Re: [PATCH] iio: add support for Analog Devices ad7194 a/d converter

[Jonathan Cameron <jic23@cam.ac.uk>]

cc'ing linux-iio and AD's driver list.

Any particular reason for posting to lm-sensors? Now it's there we'll
keep them in the list though as someone might be interested.

On 07/18/11 08:46, Paul Thomas wrote:
> This uses the iio sysfs interface, and inculdes gain and differential settings
> 
> Signed-off-by: Paul Thomas <pthomas8589@gmail.com>
> ---
>  drivers/staging/iio/adc/Kconfig  |    7 +
>  drivers/staging/iio/adc/Makefile |    1 +
>  drivers/staging/iio/adc/ad7194.c |  462 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 470 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/staging/iio/adc/ad7194.c
> 
> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
> index 8c751c4..871605b 100644
> --- a/drivers/staging/iio/adc/Kconfig
> +++ b/drivers/staging/iio/adc/Kconfig
> @@ -17,6 +17,13 @@ config AD7152
>  	  Say yes here to build support for Analog Devices capacitive sensors.
>  	  (ad7152, ad7153) Provides direct access via sysfs.
>  
> +config AD7194
> +	tristate "Analog Devices AD7194 ADC driver"
> +	depends on SPI
> +	help
> +	  Say yes here to build support for Analog Devices ad7194.
> +	  Provides direct access via sysfs.
> +
>  config AD7291
>  	tristate "Analog Devices AD7291 temperature sensor driver"
>  	depends on I2C
> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
> index 1d9b3f5..4da3c40 100644
> --- a/drivers/staging/iio/adc/Makefile
> +++ b/drivers/staging/iio/adc/Makefile
> @@ -31,6 +31,7 @@ obj-$(CONFIG_AD7298) += ad7298.o
>  
>  obj-$(CONFIG_AD7150) += ad7150.o
>  obj-$(CONFIG_AD7152) += ad7152.o
> +obj-$(CONFIG_AD7194) += ad7194.o
>  obj-$(CONFIG_AD7291) += ad7291.o
>  obj-$(CONFIG_AD7314) += ad7314.o
>  obj-$(CONFIG_AD7745) += ad7745.o
> diff --git a/drivers/staging/iio/adc/ad7194.c b/drivers/staging/iio/adc/ad7194.c
> new file mode 100644
> index 0000000..a867662
> --- /dev/null
> +++ b/drivers/staging/iio/adc/ad7194.c
> @@ -0,0 +1,462 @@
> +/*
> + *  ad7194 - driver for Analog Devices AD7194 A/D converter
> + *
> + *  Copyright (c) 2011 Paul Thomas <pthomas8589@gmail.com>
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + *  GNU General Public License for more details.
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License version 2 or
> + *  later as publishhed by the Free Software Foundation.
> + *
> + *	You need to have something like this in struct spi_board_info
> + *	{
> + *		.modalias	= "ad7194",
> + *		.max_speed_hz	= 2*1000*1000,
> + *		.chip_select	= 0,
> + *		.bus_num	= 1,
> + *	},
> + *
> + * Three sysfs files are used chX_value, chX_diff and chX_gain
> + * chX_value is read only and returns that channels value in volts.
> + * chX_gain is read/write, the chX_value is scaled by the gain so it retains
> + * it's proper units.
> + * chX_diff is read/write, if chX_diff is 0 then pseude mod is used,
> + * if chX_diff is 1 then differential mode is used.
