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 <asm/unaligned.h>
20 
21 #include "ms5611.h"
22 
23 static 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 
30 static 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 
45 static 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 = get_unaligned_be24(&buf[0]);
56 
57 	return 0;
58 }
59 
60 static 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 	const struct ms5611_osr *osr = st->temp_osr;
66 
67 	ret = i2c_smbus_write_byte(st->client, osr->cmd);
68 	if (ret < 0)
69 		return ret;
70 
71 	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
72 	ret = ms5611_i2c_read_adc(st, temp);
73 	if (ret < 0)
74 		return ret;
75 
76 	osr = st->pressure_osr;
77 	ret = i2c_smbus_write_byte(st->client, osr->cmd);
78 	if (ret < 0)
79 		return ret;
80 
81 	usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
82 	return ms5611_i2c_read_adc(st, pressure);
83 }
84 
85 static 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 -EOPNOTSUPP;
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 	i2c_set_clientdata(client, indio_dev);
103 	st->reset = ms5611_i2c_reset;
104 	st->read_prom_word = ms5611_i2c_read_prom_word;
105 	st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
106 	st->client = client;
107 
108 	return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
109 }
110 
111 static int ms5611_i2c_remove(struct i2c_client *client)
112 {
113 	return ms5611_remove(i2c_get_clientdata(client));
114 }
115 
116 #if defined(CONFIG_OF)
117 static const struct of_device_id ms5611_i2c_matches[] = {
118 	{ .compatible = "meas,ms5611" },
119 	{ .compatible = "meas,ms5607" },
120 	{ }
121 };
122 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
123 #endif
124 
125 static const struct i2c_device_id ms5611_id[] = {
126 	{ "ms5611", MS5611 },
127 	{ "ms5607", MS5607 },
128 	{ }
129 };
130 MODULE_DEVICE_TABLE(i2c, ms5611_id);
131 
132 static struct i2c_driver ms5611_driver = {
133 	.driver = {
134 		.name = "ms5611",
135 		.of_match_table = of_match_ptr(ms5611_i2c_matches)
136 	},
137 	.id_table = ms5611_id,
138 	.probe = ms5611_i2c_probe,
139 	.remove = ms5611_i2c_remove,
140 };
141 module_i2c_driver(ms5611_driver);
142 
143 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
144 MODULE_DESCRIPTION("MS5611 i2c driver");
145 MODULE_LICENSE("GPL v2");
146