linux/drivers/iio/pressure/ms5611_i2c.c
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   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
  23static 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
  30static 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
  45static 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
  60static 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
  85static 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
 111static int ms5611_i2c_remove(struct i2c_client *client)
 112{
 113        return ms5611_remove(i2c_get_clientdata(client));
 114}
 115
 116static const struct of_device_id ms5611_i2c_matches[] = {
 117        { .compatible = "meas,ms5611" },
 118        { .compatible = "meas,ms5607" },
 119        { }
 120};
 121MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
 122
 123static const struct i2c_device_id ms5611_id[] = {
 124        { "ms5611", MS5611 },
 125        { "ms5607", MS5607 },
 126        { }
 127};
 128MODULE_DEVICE_TABLE(i2c, ms5611_id);
 129
 130static 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};
 139module_i2c_driver(ms5611_driver);
 140
 141MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 142MODULE_DESCRIPTION("MS5611 i2c driver");
 143MODULE_LICENSE("GPL v2");
 144