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 | |
18 | static int ms5611_spi_reset(struct ms5611_state *st) |
19 | { |
20 | u8 cmd = MS5611_RESET; |
21 | |
22 | return spi_write_then_read(spi: st->client, txbuf: &cmd, n_tx: 1, NULL, n_rx: 0); |
23 | } |
24 | |
25 | static int ms5611_spi_read_prom_word(struct ms5611_state *st, int index, |
26 | u16 *word) |
27 | { |
28 | int ret; |
29 | |
30 | ret = spi_w8r16be(spi: st->client, MS5611_READ_PROM_WORD + (index << 1)); |
31 | if (ret < 0) |
32 | return ret; |
33 | |
34 | *word = ret; |
35 | |
36 | return 0; |
37 | } |
38 | |
39 | static int ms5611_spi_read_adc(struct ms5611_state *st, s32 *val) |
40 | { |
41 | int ret; |
42 | u8 buf[3] = { MS5611_READ_ADC }; |
43 | |
44 | ret = spi_write_then_read(spi: st->client, txbuf: buf, n_tx: 1, rxbuf: buf, n_rx: 3); |
45 | if (ret < 0) |
46 | return ret; |
47 | |
48 | *val = get_unaligned_be24(p: &buf[0]); |
49 | |
50 | return 0; |
51 | } |
52 | |
53 | static int ms5611_spi_read_adc_temp_and_pressure(struct ms5611_state *st, |
54 | s32 *temp, s32 *pressure) |
55 | { |
56 | int ret; |
57 | const struct ms5611_osr *osr = st->temp_osr; |
58 | |
59 | /* |
60 | * Warning: &osr->cmd MUST be aligned on a word boundary since used as |
61 | * 2nd argument (void*) of spi_write_then_read. |
62 | */ |
63 | ret = spi_write_then_read(spi: st->client, txbuf: &osr->cmd, n_tx: 1, NULL, n_rx: 0); |
64 | if (ret < 0) |
65 | return ret; |
66 | |
67 | usleep_range(min: osr->conv_usec, max: osr->conv_usec + (osr->conv_usec / 10UL)); |
68 | ret = ms5611_spi_read_adc(st, val: temp); |
69 | if (ret < 0) |
70 | return ret; |
71 | |
72 | osr = st->pressure_osr; |
73 | ret = spi_write_then_read(spi: st->client, txbuf: &osr->cmd, n_tx: 1, NULL, n_rx: 0); |
74 | if (ret < 0) |
75 | return ret; |
76 | |
77 | usleep_range(min: osr->conv_usec, max: osr->conv_usec + (osr->conv_usec / 10UL)); |
78 | return ms5611_spi_read_adc(st, val: pressure); |
79 | } |
80 | |
81 | static int ms5611_spi_probe(struct spi_device *spi) |
82 | { |
83 | int ret; |
84 | struct ms5611_state *st; |
85 | struct iio_dev *indio_dev; |
86 | |
87 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*st)); |
88 | if (!indio_dev) |
89 | return -ENOMEM; |
90 | |
91 | spi_set_drvdata(spi, data: indio_dev); |
92 | |
93 | spi->mode = SPI_MODE_0; |
94 | spi->max_speed_hz = min(spi->max_speed_hz, 20000000U); |
95 | spi->bits_per_word = 8; |
96 | ret = spi_setup(spi); |
97 | if (ret < 0) |
98 | return ret; |
99 | |
100 | st = iio_priv(indio_dev); |
101 | st->reset = ms5611_spi_reset; |
102 | st->read_prom_word = ms5611_spi_read_prom_word; |
103 | st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure; |
104 | st->client = spi; |
105 | |
106 | return ms5611_probe(indio_dev, dev: &spi->dev, name: spi_get_device_id(sdev: spi)->name, |
107 | type: spi_get_device_id(sdev: spi)->driver_data); |
108 | } |
109 | |
110 | static const struct of_device_id ms5611_spi_matches[] = { |
111 | { .compatible = "meas,ms5611" }, |
112 | { .compatible = "meas,ms5607" }, |
113 | { } |
114 | }; |
115 | MODULE_DEVICE_TABLE(of, ms5611_spi_matches); |
116 | |
117 | static const struct spi_device_id ms5611_id[] = { |
118 | { "ms5611" , MS5611 }, |
119 | { "ms5607" , MS5607 }, |
120 | { } |
121 | }; |
122 | MODULE_DEVICE_TABLE(spi, ms5611_id); |
123 | |
124 | static struct spi_driver ms5611_driver = { |
125 | .driver = { |
126 | .name = "ms5611" , |
127 | .of_match_table = ms5611_spi_matches |
128 | }, |
129 | .id_table = ms5611_id, |
130 | .probe = ms5611_spi_probe, |
131 | }; |
132 | module_spi_driver(ms5611_driver); |
133 | |
134 | MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>" ); |
135 | MODULE_DESCRIPTION("MS5611 spi driver" ); |
136 | MODULE_LICENSE("GPL v2" ); |
137 | MODULE_IMPORT_NS(IIO_MS5611); |
138 | |