1 /* 2 * MS5611 pressure and temperature sensor driver (I2C 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 * 7-bit I2C slave addresses: 11 * 12 * 0x77 (CSB pin low) 13 * 0x76 (CSB pin high) 14 * 15 */ 16 17 #include <linux/delay.h> 18 #include <linux/i2c.h> 19 #include <linux/module.h> 20 21 #include "ms5611.h" 22 23 static int ms5611_i2c_reset(struct device *dev) 24 { 25 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); 26 27 return i2c_smbus_write_byte(st->client, MS5611_RESET); 28 } 29 30 static int ms5611_i2c_read_prom_word(struct device *dev, int index, u16 *word) 31 { 32 int ret; 33 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); 34 35 ret = i2c_smbus_read_word_swapped(st->client, 36 MS5611_READ_PROM_WORD + (index << 1)); 37 if (ret < 0) 38 return ret; 39 40 *word = ret; 41 42 return 0; 43 } 44 45 static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val) 46 { 47 int ret; 48 u8 buf[3]; 49 50 ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC, 51 3, buf); 52 if (ret < 0) 53 return ret; 54 55 *val = (buf[0] << 16) | (buf[1] << 8) | buf[2]; 56 57 return 0; 58 } 59 60 static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev, 61 s32 *temp, s32 *pressure) 62 { 63 int ret; 64 struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); 65 66 ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV); 67 if (ret < 0) 68 return ret; 69 70 usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); 71 72 ret = ms5611_i2c_read_adc(st, temp); 73 if (ret < 0) 74 return ret; 75 76 ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV); 77 if (ret < 0) 78 return ret; 79 80 usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); 81 82 return ms5611_i2c_read_adc(st, pressure); 83 } 84 85 static int ms5611_i2c_probe(struct i2c_client *client, 86 const struct i2c_device_id *id) 87 { 88 struct ms5611_state *st; 89 struct iio_dev *indio_dev; 90 91 if (!i2c_check_functionality(client->adapter, 92 I2C_FUNC_SMBUS_WRITE_BYTE | 93 I2C_FUNC_SMBUS_READ_WORD_DATA | 94 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 95 return -ENODEV; 96 97 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); 98 if (!indio_dev) 99 return -ENOMEM; 100 101 st = iio_priv(indio_dev); 102 st->reset = ms5611_i2c_reset; 103 st->read_prom_word = ms5611_i2c_read_prom_word; 104 st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure; 105 st->client = client; 106 107 return ms5611_probe(indio_dev, &client->dev, id->driver_data); 108 } 109 110 static const struct i2c_device_id ms5611_id[] = { 111 { "ms5611", MS5611 }, 112 { "ms5607", MS5607 }, 113 { } 114 }; 115 MODULE_DEVICE_TABLE(i2c, ms5611_id); 116 117 static struct i2c_driver ms5611_driver = { 118 .driver = { 119 .name = "ms5611", 120 }, 121 .id_table = ms5611_id, 122 .probe = ms5611_i2c_probe, 123 }; 124 module_i2c_driver(ms5611_driver); 125 126 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); 127 MODULE_DESCRIPTION("MS5611 i2c driver"); 128 MODULE_LICENSE("GPL v2"); 129