1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * MS5611 pressure and temperature sensor driver (SPI bus)
  4 *
  5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
  6 *
  7 */
  8
  9#include <linux/delay.h>
 10#include <linux/module.h>
 11#include <linux/spi/spi.h>
 12#include <linux/mod_devicetable.h>
 13
 14#include <asm/unaligned.h>
 15
 16#include "ms5611.h"
 17
 18static int ms5611_spi_reset(struct ms5611_state *st)
 19{
 20	u8 cmd = MS5611_RESET;
 21
 22	return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
 23}
 24
 25static int ms5611_spi_read_prom_word(struct ms5611_state *st, int index,
 26				     u16 *word)
 27{
 28	int ret;
 29
 30	ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
 31	if (ret < 0)
 32		return ret;
 33
 34	*word = ret;
 35
 36	return 0;
 37}
 38
 39static int ms5611_spi_read_adc(struct ms5611_state *st, s32 *val)
 40{
 41	int ret;
 42	u8 buf[3] = { MS5611_READ_ADC };
 43
 44	ret = spi_write_then_read(st->client, buf, 1, buf, 3);
 45	if (ret < 0)
 46		return ret;
 47
 48	*val = get_unaligned_be24(&buf[0]);
 49
 50	return 0;
 51}
 52
 53static int ms5611_spi_read_adc_temp_and_pressure(struct ms5611_state *st,
 54						 s32 *temp, s32 *pressure)
 55{
 56	int ret;
 57	const struct ms5611_osr *osr = st->temp_osr;
 58
 59	/*
 60	 * Warning: &osr->cmd MUST be aligned on a word boundary since used as
 61	 * 2nd argument (void*) of spi_write_then_read.
 62	 */
 63	ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
 64	if (ret < 0)
 65		return ret;
 66
 67	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
 68	ret = ms5611_spi_read_adc(st, temp);
 69	if (ret < 0)
 70		return ret;
 71
 72	osr = st->pressure_osr;
 73	ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
 74	if (ret < 0)
 75		return ret;
 76
 77	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
 78	return ms5611_spi_read_adc(st, pressure);
 79}
 80
 81static int ms5611_spi_probe(struct spi_device *spi)
 82{
 83	int ret;
 84	struct ms5611_state *st;
 85	struct iio_dev *indio_dev;
 86
 87	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 88	if (!indio_dev)
 89		return -ENOMEM;
 90
 91	spi_set_drvdata(spi, indio_dev);
 92
 93	spi->mode = SPI_MODE_0;
 94	spi->max_speed_hz = min(spi->max_speed_hz, 20000000U);
 95	spi->bits_per_word = 8;
 96	ret = spi_setup(spi);
 97	if (ret < 0)
 98		return ret;
 99
100	st = iio_priv(indio_dev);
101	st->reset = ms5611_spi_reset;
102	st->read_prom_word = ms5611_spi_read_prom_word;
103	st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
104	st->client = spi;
105
106	return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
107			    spi_get_device_id(spi)->driver_data);
108}
109
110static void ms5611_spi_remove(struct spi_device *spi)
111{
112	ms5611_remove(spi_get_drvdata(spi));
113}
114
115static const struct of_device_id ms5611_spi_matches[] = {
116	{ .compatible = "meas,ms5611" },
117	{ .compatible = "meas,ms5607" },
118	{ }
119};
120MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
121
122static const struct spi_device_id ms5611_id[] = {
123	{ "ms5611", MS5611 },
124	{ "ms5607", MS5607 },
125	{ }
126};
127MODULE_DEVICE_TABLE(spi, ms5611_id);
128
129static struct spi_driver ms5611_driver = {
130	.driver = {
131		.name = "ms5611",
132		.of_match_table = ms5611_spi_matches
133	},
134	.id_table = ms5611_id,
135	.probe = ms5611_spi_probe,
136	.remove = ms5611_spi_remove,
137};
138module_spi_driver(ms5611_driver);
139
140MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
141MODULE_DESCRIPTION("MS5611 spi driver");
142MODULE_LICENSE("GPL v2");
143MODULE_IMPORT_NS(IIO_MS5611);