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/*
* AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
*
* Copyright 2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#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/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include "ad7476.h"
static int ad7476_scan_direct(struct ad7476_state *st)
{
int ret;
ret = spi_sync(st->spi, &st->msg);
if (ret)
return ret;
return (st->data[0] << 8) | st->data[1];
}
static int ad7476_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad7476_state *st = iio_priv(indio_dev);
unsigned int scale_uv;
switch (m) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
if (iio_buffer_enabled(indio_dev))
ret = -EBUSY;
else
ret = ad7476_scan_direct(st);
mutex_unlock(&indio_dev->mlock);
if (ret < 0)
return ret;
*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
RES_MASK(st->chip_info->channel[0].scan_type.realbits);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
scale_uv = (st->int_vref_mv * 1000)
>> st->chip_info->channel[0].scan_type.realbits;
*val = scale_uv/1000;
*val2 = (scale_uv%1000)*1000;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
#define AD7476_CHAN(bits) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
IIO_CHAN_INFO_SCALE_SHARED_BIT, \
.scan_type = { \
.sign = 'u', \
.realbits = bits, \
.storagebits = 16, \
.shift = 12 - bits, \
}, \
}
static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
[ID_AD7466] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7467] = {
.channel[0] = AD7476_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7468] = {
.channel[0] = AD7476_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7475] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7476] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7477] = {
.channel[0] = AD7476_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7478] = {
.channel[0] = AD7476_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7495] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.int_vref_mv = 2500,
},
};
static const struct iio_info ad7476_info = {
.driver_module = THIS_MODULE,
.read_raw = &ad7476_read_raw,
};
static int __devinit ad7476_probe(struct spi_device *spi)
{
struct ad7476_platform_data *pdata = spi->dev.platform_data;
struct ad7476_state *st;
struct iio_dev *indio_dev;
int ret, voltage_uv = 0;
indio_dev = iio_device_alloc(sizeof(*st));
if (indio_dev == NULL) {
ret = -ENOMEM;
goto error_ret;
}
st = iio_priv(indio_dev);
st->reg = regulator_get(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
goto error_put_reg;
voltage_uv = regulator_get_voltage(st->reg);
}
st->chip_info =
&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
if (st->chip_info->int_vref_mv)
st->int_vref_mv = st->chip_info->int_vref_mv;
else if (pdata && pdata->vref_mv)
st->int_vref_mv = pdata->vref_mv;
else if (voltage_uv)
st->int_vref_mv = voltage_uv / 1000;
else
dev_warn(&spi->dev, "reference voltage unspecified\n");
spi_set_drvdata(spi, indio_dev);
st->spi = spi;
/* Establish that the iio_dev is a child of the spi device */
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channel;
indio_dev->num_channels = 2;
indio_dev->info = &ad7476_info;
/* Setup default message */
st->xfer.rx_buf = &st->data;
st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
spi_message_init(&st->msg);
spi_message_add_tail(&st->xfer, &st->msg);
ret = ad7476_register_ring_funcs_and_init(indio_dev);
if (ret)
goto error_disable_reg;
ret = iio_device_register(indio_dev);
if (ret)
goto error_ring_unregister;
return 0;
error_ring_unregister:
ad7476_ring_cleanup(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);
iio_device_free(indio_dev);
error_ret:
return ret;
}
static int ad7476_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad7476_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
ad7476_ring_cleanup(indio_dev);
if (!IS_ERR(st->reg)) {
regulator_disable(st->reg);
regulator_put(st->reg);
}
iio_device_free(indio_dev);
return 0;
}
static const struct spi_device_id ad7476_id[] = {
{"ad7466", ID_AD7466},
{"ad7467", ID_AD7467},
{"ad7468", ID_AD7468},
{"ad7475", ID_AD7475},
{"ad7476", ID_AD7476},
{"ad7476a", ID_AD7476},
{"ad7477", ID_AD7477},
{"ad7477a", ID_AD7477},
{"ad7478", ID_AD7478},
{"ad7478a", ID_AD7478},
{"ad7495", ID_AD7495},
{}
};
MODULE_DEVICE_TABLE(spi, ad7476_id);
static struct spi_driver ad7476_driver = {
.driver = {
.name = "ad7476",
.owner = THIS_MODULE,
},
.probe = ad7476_probe,
.remove = __devexit_p(ad7476_remove),
.id_table = ad7476_id,
};
module_spi_driver(ad7476_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7475/6/7/8(A) AD7466/7/8 ADC");
MODULE_LICENSE("GPL v2");
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