drivers/iio/pressure/ms5611_i2c.c

   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 -EOPNOTSUPP;
  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         i2c_set_clientdata(client, indio_dev);
 103         st->reset = ms5611_i2c_reset;
 104         st->read_prom_word = ms5611_i2c_read_prom_word;
 105         st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
 106         st->client = client;
 107
 108         return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
 109 }
 110
 111 static int ms5611_i2c_remove(struct i2c_client *client)
 112 {
 113         return ms5611_remove(i2c_get_clientdata(client));
 114 }
 115
 116 static const struct i2c_device_id ms5611_id[] = {
 117         { "ms5611", MS5611 },
 118         { "ms5607", MS5607 },
 119         { }
 120 };
 121 MODULE_DEVICE_TABLE(i2c, ms5611_id);
 122
 123 static struct i2c_driver ms5611_driver = {
 124         .driver = {
 125                 .name = "ms5611",
 126         },
 127         .id_table = ms5611_id,
 128         .probe = ms5611_i2c_probe,
 129         .remove = ms5611_i2c_remove,
 130 };
 131 module_i2c_driver(ms5611_driver);
 132
 133 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 134 MODULE_DESCRIPTION("MS5611 i2c driver");
 135 MODULE_LICENSE("GPL v2");