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/of_device.h>
18 
19 #include "ms5611.h"
20 
21 static int ms5611_i2c_reset(struct device *dev)
22 {
23 	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
24 
25 	return i2c_smbus_write_byte(st->client, MS5611_RESET);
26 }
27 
28 static int ms5611_i2c_read_prom_word(struct device *dev, int index, u16 *word)
29 {
30 	int ret;
31 	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
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 = (buf[0] << 16) | (buf[1] << 8) | buf[2];
54 
55 	return 0;
56 }
57 
58 static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev,
59 						 s32 *temp, s32 *pressure)
60 {
61 	int ret;
62 	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
63 	const struct ms5611_osr *osr = st->temp_osr;
64 
65 	ret = i2c_smbus_write_byte(st->client, osr->cmd);
66 	if (ret < 0)
67 		return ret;
68 
69 	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
70 	ret = ms5611_i2c_read_adc(st, temp);
71 	if (ret < 0)
72 		return ret;
73 
74 	osr = st->pressure_osr;
75 	ret = i2c_smbus_write_byte(st->client, osr->cmd);
76 	if (ret < 0)
77 		return ret;
78 
79 	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
80 	return ms5611_i2c_read_adc(st, pressure);
81 }
82 
83 static int ms5611_i2c_probe(struct i2c_client *client,
84 			    const struct i2c_device_id *id)
85 {
86 	struct ms5611_state *st;
87 	struct iio_dev *indio_dev;
88 
89 	if (!i2c_check_functionality(client->adapter,
90 				     I2C_FUNC_SMBUS_WRITE_BYTE |
91 				     I2C_FUNC_SMBUS_READ_WORD_DATA |
92 				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
93 		return -EOPNOTSUPP;
94 
95 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
96 	if (!indio_dev)
97 		return -ENOMEM;
98 
99 	st = iio_priv(indio_dev);
100 	i2c_set_clientdata(client, indio_dev);
101 	st->reset = ms5611_i2c_reset;
102 	st->read_prom_word = ms5611_i2c_read_prom_word;
103 	st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
104 	st->client = client;
105 
106 	return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
107 }
108 
109 static int ms5611_i2c_remove(struct i2c_client *client)
110 {
111 	return ms5611_remove(i2c_get_clientdata(client));
112 }
113 
114 #if defined(CONFIG_OF)
115 static const struct of_device_id ms5611_i2c_matches[] = {
116 	{ .compatible = "meas,ms5611" },
117 	{ .compatible = "meas,ms5607" },
118 	{ }
119 };
120 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
121 #endif
122 
123 static const struct i2c_device_id ms5611_id[] = {
124 	{ "ms5611", MS5611 },
125 	{ "ms5607", MS5607 },
126 	{ }
127 };
128 MODULE_DEVICE_TABLE(i2c, ms5611_id);
129 
130 static struct i2c_driver ms5611_driver = {
131 	.driver = {
132 		.name = "ms5611",
133 		.of_match_table = of_match_ptr(ms5611_i2c_matches)
134 	},
135 	.id_table = ms5611_id,
136 	.probe = ms5611_i2c_probe,
137 	.remove = ms5611_i2c_remove,
138 };
139 module_i2c_driver(ms5611_driver);
140 
141 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
142 MODULE_DESCRIPTION("MS5611 i2c driver");
143 MODULE_LICENSE("GPL v2");
144