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 
23 static int ms5611_i2c_reset(struct ms5611_state *st)
24 {
25 	return i2c_smbus_write_byte(st->client, MS5611_RESET);
26 }
27 
28 static 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 
43 static 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 
58 static 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 
82 static 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 
108 static void ms5611_i2c_remove(struct i2c_client *client)
109 {
110 	ms5611_remove(i2c_get_clientdata(client));
111 }
112 
113 static const struct of_device_id ms5611_i2c_matches[] = {
114 	{ .compatible = "meas,ms5611" },
115 	{ .compatible = "meas,ms5607" },
116 	{ }
117 };
118 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
119 
120 static const struct i2c_device_id ms5611_id[] = {
121 	{ "ms5611", MS5611 },
122 	{ "ms5607", MS5607 },
123 	{ }
124 };
125 MODULE_DEVICE_TABLE(i2c, ms5611_id);
126 
127 static struct i2c_driver ms5611_driver = {
128 	.driver = {
129 		.name = "ms5611",
130 		.of_match_table = ms5611_i2c_matches,
131 	},
132 	.id_table = ms5611_id,
133 	.probe_new = ms5611_i2c_probe,
134 	.remove = ms5611_i2c_remove,
135 };
136 module_i2c_driver(ms5611_driver);
137 
138 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
139 MODULE_DESCRIPTION("MS5611 i2c driver");
140 MODULE_LICENSE("GPL v2");
141 MODULE_IMPORT_NS(IIO_MS5611);
142