drivers/iio/pressure/ms5611_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MS5611 pressure and temperature sensor driver (I2C bus)
   4  *
   5  * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
   6  *
   7  * 7-bit I2C slave addresses:
   8  *
   9  * 0x77 (CSB pin low)
  10  * 0x76 (CSB pin high)
  11  *
  12  */
  13
  14 #include <linux/delay.h>
  15 #include <linux/i2c.h>
  16 #include <linux/module.h>
  17 #include <linux/mod_devicetable.h>
  18
  19 #include <asm/unaligned.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 = get_unaligned_be24(&buf[0]);
  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         const struct ms5611_osr *osr = st->temp_osr;
  66
  67         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  68         if (ret < 0)
  69                 return ret;
  70
  71         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  72         ret = ms5611_i2c_read_adc(st, temp);
  73         if (ret < 0)
  74                 return ret;
  75
  76         osr = st->pressure_osr;
  77         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  78         if (ret < 0)
  79                 return ret;
  80
  81         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  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 of_device_id ms5611_i2c_matches[] = {
 117         { .compatible = "meas,ms5611" },
 118         { .compatible = "meas,ms5607" },
 119         { }
 120 };
 121 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
 122
 123 static const struct i2c_device_id ms5611_id[] = {
 124         { "ms5611", MS5611 },
 125         { "ms5607", MS5607 },
 126         { }
 127 };
 128 MODULE_DEVICE_TABLE(i2c, ms5611_id);
 129
 130 static struct i2c_driver ms5611_driver = {
 131         .driver = {
 132                 .name = "ms5611",
 133                 .of_match_table = ms5611_i2c_matches,
 134         },
 135         .id_table = ms5611_id,
 136         .probe = ms5611_i2c_probe,
 137         .remove = ms5611_i2c_remove,
 138 };
 139 module_i2c_driver(ms5611_driver);
 140
 141 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 142 MODULE_DESCRIPTION("MS5611 i2c driver");
 143 MODULE_LICENSE("GPL v2");