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 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/cpufreq.h> 16 17 #define dprintk(msg...) \ 18 cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg) 19 20 /********************************************************************* 21 * FREQUENCY TABLE HELPERS * 22 *********************************************************************/ 23 24 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 25 struct cpufreq_frequency_table *table) 26 { 27 unsigned int min_freq = ~0; 28 unsigned int max_freq = 0; 29 unsigned int i; 30 31 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 32 unsigned int freq = table[i].frequency; 33 if (freq == CPUFREQ_ENTRY_INVALID) { 34 dprintk("table entry %u is invalid, skipping\n", i); 35 36 continue; 37 } 38 dprintk("table entry %u: %u kHz, %u index\n", 39 i, freq, table[i].index); 40 if (freq < min_freq) 41 min_freq = freq; 42 if (freq > max_freq) 43 max_freq = freq; 44 } 45 46 policy->min = policy->cpuinfo.min_freq = min_freq; 47 policy->max = policy->cpuinfo.max_freq = max_freq; 48 49 if (policy->min == ~0) 50 return -EINVAL; 51 else 52 return 0; 53 } 54 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo); 55 56 57 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 58 struct cpufreq_frequency_table *table) 59 { 60 unsigned int next_larger = ~0; 61 unsigned int i; 62 unsigned int count = 0; 63 64 dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n", 65 policy->min, policy->max, policy->cpu); 66 67 if (!cpu_online(policy->cpu)) 68 return -EINVAL; 69 70 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 71 policy->cpuinfo.max_freq); 72 73 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 74 unsigned int freq = table[i].frequency; 75 if (freq == CPUFREQ_ENTRY_INVALID) 76 continue; 77 if ((freq >= policy->min) && (freq <= policy->max)) 78 count++; 79 else if ((next_larger > freq) && (freq > policy->max)) 80 next_larger = freq; 81 } 82 83 if (!count) 84 policy->max = next_larger; 85 86 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 87 policy->cpuinfo.max_freq); 88 89 dprintk("verification lead to (%u - %u kHz) for cpu %u\n", 90 policy->min, policy->max, policy->cpu); 91 92 return 0; 93 } 94 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify); 95 96 97 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 98 struct cpufreq_frequency_table *table, 99 unsigned int target_freq, 100 unsigned int relation, 101 unsigned int *index) 102 { 103 struct cpufreq_frequency_table optimal = { 104 .index = ~0, 105 .frequency = 0, 106 }; 107 struct cpufreq_frequency_table suboptimal = { 108 .index = ~0, 109 .frequency = 0, 110 }; 111 unsigned int i; 112 113 dprintk("request for target %u kHz (relation: %u) for cpu %u\n", 114 target_freq, relation, policy->cpu); 115 116 switch (relation) { 117 case CPUFREQ_RELATION_H: 118 suboptimal.frequency = ~0; 119 break; 120 case CPUFREQ_RELATION_L: 121 optimal.frequency = ~0; 122 break; 123 } 124 125 if (!cpu_online(policy->cpu)) 126 return -EINVAL; 127 128 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 129 unsigned int freq = table[i].frequency; 130 if (freq == CPUFREQ_ENTRY_INVALID) 131 continue; 132 if ((freq < policy->min) || (freq > policy->max)) 133 continue; 134 switch (relation) { 135 case CPUFREQ_RELATION_H: 136 if (freq <= target_freq) { 137 if (freq >= optimal.frequency) { 138 optimal.frequency = freq; 139 optimal.index = i; 140 } 141 } else { 142 if (freq <= suboptimal.frequency) { 143 suboptimal.frequency = freq; 144 suboptimal.index = i; 145 } 146 } 147 break; 148 case CPUFREQ_RELATION_L: 149 if (freq >= target_freq) { 150 if (freq <= optimal.frequency) { 151 optimal.frequency = freq; 152 optimal.index = i; 153 } 154 } else { 155 if (freq >= suboptimal.frequency) { 156 suboptimal.frequency = freq; 157 suboptimal.index = i; 158 } 159 } 160 break; 161 } 162 } 163 if (optimal.index > i) { 164 if (suboptimal.index > i) 165 return -EINVAL; 166 *index = suboptimal.index; 167 } else 168 *index = optimal.index; 169 170 dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency, 171 table[*index].index); 172 173 return 0; 174 } 175 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target); 176 177 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table); 178 /** 179 * show_available_freqs - show available frequencies for the specified CPU 180 */ 181 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf) 182 { 183 unsigned int i = 0; 184 unsigned int cpu = policy->cpu; 185 ssize_t count = 0; 186 struct cpufreq_frequency_table *table; 187 188 if (!per_cpu(cpufreq_show_table, cpu)) 189 return -ENODEV; 190 191 table = per_cpu(cpufreq_show_table, cpu); 192 193 for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 194 if (table[i].frequency == CPUFREQ_ENTRY_INVALID) 195 continue; 196 count += sprintf(&buf[count], "%d ", table[i].frequency); 197 } 198 count += sprintf(&buf[count], "\n"); 199 200 return count; 201 202 } 203 204 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = { 205 .attr = { .name = "scaling_available_frequencies", 206 .mode = 0444, 207 }, 208 .show = show_available_freqs, 209 }; 210 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs); 211 212 /* 213 * if you use these, you must assure that the frequency table is valid 214 * all the time between get_attr and put_attr! 215 */ 216 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 217 unsigned int cpu) 218 { 219 dprintk("setting show_table for cpu %u to %p\n", cpu, table); 220 per_cpu(cpufreq_show_table, cpu) = table; 221 } 222 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr); 223 224 void cpufreq_frequency_table_put_attr(unsigned int cpu) 225 { 226 dprintk("clearing show_table for cpu %u\n", cpu); 227 per_cpu(cpufreq_show_table, cpu) = NULL; 228 } 229 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr); 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