iio/pressure/ms5611_i2c.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * MS5611 pressure and temperature sensor driver (I2C bus)
0004  *
0005  * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
0006  *
0007  * 7-bit I2C slave addresses:
0008  *
0009  * 0x77 (CSB pin low)
0010  * 0x76 (CSB pin high)
0011  *
0012  */
0013
0014 #include <linux/delay.h>
0015 #include <linux/i2c.h>
0016 #include <linux/module.h>
0017 #include <linux/mod_devicetable.h>
0018
0019 #include <asm/unaligned.h>
0020
0021 #include "ms5611.h"
0022
0023 static int ms5611_i2c_reset(struct ms5611_state *st)
0024 {
0025     return i2c_smbus_write_byte(st->client, MS5611_RESET);
0026 }
0027
0028 static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
0029                      u16 *word)
0030 {
0031     int ret;
0032
0033     ret = i2c_smbus_read_word_swapped(st->client,
0034             MS5611_READ_PROM_WORD + (index << 1));
0035     if (ret < 0)
0036         return ret;
0037
0038     *word = ret;
0039
0040     return 0;
0041 }
0042
0043 static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
0044 {
0045     int ret;
0046     u8 buf[3];
0047
0048     ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
0049                         3, buf);
0050     if (ret < 0)
0051         return ret;
0052
0053     *val = get_unaligned_be24(&buf[0]);
0054
0055     return 0;
0056 }
0057
0058 static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
0059                          s32 *temp, s32 *pressure)
0060 {
0061     int ret;
0062     const struct ms5611_osr *osr = st->temp_osr;
0063
0064     ret = i2c_smbus_write_byte(st->client, osr->cmd);
0065     if (ret < 0)
0066         return ret;
0067
0068     usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
0069     ret = ms5611_i2c_read_adc(st, temp);
0070     if (ret < 0)
0071         return ret;
0072
0073     osr = st->pressure_osr;
0074     ret = i2c_smbus_write_byte(st->client, osr->cmd);
0075     if (ret < 0)
0076         return ret;
0077
0078     usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
0079     return ms5611_i2c_read_adc(st, pressure);
0080 }
0081
0082 static int ms5611_i2c_probe(struct i2c_client *client,
0083                 const struct i2c_device_id *id)
0084 {
0085     struct ms5611_state *st;
0086     struct iio_dev *indio_dev;
0087
0088     if (!i2c_check_functionality(client->adapter,
0089                      I2C_FUNC_SMBUS_WRITE_BYTE |
0090                      I2C_FUNC_SMBUS_READ_WORD_DATA |
0091                      I2C_FUNC_SMBUS_READ_I2C_BLOCK))
0092         return -EOPNOTSUPP;
0093
0094     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
0095     if (!indio_dev)
0096         return -ENOMEM;
0097
0098     st = iio_priv(indio_dev);
0099     i2c_set_clientdata(client, indio_dev);
0100     st->reset = ms5611_i2c_reset;
0101     st->read_prom_word = ms5611_i2c_read_prom_word;
0102     st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
0103     st->client = client;
0104
0105     return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
0106 }
0107
0108 static int ms5611_i2c_remove(struct i2c_client *client)
0109 {
0110     ms5611_remove(i2c_get_clientdata(client));
0111
0112     return 0;
0113 }
0114
0115 static const struct of_device_id ms5611_i2c_matches[] = {
0116     { .compatible = "meas,ms5611" },
0117     { .compatible = "meas,ms5607" },
0118     { }
0119 };
0120 MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
0121
0122 static const struct i2c_device_id ms5611_id[] = {
0123     { "ms5611", MS5611 },
0124     { "ms5607", MS5607 },
0125     { }
0126 };
0127 MODULE_DEVICE_TABLE(i2c, ms5611_id);
0128
0129 static struct i2c_driver ms5611_driver = {
0130     .driver = {
0131         .name = "ms5611",
0132         .of_match_table = ms5611_i2c_matches,
0133     },
0134     .id_table = ms5611_id,
0135     .probe = ms5611_i2c_probe,
0136     .remove = ms5611_i2c_remove,
0137 };
0138 module_i2c_driver(ms5611_driver);
0139
0140 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
0141 MODULE_DESCRIPTION("MS5611 i2c driver");
0142 MODULE_LICENSE("GPL v2");
0143 MODULE_IMPORT_NS(IIO_MS5611);