drivers/staging/adis16255/adis16255.c - linux - Git at Google

 /*
  * Analog Devices ADIS16250/ADIS16255 Low Power Gyroscope
  *
  * Written by: Matthias Brugger <m_brugger@web.de>
  *
  * Copyright (C) 2010 Fraunhofer Institute for Integrated Circuits
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the
  * Free Software Foundation, Inc.,
  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */

 /*
  * The driver just has a bare interface to the sysfs (sample rate in Hz,
  * orientation (x, y, z) and gyroscope data in °/sec.
  *
  * It should be added to iio subsystem when this has left staging.
  *
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>

 #include <linux/interrupt.h>
 #include <linux/sysfs.h>
 #include <linux/stat.h>
 #include <linux/delay.h>

 #include <linux/gpio.h>

 #include <linux/spi/spi.h>
 #include <linux/workqueue.h>

 #include "adis16255.h"

 #define ADIS_STATUS        0x3d
 #define ADIS_SMPL_PRD_MSB  0x37
 #define ADIS_SMPL_PRD_LSB  0x36
 #define ADIS_MSC_CTRL_MSB  0x35
 #define ADIS_MSC_CTRL_LSB  0x34
 #define ADIS_GPIO_CTRL     0x33
 #define ADIS_ALM_SMPL1     0x25
 #define ADIS_ALM_MAG1      0x21
 #define ADIS_GYRO_SCALE    0x17
 #define ADIS_GYRO_OUT      0x05
 #define ADIS_SUPPLY_OUT    0x03
 #define ADIS_ENDURANCE     0x01

 /*
  * data structure for every sensor
  *
  * @dev:       Driver model representation of the device.
  * @spi:       Pointer to the spi device which will manage i/o to spi bus.
  * @data:      Last read data from device.
  * @irq_adis:  GPIO Number of IRQ signal
  * @irq:       irq line manage by kernel
  * @negative:  indicates if sensor is upside down (negative == 1)
  * @direction: indicates axis (x, y, z) the sensor is meassuring
  */
 struct spi_adis16255_data {
 	struct device dev;
 	struct spi_device *spi;
 	s16 data;
 	int irq;
 	u8 negative;
 	char direction;
 };

 /*-------------------------------------------------------------------------*/

 static int spi_adis16255_read_data(struct spi_adis16255_data *spiadis,
 					u8 adr,
 					u8 *rbuf)
 {
 	struct spi_device *spi = spiadis->spi;
 	struct spi_message msg;
 	struct spi_transfer xfer1, xfer2;
 	u8 *buf, *rx;
 	int ret;

 	buf = kzalloc(4, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;

 	rx = kzalloc(4, GFP_KERNEL);
 	if (rx == NULL) {
 		ret = -ENOMEM;
 		goto err_buf;
 	}

 	buf[0] = adr;

 	spi_message_init(&msg);
 	memset(&xfer1, 0, sizeof(xfer1));
 	memset(&xfer2, 0, sizeof(xfer2));

 	xfer1.tx_buf = buf;
 	xfer1.rx_buf = buf + 2;
 	xfer1.len = 2;
 	xfer1.delay_usecs = 9;

 	xfer2.tx_buf = rx + 2;
 	xfer2.rx_buf = rx;
 	xfer2.len = 2;

 	spi_message_add_tail(&xfer1, &msg);
 	spi_message_add_tail(&xfer2, &msg);

 	ret = spi_sync(spi, &msg);
 	if (ret == 0) {
 		rbuf[0] = rx[0];
 		rbuf[1] = rx[1];
 	}

 	kfree(rx);
 err_buf:
 	kfree(buf);

 	return ret;
 }

 static int spi_adis16255_write_data(struct spi_adis16255_data *spiadis,
 					u8 adr1,
 					u8 adr2,
 					u8 *wbuf)
 {
 	struct spi_device *spi = spiadis->spi;
 	struct spi_message   msg;
 	struct spi_transfer  xfer1, xfer2;
 	u8       *buf, *rx;
 	int         ret;

