linux-imx

/*

 * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver

 *

 * Copyright 2010-2011 Analog Devices Inc.

 *

 * Licensed under the GPL-2.

 */

​

#include <linux/interrupt.h>

#include <linux/fs.h>

#include <linux/device.h>

#include <linux/kernel.h>

#include <linux/spi/spi.h>

#include <linux/slab.h>

#include <linux/sysfs.h>

#include <linux/regulator/consumer.h>

#include <linux/module.h>

​

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

​

#include "ad5624r.h"

​

static int ad5624r_spi_write(struct spi_device *spi,

                 u8 cmd, u8 addr, u16 val, u8 shift)

{

    u32 data;

    u8 msg[3];

​

    /*

     * The input shift register is 24 bits wide. The first two bits are

     * don't care bits. The next three are the command bits, C2 to C0,

     * followed by the 3-bit DAC address, A2 to A0, and then the

     * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,

     * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,

     * for the AD5664R, AD5644R, and AD5624R, respectively.

     */

    data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);

    msg[0] = data >> 16;

    msg[1] = data >> 8;

    msg[2] = data;

​

    return spi_write(spi, msg, 3);

}

​

static int ad5624r_read_raw(struct iio_dev *indio_dev,

               struct iio_chan_spec const *chan,

               int *val,

               int *val2,

               long m)

{

    struct ad5624r_state *st = iio_priv(indio_dev);

​

    switch (m) {

    case IIO_CHAN_INFO_SCALE:

        *val = st->vref_mv;

        *val2 = chan->scan_type.realbits;

        return IIO_VAL_FRACTIONAL_LOG2;

    }

    return -EINVAL;

}

​

static int ad5624r_write_raw(struct iio_dev *indio_dev,