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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/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
struct ad7476_state;
struct ad7476_chip_info {
unsigned int int_vref_uv;
struct iio_chan_spec channel[2];
void (*reset)(struct ad7476_state *);
};
struct ad7476_state {
struct spi_device *spi;
const struct ad7476_chip_info *chip_info;
struct regulator *reg;
struct spi_transfer xfer;
struct spi_message msg;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
* Make the buffer large enough for one 16 bit sample and one 64 bit
* aligned 64 bit timestamp.
*/
unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
____cacheline_aligned;
};
enum ad7476_supported_device_ids {
ID_AD7091R,
ID_AD7276,
ID_AD7277,
ID_AD7278,
ID_AD7466,
ID_AD7467,
ID_AD7468,
ID_AD7495,
ID_AD7940,
};
static irqreturn_t ad7476_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7476_state *st = iio_priv(indio_dev);
int b_sent;
b_sent = spi_sync(st->spi, &st->msg);
if (b_sent < 0)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, st->data,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static void ad7091_reset(struct ad7476_state *st)
{
/* Any transfers with 8 scl cycles will reset the device */
spi_read(st->spi, st->data, 1);
}
static int ad7476_scan_direct(struct ad7476_state *st)
{
int ret;
ret = spi_sync(st->spi, &st->msg);
if (ret)
return ret;
return be16_to_cpup((__be16 *)st->data);
}
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);
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) &
GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (!st->chip_info->int_vref_uv) {
scale_uv = regulator_get_voltage(st->reg);
if (scale_uv < 0)
return scale_uv;
} else {
scale_uv = st->chip_info->int_vref_uv;
}
*val = scale_uv / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.info_mask_separate = _info_mask_sep, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = (_shift), \
.endianness = IIO_BE, \
}, \
}
#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
[ID_AD7091R] = {
.channel[0] = AD7091R_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.reset = ad7091_reset,
},
[ID_AD7276] = {
.channel[0] = AD7940_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7277] = {
.channel[0] = AD7940_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7278] = {
.channel[0] = AD7940_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[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_AD7495] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.int_vref_uv = 2500000,
},
[ID_AD7940] = {
.channel[0] = AD7940_CHAN(14),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
};
static const struct iio_info ad7476_info = {
.driver_module = THIS_MODULE,
.read_raw = &ad7476_read_raw,
};
static int ad7476_probe(struct spi_device *spi)
{
struct ad7476_state *st;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->chip_info =
&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
st->reg = devm_regulator_get(&spi->dev, "vcc");
if (IS_ERR(st->reg))
return PTR_ERR(st->reg);
ret = regulator_enable(st->reg);
if (ret)
return ret;
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 = iio_triggered_buffer_setup(indio_dev, NULL,
&ad7476_trigger_handler, NULL);
if (ret)
goto error_disable_reg;
if (st->chip_info->reset)
st->chip_info->reset(st);
ret = iio_device_register(indio_dev);
if (ret)
goto error_ring_unregister;
return 0;
error_ring_unregister:
iio_triggered_buffer_cleanup(indio_dev);
error_disable_reg:
regulator_disable(st->reg);
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);
iio_triggered_buffer_cleanup(indio_dev);
regulator_disable(st->reg);
return 0;
}
static const struct spi_device_id ad7476_id[] = {
{"ad7091r", ID_AD7091R},
{"ad7273", ID_AD7277},
{"ad7274", ID_AD7276},
{"ad7276", ID_AD7276},
{"ad7277", ID_AD7277},
{"ad7278", ID_AD7278},
{"ad7466", ID_AD7466},
{"ad7467", ID_AD7467},
{"ad7468", ID_AD7468},
{"ad7475", ID_AD7466},
{"ad7476", ID_AD7466},
{"ad7476a", ID_AD7466},
{"ad7477", ID_AD7467},
{"ad7477a", ID_AD7467},
{"ad7478", ID_AD7468},
{"ad7478a", ID_AD7468},
{"ad7495", ID_AD7495},
{"ad7910", ID_AD7467},
{"ad7920", ID_AD7466},
{"ad7940", ID_AD7940},
{}
};
MODULE_DEVICE_TABLE(spi, ad7476_id);
static struct spi_driver ad7476_driver = {
.driver = {
.name = "ad7476",
.owner = THIS_MODULE,
},
.probe = ad7476_probe,
.remove = ad7476_remove,
.id_table = ad7476_id,
};
module_spi_driver(ad7476_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
MODULE_LICENSE("GPL v2");
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