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"); 240