linux-imx

/*

 * Windfarm PowerMac thermal control.  MAX6690 sensor.

 *

 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>

 *

 * Use and redistribute under the terms of the GNU GPL v2.

 */

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <asm/prom.h>

#include <asm/pmac_low_i2c.h>

​

#include "windfarm.h"

​

#define VERSION "1.0"

​

/* This currently only exports the external temperature sensor,

   since that's all the control loops need. */

​

/* Some MAX6690 register numbers */

#define MAX6690_INTERNAL_TEMP   0

#define MAX6690_EXTERNAL_TEMP   1

​

struct wf_6690_sensor {

    struct i2c_client   *i2c;

    struct wf_sensor    sens;

};

​

#define wf_to_6690(x)   container_of((x), struct wf_6690_sensor, sens)

​

static int wf_max6690_get(struct wf_sensor *sr, s32 *value)

{

    struct wf_6690_sensor *max = wf_to_6690(sr);

    s32 data;

​

    if (max->i2c == NULL)

        return -ENODEV;

​

    /* chip gets initialized by firmware */

    data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP);

    if (data < 0)

        return data;

    *value = data << 16;

    return 0;

}

​

static void wf_max6690_release(struct wf_sensor *sr)

{

    struct wf_6690_sensor *max = wf_to_6690(sr);

​

    kfree(max);

}

​

static const struct wf_sensor_ops wf_max6690_ops = {

    .get_value  = wf_max6690_get,

    .release    = wf_max6690_release,

    .owner      = THIS_MODULE,

};

​