 	buf = kmalloc(4, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;

 	rx = kzalloc(4, GFP_KERNEL);
 	if (rx == NULL) {
 		ret = -ENOMEM;
 		goto err_buf;
 	}

 	spi_message_init(&msg);
 	memset(&xfer1, 0, sizeof(xfer1));
 	memset(&xfer2, 0, sizeof(xfer2));

 	buf[0] = adr1 | 0x80;
 	buf[1] = *wbuf;

 	buf[2] = adr2 | 0x80;
 	buf[3] = *(wbuf + 1);

 	xfer1.tx_buf = buf;
 	xfer1.rx_buf = rx;
 	xfer1.len = 2;
 	xfer1.delay_usecs = 9;

 	xfer2.tx_buf = buf+2;
 	xfer2.rx_buf = rx+2;
 	xfer2.len = 2;

 	spi_message_add_tail(&xfer1, &msg);
 	spi_message_add_tail(&xfer2, &msg);

 	ret = spi_sync(spi, &msg);
 	if (ret != 0)
 		dev_warn(&spi->dev, "write data to %#x %#x failed\n",
 				buf[0], buf[2]);

 	kfree(rx);
 err_buf:
 	kfree(buf);
 	return ret;
 }

 /*-------------------------------------------------------------------------*/

 static irqreturn_t adis_irq_thread(int irq, void *dev_id)
 {
 	struct spi_adis16255_data *spiadis = dev_id;
 	int status;
 	u16 value = 0;

 	status =  spi_adis16255_read_data(spiadis, ADIS_GYRO_OUT, (u8 *)&value);
 	if (status != 0) {
 		dev_warn(&spiadis->spi->dev, "SPI FAILED\n");
 		goto exit;
 	}

 	/* perform on new data only... */
 	if (value & 0x8000) {
 		/* delete error and new data bit */
 		value = value & 0x3fff;
 		/* set negative value */
 		if (value & 0x2000)
 			value = value | 0xe000;

 		if (likely(spiadis->negative))
 			value = -value;

 		spiadis->data = (s16) value;
 	}

 exit:
 	return IRQ_HANDLED;
 }

 /*-------------------------------------------------------------------------*/

 ssize_t adis16255_show_data(struct device *device,
 		struct device_attribute *da,
 		char *buf)
 {
 	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
 	return snprintf(buf, PAGE_SIZE, "%d\n", spiadis->data);
 }
 DEVICE_ATTR(data, S_IRUGO , adis16255_show_data, NULL);

 ssize_t adis16255_show_direction(struct device *device,
 		struct device_attribute *da,
 		char *buf)
 {
 	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
 	return snprintf(buf, PAGE_SIZE, "%c\n", spiadis->direction);
 }
 DEVICE_ATTR(direction, S_IRUGO , adis16255_show_direction, NULL);

 ssize_t adis16255_show_sample_rate(struct device *device,
 		struct device_attribute *da,
 		char *buf)
 {
 	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
 	int status = 0;
 	u16 value = 0;
 	int ts = 0;

 	status = spi_adis16255_read_data(spiadis, ADIS_SMPL_PRD_MSB,
 				(u8 *)&value);
 	if (status != 0)
 		return -EINVAL;

 	if (value & 0x80) {
 		/* timebase = 60.54 ms */
 		ts = 60540 * ((0x7f & value) + 1);
 	} else {
 		/* timebase = 1.953 ms */
 		ts = 1953 * ((0x7f & value) + 1);
 	}

 	return snprintf(buf, PAGE_SIZE, "%d\n", (1000*1000)/ts);
 }
 DEVICE_ATTR(sample_rate, S_IRUGO , adis16255_show_sample_rate, NULL);

 static struct attribute *adis16255_attributes[] = {
 	&dev_attr_data.attr,
 	&dev_attr_direction.attr,
 	&dev_attr_sample_rate.attr,
 	NULL
 };

 static const struct attribute_group adis16255_attr_group = {
 	.attrs = adis16255_attributes,
 };

