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 = 0; 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 = 0; 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 = { .index = ~0, }; 95 struct cpufreq_frequency_table suboptimal = { .index = ~0, }; 96 unsigned int i; 97 98 dprintk("request for target %u kHz (relation: %u) for cpu %u\n", target_freq, relation, policy->cpu); 99 100 switch (relation) { 101 case CPUFREQ_RELATION_H: 102 optimal.frequency = 0; 103 suboptimal.frequency = ~0; 104 break; 105 case CPUFREQ_RELATION_L: 106 optimal.frequency = ~0; 107 suboptimal.frequency = 0; 108 break; 109 } 110 111 if (!cpu_online(policy->cpu)) 112 return -EINVAL; 113 114 for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 115 unsigned int freq = table[i].frequency; 116 if (freq == CPUFREQ_ENTRY_INVALID) 117 continue; 118 if ((freq < policy->min) || (freq > policy->max)) 119 continue; 120 switch(relation) { 121 case CPUFREQ_RELATION_H: 122 if (freq <= target_freq) { 123 if (freq >= optimal.frequency) { 124 optimal.frequency = freq; 125 optimal.index = i; 126 } 127 } else { 128 if (freq <= suboptimal.frequency) { 129 suboptimal.frequency = freq; 130 suboptimal.index = i; 131 } 132 } 133 break; 134 case CPUFREQ_RELATION_L: 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 } 148 } 149 if (optimal.index > i) { 150 if (suboptimal.index > i) 151 return -EINVAL; 152 *index = suboptimal.index; 153 } else 154 *index = optimal.index; 155 156 dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency, 157 table[*index].index); 158 159 return 0; 160 } 161 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target); 162 163 static struct cpufreq_frequency_table *show_table[NR_CPUS]; 164 /** 165 * show_scaling_governor - show the current policy for the specified CPU 166 */ 167 static ssize_t show_available_freqs (struct cpufreq_policy *policy, char *buf) 168 { 169 unsigned int i = 0; 170 unsigned int cpu = policy->cpu; 171 ssize_t count = 0; 172 struct cpufreq_frequency_table *table; 173 174 if (!show_table[cpu]) 175 return -ENODEV; 176 177 table = show_table[cpu]; 178 179 for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { 180 if (table[i].frequency == CPUFREQ_ENTRY_INVALID) 181 continue; 182 count += sprintf(&buf[count], "%d ", table[i].frequency); 183 } 184 count += sprintf(&buf[count], "\n"); 185 186 return count; 187 188 } 189 190 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = { 191 .attr = { .name = "scaling_available_frequencies", .mode = 0444, .owner=THIS_MODULE }, 192 .show = show_available_freqs, 193 }; 194 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs); 195 196 /* 197 * if you use these, you must assure that the frequency table is valid 198 * all the time between get_attr and put_attr! 199 */ 200 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 201 unsigned int cpu) 202 { 203 dprintk("setting show_table for cpu %u to %p\n", cpu, table); 204 show_table[cpu] = table; 205 } 206 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr); 207 208 void cpufreq_frequency_table_put_attr(unsigned int cpu) 209 { 210 dprintk("clearing show_table for cpu %u\n", cpu); 211 show_table[cpu] = NULL; 212 } 213 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr); 214 215 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu) 216 { 217 return show_table[cpu]; 218 } 219 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table); 220 221 MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>"); 222 MODULE_DESCRIPTION ("CPUfreq frequency table helpers"); 223 MODULE_LICENSE ("GPL"); 224