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/*
* AD7298 SPI ADC driver
*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/workqueue.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/delay.h>
#include "../iio.h"
#include "../sysfs.h"
#include "../ring_generic.h"
#include "adc.h"
#include "ad7298.h"
static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
{
int ret;
st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref |
(AD7298_CH(0) >> ch));
ret = spi_sync(st->spi, &st->scan_single_msg);
if (ret)
return ret;
return be16_to_cpu(st->rx_buf[0]);
}
static ssize_t ad7298_scan(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_state *st = dev_info->dev_data;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
int ret;
mutex_lock(&dev_info->mlock);
if (iio_ring_enabled(dev_info))
ret = ad7298_scan_from_ring(st, this_attr->address);
else
ret = ad7298_scan_direct(st, this_attr->address);
mutex_unlock(&dev_info->mlock);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", ret & RES_MASK(AD7298_BITS));
}
static IIO_DEV_ATTR_IN_RAW(0, ad7298_scan, 0);
static IIO_DEV_ATTR_IN_RAW(1, ad7298_scan, 1);
static IIO_DEV_ATTR_IN_RAW(2, ad7298_scan, 2);
static IIO_DEV_ATTR_IN_RAW(3, ad7298_scan, 3);
static IIO_DEV_ATTR_IN_RAW(4, ad7298_scan, 4);
static IIO_DEV_ATTR_IN_RAW(5, ad7298_scan, 5);
static IIO_DEV_ATTR_IN_RAW(6, ad7298_scan, 6);
static IIO_DEV_ATTR_IN_RAW(7, ad7298_scan, 7);
static ssize_t ad7298_show_temp(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_state *st = iio_dev_get_devdata(dev_info);
int tmp;
tmp = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE |
AD7298_TAVG | st->ext_ref);
mutex_lock(&dev_info->mlock);
spi_write(st->spi, (u8 *)&tmp, 2);
tmp = 0;
spi_write(st->spi, (u8 *)&tmp, 2);
usleep_range(101, 1000); /* sleep > 100us */
spi_read(st->spi, (u8 *)&tmp, 2);
mutex_unlock(&dev_info->mlock);
tmp = be16_to_cpu(tmp) & RES_MASK(AD7298_BITS);
/*
* One LSB of the ADC corresponds to 0.25 deg C.
* The temperature reading is in 12-bit twos complement format
*/
if (tmp & (1 << (AD7298_BITS - 1))) {
tmp = (4096 - tmp) * 250;
tmp -= (2 * tmp);
} else {
tmp *= 250; /* temperature in milli degrees Celsius */
}
return sprintf(buf, "%d\n", tmp);
}
static IIO_DEVICE_ATTR(temp0_input, S_IRUGO, ad7298_show_temp, NULL, 0);
static ssize_t ad7298_show_scale(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_state *st = iio_dev_get_devdata(dev_info);
/* Corresponds to Vref / 2^(bits) */
unsigned int scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS;
return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
}
static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7298_show_scale, NULL, 0);
static ssize_t ad7298_show_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_state *st = iio_dev_get_devdata(dev_info);
return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
}
static IIO_DEVICE_ATTR(name, S_IRUGO, ad7298_show_name, NULL, 0);
static struct attribute *ad7298_attributes[] = {
&iio_dev_attr_in0_raw.dev_attr.attr,
&iio_dev_attr_in1_raw.dev_attr.attr,
&iio_dev_attr_in2_raw.dev_attr.attr,
&iio_dev_attr_in3_raw.dev_attr.attr,
&iio_dev_attr_in4_raw.dev_attr.attr,
&iio_dev_attr_in5_raw.dev_attr.attr,
&iio_dev_attr_in6_raw.dev_attr.attr,
&iio_dev_attr_in7_raw.dev_attr.attr,
&iio_dev_attr_in_scale.dev_attr.attr,
&iio_dev_attr_temp0_input.dev_attr.attr,
&iio_dev_attr_name.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7298_attribute_group = {
.attrs = ad7298_attributes,
};
static int __devinit ad7298_probe(struct spi_device *spi)
{
struct ad7298_platform_data *pdata = spi->dev.platform_data;
struct ad7298_state *st;
int ret;
st = kzalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL) {
ret = -ENOMEM;
goto error_ret;
}
st->reg = regulator_get(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
goto error_put_reg;
}
spi_set_drvdata(spi, st);
atomic_set(&st->protect_ring, 0);
st->spi = spi;
st->indio_dev = iio_allocate_device();
if (st->indio_dev == NULL) {
ret = -ENOMEM;
goto error_disable_reg;
}
st->indio_dev->dev.parent = &spi->dev;
st->indio_dev->attrs = &ad7298_attribute_group;
st->indio_dev->dev_data = (void *)(st);
st->indio_dev->driver_module = THIS_MODULE;
st->indio_dev->modes = INDIO_DIRECT_MODE;
/* Setup default message */
st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
st->scan_single_xfer[0].len = 2;
st->scan_single_xfer[0].cs_change = 1;
st->scan_single_xfer[1].tx_buf = &st->tx_buf[1];
st->scan_single_xfer[1].len = 2;
st->scan_single_xfer[1].cs_change = 1;
st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
st->scan_single_xfer[2].len = 2;
spi_message_init(&st->scan_single_msg);
spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
if (pdata && pdata->vref_mv) {
st->int_vref_mv = pdata->vref_mv;
st->ext_ref = AD7298_EXTREF;
} else {
st->int_vref_mv = AD7298_INTREF_mV;
}
ret = ad7298_register_ring_funcs_and_init(st->indio_dev);
if (ret)
goto error_free_device;
ret = iio_device_register(st->indio_dev);
if (ret)
goto error_free_device;
ret = iio_ring_buffer_register(st->indio_dev->ring, 0);
if (ret)
goto error_cleanup_ring;
return 0;
error_cleanup_ring:
ad7298_ring_cleanup(st->indio_dev);
iio_device_unregister(st->indio_dev);
error_free_device:
iio_free_device(st->indio_dev);
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
error_put_reg:
if (!IS_ERR(st->reg))
regulator_put(st->reg);
kfree(st);
error_ret:
return ret;
}
static int __devexit ad7298_remove(struct spi_device *spi)
{
struct ad7298_state *st = spi_get_drvdata(spi);
struct iio_dev *indio_dev = st->indio_dev;
iio_ring_buffer_unregister(indio_dev->ring);
ad7298_ring_cleanup(indio_dev);
iio_device_unregister(indio_dev);
if (!IS_ERR(st->reg)) {
regulator_disable(st->reg);
regulator_put(st->reg);
}
kfree(st);
return 0;
}
static const struct spi_device_id ad7298_id[] = {
{"ad7298", 0},
{}
};
static struct spi_driver ad7298_driver = {
.driver = {
.name = "ad7298",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ad7298_probe,
.remove = __devexit_p(ad7298_remove),
.id_table = ad7298_id,
};
static int __init ad7298_init(void)
{
return spi_register_driver(&ad7298_driver);
}
module_init(ad7298_init);
static void __exit ad7298_exit(void)
{
spi_unregister_driver(&ad7298_driver);
}
module_exit(ad7298_exit);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7298 ADC");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:ad7298");
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