1 /* 2 * MS5611 pressure and temperature sensor driver (SPI bus) 3 * 4 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 */ 11 12 #include <linux/delay.h> 13 #include <linux/module.h> 14 #include <linux/spi/spi.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 = (buf[0] << 16) | (buf[1] << 8) | buf[2]; 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 u8 cmd; 59 int ret; 60 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); 61 62 cmd = MS5611_START_TEMP_CONV; 63 ret = spi_write_then_read(st->client, &cmd, 1, NULL, 0); 64 if (ret < 0) 65 return ret; 66 67 usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); 68 69 ret = ms5611_spi_read_adc(dev, temp); 70 if (ret < 0) 71 return ret; 72 73 cmd = MS5611_START_PRESSURE_CONV; 74 ret = spi_write_then_read(st->client, &cmd, 1, NULL, 0); 75 if (ret < 0) 76 return ret; 77 78 usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); 79 80 return ms5611_spi_read_adc(dev, pressure); 81 } 82 83 static int ms5611_spi_probe(struct spi_device *spi) 84 { 85 int ret; 86 struct ms5611_state *st; 87 struct iio_dev *indio_dev; 88 89 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 90 if (!indio_dev) 91 return -ENOMEM; 92 93 spi->mode = SPI_MODE_0; 94 spi->max_speed_hz = 20000000; 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, 107 spi_get_device_id(spi)->driver_data); 108 } 109 110 static const struct spi_device_id ms5611_id[] = { 111 { "ms5611", MS5611 }, 112 { "ms5607", MS5607 }, 113 { } 114 }; 115 MODULE_DEVICE_TABLE(spi, ms5611_id); 116 117 static struct spi_driver ms5611_driver = { 118 .driver = { 119 .name = "ms5611", 120 }, 121 .id_table = ms5611_id, 122 .probe = ms5611_spi_probe, 123 }; 124 module_spi_driver(ms5611_driver); 125 126 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); 127 MODULE_DESCRIPTION("MS5611 spi driver"); 128 MODULE_LICENSE("GPL v2"); 129