 /*-------------------------------------------------------------------------*/

 static int spi_adis16255_shutdown(struct spi_adis16255_data *spiadis)
 {
 	u16 value = 0;
 	/* turn sensor off */
 	spi_adis16255_write_data(spiadis,
 			ADIS_SMPL_PRD_MSB, ADIS_SMPL_PRD_LSB,
 			(u8 *)&value);
 	spi_adis16255_write_data(spiadis,
 			ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
 			(u8 *)&value);
 	return 0;
 }

 static int spi_adis16255_bringup(struct spi_adis16255_data *spiadis)
 {
 	int status = 0;
 	u16 value = 0;

 	status = spi_adis16255_read_data(spiadis, ADIS_GYRO_SCALE,
 				(u8 *)&value);
 	if (status != 0)
 		goto err;
 	if (value != 0x0800) {
 		dev_warn(&spiadis->spi->dev, "Scale factor is none default "
 				"value (%.4x)\n", value);
 	}

 	/* timebase = 1.953 ms, Ns = 0 -> 512 Hz sample rate */
 	value =  0x0001;
 	status = spi_adis16255_write_data(spiadis,
 				ADIS_SMPL_PRD_MSB, ADIS_SMPL_PRD_LSB,
 				(u8 *)&value);
 	if (status != 0)
 		goto err;

 	/* start internal self-test */
 	value = 0x0400;
 	status = spi_adis16255_write_data(spiadis,
 				ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
 				(u8 *)&value);
 	if (status != 0)
 		goto err;

 	/* wait 35 ms to finish self-test */
 	msleep(35);

 	value = 0x0000;
 	status = spi_adis16255_read_data(spiadis, ADIS_STATUS,
 				(u8 *)&value);
 	if (status != 0)
 		goto err;

 	if (value & 0x23) {
 		if (value & 0x20) {
 			dev_warn(&spiadis->spi->dev, "self-test error\n");
 			status = -ENODEV;
 			goto err;
 		} else if (value & 0x3)	{
 			dev_warn(&spiadis->spi->dev, "Sensor voltage "
 						"out of range.\n");
 			status = -ENODEV;
 			goto err;
 		}
 	}

 	/* set interrupt to active high on DIO0 when data ready */
 	value = 0x0006;
 	status = spi_adis16255_write_data(spiadis,
 				ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
 				(u8 *)&value);
 	if (status != 0)
 		goto err;
 	return status;

 err:
 	spi_adis16255_shutdown(spiadis);
 	return status;
 }

 /*-------------------------------------------------------------------------*/

 static int __devinit spi_adis16255_probe(struct spi_device *spi)
 {

 	struct adis16255_init_data *init_data = spi->dev.platform_data;
 	struct spi_adis16255_data  *spiadis;
 	int status = 0;

 	spiadis = kzalloc(sizeof(*spiadis), GFP_KERNEL);
 	if (!spiadis)
 		return -ENOMEM;

 	spiadis->spi = spi;
 	spiadis->direction = init_data->direction;

 	if (init_data->negative)
 		spiadis->negative = 1;

 	status = gpio_request(init_data->irq, "adis16255");
 	if (status != 0)
 		goto err;

 	status = gpio_direction_input(init_data->irq);
 	if (status != 0)
 		goto gpio_err;

 	spiadis->irq = gpio_to_irq(init_data->irq);

 	status = request_threaded_irq(spiadis->irq,
 			NULL, adis_irq_thread,
 			IRQF_DISABLED, "adis-driver", spiadis);

 	if (status != 0) {
 		dev_err(&spi->dev, "IRQ request failed\n");
 		goto gpio_err;
 	}

