blob: 55d66e290f7d1d80eb0e1603c12b4b7224031c0e [file] [log] [blame]
/*
* 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");