1/*
2 * MS5611 pressure and temperature sensor driver (I2C bus)
3 *
4 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * 7-bit I2C slave addresses:
11 *
12 * 0x77 (CSB pin low)
13 * 0x76 (CSB pin high)
14 *
15 */
16
17#include <linux/delay.h>
18#include <linux/i2c.h>
19#include <linux/module.h>
20
21#include "ms5611.h"
22
23static int ms5611_i2c_reset(struct device *dev)
24{
25	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
26
27	return i2c_smbus_write_byte(st->client, MS5611_RESET);
28}
29
30static int ms5611_i2c_read_prom_word(struct device *dev, int index, u16 *word)
31{
32	int ret;
33	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
34
35	ret = i2c_smbus_read_word_swapped(st->client,
36			MS5611_READ_PROM_WORD + (index << 1));
37	if (ret < 0)
38		return ret;
39
40	*word = ret;
41
42	return 0;
43}
44
45static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
46{
47	int ret;
48	u8 buf[3];
49
50	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
51					    3, buf);
52	if (ret < 0)
53		return ret;
54
55	*val = (buf[0] << 16) | (buf[1] << 8) | buf[2];
56
57	return 0;
58}
59
60static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev,
61						 s32 *temp, s32 *pressure)
62{
63	int ret;
64	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
65
66	ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV);
67	if (ret < 0)
68		return ret;
69
70	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
71
72	ret = ms5611_i2c_read_adc(st, temp);
73	if (ret < 0)
74		return ret;
75
76	ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV);
77	if (ret < 0)
78		return ret;
79
80	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
81
82	return ms5611_i2c_read_adc(st, pressure);
83}
84
85static int ms5611_i2c_probe(struct i2c_client *client,
86			    const struct i2c_device_id *id)
87{
88	struct ms5611_state *st;
89	struct iio_dev *indio_dev;
90
91	if (!i2c_check_functionality(client->adapter,
92				     I2C_FUNC_SMBUS_WRITE_BYTE |
93				     I2C_FUNC_SMBUS_READ_WORD_DATA |
94				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
95		return -ENODEV;
96
97	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
98	if (!indio_dev)
99		return -ENOMEM;
100
101	st = iio_priv(indio_dev);
102	st->reset = ms5611_i2c_reset;
103	st->read_prom_word = ms5611_i2c_read_prom_word;
104	st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
105	st->client = client;
106
107	return ms5611_probe(indio_dev, &client->dev);
108}
109
110static const struct i2c_device_id ms5611_id[] = {
111	{ "ms5611", 0 },
112	{ }
113};
114MODULE_DEVICE_TABLE(i2c, ms5611_id);
115
116static struct i2c_driver ms5611_driver = {
117	.driver = {
118		.name = "ms5611",
119		.owner = THIS_MODULE,
120	},
121	.id_table = ms5611_id,
122	.probe = ms5611_i2c_probe,
123};
124module_i2c_driver(ms5611_driver);
125
126MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
127MODULE_DESCRIPTION("MS5611 i2c driver");
128MODULE_LICENSE("GPL v2");
129