240 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			240 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * linux/drivers/cpufreq/freq_table.c
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|  *
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|  * Copyright (C) 2002 - 2003 Dominik Brodowski
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/module.h>
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| #include <linux/init.h>
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| #include <linux/cpufreq.h>
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| 
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| #define dprintk(msg...) \
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| 	cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg)
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| 
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| /*********************************************************************
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|  *                     FREQUENCY TABLE HELPERS                       *
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|  *********************************************************************/
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| 
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| int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
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| 				    struct cpufreq_frequency_table *table)
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| {
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| 	unsigned int min_freq = ~0;
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| 	unsigned int max_freq = 0;
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| 	unsigned int i;
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| 
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| 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
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| 		unsigned int freq = table[i].frequency;
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| 		if (freq == CPUFREQ_ENTRY_INVALID) {
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| 			dprintk("table entry %u is invalid, skipping\n", i);
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| 
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| 			continue;
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| 		}
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| 		dprintk("table entry %u: %u kHz, %u index\n",
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| 					i, freq, table[i].index);
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| 		if (freq < min_freq)
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| 			min_freq = freq;
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| 		if (freq > max_freq)
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| 			max_freq = freq;
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| 	}
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| 
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| 	policy->min = policy->cpuinfo.min_freq = min_freq;
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| 	policy->max = policy->cpuinfo.max_freq = max_freq;
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| 
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| 	if (policy->min == ~0)
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| 		return -EINVAL;
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| 	else
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| 		return 0;
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
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| 
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| 
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| int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
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| 				   struct cpufreq_frequency_table *table)
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| {
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| 	unsigned int next_larger = ~0;
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| 	unsigned int i;
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| 	unsigned int count = 0;
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| 
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| 	dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n",
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| 					policy->min, policy->max, policy->cpu);
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| 
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| 	if (!cpu_online(policy->cpu))
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| 		return -EINVAL;
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| 
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| 	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
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| 				     policy->cpuinfo.max_freq);
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| 
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| 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
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| 		unsigned int freq = table[i].frequency;
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| 		if (freq == CPUFREQ_ENTRY_INVALID)
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| 			continue;
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| 		if ((freq >= policy->min) && (freq <= policy->max))
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| 			count++;
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| 		else if ((next_larger > freq) && (freq > policy->max))
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| 			next_larger = freq;
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| 	}
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| 
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| 	if (!count)
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| 		policy->max = next_larger;
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| 
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| 	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
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| 				     policy->cpuinfo.max_freq);
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| 
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| 	dprintk("verification lead to (%u - %u kHz) for cpu %u\n",
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| 				policy->min, policy->max, policy->cpu);
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
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| 
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| 
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| int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
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| 				   struct cpufreq_frequency_table *table,
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| 				   unsigned int target_freq,
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| 				   unsigned int relation,
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| 				   unsigned int *index)
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| {
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| 	struct cpufreq_frequency_table optimal = {
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| 		.index = ~0,
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| 		.frequency = 0,
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| 	};
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| 	struct cpufreq_frequency_table suboptimal = {
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| 		.index = ~0,
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| 		.frequency = 0,
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| 	};
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| 	unsigned int i;
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| 
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| 	dprintk("request for target %u kHz (relation: %u) for cpu %u\n",
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| 					target_freq, relation, policy->cpu);
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| 
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| 	switch (relation) {
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| 	case CPUFREQ_RELATION_H:
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| 		suboptimal.frequency = ~0;
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| 		break;
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| 	case CPUFREQ_RELATION_L:
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| 		optimal.frequency = ~0;
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| 		break;
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| 	}
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| 
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| 	if (!cpu_online(policy->cpu))
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| 		return -EINVAL;
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| 
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| 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
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| 		unsigned int freq = table[i].frequency;
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| 		if (freq == CPUFREQ_ENTRY_INVALID)
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| 			continue;
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| 		if ((freq < policy->min) || (freq > policy->max))
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| 			continue;
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| 		switch (relation) {
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| 		case CPUFREQ_RELATION_H:
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| 			if (freq <= target_freq) {
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| 				if (freq >= optimal.frequency) {
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| 					optimal.frequency = freq;
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| 					optimal.index = i;
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| 				}
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| 			} else {
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| 				if (freq <= suboptimal.frequency) {
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| 					suboptimal.frequency = freq;
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| 					suboptimal.index = i;
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| 				}
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| 			}
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| 			break;
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| 		case CPUFREQ_RELATION_L:
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| 			if (freq >= target_freq) {
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| 				if (freq <= optimal.frequency) {
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| 					optimal.frequency = freq;
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| 					optimal.index = i;
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| 				}
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| 			} else {
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| 				if (freq >= suboptimal.frequency) {
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| 					suboptimal.frequency = freq;
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| 					suboptimal.index = i;
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| 				}
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| 			}
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| 			break;
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| 		}
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| 	}
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| 	if (optimal.index > i) {
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| 		if (suboptimal.index > i)
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| 			return -EINVAL;
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| 		*index = suboptimal.index;
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| 	} else
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| 		*index = optimal.index;
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| 
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| 	dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
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| 		table[*index].index);
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
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| 
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| static DEFINE_PER_CPU(struct cpufreq_frequency_table *, show_table);
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| /**
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|  * show_available_freqs - show available frequencies for the specified CPU
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|  */
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| static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)
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| {
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| 	unsigned int i = 0;
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| 	unsigned int cpu = policy->cpu;
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| 	ssize_t count = 0;
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| 	struct cpufreq_frequency_table *table;
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| 
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| 	if (!per_cpu(show_table, cpu))
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| 		return -ENODEV;
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| 
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| 	table = per_cpu(show_table, cpu);
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| 
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| 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
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| 		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
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| 			continue;
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| 		count += sprintf(&buf[count], "%d ", table[i].frequency);
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| 	}
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| 	count += sprintf(&buf[count], "\n");
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| 
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| 	return count;
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| 
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| }
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| 
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| struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
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| 	.attr = { .name = "scaling_available_frequencies",
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| 		  .mode = 0444,
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| 		},
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| 	.show = show_available_freqs,
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| };
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| EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
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| 
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| /*
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|  * if you use these, you must assure that the frequency table is valid
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|  * all the time between get_attr and put_attr!
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|  */
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| void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
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| 				      unsigned int cpu)
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| {
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| 	dprintk("setting show_table for cpu %u to %p\n", cpu, table);
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| 	per_cpu(show_table, cpu) = table;
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
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| 
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| void cpufreq_frequency_table_put_attr(unsigned int cpu)
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| {
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| 	dprintk("clearing show_table for cpu %u\n", cpu);
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| 	per_cpu(show_table, cpu) = NULL;
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
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| 
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| struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
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| {
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| 	return per_cpu(show_table, cpu);
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| }
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| EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
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| 
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| MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
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| MODULE_DESCRIPTION("CPUfreq frequency table helpers");
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| MODULE_LICENSE("GPL");
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