> + * In this mode ch1_value selects ch1-ch2, and ch2_value selects ch2-ch1
> + */
> +
> +#define DEBUG 1
> +
> +/*From Table 15 in the datasheet*/
> +/*Register addresses*/
> +#define REG_STATUS  0
> +#define REG_MODE    1
> +#define REG_CONF    2
> +#define REG_DATA    3
> +#define REG_ID      4
> +#define REG_GPOCON  5
> +#define REG_OFFSET  6
> +#define REG_FS      7
> +
> +/*From Table 15 in the datasheet*/
> +#define COMM_ADDR_bp 3
> +#define COMM_READ_bm (1 << 6)
> +
> +#define CONF_CHOP_bm (1 << 23)
> +#define CONF_PSEUDO_bm (1 << 18)
> +#define CONF_BUF_bm (1 << 4)
> +#define CONF_CHAN_NEG_bp 8
> +#define CONF_CHAN_POS_bp 12
> +
> +
> +#define MODE_MD_SINGLE_gc (0x01 << 21)
> +#define MODE_MD_ZS_CAL_gc (0x04 << 21)
> +#define MODE_MD_FS_CAL_gc (0x05 << 21)
> +#define MODE_CLK_INTTRI_gc (0x02 << 18)
> +/*Table 8 in the datasheet provides options for the Filter Word*/
> +#define MODE_FILTER_WORD 1
> +#define SETTLE_MS 2
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/spi/spi.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/delay.h>
> +
> +#include "../iio.h"
> +#include "../sysfs.h"
> +
> +#define DEVICE_NAME	"ad7194"
> +#define NUM_CHANNELS 16
> +
> +const uint8_t gains[NUM_CHANNELS] = {1, 0, 0, 8, 16, 32, 64, 128};
> +
> +struct ad7194_data {
> +	struct spi_device *spi_dev;
> +	struct iio_dev *indio_dev;
> +	uint8_t gain[NUM_CHANNELS];
> +	uint8_t diff[NUM_CHANNELS];
> +	struct mutex lock;
> +};
> +
> +static ssize_t show_gain(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad7194_data *pdata = dev_info->dev_data;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> +	return sprintf(buf, "%d\n", gains[pdata->gain[this_attr->address]]);
> +}
> +
> +static ssize_t set_gain(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	uint8_t gain_real, i;
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad7194_data *pdata = dev_info->dev_data;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> +	gain_real = simple_strtol(buf, NULL, 10);
> +	if (gain_real == 0)
> +		return -EPERM;
> +	for (i = 0; i < NUM_CHANNELS; i++) {
> +		if (gains[i] == gain_real) {
> +			pdata->gain[this_attr->address] =  i;
> +			return count;
> +		}
> +	}
> +	return -EPERM;
> +}
> +
> +static ssize_t show_diff(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad7194_data *pdata = dev_info->dev_data;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> +	return sprintf(buf, "%d\n", pdata->diff[this_attr->address]);
> +}
> +
> +static ssize_t set_diff(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	uint8_t diff;
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad7194_data *pdata = dev_info->dev_data;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> +	diff = simple_strtol(buf, NULL, 10);
> +	if (diff)
> +		pdata->diff[this_attr->address] = 1;
> +	else
> +		pdata->diff[this_attr->address] = 0;
> +	return count;
> +}
> +
> +static inline int ad7194_read_reg8(struct spi_device *spi,
> +		int reg, uint8_t *val)
> +{
> +	int ret;
> +	uint8_t tx[1], rx[1];
> +
> +	tx[0] = (COMM_READ_bm | (reg << COMM_ADDR_bp));
> +
> +	ret = spi_write_then_read(spi, tx, 1, rx, 1);
> +	*val = rx[0];
> +	return ret;
> +}
> +
> +static inline int ad7194_read_reg24(struct spi_device *spi,
> +		int reg, uint32_t *val)
> +{
> +	int ret;
> +	uint8_t tx[1], rx[3];
> +
> +	tx[0] = (COMM_READ_bm | (reg << COMM_ADDR_bp));
> +
> +	ret = spi_write_then_read(spi, tx, 1, rx, 3);
> +	*val = (rx[0] << 16) + (rx[1] << 8) + rx[2];
> +	return ret;
> +}
> +
> +static inline int ad7194_write_reg24(struct spi_device *spi,
