summaryrefslogtreecommitdiffstats
path: root/drivers/iio/pressure/ms5611_i2c.c
blob: cccc40f7df0b9f4284c87fd95fdb4be7d6b7f1c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
// SPDX-License-Identifier: GPL-2.0
/*
 * MS5611 pressure and temperature sensor driver (I2C bus)
 *
 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
 *
 * 7-bit I2C slave addresses:
 *
 * 0x77 (CSB pin low)
 * 0x76 (CSB pin high)
 *
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>

#include <asm/unaligned.h>

#include "ms5611.h"

static int ms5611_i2c_reset(struct ms5611_state *st)
{
	return i2c_smbus_write_byte(st->client, MS5611_RESET);
}

static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
				     u16 *word)
{
	int ret;

	ret = i2c_smbus_read_word_swapped(st->client,
			MS5611_READ_PROM_WORD + (index << 1));
	if (ret < 0)
		return ret;

	*word = ret;

	return 0;
}

static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
{
	int ret;
	u8 buf[3];

	ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
					    3, buf);
	if (ret < 0)
		return ret;

	*val = get_unaligned_be24(&buf[0]);

	return 0;
}

static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
						 s32 *temp, s32 *pressure)
{
	int ret;
	const struct ms5611_osr *osr = st->temp_osr;

	ret = i2c_smbus_write_byte(st->client, osr->cmd);
	if (ret < 0)
		return ret;

	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
	ret = ms5611_i2c_read_adc(st, temp);
	if (ret < 0)
		return ret;

	osr = st->pressure_osr;
	ret = i2c_smbus_write_byte(st->client, osr->cmd);
	if (ret < 0)
		return ret;

	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
	return ms5611_i2c_read_adc(st, pressure);
}

static int ms5611_i2c_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	struct ms5611_state *st;
	struct iio_dev *indio_dev;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_WRITE_BYTE |
				     I2C_FUNC_SMBUS_READ_WORD_DATA |
				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
		return -EOPNOTSUPP;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	st->reset = ms5611_i2c_reset;
	st->read_prom_word = ms5611_i2c_read_prom_word;
	st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
	st->client = client;

	return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
}

static int ms5611_i2c_remove(struct i2c_client *client)
{
	return ms5611_remove(i2c_get_clientdata(client));
}

static const struct of_device_id ms5611_i2c_matches[] = {
	{ .compatible = "meas,ms5611" },
	{ .compatible = "meas,ms5607" },
	{ }
};
MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);

static const struct i2c_device_id ms5611_id[] = {
	{ "ms5611", MS5611 },
	{ "ms5607", MS5607 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ms5611_id);

static struct i2c_driver ms5611_driver = {
	.driver = {
		.name = "ms5611",
		.of_match_table = ms5611_i2c_matches,
	},
	.id_table = ms5611_id,
	.probe = ms5611_i2c_probe,
	.remove = ms5611_i2c_remove,
};
module_i2c_driver(ms5611_driver);

MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 i2c driver");
MODULE_LICENSE("GPL v2");