_table suboptimal = {
 131                 .driver_data = ~0,
 132                 .frequency = 0,
 133         };
 134         struct cpufreq_frequency_table *pos;
 135         unsigned int freq, diff, i = 0;
 136
 137         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
 138                                         target_freq, relation, policy->cpu);
 139
 140         switch (relation) {
 141         case CPUFREQ_RELATION_H:
 142                 suboptimal.frequency = ~0;
 143                 break;
 144         case CPUFREQ_RELATION_L:
 145         case CPUFREQ_RELATION_C:
 146                 optimal.frequency = ~0;
 147                 break;
 148         }
 149
 150         cpufreq_for_each_valid_entry(pos, table) {
 151                 freq = pos->frequency;
 152
 153                 i = pos - table;
 154                 if ((freq < policy->min) || (freq > policy->max))
 155                         continue;
 156                 if (freq == target_freq) {
 157                         optimal.driver_data = i;
 158                         break;
 159                 }
 160                 switch (relation) {
 161                 case CPUFREQ_RELATION_H:
 162                         if (freq < target_freq) {
 163                                 if (freq >= optimal.frequency) {
 164                                         optimal.frequency = freq;
 165                                         optimal.driver_data = i;
 166                                 }
 167                         } else {
 168                                 if (freq <= suboptimal.frequency) {
 169                                         suboptimal.frequency = freq;
 170                                         suboptimal.driver_data = i;
 171                                 }
 172                         }
 173                         break;
 174                 case CPUFREQ_RELATION_L:
 175                         if (freq > target_freq) {
 176                                 if (freq <= optimal.frequency) {
 177                                         optimal.frequency = freq;
 178                                         optimal.driver_data = i;
 179                                 }
 180                         } else {
 181                                 if (freq >= suboptimal.frequency) {
 182                                         suboptimal.frequency = freq;
 183                                         suboptimal.driver_data = i;
 184                                 }
 185                         }
 186                         break;
 187                 case CPUFREQ_RELATION_C:
 188                         diff = abs(freq - target_freq);
 189                         if (diff < optimal.frequency ||
 190                             (diff == optimal.frequency &&
 191                              freq > table[optimal.driver_data].frequency)) {
 192                                 optimal.frequency = diff;
 193                                 optimal.driver_data = i;
 194                         }
 195                         break;
 196                 }
 197         }
 198         if (optimal.driver_data > i) {
 199                 if (suboptimal.driver_data > i)
 200                         return -EINVAL;
 201                 *index = suboptimal.driver_data;
 202         } else
 203                 *index = optimal.driver_data;
 204
 205         pr_debug("target index is %u, freq is:%u kHz\n", *index,
 206                  table[*index].frequency);
 207
 208         return 0;
 209 }
 210 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 211
 212 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 213                 unsigned int freq)
 214 {
 215         struct cpufreq_frequency_table *pos, *table;
 216
 217         table = cpufreq_frequency_get_table(policy->cpu);
 218         if (unlikely(!table)) {
 219                 pr_debug("%s: Unable to find frequency table\n", __func__);
 220                 return -ENOENT;
 221         }
 222
 223         cpufreq_for_each_valid_entry(pos, table)
 224                 if (pos->frequency == freq)
 225                         return pos - table;
 226
 227         return -EINVAL;
 228 }
 229 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
 230
 231 /**
 232  * show_available_freqs - show available frequencies for the specified CPU
 233  */
 234 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
 235                                     bool show_boost)
 236 {
 237         ssize_t count = 0;
 238         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
 239
 240         if (!table)
 241                 return -ENODEV;
 242
 243         cpufreq_for_each_valid_entry(pos, table) {
 244                 /*
 245                  * show_boost = true and driver_data = BOOST freq
 246                  * display BOOST freqs
 247                  *
 248                  * show_boost = false and driver_data = BOOST freq
 249                  * show_boost = true and driver_data != BOOST freq
 250                  * continue - do not display anything
 251                  *
 252                  * show_boost = false and driver_data != BOOST freq
 253                  * display NON BOOST freqs
 254                  */
 255                 if (show_boost ^ (pos->flags & CPUFREQ_BOOST_FREQ))
 256                         continue;
 257
 258                 count += sprintf(&buf[count], "%d ", pos->frequency);
 259         }
 260         count += sprintf(&buf[count], "\n");
 261
 262         return count;
 263
 264 }
 265
 266 #define cpufreq_attr_available_freq(_name)        \
 267 struct freq_attr cpufreq_freq_attr_##_name##_freqs =     \
 268 __ATTR_RO(_name##_frequencies)
 269
 270 /**
 271  * show_scaling_available_frequencies - show available normal frequencies for
 272  * the specified CPU
 273  */
 274 static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
 275                                                   char *buf)
 276 {
 277         return show_available_freqs(policy, buf, false);
 278 }
 279 cpufreq_attr_available_freq(scaling_available);
 280 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
 281
 282 /**
 283  * show_available_boost_freqs - show available boost frequencies for
 284  * the specified CPU
 285  */
 286 static ssize_t scaling_boost_frequencies_show(struct cpufreq_policy *policy,
 287                                               char *buf)
 288 {
 289         return show_available_freqs(policy, buf, true);
 290 }
 291 cpufreq_attr_available_freq(scaling_boost);
 292 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_boost_freqs);
 293
 294 struct freq_attr *cpufreq_generic_attr[] = {
 295         &cpufreq_freq_attr_scaling_available_freqs,
 296 #ifdef CONFIG_CPU_FREQ_BOOST_SW
 297         &cpufreq_freq_attr_scaling_boost_freqs,
 298 #endif
 299         NULL,
 300 };
 301 EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
 302
 303 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 304                                       struct cpufreq_frequency_table *table)
 305 {
 306         int ret = cpufreq_frequency_table_cpuinfo(policy, table);
 307
 308         if (!ret)
 309                 policy->freq_table = table;
 310
 311         return ret;
 312 }
 313 EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
 314
 315 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
 316 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
 317 MODULE_LICENSE("GPL");