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;
  58         unsigned int i;
  59         unsigned int count = 0;
  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_limits(policy, policy->cpuinfo.min_freq,
  65                                      policy->cpuinfo.max_freq);
  66
  67         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
  68                 unsigned int freq = table[i].frequency;
  69                 if (freq == CPUFREQ_ENTRY_INVALID)
  70                         continue;
  71                 if ((freq >= policy->min) && (freq <= policy->max))
  72                         count++;
  73                 else if ((next_larger > freq) && (freq > policy->max))
  74                         next_larger = freq;
  75         }
  76
  77         if (!count)
  78                 policy->max = next_larger;
  79
  80         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  81                                      policy->cpuinfo.max_freq);
  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 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
  92                                    struct cpufreq_frequency_table *table,
  93                                    unsigned int target_freq,
  94                                    unsigned int relation,
  95                                    unsigned int *index)
  96 {
  97         struct cpufreq_frequency_table optimal = {
  98                 .driver_data = ~0,
  99                 .frequency = 0,
 100         };
 101         struct cpufreq_frequency_table suboptimal = {
 102                 .driver_data = ~0,
 103                 .frequency = 0,
 104         };
 105         unsigned int i;
 106
 107         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
 108                                         target_freq, relation, policy->cpu);
 109
 110         switch (relation) {
 111         case CPUFREQ_RELATION_H:
 112                 suboptimal.frequency = ~0;
 113                 break;
 114         case CPUFREQ_RELATION_L:
 115                 optimal.frequency = ~0;
 116                 break;
 117         }
 118
 119         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 120                 unsigned int freq = table[i].frequency;
 121                 if (freq == CPUFREQ_ENTRY_INVALID)
 122                         continue;
 123                 if ((freq < policy->min) || (freq > policy->max))
 124                         continue;
 125                 switch (relation) {
 126                 case CPUFREQ_RELATION_H:
 127                         if (freq <= target_freq) {
 128                                 if (freq >= optimal.frequency) {
 129                                         optimal.frequency = freq;
 130                                         optimal.driver_data = i;
 131                                 }
 132                         } else {
 133                                 if (freq <= suboptimal.frequency) {
 134                                         suboptimal.frequency = freq;
 135                                         suboptimal.driver_data = i;
 136                                 }
 137                         }
 138                         break;
 139                 case CPUFREQ_RELATION_L:
 140                         if (freq >= target_freq) {
 141                                 if (freq <= optimal.frequency) {
 142                                         optimal.frequency = freq;
 143                                         optimal.driver_data = i;
 144                                 }
 145                         } else {
 146                                 if (freq >= suboptimal.frequency) {
 147                                         suboptimal.frequency = freq;
 148                                         suboptimal.driver_data = i;
 149                                 }
 150                         }
 151                         break;
 152                 }
 153         }
 154         if (optimal.driver_data > i) {
 155                 if (suboptimal.driver_data > i)
 156                         return -EINVAL;
 157                 *index = suboptimal.driver_data;
 158         } else
 159                 *index = optimal.driver_data;
 160
 161         pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
 162                 table[*index].driver_data);
 163
 164         return 0;
 165 }
 166 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 167
 168 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
 169 /**
 170  * show_available_freqs - show available frequencies for the specified CPU
 171  */
 172 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)
 173 {
 174         unsigned int i = 0;
 175         unsigned int cpu = policy->cpu;
 176         ssize_t count = 0;
 177         struct cpufreq_frequency_table *table;
 178
 179         if (!per_cpu(cpufreq_show_table, cpu))
 180                 return -ENODEV;
 181
 182         table = per_cpu(cpufreq_show_table, cpu);
 183
 184         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 185                 if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
 186                         continue;
 187                 count += sprintf(&buf[count], "%d ", table[i].frequency);
 188         }
 189         count += sprintf(&buf[count], "\n");
 190
 191         return count;
 192
 193 }
 194
 195 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
 196         .attr = { .name = "scaling_available_frequencies",
 197                   .mode = 0444,
 198                 },
 199         .show = show_available_freqs,
 200 };
 201 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
 202
 203 /*
 204  * if you use these, you must assure that the frequency table is valid
 205  * all the time between get_attr and put_attr!
 206  */
 207 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 208                                       unsigned int cpu)
 209 {
 210         pr_debug("setting show_table for cpu %u to %p\n", cpu, table);
 211         per_cpu(cpufreq_show_table, cpu) = table;
 212 }
 213 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
 214
 215 void cpufreq_frequency_table_put_attr(unsigned int cpu)
 216 {
 217         pr_debug("clearing show_table for cpu %u\n", cpu);
 218         per_cpu(cpufreq_show_table, cpu) = NULL;
 219 }
 220 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
 221
 222 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy)
 223 {
 224         pr_debug("Updating show_table for new_cpu %u from last_cpu %u\n",
 225                         policy->cpu, policy->last_cpu);
 226         per_cpu(cpufreq_show_table, policy->cpu) = per_cpu(cpufreq_show_table,
 227                         policy->last_cpu);
 228         per_cpu(cpufreq_show_table, policy->last_cpu) = NULL;
 229 }
 230
 231 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
 232 {
 233         return per_cpu(cpufreq_show_table, cpu);
 234 }
 235 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
 236
 237 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
 238 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
 239 MODULE_LICENSE("GPL");