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 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 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 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 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 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 } 112 113 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