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