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         unsigned int min_freq = ~0;
  25         unsigned int max_freq = 0;
  26         unsigned int i;
  27
  28         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
  29                 unsigned int freq = table[i].frequency;
  30                 if (freq == CPUFREQ_ENTRY_INVALID) {
  31                         pr_debug("table entry %u is invalid, skipping\n", i);
  32
  33                         continue;
  34                 }
  35                 pr_debug("table entry %u: %u kHz, %u driver_data\n",
  36                                         i, freq, table[i].driver_data);
  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         unsigned int next_larger = ~0, freq, i = 0;
  58         bool found = false;
  59
  60         pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
  61                                         policy->min, policy->max, policy->cpu);
  62
  63         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  64                                      policy->cpuinfo.max_freq);
  65
  66         for (; freq = table[i].frequency, freq != CPUFREQ_TABLE_END; i++) {
  67                 if (freq == CPUFREQ_ENTRY_INVALID)
  68                         continue;
  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_limits(policy, policy->cpuinfo.min_freq,
  81                                 policy->cpuinfo.max_freq);
  82         }
  83
  84         pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
  85                                 policy->min, policy->max, policy->cpu);
  86
  87         return 0;
  88 }
  89 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
  90
  91
  92 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
  93                                    struct cpufreq_frequency_table *table,
  94                                    unsigned int target_freq,
  95                                    unsigned int relation,
  96                                    unsigned int *index)
  97 {
  98         struct cpufreq_frequency_table optimal = {
  99                 .driver_data = ~0,
 100                 .frequency = 0,
 101         };
 102         struct cpufreq_frequency_table suboptimal = {
 103                 .driver_data = ~0,
 104                 .frequency = 0,
 105         };
 106         unsigned int i;
 107
 108         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
 109                                         target_freq, relation, policy->cpu);
 110
 111         switch (relation) {
 112         case CPUFREQ_RELATION_H:
 113                 suboptimal.frequency = ~0;
 114                 break;
 115         case CPUFREQ_RELATION_L:
 116                 optimal.frequency = ~0;
 117                 break;
 118         }
 119
 120         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 121                 unsigned int freq = table[i].frequency;
 122                 if (freq == CPUFREQ_ENTRY_INVALID)
 123                         continue;
 124                 if ((freq < policy->min) || (freq > policy->max))
 125                         continue;
 126                 switch (relation) {
 127                 case CPUFREQ_RELATION_H:
 128                         if (freq <= target_freq) {
 129                                 if (freq >= optimal.frequency) {
 130                                         optimal.frequency = freq;
 131                                         optimal.driver_data = i;
 132                                 }
 133                         } else {
 134                                 if (freq <= suboptimal.frequency) {
 135                                         suboptimal.frequency = freq;
 136                                         suboptimal.driver_data = i;
 137                                 }
 138                         }
 139                         break;
 140                 case CPUFREQ_RELATION_L:
 141                         if (freq >= target_freq) {
 142                                 if (freq <= optimal.frequency) {
 143                                         optimal.frequency = freq;
 144                                         optimal.driver_data = i;
 145                                 }
 146                         } else {
 147                                 if (freq >= suboptimal.frequency) {
 148                                         suboptimal.frequency = freq;
 149                                         suboptimal.driver_data = i;
 150                                 }
 151                         }
 152                         break;
 153                 }
 154         }
 155         if (optimal.driver_data > i) {
 156                 if (suboptimal.driver_data > i)
 157                         return -EINVAL;
 158                 *index = suboptimal.driver_data;
 159         } else
 160                 *index = optimal.driver_data;
 161
 162         pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
 163                 table[*index].driver_data);
 164
 165         return 0;
 166 }
 167 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 168
 169 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
 170 /**
 171  * show_available_freqs - show available frequencies for the specified CPU
 172  */
 173 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)
 174 {
 175         unsigned int i = 0;
 176         unsigned int cpu = policy->cpu;
 177         ssize_t count = 0;
 178         struct cpufreq_frequency_table *table;
 179
 180         if (!per_cpu(cpufreq_show_table, cpu))
 181                 return -ENODEV;
 182
 183         table = per_cpu(cpufreq_show_table, cpu);
 184
 185         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 186                 if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
 187                         continue;
 188                 count += sprintf(&buf[count], "%d ", table[i].frequency);
 189         }
 190         count += sprintf(&buf[count], "\n");
 191
 192         return count;
 193
 194 }
 195
 196 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
 197         .attr = { .name = "scaling_available_frequencies",
 198                   .mode = 0444,
 199                 },
 200         .show = show_available_freqs,
 201 };
 202 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
 203
 204 /*
 205  * if you use these, you must assure that the frequency table is valid
 206  * all the time between get_attr and put_attr!
 207  */
 208 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 209                                       unsigned int cpu)
 210 {
 211         pr_debug("setting show_table for cpu %u to %p\n", cpu, table);
 212         per_cpu(cpufreq_show_table, cpu) = table;
 213 }
 214 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
 215
 216 void cpufreq_frequency_table_put_attr(unsigned int cpu)
 217 {
 218         pr_debug("clearing show_table for cpu %u\n", cpu);
 219         per_cpu(cpufreq_show_table, cpu) = NULL;
 220 }
 221 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
 222
 223 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 224                                       struct cpufreq_frequency_table *table)
 225 {
 226         int ret = cpufreq_frequency_table_cpuinfo(policy, table);
 227
 228         if (!ret)
 229                 cpufreq_frequency_table_get_attr(table, policy->cpu);
 230
 231         return ret;
 232 }
 233 EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
 234
 235 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy)
 236 {
 237         pr_debug("Updating show_table for new_cpu %u from last_cpu %u\n",
 238                         policy->cpu, policy->last_cpu);
 239         per_cpu(cpufreq_show_table, policy->cpu) = per_cpu(cpufreq_show_table,
 240                         policy->last_cpu);
 241         per_cpu(cpufreq_show_table, policy->last_cpu) = NULL;
 242 }
 243
 244 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
 245 {
 246         return per_cpu(cpufreq_show_table, cpu);
 247 }
 248 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
 249
 250 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
 251 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
 252 MODULE_LICENSE("GPL");