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 <linux/unaligned.h>
  20
  21 #include "ms5611.h"
  22
  23 static int ms5611_i2c_reset(struct ms5611_state *st)
  24 {
  25         return i2c_smbus_write_byte(st->client, MS5611_RESET);
  26 }
  27
  28 static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
  29                                      u16 *word)
  30 {
  31         int ret;
  32
  33         ret = i2c_smbus_read_word_swapped(st->client,
  34                         MS5611_READ_PROM_WORD + (index << 1));
  35         if (ret < 0)
  36                 return ret;
  37
  38         *word = ret;
  39
  40         return 0;
  41 }
  42
  43 static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
  44 {
  45         int ret;
  46         u8 buf[3];
  47
  48         ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
  49                                             3, buf);
  50         if (ret < 0)
  51                 return ret;
  52
  53         *val = get_unaligned_be24(&buf[0]);
  54
  55         return 0;
  56 }
  57
  58 static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
  59                                                  s32 *temp, s32 *pressure)
  60 {
  61         int ret;
  62         const struct ms5611_osr *osr = st->temp_osr;
  63
  64         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  65         if (ret < 0)
  66                 return ret;
  67
  68         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  69         ret = ms5611_i2c_read_adc(st, temp);
  70         if (ret < 0)
  71                 return ret;
  72
  73         osr = st->pressure_osr;
  74         ret = i2c_smbus_write_byte(st->client, osr->cmd);
  75         if (ret < 0)
  76                 return ret;
  77
  78         usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  79         return ms5611_i2c_read_adc(st, pressure);
  80 }
  81
  82 static int ms5611_i2c_probe(struct i2c_client *client)
  83 {
  84         const struct i2c_device_id *id = i2c_client_get_device_id(client);
  85         struct ms5611_state *st;
  86         struct iio_dev *indio_dev;
  87
  88         if (!i2c_check_functionality(client->adapter,
  89                                      I2C_FUNC_SMBUS_WRITE_BYTE |
  90                                      I2C_FUNC_SMBUS_READ_WORD_DATA |
  91                                      I2C_FUNC_SMBUS_READ_I2C_BLOCK))
  92                 return -EOPNOTSUPP;
  93
  94         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
  95         if (!indio_dev)
  96                 return -ENOMEM;
  97
  98         st = iio_priv(indio_dev);
  99         i2c_set_clientdata(client, indio_dev);
 100         st->reset = ms5611_i2c_reset;
 101         st->read_prom_word = ms5611_i2c_read_prom_word;
 102         st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
 103         st->client = client;
 104
 105         return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
 106 }
 107
 108 static const struct of_device_id ms5611_i2c_matches[] = {
 109         { .compatible = "meas,ms5611" },
 110         { .compatible = "meas,ms5607" },
 111         { }
 112 };
 113 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
 114
 115 static const struct i2c_device_id ms5611_id[] = {
 116         { "ms5611", MS5611 },
 117         { "ms5607", MS5607 },
 118         { }
 119 };
 120 MODULE_DEVICE_TABLE(i2c, ms5611_id);
 121
 122 static struct i2c_driver ms5611_driver = {
 123         .driver = {
 124                 .name = "ms5611",
 125                 .of_match_table = ms5611_i2c_matches,
 126         },
 127         .id_table = ms5611_id,
 128         .probe = ms5611_i2c_probe,
 129 };
 130 module_i2c_driver(ms5611_driver);
 131
 132 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 133 MODULE_DESCRIPTION("MS5611 i2c driver");
 134 MODULE_LICENSE("GPL v2");
 135 MODULE_IMPORT_NS("IIO_MS5611");