> +		int reg, uint32_t *val)
> +{
> +	uint8_t tx[4];
> +
> +	tx[0] = (reg << COMM_ADDR_bp);
> +	tx[1] = (*val >> 16) & 0xff;
> +	tx[2] = (*val >> 8) & 0xff;
> +	tx[3] = (*val >> 0) & 0xff;
> +
> +	return spi_write(spi, tx, 4);
> +}
> +
> +static ssize_t show_voltage(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	uint32_t conf, mode, val, sign, pos_chan, neg_chan = 0;
> +	uint8_t status, gain, diff;
> +	int32_t whole, fract;
> +	int ret;
> +
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad7194_data *pdata = dev_info->dev_data;
> +	struct spi_device *spi = pdata->spi_dev;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +
> +	pos_chan = this_attr->address;
> +	gain = pdata->gain[this_attr->address];
> +	diff = pdata->diff[this_attr->address];
> +
> +	if (diff == 1) {
> +		/*if in0_diff is true, reading in0_input still returns
> +		* in0, but it is in0-in1, if you read in1_input
> +		* then you get in1-in0 */
> +		if ((pos_chan % 2) == 0)
> +			neg_chan = pos_chan+1;
> +		else
> +			neg_chan = pos_chan-1;
> +
> +		conf = CONF_CHOP_bm | CONF_BUF_bm |
> +			(pos_chan << CONF_CHAN_POS_bp) |
> +			(neg_chan << CONF_CHAN_NEG_bp) | gain;
> +	} else {
> +		conf = CONF_CHOP_bm | CONF_PSEUDO_bm | CONF_BUF_bm |
> +			(pos_chan << CONF_CHAN_POS_bp) | gain;
> +	}
> +
> +	ret = mutex_lock_interruptible(&pdata->lock);
> +	if (ret != 0)
> +		return ret;
> +
> +	ret = ad7194_write_reg24(spi, REG_CONF, &conf);
> +	if (ret != 0)
> +		goto out;
> +
> +	mode = MODE_MD_SINGLE_gc | MODE_CLK_INTTRI_gc | MODE_FILTER_WORD;
> +	ret = ad7194_write_reg24(spi, REG_MODE, &mode);
> +	if (ret != 0)
> +		goto out;
> +
> +	msleep_interruptible(SETTLE_MS);
> +
> +	ret = ad7194_read_reg8(spi, REG_STATUS, &status);
> +	if (ret != 0)
> +		goto out;
> +	status = (status >> 6) & 0x01;
> +
> +	ret = ad7194_read_reg24(spi, REG_DATA, &val);
> +	if (ret != 0)
> +		goto out;
> +
> +	sign = (val & 0x800000) >> 23;
> +	if (sign)
> +		fract = (val & 0x7fffff);
> +	else
> +		fract = 0x7fffff - (val & 0x7fffff);
> +	fract = ((int64_t)fract*4095000) >> 23;
> +	fract = fract / gains[gain];
> +	whole = fract / 1000000;
> +	fract = fract % 1000000;
> +
> +	if (status == 0) {
> +		mutex_unlock(&pdata->lock);
> +		if (sign)
> +			return sprintf(buf, "%d.%.6d\n", whole, fract);
> +		else
> +			return sprintf(buf, "-%d.%.6d\n", whole, fract);
> +	} else {
> +		ret = -EAGAIN;
> +		goto out;
> +	}
> +
> +out:
> +	mutex_unlock(&pdata->lock);
> +	return ret;
> +}
> +
> +static IIO_DEVICE_ATTR(ch1_value, S_IRUGO, show_voltage, NULL, 0);
> +static IIO_DEVICE_ATTR(ch2_value, S_IRUGO, show_voltage, NULL, 1);
> +static IIO_DEVICE_ATTR(ch3_value, S_IRUGO, show_voltage, NULL, 2);
> +static IIO_DEVICE_ATTR(ch4_value, S_IRUGO, show_voltage, NULL, 3);
> +static IIO_DEVICE_ATTR(ch5_value, S_IRUGO, show_voltage, NULL, 4);
> +static IIO_DEVICE_ATTR(ch6_value, S_IRUGO, show_voltage, NULL, 5);
> +static IIO_DEVICE_ATTR(ch7_value, S_IRUGO, show_voltage, NULL, 6);
> +static IIO_DEVICE_ATTR(ch8_value, S_IRUGO, show_voltage, NULL, 7);
> +static IIO_DEVICE_ATTR(ch9_value, S_IRUGO, show_voltage, NULL, 8);
> +static IIO_DEVICE_ATTR(ch10_value, S_IRUGO, show_voltage, NULL, 9);
> +static IIO_DEVICE_ATTR(ch11_value, S_IRUGO, show_voltage, NULL, 10);
> +static IIO_DEVICE_ATTR(ch12_value, S_IRUGO, show_voltage, NULL, 11);
> +static IIO_DEVICE_ATTR(ch13_value, S_IRUGO, show_voltage, NULL, 12);
> +static IIO_DEVICE_ATTR(ch14_value, S_IRUGO, show_voltage, NULL, 13);
> +static IIO_DEVICE_ATTR(ch15_value, S_IRUGO, show_voltage, NULL, 14);
> +static IIO_DEVICE_ATTR(ch16_value, S_IRUGO, show_voltage, NULL, 15);