 	dev_dbg(&spi->dev, "GPIO %d IRQ %d\n", init_data->irq, spiadis->irq);

 	dev_set_drvdata(&spi->dev, spiadis);
 	status = sysfs_create_group(&spi->dev.kobj, &adis16255_attr_group);
 	if (status != 0)
 		goto irq_err;

 	status = spi_adis16255_bringup(spiadis);
 	if (status != 0)
 		goto irq_err;

 	dev_info(&spi->dev, "spi_adis16255 driver added!\n");

 	return status;

 irq_err:
 	free_irq(spiadis->irq, spiadis);
 gpio_err:
 	gpio_free(init_data->irq);
 err:
 	kfree(spiadis);
 	return status;
 }

 static int __devexit spi_adis16255_remove(struct spi_device *spi)
 {
 	struct spi_adis16255_data  *spiadis    = dev_get_drvdata(&spi->dev);

 	spi_adis16255_shutdown(spiadis);

 	free_irq(spiadis->irq, spiadis);
 	gpio_free(irq_to_gpio(spiadis->irq));

 	sysfs_remove_group(&spiadis->spi->dev.kobj, &adis16255_attr_group);

 	kfree(spiadis);

 	dev_info(&spi->dev, "spi_adis16255 driver removed!\n");
 	return 0;
 }

 static struct spi_driver spi_adis16255_drv = {
 	.driver = {
 		.name =  "spi_adis16255",
 		.owner = THIS_MODULE,
 	},
 	.probe = spi_adis16255_probe,
 	.remove =   __devexit_p(spi_adis16255_remove),
 };

 /*-------------------------------------------------------------------------*/

 static int __init spi_adis16255_init(void)
 {
 	return spi_register_driver(&spi_adis16255_drv);
 }
 module_init(spi_adis16255_init);

 static void __exit spi_adis16255_exit(void)
 {
 	spi_unregister_driver(&spi_adis16255_drv);
 }
 module_exit(spi_adis16255_exit);

 MODULE_AUTHOR("Matthias Brugger");
 MODULE_DESCRIPTION("SPI device driver for ADIS16255 sensor");
 MODULE_LICENSE("GPL");
	/*
	* Analog Devices ADIS16250/ADIS16255 Low Power Gyroscope
	*
	* Written by: Matthias Brugger <m_brugger@web.de>
	*
	* Copyright (C) 2010 Fraunhofer Institute for Integrated Circuits
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the
	* Free Software Foundation, Inc.,
	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*/

	/*
	* The driver just has a bare interface to the sysfs (sample rate in Hz,
	* orientation (x, y, z) and gyroscope data in °/sec.
	*
	* It should be added to iio subsystem when this has left staging.
	*
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/device.h>
	#include <linux/list.h>
	#include <linux/errno.h>
	#include <linux/mutex.h>
	#include <linux/slab.h>

	#include <linux/interrupt.h>
	#include <linux/sysfs.h>
	#include <linux/stat.h>
	#include <linux/delay.h>

	#include <linux/gpio.h>

	#include <linux/spi/spi.h>
	#include <linux/workqueue.h>

	#include "adis16255.h"

	#define ADIS_STATUS 0x3d
	#define ADIS_SMPL_PRD_MSB 0x37
	#define ADIS_SMPL_PRD_LSB 0x36
	#define ADIS_MSC_CTRL_MSB 0x35
	#define ADIS_MSC_CTRL_LSB 0x34
	#define ADIS_GPIO_CTRL 0x33
	#define ADIS_ALM_SMPL1 0x25
	#define ADIS_ALM_MAG1 0x21
	#define ADIS_GYRO_SCALE 0x17
	#define ADIS_GYRO_OUT 0x05
	#define ADIS_SUPPLY_OUT 0x03
	#define ADIS_ENDURANCE 0x01

