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/kernel.h> 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/cpufreq.h> 18 19 /********************************************************************* 20 * FREQUENCY TABLE HELPERS * 21 *********************************************************************/ 22 23 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 24 struct cpufreq_frequency_table *table) 25 { 26 unsigned int min_freq = ~0; 27 unsigned int max_freq = 0; 28 unsigned int i; 29 30 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 31 unsigned int freq = table[i].frequency; 32 if (freq == CPUFREQ_ENTRY_INVALID) { 33 pr_debug("table entry %u is invalid, skipping\n", i); 34 35 continue; 36 } 37 pr_debug("table entry %u: %u kHz, %u index\n", 38 i, freq, table[i].index); 39 if (freq < min_freq) 40 min_freq = freq; 41 if (freq > max_freq) 42 max_freq = freq; 43 } 44 45 policy->min = policy->cpuinfo.min_freq = min_freq; 46 policy->max = policy->cpuinfo.max_freq = max_freq; 47 48 if (policy->min == ~0) 49 return -EINVAL; 50 else 51 return 0; 52 } 53 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo); 54 55 56 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 57 struct cpufreq_frequency_table *table) 58 { 59 unsigned int next_larger = ~0; 60 unsigned int i; 61 unsigned int count = 0; 62 63 pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n", 64 policy->min, policy->max, policy->cpu); 65 66 if (!cpu_online(policy->cpu)) 67 return -EINVAL; 68 69 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 70 policy->cpuinfo.max_freq); 71 72 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 73 unsigned int freq = table[i].frequency; 74 if (freq == CPUFREQ_ENTRY_INVALID) 75 continue; 76 if ((freq >= policy->min) && (freq <= policy->max)) 77 count++; 78 else if ((next_larger > freq) && (freq > policy->max)) 79 next_larger = freq; 80 } 81 82 if (!count) 83 policy->max = next_larger; 84 85 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 86 policy->cpuinfo.max_freq); 87 88 pr_debug("verification lead to (%u - %u kHz) for cpu %u\n", 89 policy->min, policy->max, policy->cpu); 90 91 return 0; 92 } 93 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify); 94 95 96 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 97 struct cpufreq_frequency_table *table, 98 unsigned int target_freq, 99 unsigned int relation, 100 unsigned int *index) 101 { 102 struct cpufreq_frequency_table optimal = { 103 .index = ~0, 104 .frequency = 0, 105 }; 106 struct cpufreq_frequency_table suboptimal = { 107 .index = ~0, 108 .frequency = 0, 109 }; 110 unsigned int i; 111 112 pr_debug("request for target %u kHz (relation: %u) for cpu %u\n", 113 target_freq, relation, policy->cpu); 114 115 switch (relation) { 116 case CPUFREQ_RELATION_H: 117 suboptimal.frequency = ~0; 118 break; 119 case CPUFREQ_RELATION_L: 120 optimal.frequency = ~0; 121 break; 122 } 123 124 if (!cpu_online(policy->cpu)) 125 return -EINVAL; 126 127 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 128 unsigned int freq = table[i].frequency; 129 if (freq == CPUFREQ_ENTRY_INVALID) 130 continue; 131 if ((freq < policy->min) || (freq > policy->max)) 132 continue; 133 switch (relation) { 134 case CPUFREQ_RELATION_H: 135 if (freq <= target_freq) { 136 if (freq >= optimal.frequency) { 137 optimal.frequency = freq; 138 optimal.index = i; 139 } 140 } else { 141 if (freq <= suboptimal.frequency) { 142 suboptimal.frequency = freq; 143 suboptimal.index = i; 144 } 145 } 146 break; 147 case CPUFREQ_RELATION_L: 148 if (freq >= target_freq) { 149 if (freq <= optimal.frequency) { 150 optimal.frequency = freq; 151 optimal.index = i; 152 } 153 } else { 154 if (freq >= suboptimal.frequency) { 155 suboptimal.frequency = freq; 156 suboptimal.index = i; 157 } 158 } 159 break; 160 } 161 } 162 if (optimal.index > i) { 163 if (suboptimal.index > i) 164 return -EINVAL; 165 *index = suboptimal.index; 166 } else 167 *index = optimal.index; 168 169 pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency, 170 table[*index].index); 171 172 return 0; 173 } 174 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target); 175 176 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table); 177 /** 178 * show_available_freqs - show available frequencies for the specified CPU 179 */ 180 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf) 181 { 182 unsigned int i = 0; 183 unsigned int cpu = policy->cpu; 184 ssize_t count = 0; 185 struct cpufreq_frequency_table *table; 186 187 if (!per_cpu(cpufreq_show_table, cpu)) 188 return -ENODEV; 189 190 table = per_cpu(cpufreq_show_table, cpu); 191 192 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 193 if (table[i].frequency == CPUFREQ_ENTRY_INVALID) 194 continue; 195 count += sprintf(&buf[count], "%d ", table[i].frequency); 196 } 197 count += sprintf(&buf[count], "\n"); 198 199 return count; 200 201 } 202 203 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = { 204 .attr = { .name = "scaling_available_frequencies", 205 .mode = 0444, 206 }, 207 .show = show_available_freqs, 208 }; 209 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs); 210 211 /* 212 * if you use these, you must assure that the frequency table is valid 213 * all the time between get_attr and put_attr! 214 */ 215 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 216 unsigned int cpu) 217 { 218 pr_debug("setting show_table for cpu %u to %p\n", cpu, table); 219 per_cpu(cpufreq_show_table, cpu) = table; 220 } 221 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr); 222 223 void cpufreq_frequency_table_put_attr(unsigned int cpu) 224 { 225 pr_debug("clearing show_table for cpu %u\n", cpu); 226 per_cpu(cpufreq_show_table, cpu) = NULL; 227 } 228 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr); 229 230 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu) 231 { 232 return per_cpu(cpufreq_show_table, cpu); 233 } 234 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table); 235 236 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>"); 237 MODULE_DESCRIPTION("CPUfreq frequency table helpers"); 238 MODULE_LICENSE("GPL"); 239