> +
> +static IIO_DEVICE_ATTR(ch1_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 0);
> +static IIO_DEVICE_ATTR(ch2_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 1);
> +static IIO_DEVICE_ATTR(ch3_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 2);
> +static IIO_DEVICE_ATTR(ch4_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 3);
> +static IIO_DEVICE_ATTR(ch5_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 4);
> +static IIO_DEVICE_ATTR(ch6_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 5);
> +static IIO_DEVICE_ATTR(ch7_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 6);
> +static IIO_DEVICE_ATTR(ch8_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 7);
> +static IIO_DEVICE_ATTR(ch9_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 8);
> +static IIO_DEVICE_ATTR(ch10_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 9);
> +static IIO_DEVICE_ATTR(ch11_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 10);
> +static IIO_DEVICE_ATTR(ch12_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 11);
> +static IIO_DEVICE_ATTR(ch13_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 12);
> +static IIO_DEVICE_ATTR(ch14_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 13);
> +static IIO_DEVICE_ATTR(ch15_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 14);
> +static IIO_DEVICE_ATTR(ch16_gain, S_IWUSR | S_IRUGO, show_gain, set_gain, 15);
> +
> +static IIO_DEVICE_ATTR(ch1_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 0);
> +static IIO_DEVICE_ATTR(ch2_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 1);
> +static IIO_DEVICE_ATTR(ch3_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 2);
> +static IIO_DEVICE_ATTR(ch4_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 3);
> +static IIO_DEVICE_ATTR(ch5_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 4);
> +static IIO_DEVICE_ATTR(ch6_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 5);
> +static IIO_DEVICE_ATTR(ch7_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 6);
> +static IIO_DEVICE_ATTR(ch8_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 7);
> +static IIO_DEVICE_ATTR(ch9_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 8);
> +static IIO_DEVICE_ATTR(ch10_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 9);
> +static IIO_DEVICE_ATTR(ch11_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 10);
> +static IIO_DEVICE_ATTR(ch12_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 11);
> +static IIO_DEVICE_ATTR(ch13_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 12);
> +static IIO_DEVICE_ATTR(ch14_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 13);
> +static IIO_DEVICE_ATTR(ch15_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 14);
> +static IIO_DEVICE_ATTR(ch16_diff, S_IWUSR | S_IRUGO, show_diff, set_diff, 15);
> +
> +static struct attribute *ad7194_attributes[] = {
> +	&iio_dev_attr_ch1_value.dev_attr.attr,
> +	&iio_dev_attr_ch2_value.dev_attr.attr,
> +	&iio_dev_attr_ch3_value.dev_attr.attr,
> +	&iio_dev_attr_ch4_value.dev_attr.attr,
> +	&iio_dev_attr_ch5_value.dev_attr.attr,
> +	&iio_dev_attr_ch6_value.dev_attr.attr,
> +	&iio_dev_attr_ch7_value.dev_attr.attr,
> +	&iio_dev_attr_ch8_value.dev_attr.attr,
> +	&iio_dev_attr_ch9_value.dev_attr.attr,
> +	&iio_dev_attr_ch10_value.dev_attr.attr,
> +	&iio_dev_attr_ch11_value.dev_attr.attr,
> +	&iio_dev_attr_ch12_value.dev_attr.attr,
> +	&iio_dev_attr_ch13_value.dev_attr.attr,
> +	&iio_dev_attr_ch14_value.dev_attr.attr,
> +	&iio_dev_attr_ch15_value.dev_attr.attr,
