1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MS5611 pressure and temperature sensor driver (SPI bus)
4 *
5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
6 *
7 */
8
9 #include <linux/delay.h>
10 #include <linux/module.h>
11 #include <linux/spi/spi.h>
12 #include <linux/mod_devicetable.h>
13
14 #include <asm/unaligned.h>
15
16 #include "ms5611.h"
17
ms5611_spi_reset(struct device * dev)18 static int ms5611_spi_reset(struct device *dev)
19 {
20 u8 cmd = MS5611_RESET;
21 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
22
23 return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
24 }
25
ms5611_spi_read_prom_word(struct device * dev,int index,u16 * word)26 static int ms5611_spi_read_prom_word(struct device *dev, int index, u16 *word)
27 {
28 int ret;
29 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
30
31 ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
32 if (ret < 0)
33 return ret;
34
35 *word = ret;
36
37 return 0;
38 }
39
ms5611_spi_read_adc(struct device * dev,s32 * val)40 static int ms5611_spi_read_adc(struct device *dev, s32 *val)
41 {
42 int ret;
43 u8 buf[3] = { MS5611_READ_ADC };
44 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
45
46 ret = spi_write_then_read(st->client, buf, 1, buf, 3);
47 if (ret < 0)
48 return ret;
49
50 *val = get_unaligned_be24(&buf[0]);
51
52 return 0;
53 }
54
ms5611_spi_read_adc_temp_and_pressure(struct device * dev,s32 * temp,s32 * pressure)55 static int ms5611_spi_read_adc_temp_and_pressure(struct device *dev,
56 s32 *temp, s32 *pressure)
57 {
58 int ret;
59 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
60 const struct ms5611_osr *osr = st->temp_osr;
61
62 /*
63 * Warning: &osr->cmd MUST be aligned on a word boundary since used as
64 * 2nd argument (void*) of spi_write_then_read.
65 */
66 ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
67 if (ret < 0)
68 return ret;
69
70 usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
71 ret = ms5611_spi_read_adc(dev, temp);
72 if (ret < 0)
73 return ret;
74
75 osr = st->pressure_osr;
76 ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
77 if (ret < 0)
78 return ret;
79
80 usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
81 return ms5611_spi_read_adc(dev, pressure);
82 }
83
ms5611_spi_probe(struct spi_device * spi)84 static int ms5611_spi_probe(struct spi_device *spi)
85 {
86 int ret;
87 struct ms5611_state *st;
88 struct iio_dev *indio_dev;
89
90 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
91 if (!indio_dev)
92 return -ENOMEM;
93
94 spi_set_drvdata(spi, indio_dev);
95
96 spi->mode = SPI_MODE_0;
97 spi->max_speed_hz = 20000000;
98 spi->bits_per_word = 8;
99 ret = spi_setup(spi);
100 if (ret < 0)
101 return ret;
102
103 st = iio_priv(indio_dev);
104 st->reset = ms5611_spi_reset;
105 st->read_prom_word = ms5611_spi_read_prom_word;
106 st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
107 st->client = spi;
108
109 return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
110 spi_get_device_id(spi)->driver_data);
111 }
112
ms5611_spi_remove(struct spi_device * spi)113 static int ms5611_spi_remove(struct spi_device *spi)
114 {
115 ms5611_remove(spi_get_drvdata(spi));
116
117 return 0;
118 }
119
120 static const struct of_device_id ms5611_spi_matches[] = {
121 { .compatible = "meas,ms5611" },
122 { .compatible = "meas,ms5607" },
123 { }
124 };
125 MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
126
127 static const struct spi_device_id ms5611_id[] = {
128 { "ms5611", MS5611 },
129 { "ms5607", MS5607 },
130 { }
131 };
132 MODULE_DEVICE_TABLE(spi, ms5611_id);
133
134 static struct spi_driver ms5611_driver = {
135 .driver = {
136 .name = "ms5611",
137 .of_match_table = ms5611_spi_matches
138 },
139 .id_table = ms5611_id,
140 .probe = ms5611_spi_probe,
141 .remove = ms5611_spi_remove,
142 };
143 module_spi_driver(ms5611_driver);
144
145 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
146 MODULE_DESCRIPTION("MS5611 spi driver");
147 MODULE_LICENSE("GPL v2");
148