	/*
	* data structure for every sensor
	*
	* @dev: Driver model representation of the device.
	* @spi: Pointer to the spi device which will manage i/o to spi bus.
	* @data: Last read data from device.
	* @irq_adis: GPIO Number of IRQ signal
	* @irq: irq line manage by kernel
	* @negative: indicates if sensor is upside down (negative == 1)
	* @direction: indicates axis (x, y, z) the sensor is meassuring
	*/
	struct spi_adis16255_data {
	struct device dev;
	struct spi_device *spi;
	s16 data;
	int irq;
	u8 negative;
	char direction;
	};

	/-------------------------------------------------------------------------/

	static int spi_adis16255_read_data(struct spi_adis16255_data *spiadis,
	u8 adr,
	u8 *rbuf)
	{
	struct spi_device *spi = spiadis->spi;
	struct spi_message msg;
	struct spi_transfer xfer1, xfer2;
	u8 buf, rx;
	int ret;

	buf = kzalloc(4, GFP_KERNEL);
	if (buf == NULL)
	return -ENOMEM;

	rx = kzalloc(4, GFP_KERNEL);
	if (rx == NULL) {
	ret = -ENOMEM;
	goto err_buf;
	}

	buf[0] = adr;

	spi_message_init(&msg);
	memset(&xfer1, 0, sizeof(xfer1));
	memset(&xfer2, 0, sizeof(xfer2));

	xfer1.tx_buf = buf;
	xfer1.rx_buf = buf + 2;
	xfer1.len = 2;
	xfer1.delay_usecs = 9;

	xfer2.tx_buf = rx + 2;
	xfer2.rx_buf = rx;
	xfer2.len = 2;

	spi_message_add_tail(&xfer1, &msg);
	spi_message_add_tail(&xfer2, &msg);

	ret = spi_sync(spi, &msg);
	if (ret == 0) {
	rbuf[0] = rx[0];
	rbuf[1] = rx[1];
	}

	kfree(rx);
	err_buf:
	kfree(buf);

	return ret;
	}

	static int spi_adis16255_write_data(struct spi_adis16255_data *spiadis,
	u8 adr1,
	u8 adr2,
	u8 *wbuf)
	{
	struct spi_device *spi = spiadis->spi;
	struct spi_message msg;
	struct spi_transfer xfer1, xfer2;
	u8 buf, rx;
	int ret;

	buf = kmalloc(4, GFP_KERNEL);
	if (buf == NULL)
	return -ENOMEM;

	rx = kzalloc(4, GFP_KERNEL);
	if (rx == NULL) {
	ret = -ENOMEM;
	goto err_buf;
	}

	spi_message_init(&msg);
	memset(&xfer1, 0, sizeof(xfer1));
	memset(&xfer2, 0, sizeof(xfer2));

	buf[0] = adr1 \| 0x80;
	buf[1] = *wbuf;

	buf[2] = adr2 \| 0x80;
	buf[3] = *(wbuf + 1);

	xfer1.tx_buf = buf;
	xfer1.rx_buf = rx;
	xfer1.len = 2;
	xfer1.delay_usecs = 9;

	xfer2.tx_buf = buf+2;
	xfer2.rx_buf = rx+2;
	xfer2.len = 2;

	spi_message_add_tail(&xfer1, &msg);
	spi_message_add_tail(&xfer2, &msg);

	ret = spi_sync(spi, &msg);
	if (ret != 0)
	dev_warn(&spi->dev, "write data to %#x %#x failed\n",
	buf[0], buf[2]);

	kfree(rx);
	err_buf:
	kfree(buf);
	return ret;
	}

	/-------------------------------------------------------------------------/

	static irqreturn_t adis_irq_thread(int irq, void *dev_id)
	{
	struct spi_adis16255_data *spiadis = dev_id;
	int status;
	u16 value = 0;

	status = spi_adis16255_read_data(spiadis, ADIS_GYRO_OUT, (u8 *)&value);
	if (status != 0) {
	dev_warn(&spiadis->spi->dev, "SPI FAILED\n");
	goto exit;
	}

