1 // SPDX-License-Identifier: GPL-2.0-only
3 * ltc2496.c - Driver for Analog Devices/Linear Technology LTC2496 ADC
5 * Based on ltc2497.c which has
6 * Copyright (C) 2017 Analog Devices Inc.
8 * Licensed under the GPL-2.
10 * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2496fc.pdf
13 #include <linux/spi/spi.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/driver.h>
16 #include <linux/module.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/property.h>
22 struct ltc2496_driverdata {
23 /* this must be the first member */
24 struct ltc2497core_driverdata common_ddata;
25 struct spi_device *spi;
28 * DMA (thus cache coherency maintenance) may require the
29 * transfer buffers to live in their own cache lines.
31 unsigned char rxbuf[3] __aligned(IIO_DMA_MINALIGN);
32 unsigned char txbuf[3];
35 static int ltc2496_result_and_measure(struct ltc2497core_driverdata *ddata,
38 struct ltc2496_driverdata *st =
39 container_of(ddata, struct ltc2496_driverdata, common_ddata);
40 struct spi_transfer t = {
43 .len = sizeof(st->txbuf),
47 st->txbuf[0] = LTC2497_ENABLE | address;
49 ret = spi_sync_transfer(st->spi, &t, 1);
51 dev_err(&st->spi->dev, "spi_sync_transfer failed: %pe\n",
57 *val = ((st->rxbuf[0] & 0x3f) << 12 |
58 st->rxbuf[1] << 4 | st->rxbuf[2] >> 4) -
64 static int ltc2496_probe(struct spi_device *spi)
66 struct iio_dev *indio_dev;
67 struct ltc2496_driverdata *st;
68 struct device *dev = &spi->dev;
70 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
74 st = iio_priv(indio_dev);
75 spi_set_drvdata(spi, indio_dev);
77 st->common_ddata.result_and_measure = ltc2496_result_and_measure;
78 st->common_ddata.chip_info = device_get_match_data(dev);
80 return ltc2497core_probe(dev, indio_dev);
83 static void ltc2496_remove(struct spi_device *spi)
85 struct iio_dev *indio_dev = spi_get_drvdata(spi);
87 ltc2497core_remove(indio_dev);
90 static const struct ltc2497_chip_info ltc2496_info = {
95 static const struct of_device_id ltc2496_of_match[] = {
96 { .compatible = "lltc,ltc2496", .data = <c2496_info, },
99 MODULE_DEVICE_TABLE(of, ltc2496_of_match);
101 static struct spi_driver ltc2496_driver = {
104 .of_match_table = ltc2496_of_match,
106 .probe = ltc2496_probe,
107 .remove = ltc2496_remove,
109 module_spi_driver(ltc2496_driver);
112 MODULE_DESCRIPTION("Linear Technology LTC2496 ADC driver");
113 MODULE_LICENSE("GPL v2");