> +	&iio_dev_attr_ch16_value.dev_attr.attr,
> +	&iio_dev_attr_ch1_gain.dev_attr.attr,
> +	&iio_dev_attr_ch2_gain.dev_attr.attr,
> +	&iio_dev_attr_ch3_gain.dev_attr.attr,
> +	&iio_dev_attr_ch4_gain.dev_attr.attr,
> +	&iio_dev_attr_ch5_gain.dev_attr.attr,
> +	&iio_dev_attr_ch6_gain.dev_attr.attr,
> +	&iio_dev_attr_ch7_gain.dev_attr.attr,
> +	&iio_dev_attr_ch8_gain.dev_attr.attr,
> +	&iio_dev_attr_ch9_gain.dev_attr.attr,
> +	&iio_dev_attr_ch10_gain.dev_attr.attr,
> +	&iio_dev_attr_ch11_gain.dev_attr.attr,
> +	&iio_dev_attr_ch12_gain.dev_attr.attr,
> +	&iio_dev_attr_ch13_gain.dev_attr.attr,
> +	&iio_dev_attr_ch14_gain.dev_attr.attr,
> +	&iio_dev_attr_ch15_gain.dev_attr.attr,
> +	&iio_dev_attr_ch16_gain.dev_attr.attr,
> +	&iio_dev_attr_ch1_diff.dev_attr.attr,
> +	&iio_dev_attr_ch2_diff.dev_attr.attr,
> +	&iio_dev_attr_ch3_diff.dev_attr.attr,
> +	&iio_dev_attr_ch4_diff.dev_attr.attr,
> +	&iio_dev_attr_ch5_diff.dev_attr.attr,
> +	&iio_dev_attr_ch6_diff.dev_attr.attr,
> +	&iio_dev_attr_ch7_diff.dev_attr.attr,
> +	&iio_dev_attr_ch8_diff.dev_attr.attr,
> +	&iio_dev_attr_ch9_diff.dev_attr.attr,
> +	&iio_dev_attr_ch10_diff.dev_attr.attr,
> +	&iio_dev_attr_ch11_diff.dev_attr.attr,
> +	&iio_dev_attr_ch12_diff.dev_attr.attr,
> +	&iio_dev_attr_ch13_diff.dev_attr.attr,
> +	&iio_dev_attr_ch14_diff.dev_attr.attr,
> +	&iio_dev_attr_ch15_diff.dev_attr.attr,
> +	&iio_dev_attr_ch16_diff.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group ad7194_attribute_group = {
> +	.attrs = ad7194_attributes,
> +};
> +
> +static const struct iio_info ad7194_info = {
> +	.attrs = &ad7194_attribute_group,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int __devinit ad7194_probe(struct spi_device *spi)
> +{
> +	int ret, err;
> +	struct ad7194_data *pdata;
> +
> +	/* Configure the SPI bus */
> +	spi->mode = (SPI_MODE_0);
> +	spi->bits_per_word = 8;
> +	spi_setup(spi);
> +
> +	pdata = kzalloc(sizeof(struct ad7194_data), GFP_KERNEL);
> +	if (!pdata) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	dev_set_drvdata(&spi->dev, pdata);
> +
> +	pdata->spi_dev = spi;
> +
> +	pdata->indio_dev = iio_allocate_device(0);
> +	if (pdata->indio_dev == NULL) {
> +		ret = -ENOMEM;
> +		goto error_free;
> +	}
> +
> +	mutex_init(&pdata->lock);
> +	pdata->indio_dev->name = "ad7194";
> +	pdata->indio_dev->dev.parent = &spi->dev;
> +	pdata->indio_dev->info = &ad7194_info;
> +	pdata->indio_dev->dev_data = (void *)pdata;
> +
> +	ret = iio_device_register(pdata->indio_dev);
> +	if (ret)
> +		goto error_free_dev;
> +
> +	return 0;
> +
> +error_free_dev:
> +	iio_free_device(pdata->indio_dev);
> +error_free:
> +	kfree(pdata);
> +exit:
> +	return err;
> +}
> +
> +static int __devexit ad7194_remove(struct spi_device *spi)
> +{
> +	struct ad7194_data *pdata = dev_get_drvdata(&spi->dev);
> +
> +	dev_set_drvdata(&spi->dev, NULL);
> +	iio_device_unregister(pdata->indio_dev);
> +	iio_free_device(pdata->indio_dev);
> +	kfree(pdata);
> +	return 0;
> +}
> +
> +static struct spi_driver ad7194_driver = {
> +	.driver = {
> +		.name = DEVICE_NAME,
> +		.bus = &spi_bus_type,
> +		.owner = THIS_MODULE,
> +	},
> +
> +	.probe = ad7194_probe,
> +	.remove = __devexit_p(ad7194_remove),
> +};
> +
> +static int __init ad7194_init(void)
> +{
> +	return spi_register_driver(&ad7194_driver);
> +}
> +
> +static void __exit ad7194_exit(void)
> +{
> +	spi_unregister_driver(&ad7194_driver);
> +}
> +
> +module_init(ad7194_init);
> +module_exit(ad7194_exit);
> +
> +MODULE_AUTHOR("Paul Thomas <pthomas8589@gmail.com>");
> +MODULE_DESCRIPTION("TI AD7194 A/D driver");
> +MODULE_LICENSE("GPL");