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