	/* perform on new data only... */
	if (value & 0x8000) {
	/* delete error and new data bit */
	value = value & 0x3fff;
	/* set negative value */
	if (value & 0x2000)
	value = value \| 0xe000;

	if (likely(spiadis->negative))
	value = -value;

	spiadis->data = (s16) value;
	}

	exit:
	return IRQ_HANDLED;
	}

	/-------------------------------------------------------------------------/

	ssize_t adis16255_show_data(struct device *device,
	struct device_attribute *da,
	char *buf)
	{
	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
	return snprintf(buf, PAGE_SIZE, "%d\n", spiadis->data);
	}
	DEVICE_ATTR(data, S_IRUGO , adis16255_show_data, NULL);

	ssize_t adis16255_show_direction(struct device *device,
	struct device_attribute *da,
	char *buf)
	{
	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
	return snprintf(buf, PAGE_SIZE, "%c\n", spiadis->direction);
	}
	DEVICE_ATTR(direction, S_IRUGO , adis16255_show_direction, NULL);

	ssize_t adis16255_show_sample_rate(struct device *device,
	struct device_attribute *da,
	char *buf)
	{
	struct spi_adis16255_data *spiadis = dev_get_drvdata(device);
	int status = 0;
	u16 value = 0;
	int ts = 0;

	status = spi_adis16255_read_data(spiadis, ADIS_SMPL_PRD_MSB,
	(u8 *)&value);
	if (status != 0)
	return -EINVAL;

	if (value & 0x80) {
	/* timebase = 60.54 ms */
	ts = 60540 * ((0x7f & value) + 1);
	} else {
	/* timebase = 1.953 ms */
	ts = 1953 * ((0x7f & value) + 1);
	}

	return snprintf(buf, PAGE_SIZE, "%d\n", (1000*1000)/ts);
	}
	DEVICE_ATTR(sample_rate, S_IRUGO , adis16255_show_sample_rate, NULL);

	static struct attribute *adis16255_attributes[] = {
	&dev_attr_data.attr,
	&dev_attr_direction.attr,
	&dev_attr_sample_rate.attr,
	NULL
	};

	static const struct attribute_group adis16255_attr_group = {
	.attrs = adis16255_attributes,
	};

	/-------------------------------------------------------------------------/

	static int spi_adis16255_shutdown(struct spi_adis16255_data *spiadis)
	{
	u16 value = 0;
	/* turn sensor off */
	spi_adis16255_write_data(spiadis,
	ADIS_SMPL_PRD_MSB, ADIS_SMPL_PRD_LSB,
	(u8 *)&value);
	spi_adis16255_write_data(spiadis,
	ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
	(u8 *)&value);
	return 0;
	}

	static int spi_adis16255_bringup(struct spi_adis16255_data *spiadis)
	{
	int status = 0;
	u16 value = 0;

	status = spi_adis16255_read_data(spiadis, ADIS_GYRO_SCALE,
	(u8 *)&value);
	if (status != 0)
	goto err;
	if (value != 0x0800) {
	dev_warn(&spiadis->spi->dev, "Scale factor is none default "
	"value (%.4x)\n", value);
	}

	/* timebase = 1.953 ms, Ns = 0 -> 512 Hz sample rate */
	value = 0x0001;
	status = spi_adis16255_write_data(spiadis,
	ADIS_SMPL_PRD_MSB, ADIS_SMPL_PRD_LSB,
	(u8 *)&value);
	if (status != 0)
	goto err;

	/* start internal self-test */
	value = 0x0400;
	status = spi_adis16255_write_data(spiadis,
	ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
	(u8 *)&value);
	if (status != 0)
	goto err;

