drivers/cpufreq/freq_table.c

   1 /*
   2  * linux/drivers/cpufreq/freq_table.c
   3  *
   4  * Copyright (C) 2002 - 2003 Dominik Brodowski
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/cpufreq.h>
  11
  12 #define dprintk(msg...) \
  13         cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg)
  14
  15 /*********************************************************************
  16  *                     FREQUENCY TABLE HELPERS                       *
  17  *********************************************************************/
  18
  19 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
  20                                     struct cpufreq_frequency_table *table)
  21 {
  22         unsigned int min_freq = ~0;
  23         unsigned int max_freq = 0;
  24         unsigned int i;
  25
  26         for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
  27                 unsigned int freq = table[i].frequency;
  28                 if (freq == CPUFREQ_ENTRY_INVALID) {
  29                         dprintk("table entry %u is invalid, skipping\n", i);
  30
  31                         continue;
  32                 }
  33                 dprintk("table entry %u: %u kHz, %u index\n",
  34                                         i, freq, table[i].index);
  35                 if (freq < min_freq)
  36                         min_freq = freq;
  37                 if (freq > max_freq)
  38                         max_freq = freq;
  39         }
  40
  41         policy->min = policy->cpuinfo.min_freq = min_freq;
  42         policy->max = policy->cpuinfo.max_freq = max_freq;
  43
  44         if (policy->min == ~0)
  45                 return -EINVAL;
  46         else
  47                 return 0;
  48 }
  49 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
  50
  51
  52 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
  53                                    struct cpufreq_frequency_table *table)
  54 {
  55         unsigned int next_larger = ~0;
  56         unsigned int i;
  57         unsigned int count = 0;
  58
  59         dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n",
  60                                         policy->min, policy->max, policy->cpu);
  61
  62         if (!cpu_online(policy->cpu))
  63                 return -EINVAL;
  64
  65         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  66                                      policy->cpuinfo.max_freq);
  67
  68         for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
  69                 unsigned int freq = table[i].frequency;
  70                 if (freq == CPUFREQ_ENTRY_INVALID)
  71                         continue;
  72                 if ((freq >= policy->min) && (freq <= policy->max))
  73                         count++;
  74                 else if ((next_larger > freq) && (freq > policy->max))
  75                         next_larger = freq;
  76         }
  77
  78         if (!count)
  79                 policy->max = next_larger;
  80
  81         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  82                                      policy->cpuinfo.max_freq);
  83
  84         dprintk("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                 .index = ~0,
 100                 .frequency = 0,
 101         };
 102         struct cpufreq_frequency_table suboptimal = {
 103                 .index = ~0,
 104                 .frequency = 0,
 105         };
 106         unsigned int i;
 107
 108         dprintk("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         if (!cpu_online(policy->cpu))
 121                 return -EINVAL;
 122
 123         for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 124                 unsigned int freq = table[i].frequency;
 125                 if (freq == CPUFREQ_ENTRY_INVALID)
 126                         continue;
 127                 if ((freq < policy->min) || (freq > policy->max))
 128                         continue;
 129                 switch(relation) {
 130                 case CPUFREQ_RELATION_H:
 131                         if (freq <= target_freq) {
 132                                 if (freq >= optimal.frequency) {
 133                                         optimal.frequency = freq;
 134                                         optimal.index = i;
 135                                 }
 136                         } else {
 137                                 if (freq <= suboptimal.frequency) {
 138                                         suboptimal.frequency = freq;
 139                                         suboptimal.index = i;
 140                                 }
 141                         }
 142                         break;
 143                 case CPUFREQ_RELATION_L:
 144                         if (freq >= target_freq) {
 145                                 if (freq <= optimal.frequency) {
 146                                         optimal.frequency = freq;
 147                                         optimal.index = i;
 148                                 }
 149                         } else {
 150                                 if (freq >= suboptimal.frequency) {
 151                                         suboptimal.frequency = freq;
 152                                         suboptimal.index = i;
 153                                 }
 154                         }
 155                         break;
 156                 }
 157         }
 158         if (optimal.index > i) {
 159                 if (suboptimal.index > i)
 160                         return -EINVAL;
 161                 *index = suboptimal.index;
 162         } else
 163                 *index = optimal.index;
 164
 165         dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
 166                 table[*index].index);
 167
 168         return 0;
 169 }
 170 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 171
 172 static struct cpufreq_frequency_table *show_table[NR_CPUS];
 173 /**
 174  * show_available_freqs - show available frequencies for the specified CPU
 175  */
 176 static ssize_t show_available_freqs (struct cpufreq_policy *policy, char *buf)
 177 {
 178         unsigned int i = 0;
 179         unsigned int cpu = policy->cpu;
 180         ssize_t count = 0;
 181         struct cpufreq_frequency_table *table;
 182
 183         if (!show_table[cpu])
 184                 return -ENODEV;
 185
 186         table = show_table[cpu];
 187
 188         for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 189                 if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
 190                         continue;
 191                 count += sprintf(&buf[count], "%d ", table[i].frequency);
 192         }
 193         count += sprintf(&buf[count], "\n");
 194
 195         return count;
 196
 197 }
 198
 199 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
 200         .attr = { .name = "scaling_available_frequencies",
 201                   .mode = 0444,
 202                 },
 203         .show = show_available_freqs,
 204 };
 205 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
 206
 207 /*
 208  * if you use these, you must assure that the frequency table is valid
 209  * all the time between get_attr and put_attr!
 210  */
 211 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 212                                       unsigned int cpu)
 213 {
 214         dprintk("setting show_table for cpu %u to %p\n", cpu, table);
 215         show_table[cpu] = table;
 216 }
 217 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
 218
 219 void cpufreq_frequency_table_put_attr(unsigned int cpu)
 220 {
 221         dprintk("clearing show_table for cpu %u\n", cpu);
 222         show_table[cpu] = NULL;
 223 }
 224 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
 225
 226 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
 227 {
 228         return show_table[cpu];
 229 }
 230 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
 231
 232 MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
 233 MODULE_DESCRIPTION ("CPUfreq frequency table helpers");
 234 MODULE_LICENSE ("GPL");