linux-imx

/*

 *  linux/drivers/devfreq/governor_userspace.c

 *

 *  Copyright (C) 2011 Samsung Electronics

 *  MyungJoo Ham <myungjoo.ham@samsung.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/slab.h>

#include <linux/device.h>

#include <linux/devfreq.h>

#include <linux/pm.h>

#include <linux/mutex.h>

#include <linux/module.h>

#include "governor.h"

​

struct userspace_data {

    unsigned long user_frequency;

    bool valid;

};

​

static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)

{

    struct userspace_data *data = df->data;

​

    if (data->valid)

        *freq = data->user_frequency;

    else

        *freq = df->previous_freq; /* No user freq specified yet */

​

    return 0;

}

​

static ssize_t store_freq(struct device *dev, struct device_attribute *attr,

              const char *buf, size_t count)

{

    struct devfreq *devfreq = to_devfreq(dev);

    struct userspace_data *data;

    unsigned long wanted;

    int err = 0;

​

    mutex_lock(&devfreq->lock);

    data = devfreq->data;

​

    sscanf(buf, "%lu", &wanted);

    data->user_frequency = wanted;

    data->valid = true;

    err = update_devfreq(devfreq);

    if (err == 0)

        err = count;

    mutex_unlock(&devfreq->lock);

    return err;

}

​

static ssize_t show_freq(struct device *dev, struct device_attribute *attr,

             char *buf)

{

    struct devfreq *devfreq = to_devfreq(dev);

    struct userspace_data *data;

    int err = 0;