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 <linux/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(st->client, &cmd, 1, NULL, 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(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(st->client, buf, 1, buf, 3); 45 if (ret < 0) 46 return ret; 47 48 *val = get_unaligned_be24(&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(st->client, &osr->cmd, 1, NULL, 0); 64 if (ret < 0) 65 return ret; 66 67 usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL)); 68 ret = ms5611_spi_read_adc(st, temp); 69 if (ret < 0) 70 return ret; 71 72 osr = st->pressure_osr; 73 ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0); 74 if (ret < 0) 75 return ret; 76 77 usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL)); 78 return ms5611_spi_read_adc(st, 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(&spi->dev, sizeof(*st)); 88 if (!indio_dev) 89 return -ENOMEM; 90 91 spi_set_drvdata(spi, 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, &spi->dev, spi_get_device_id(spi)->name, 107 spi_get_device_id(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