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