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 #include <linux/of_device.h>
  21
  22 #include "ms5611.h"
  23
  24 static int ms5611_i2c_reset(struct device *dev)
  25 {
  26         struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  27
  28         return i2c_smbus_write_byte(st->client, MS5611_RESET);
  29 }
  30
  31 static int ms5611_i2c_read_prom_word(struct device *dev, int index, u16 *word)
  32 {
  33         int ret;
  34         struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  35
  36         ret = i2c_smbus_read_word_swapped(st->client,
  37                         MS5611_READ_PROM_WORD + (index << 1));
  38         if (ret < 0)
  39                 return ret;
  40
  41         *word = ret;
  42
  43         return 0;
  44 }
  45
  46 static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
  47 {
  48         int ret;
  49         u8 buf[3];
  50
  51         ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
  52                                             3, buf);
  53         if (ret < 0)
  54                 return ret;
  55
  56         *val = (buf[0] << 16) | (buf[1] << 8) | buf[2];
  57
  58         return 0;
  59 }
  60
  61 static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev,
  62                                                  s32 *temp, s32 *pressure)
  63 {
  64         int ret;
  65         struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  66         const struct ms5611_osr *osr = st->temp_osr;
  67
  68         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  69         if (ret < 0)
  70                 return ret;
  71
  72         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  73         ret = ms5611_i2c_read_adc(st, temp);
  74         if (ret < 0)
  75                 return ret;
  76
  77         osr = st->pressure_osr;
  78         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  79         if (ret < 0)
  80                 return ret;
  81
  82         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  83         return ms5611_i2c_read_adc(st, pressure);
  84 }
  85
  86 static int ms5611_i2c_probe(struct i2c_client *client,
  87                             const struct i2c_device_id *id)
  88 {
  89         struct ms5611_state *st;
  90         struct iio_dev *indio_dev;
  91
  92         if (!i2c_check_functionality(client->adapter,
  93                                      I2C_FUNC_SMBUS_WRITE_BYTE |
  94                                      I2C_FUNC_SMBUS_READ_WORD_DATA |
  95                                      I2C_FUNC_SMBUS_READ_I2C_BLOCK))
  96                 return -EOPNOTSUPP;
  97
  98         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
  99         if (!indio_dev)
 100                 return -ENOMEM;
 101
 102         st = iio_priv(indio_dev);
 103         i2c_set_clientdata(client, indio_dev);
 104         st->reset = ms5611_i2c_reset;
 105         st->read_prom_word = ms5611_i2c_read_prom_word;
 106         st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
 107         st->client = client;
 108
 109         return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
 110 }
 111
 112 static int ms5611_i2c_remove(struct i2c_client *client)
 113 {
 114         return ms5611_remove(i2c_get_clientdata(client));
 115 }
 116
 117 #if defined(CONFIG_OF)
 118 static const struct of_device_id ms5611_i2c_matches[] = {
 119         { .compatible = "meas,ms5611" },
 120         { .compatible = "ms5611" },
 121         { .compatible = "meas,ms5607" },
 122         { .compatible = "ms5607" },
 123         { }
 124 };
 125 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
 126 #endif
 127
 128 static const struct i2c_device_id ms5611_id[] = {
 129         { "ms5611", MS5611 },
 130         { "ms5607", MS5607 },
 131         { }
 132 };
 133 MODULE_DEVICE_TABLE(i2c, ms5611_id);
 134
 135 static struct i2c_driver ms5611_driver = {
 136         .driver = {
 137                 .name = "ms5611",
 138                 .of_match_table = of_match_ptr(ms5611_i2c_matches)
 139         },
 140         .id_table = ms5611_id,
 141         .probe = ms5611_i2c_probe,
 142         .remove = ms5611_i2c_remove,
 143 };
 144 module_i2c_driver(ms5611_driver);
 145
 146 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 147 MODULE_DESCRIPTION("MS5611 i2c driver");
 148 MODULE_LICENSE("GPL v2");