1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * MS5611 pressure and temperature sensor driver (I2C bus)
  4 *
  5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
  6 *
  7 * 7-bit I2C slave addresses:
  8 *
  9 * 0x77 (CSB pin low)
 10 * 0x76 (CSB pin high)
 11 *
 12 */
 13
 14#include <linux/delay.h>
 15#include <linux/i2c.h>
 16#include <linux/module.h>
 17#include <linux/mod_devicetable.h>
 18
 19#include <asm/unaligned.h>
 20
 21#include "ms5611.h"
 22
 23static int ms5611_i2c_reset(struct ms5611_state *st)
 24{
 25	return i2c_smbus_write_byte(st->client, MS5611_RESET);
 26}
 27
 28static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
 29				     u16 *word)
 30{
 31	int ret;
 32
 33	ret = i2c_smbus_read_word_swapped(st->client,
 34			MS5611_READ_PROM_WORD + (index << 1));
 35	if (ret < 0)
 36		return ret;
 37
 38	*word = ret;
 39
 40	return 0;
 41}
 42
 43static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
 44{
 45	int ret;
 46	u8 buf[3];
 47
 48	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
 49					    3, buf);
 50	if (ret < 0)
 51		return ret;
 52
 53	*val = get_unaligned_be24(&buf[0]);
 54
 55	return 0;
 56}
 57
 58static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
 59						 s32 *temp, s32 *pressure)
 60{
 61	int ret;
 62	const struct ms5611_osr *osr = st->temp_osr;
 63
 64	ret = i2c_smbus_write_byte(st->client, osr->cmd);
 65	if (ret < 0)
 66		return ret;
 67
 68	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
 69	ret = ms5611_i2c_read_adc(st, temp);
 70	if (ret < 0)
 71		return ret;
 72
 73	osr = st->pressure_osr;
 74	ret = i2c_smbus_write_byte(st->client, osr->cmd);
 75	if (ret < 0)
 76		return ret;
 77
 78	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
 79	return ms5611_i2c_read_adc(st, pressure);
 80}
 81
 82static int ms5611_i2c_probe(struct i2c_client *client)
 83{
 84	const struct i2c_device_id *id = i2c_client_get_device_id(client);
 85	struct ms5611_state *st;
 86	struct iio_dev *indio_dev;
 87
 88	if (!i2c_check_functionality(client->adapter,
 89				     I2C_FUNC_SMBUS_WRITE_BYTE |
 90				     I2C_FUNC_SMBUS_READ_WORD_DATA |
 91				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
 92		return -EOPNOTSUPP;
 93
 94	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
 95	if (!indio_dev)
 96		return -ENOMEM;
 97
 98	st = iio_priv(indio_dev);
 99	i2c_set_clientdata(client, indio_dev);
100	st->reset = ms5611_i2c_reset;
101	st->read_prom_word = ms5611_i2c_read_prom_word;
102	st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
103	st->client = client;
104
105	return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
106}
107
108static const struct of_device_id ms5611_i2c_matches[] = {
109	{ .compatible = "meas,ms5611" },
110	{ .compatible = "meas,ms5607" },
111	{ }
112};
113MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
114
115static const struct i2c_device_id ms5611_id[] = {
116	{ "ms5611", MS5611 },
117	{ "ms5607", MS5607 },
118	{ }
119};
120MODULE_DEVICE_TABLE(i2c, ms5611_id);
121
122static struct i2c_driver ms5611_driver = {
123	.driver = {
124		.name = "ms5611",
125		.of_match_table = ms5611_i2c_matches,
126	},
127	.id_table = ms5611_id,
128	.probe = ms5611_i2c_probe,
129};
130module_i2c_driver(ms5611_driver);
131
132MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
133MODULE_DESCRIPTION("MS5611 i2c driver");
134MODULE_LICENSE("GPL v2");
135MODULE_IMPORT_NS(IIO_MS5611);