13017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald/* 23017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * mpl115.c - Support for Freescale MPL115A2 pressure/temperature sensor 33017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * 43017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net> 53017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * 63017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * This file is subject to the terms and conditions of version 2 of 73017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * the GNU General Public License. See the file COPYING in the main 83017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * directory of this archive for more details. 93017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * 103017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * (7-bit I2C slave address 0x60) 113017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * 123017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * TODO: shutdown pin 133017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald * 143017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald */ 153017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 163017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#include <linux/module.h> 173017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#include <linux/i2c.h> 183017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#include <linux/iio/iio.h> 193017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#include <linux/delay.h> 203017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 213017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_PADC 0x00 /* pressure ADC output value, MSB first, 10 bit */ 223017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_TADC 0x02 /* temperature ADC output value, MSB first, 10 bit */ 233017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_A0 0x04 /* 12 bit integer, 3 bit fraction */ 243017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_B1 0x06 /* 2 bit integer, 13 bit fraction */ 253017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_B2 0x08 /* 1 bit integer, 14 bit fraction */ 263017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_C12 0x0a /* 0 bit integer, 13 bit fraction */ 273017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald#define MPL115_CONVERT 0x12 /* convert temperature and pressure */ 283017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 293017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstruct mpl115_data { 303017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct i2c_client *client; 313017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct mutex lock; 323017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald s16 a0; 333017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald s16 b1, b2; 343017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald s16 c12; 353017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald}; 363017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 373017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic int mpl115_request(struct mpl115_data *data) 383017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald{ 393017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int ret = i2c_smbus_write_byte_data(data->client, MPL115_CONVERT, 0); 403017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 413017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 423017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 433017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald usleep_range(3000, 4000); 443017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 453017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return 0; 463017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald} 473017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 483017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic int mpl115_comp_pressure(struct mpl115_data *data, int *val, int *val2) 493017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald{ 503017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int ret; 513017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald u16 padc, tadc; 523017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int a1, y1, pcomp; 533017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald unsigned kpa; 543017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 553017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald mutex_lock(&data->lock); 563017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = mpl115_request(data); 573017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 583017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald goto done; 593017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 603017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_PADC); 613017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 623017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald goto done; 633017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald padc = ret >> 6; 643017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 653017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC); 663017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 673017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald goto done; 683017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald tadc = ret >> 6; 693017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 703017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald /* see Freescale AN3785 */ 713017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald a1 = data->b1 + ((data->c12 * tadc) >> 11); 723017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald y1 = (data->a0 << 10) + a1 * padc; 733017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 743017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald /* compensated pressure with 4 fractional bits */ 753017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald pcomp = (y1 + ((data->b2 * (int) tadc) >> 1)) >> 9; 763017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 773017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald kpa = pcomp * (115 - 50) / 1023 + (50 << 4); 783017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val = kpa >> 4; 793017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val2 = (kpa & 15) * (1000000 >> 4); 803017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwalddone: 813017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald mutex_unlock(&data->lock); 823017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 833017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald} 843017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 853017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic int mpl115_read_temp(struct mpl115_data *data) 863017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald{ 873017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int ret; 883017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 893017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald mutex_lock(&data->lock); 903017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = mpl115_request(data); 913017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 923017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald goto done; 933017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC); 943017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwalddone: 953017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald mutex_unlock(&data->lock); 963017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 973017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald} 983017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 993017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic int mpl115_read_raw(struct iio_dev *indio_dev, 1003017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct iio_chan_spec const *chan, 1013017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int *val, int *val2, long mask) 1023017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald{ 1033017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct mpl115_data *data = iio_priv(indio_dev); 1043017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int ret; 