// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* ltc2496.c - Driver for Analog Devices/Linear Technology LTC2496 ADC
|
*
|
* Based on ltc2497.c which has
|
* Copyright (C) 2017 Analog Devices Inc.
|
*
|
* Licensed under the GPL-2.
|
*
|
* Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2496fc.pdf
|
*/
|
|
#include <linux/spi/spi.h>
|
#include <linux/iio/iio.h>
|
#include <linux/iio/driver.h>
|
#include <linux/module.h>
|
#include <linux/mod_devicetable.h>
|
|
#include "ltc2497.h"
|
|
struct ltc2496_driverdata {
|
/* this must be the first member */
|
struct ltc2497core_driverdata common_ddata;
|
struct spi_device *spi;
|
|
/*
|
* DMA (thus cache coherency maintenance) requires the
|
* transfer buffers to live in their own cache lines.
|
*/
|
unsigned char rxbuf[3] ____cacheline_aligned;
|
unsigned char txbuf[3];
|
};
|
|
static int ltc2496_result_and_measure(struct ltc2497core_driverdata *ddata,
|
u8 address, int *val)
|
{
|
struct ltc2496_driverdata *st =
|
container_of(ddata, struct ltc2496_driverdata, common_ddata);
|
struct spi_transfer t = {
|
.tx_buf = st->txbuf,
|
.rx_buf = st->rxbuf,
|
.len = sizeof(st->txbuf),
|
};
|
int ret;
|
|
st->txbuf[0] = LTC2497_ENABLE | address;
|
|
ret = spi_sync_transfer(st->spi, &t, 1);
|
if (ret < 0) {
|
dev_err(&st->spi->dev, "spi_sync_transfer failed: %pe\n",
|
ERR_PTR(ret));
|
return ret;
|
}
|
|
if (val)
|
*val = ((st->rxbuf[0] & 0x3f) << 12 |
|
st->rxbuf[1] << 4 | st->rxbuf[2] >> 4) -
|
(1 << 17);
|
|
return 0;
|
}
|
|
static int ltc2496_probe(struct spi_device *spi)
|
{
|
struct iio_dev *indio_dev;
|
struct ltc2496_driverdata *st;
|
struct device *dev = &spi->dev;
|
|
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
|
if (!indio_dev)
|
return -ENOMEM;
|
|
st = iio_priv(indio_dev);
|
spi_set_drvdata(spi, indio_dev);
|
st->spi = spi;
|
st->common_ddata.result_and_measure = ltc2496_result_and_measure;
|
|
return ltc2497core_probe(dev, indio_dev);
|
}
|
|
static int ltc2496_remove(struct spi_device *spi)
|
{
|
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
|
ltc2497core_remove(indio_dev);
|
|
return 0;
|
}
|
|
static const struct of_device_id ltc2496_of_match[] = {
|
{ .compatible = "lltc,ltc2496", },
|
{},
|
};
|
MODULE_DEVICE_TABLE(of, ltc2496_of_match);
|
|
static struct spi_driver ltc2496_driver = {
|
.driver = {
|
.name = "ltc2496",
|
.of_match_table = ltc2496_of_match,
|
},
|
.probe = ltc2496_probe,
|
.remove = ltc2496_remove,
|
};
|
module_spi_driver(ltc2496_driver);
|
|
MODULE_AUTHOR("Uwe Kleine-König <u.kleine-könig@pengutronix.de>");
|
MODULE_DESCRIPTION("Linear Technology LTC2496 ADC driver");
|
MODULE_LICENSE("GPL v2");
|
