linux-imx

/*

 *  drivers/cpufreq/cpufreq_stats.c

 *

 *  Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.

 *  (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

​

#include <linux/cpu.h>

#include <linux/cpufreq.h>

#include <linux/module.h>

#include <linux/slab.h>

​

static DEFINE_SPINLOCK(cpufreq_stats_lock);

​

struct cpufreq_stats {

    unsigned int total_trans;

    unsigned long long last_time;

    unsigned int max_state;

    unsigned int state_num;

    unsigned int last_index;

    u64 *time_in_state;

    unsigned int *freq_table;

    unsigned int *trans_table;

};

​

static void cpufreq_stats_update(struct cpufreq_stats *stats)

{

    unsigned long long cur_time = get_jiffies_64();

​

    stats->time_in_state[stats->last_index] += cur_time - stats->last_time;

    stats->last_time = cur_time;

}

​

static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)

{

    unsigned int count = stats->max_state;

​

    spin_lock(&cpufreq_stats_lock);

    memset(stats->time_in_state, 0, count * sizeof(u64));

    memset(stats->trans_table, 0, count * count * sizeof(int));

    stats->last_time = get_jiffies_64();

    stats->total_trans = 0;

    spin_unlock(&cpufreq_stats_lock);

}

​

static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)

{

    return sprintf(buf, "%d\n", policy->stats->total_trans);

}

cpufreq_freq_attr_ro(total_trans);

​

static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)

{

    struct cpufreq_stats *stats = policy->stats;

    ssize_t len = 0;

    int i;

​

    if (policy->fast_switch_enabled)

        return 0;

​

    spin_lock(&cpufreq_stats_lock);

    cpufreq_stats_update(stats);

    spin_unlock(&cpufreq_stats_lock);

​

    for (i = 0; i < stats->state_num; i++) {

        len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],

            (unsigned long long)

            jiffies_64_to_clock_t(stats->time_in_state[i]));

    }

    return len;

}

cpufreq_freq_attr_ro(time_in_state);

​

static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,

               size_t count)

{

    /* We don't care what is written to the attribute. */

    cpufreq_stats_clear_table(policy->stats);

    return count;

}

cpufreq_freq_attr_wo(reset);

​

static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)

{

    struct cpufreq_stats *stats = policy->stats;

    ssize_t len = 0;

    int i, j;

​