1053017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1063017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald switch (mask) { 1073017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald case IIO_CHAN_INFO_PROCESSED: 1083017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = mpl115_comp_pressure(data, val, val2); 1093017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1103017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1113017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return IIO_VAL_INT_PLUS_MICRO; 1123017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald case IIO_CHAN_INFO_RAW: 1133017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald /* temperature -5.35 C / LSB, 472 LSB is 25 C */ 1143017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = mpl115_read_temp(data); 1153017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1163017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1173017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val = ret >> 6; 1183017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return IIO_VAL_INT; 1193017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald case IIO_CHAN_INFO_OFFSET: 1203017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val = 605; 1213017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val2 = 750000; 1223017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return IIO_VAL_INT_PLUS_MICRO; 1233017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald case IIO_CHAN_INFO_SCALE: 1243017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val = -186; 1253017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald *val2 = 915888; 1263017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return IIO_VAL_INT_PLUS_MICRO; 1273017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald } 1283017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return -EINVAL; 1293017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald} 1303017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1313017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic const struct iio_chan_spec mpl115_channels[] = { 1323017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald { 1333017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .type = IIO_PRESSURE, 1343017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 1353017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald }, 1363017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald { 1373017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .type = IIO_TEMP, 1383017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 1393017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), 1403017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald }, 1413017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald}; 1423017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1433017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic const struct iio_info mpl115_info = { 1443017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .read_raw = &mpl115_read_raw, 1453017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .driver_module = THIS_MODULE, 1463017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald}; 1473017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1483017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic int mpl115_probe(struct i2c_client *client, 1493017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald const struct i2c_device_id *id) 1503017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald{ 1513017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct mpl115_data *data; 1523017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald struct iio_dev *indio_dev; 1533017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald int ret; 1543017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1553017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 1563017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return -ENODEV; 1573017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1583017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 1593017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (!indio_dev) 1603017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return -ENOMEM; 1613017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1623017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data = iio_priv(indio_dev); 1633017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data->client = client; 1643017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald mutex_init(&data->lock); 1653017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1663017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald i2c_set_clientdata(client, indio_dev); 1673017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->info = &mpl115_info; 1683017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->name = id->name; 1693017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->dev.parent = &client->dev; 1703017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->modes = INDIO_DIRECT_MODE; 1713017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->channels = mpl115_channels; 1723017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald indio_dev->num_channels = ARRAY_SIZE(mpl115_channels); 1733017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1743017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_A0); 1753017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1763017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1773017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data->a0 = ret; 1783017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_B1); 1793017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1803017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1813017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data->b1 = ret; 1823017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_B2); 1833017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1843017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1853017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data->b2 = ret; 1863017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald ret = i2c_smbus_read_word_swapped(data->client, MPL115_C12); 1873017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald if (ret < 0) 1883017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return ret; 1893017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald data->c12 = ret; 1903017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1913017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald return devm_iio_device_register(&client->dev, indio_dev); 1923017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald} 1933017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 1943017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic const struct i2c_device_id mpl115_id[] = { 1953017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald { "mpl115", 0 }, 1963017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald { } 1973017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald}; 1983017d90e8931fbd5dbde06b4e793aebb141e4977Peter MeerwaldMODULE_DEVICE_TABLE(i2c, mpl115_id); 1993017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 2003017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldstatic struct i2c_driver mpl115_driver = { 2013017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .driver = { 2023017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .name = "mpl115", 2033017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald }, 2043017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .probe = mpl115_probe, 2053017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald .id_table = mpl115_id, 2063017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald}; 2073017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwaldmodule_i2c_driver(mpl115_driver); 2083017d90e8931fbd5dbde06b4e793aebb141e4977Peter Meerwald 2093017d90e8931fbd5dbde06b4e793aebb141e4977Peter MeerwaldMODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); 2103017d90e8931fbd5dbde06b4e793aebb141e4977Peter MeerwaldMODULE_DESCRIPTION("Freescale MPL115 pressure/temperature driver"); 2113017d90e8931fbd5dbde06b4e793aebb141e4977Peter MeerwaldMODULE_LICENSE("GPL"); 212