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
ms5611_i2c_reset(struct ms5611_state * st)23 static int ms5611_i2c_reset(struct ms5611_state *st)
24 {
25 return i2c_smbus_write_byte(st->client, MS5611_RESET);
26 }
27
ms5611_i2c_read_prom_word(struct ms5611_state * st,int index,u16 * word)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
ms5611_i2c_read_adc(struct ms5611_state * st,s32 * val)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
ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state * st,s32 * temp,s32 * pressure)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
ms5611_i2c_probe(struct i2c_client * client)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 const struct of_device_id ms5611_i2c_matches[] = {
109 { .compatible = "meas,ms5611" },
110 { .compatible = "meas,ms5607" },
111 { }
112 };
113 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
114
115 static const struct i2c_device_id ms5611_id[] = {
116 { "ms5611", MS5611 },
117 { "ms5607", MS5607 },
118 { }
119 };
120 MODULE_DEVICE_TABLE(i2c, ms5611_id);
121
122 static struct i2c_driver ms5611_driver = {
123 .driver = {
124 .name = "ms5611",
125 .of_match_table = ms5611_i2c_matches,
126 },
127 .id_table = ms5611_id,
128 .probe = ms5611_i2c_probe,
129 };
130 module_i2c_driver(ms5611_driver);
131
132 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
133 MODULE_DESCRIPTION("MS5611 i2c driver");
134 MODULE_LICENSE("GPL v2");
135 MODULE_IMPORT_NS(IIO_MS5611);
136