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"); 235