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iio: Add Freescale MPL115A2 pressure / temperature sensor driver
I2C-controlled sensor with 10-bit pressure and temperature measurement datasheet: http://cache.freescale.com/files/sensors/doc/data_sheet/MPL3115A2.pdf v2: * use devm_iio_device_register() Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Peter Meerwald
Jonathan Cameron
parent
0828eddc56
commit
3017d90e89
@ -19,6 +19,16 @@ config HID_SENSOR_PRESS
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To compile this driver as a module, choose M here: the module
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will be called hid-sensor-press.
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config MPL115
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tristate "Freescale MPL115A2 pressure sensor driver"
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depends on I2C
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help
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Say yes here to build support for the Freescale MPL115A2
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pressure sensor connected via I2C.
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To compile this driver as a module, choose M here: the module
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will be called mpl115.
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config MPL3115
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tristate "Freescale MPL3115A2 pressure sensor driver"
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depends on I2C
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@ -4,6 +4,7 @@
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# When adding new entries keep the list in alphabetical order
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obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
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obj-$(CONFIG_MPL115) += mpl115.o
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obj-$(CONFIG_MPL3115) += mpl3115.o
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obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
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st_pressure-y := st_pressure_core.o
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211
drivers/iio/pressure/mpl115.c
Normal file
211
drivers/iio/pressure/mpl115.c
Normal file
@ -0,0 +1,211 @@
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/*
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* mpl115.c - Support for Freescale MPL115A2 pressure/temperature sensor
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*
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* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* (7-bit I2C slave address 0x60)
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*
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* TODO: shutdown pin
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*
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#include <linux/delay.h>
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#define MPL115_PADC 0x00 /* pressure ADC output value, MSB first, 10 bit */
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#define MPL115_TADC 0x02 /* temperature ADC output value, MSB first, 10 bit */
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#define MPL115_A0 0x04 /* 12 bit integer, 3 bit fraction */
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#define MPL115_B1 0x06 /* 2 bit integer, 13 bit fraction */
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#define MPL115_B2 0x08 /* 1 bit integer, 14 bit fraction */
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#define MPL115_C12 0x0a /* 0 bit integer, 13 bit fraction */
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#define MPL115_CONVERT 0x12 /* convert temperature and pressure */
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struct mpl115_data {
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struct i2c_client *client;
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struct mutex lock;
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s16 a0;
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s16 b1, b2;
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s16 c12;
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};
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static int mpl115_request(struct mpl115_data *data)
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{
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int ret = i2c_smbus_write_byte_data(data->client, MPL115_CONVERT, 0);
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if (ret < 0)
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return ret;
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usleep_range(3000, 4000);
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return 0;
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}
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static int mpl115_comp_pressure(struct mpl115_data *data, int *val, int *val2)
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{
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int ret;
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u16 padc, tadc;
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int a1, y1, pcomp;
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unsigned kpa;
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mutex_lock(&data->lock);
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ret = mpl115_request(data);
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if (ret < 0)
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goto done;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_PADC);
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if (ret < 0)
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goto done;
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padc = ret >> 6;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC);
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if (ret < 0)
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goto done;
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tadc = ret >> 6;
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/* see Freescale AN3785 */
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a1 = data->b1 + ((data->c12 * tadc) >> 11);
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y1 = (data->a0 << 10) + a1 * padc;
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/* compensated pressure with 4 fractional bits */
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pcomp = (y1 + ((data->b2 * (int) tadc) >> 1)) >> 9;
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kpa = pcomp * (115 - 50) / 1023 + (50 << 4);
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*val = kpa >> 4;
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*val2 = (kpa & 15) * (1000000 >> 4);
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done:
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mutex_unlock(&data->lock);
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return ret;
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}
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static int mpl115_read_temp(struct mpl115_data *data)
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{
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int ret;
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mutex_lock(&data->lock);
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ret = mpl115_request(data);
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if (ret < 0)
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goto done;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC);
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done:
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mutex_unlock(&data->lock);
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return ret;
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}
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static int mpl115_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct mpl115_data *data = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED:
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ret = mpl115_comp_pressure(data, val, val2);
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if (ret < 0)
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return ret;
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_RAW:
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/* temperature -5.35 C / LSB, 472 LSB is 25 C */
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ret = mpl115_read_temp(data);
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if (ret < 0)
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return ret;
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*val = ret >> 6;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_OFFSET:
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*val = 605;
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*val2 = 750000;
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_SCALE:
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*val = -186;
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*val2 = 915888;
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static const struct iio_chan_spec mpl115_channels[] = {
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{
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.type = IIO_PRESSURE,
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
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},
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{
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.type = IIO_TEMP,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),
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},
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};
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static const struct iio_info mpl115_info = {
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.read_raw = &mpl115_read_raw,
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.driver_module = THIS_MODULE,
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};
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static int mpl115_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct mpl115_data *data;
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struct iio_dev *indio_dev;
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int ret;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
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return -ENODEV;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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data->client = client;
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mutex_init(&data->lock);
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i2c_set_clientdata(client, indio_dev);
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indio_dev->info = &mpl115_info;
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indio_dev->name = id->name;
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indio_dev->dev.parent = &client->dev;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = mpl115_channels;
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indio_dev->num_channels = ARRAY_SIZE(mpl115_channels);
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_A0);
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if (ret < 0)
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return ret;
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data->a0 = ret;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_B1);
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if (ret < 0)
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return ret;
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data->b1 = ret;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_B2);
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if (ret < 0)
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return ret;
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data->b2 = ret;
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ret = i2c_smbus_read_word_swapped(data->client, MPL115_C12);
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if (ret < 0)
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return ret;
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data->c12 = ret;
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return devm_iio_device_register(&client->dev, indio_dev);
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}
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static const struct i2c_device_id mpl115_id[] = {
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{ "mpl115", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, mpl115_id);
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static struct i2c_driver mpl115_driver = {
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.driver = {
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.name = "mpl115",
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},
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.probe = mpl115_probe,
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.id_table = mpl115_id,
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};
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module_i2c_driver(mpl115_driver);
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MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("Freescale MPL115 pressure/temperature driver");
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MODULE_LICENSE("GPL");
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