	/* wait 35 ms to finish self-test */
	msleep(35);

	value = 0x0000;
	status = spi_adis16255_read_data(spiadis, ADIS_STATUS,
	(u8 *)&value);
	if (status != 0)
	goto err;

	if (value & 0x23) {
	if (value & 0x20) {
	dev_warn(&spiadis->spi->dev, "self-test error\n");
	status = -ENODEV;
	goto err;
	} else if (value & 0x3) {
	dev_warn(&spiadis->spi->dev, "Sensor voltage "
	"out of range.\n");
	status = -ENODEV;
	goto err;
	}
	}

	/* set interrupt to active high on DIO0 when data ready */
	value = 0x0006;
	status = spi_adis16255_write_data(spiadis,
	ADIS_MSC_CTRL_MSB, ADIS_MSC_CTRL_LSB,
	(u8 *)&value);
	if (status != 0)
	goto err;
	return status;

	err:
	spi_adis16255_shutdown(spiadis);
	return status;
	}

	/-------------------------------------------------------------------------/

	static int __devinit spi_adis16255_probe(struct spi_device *spi)
	{

	struct adis16255_init_data *init_data = spi->dev.platform_data;
	struct spi_adis16255_data *spiadis;
	int status = 0;

	spiadis = kzalloc(sizeof(*spiadis), GFP_KERNEL);
	if (!spiadis)
	return -ENOMEM;

	spiadis->spi = spi;
	spiadis->direction = init_data->direction;

	if (init_data->negative)
	spiadis->negative = 1;

	status = gpio_request(init_data->irq, "adis16255");
	if (status != 0)
	goto err;

	status = gpio_direction_input(init_data->irq);
	if (status != 0)
	goto gpio_err;

	spiadis->irq = gpio_to_irq(init_data->irq);

	status = request_threaded_irq(spiadis->irq,
	NULL, adis_irq_thread,
	IRQF_DISABLED, "adis-driver", spiadis);

	if (status != 0) {
	dev_err(&spi->dev, "IRQ request failed\n");
	goto gpio_err;
	}

	dev_dbg(&spi->dev, "GPIO %d IRQ %d\n", init_data->irq, spiadis->irq);

	dev_set_drvdata(&spi->dev, spiadis);
	status = sysfs_create_group(&spi->dev.kobj, &adis16255_attr_group);
	if (status != 0)
	goto irq_err;

	status = spi_adis16255_bringup(spiadis);
	if (status != 0)
	goto irq_err;

	dev_info(&spi->dev, "spi_adis16255 driver added!\n");

	return status;

	irq_err:
	free_irq(spiadis->irq, spiadis);
	gpio_err:
	gpio_free(init_data->irq);
	err:
	kfree(spiadis);
	return status;
	}

	static int __devexit spi_adis16255_remove(struct spi_device *spi)
	{
	struct spi_adis16255_data *spiadis = dev_get_drvdata(&spi->dev);

	spi_adis16255_shutdown(spiadis);

	free_irq(spiadis->irq, spiadis);
	gpio_free(irq_to_gpio(spiadis->irq));

	sysfs_remove_group(&spiadis->spi->dev.kobj, &adis16255_attr_group);

	kfree(spiadis);

	dev_info(&spi->dev, "spi_adis16255 driver removed!\n");
	return 0;
	}

	static struct spi_driver spi_adis16255_drv = {
	.driver = {
	.name = "spi_adis16255",
	.owner = THIS_MODULE,
	},
	.probe = spi_adis16255_probe,
	.remove = __devexit_p(spi_adis16255_remove),
	};

	/-------------------------------------------------------------------------/

	static int __init spi_adis16255_init(void)
	{
	return spi_register_driver(&spi_adis16255_drv);
	}
	module_init(spi_adis16255_init);

	static void __exit spi_adis16255_exit(void)
	{
	spi_unregister_driver(&spi_adis16255_drv);
	}
	module_exit(spi_adis16255_exit);

	MODULE_AUTHOR("Matthias Brugger");
	MODULE_DESCRIPTION("SPI device driver for ADIS16255 sensor");
	MODULE_LICENSE("GPL");