forked from Freescale/linux-fslc
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
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 <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>
- Loading branch information
Showing
3 changed files
with
222 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,211 @@ | ||
/* | ||
* mpl115.c - Support for Freescale MPL115A2 pressure/temperature sensor | ||
* | ||
* Copyright (c) 2014 Peter Meerwald <[email protected]> | ||
* | ||
* This file is subject to the terms and conditions of version 2 of | ||
* the GNU General Public License. See the file COPYING in the main | ||
* directory of this archive for more details. | ||
* | ||
* (7-bit I2C slave address 0x60) | ||
* | ||
* TODO: shutdown pin | ||
* | ||
*/ | ||
|
||
#include <linux/module.h> | ||
#include <linux/i2c.h> | ||
#include <linux/iio/iio.h> | ||
#include <linux/delay.h> | ||
|
||
#define MPL115_PADC 0x00 /* pressure ADC output value, MSB first, 10 bit */ | ||
#define MPL115_TADC 0x02 /* temperature ADC output value, MSB first, 10 bit */ | ||
#define MPL115_A0 0x04 /* 12 bit integer, 3 bit fraction */ | ||
#define MPL115_B1 0x06 /* 2 bit integer, 13 bit fraction */ | ||
#define MPL115_B2 0x08 /* 1 bit integer, 14 bit fraction */ | ||
#define MPL115_C12 0x0a /* 0 bit integer, 13 bit fraction */ | ||
#define MPL115_CONVERT 0x12 /* convert temperature and pressure */ | ||
|
||
struct mpl115_data { | ||
struct i2c_client *client; | ||
struct mutex lock; | ||
s16 a0; | ||
s16 b1, b2; | ||
s16 c12; | ||
}; | ||
|
||
static int mpl115_request(struct mpl115_data *data) | ||
{ | ||
int ret = i2c_smbus_write_byte_data(data->client, MPL115_CONVERT, 0); | ||
if (ret < 0) | ||
return ret; | ||
|
||
usleep_range(3000, 4000); | ||
|
||
return 0; | ||
} | ||
|
||
static int mpl115_comp_pressure(struct mpl115_data *data, int *val, int *val2) | ||
{ | ||
int ret; | ||
u16 padc, tadc; | ||
int a1, y1, pcomp; | ||
unsigned kpa; | ||
|
||
mutex_lock(&data->lock); | ||
ret = mpl115_request(data); | ||
if (ret < 0) | ||
goto done; | ||
|
||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_PADC); | ||
if (ret < 0) | ||
goto done; | ||
padc = ret >> 6; | ||
|
||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC); | ||
if (ret < 0) | ||
goto done; | ||
tadc = ret >> 6; | ||
|
||
/* see Freescale AN3785 */ | ||
a1 = data->b1 + ((data->c12 * tadc) >> 11); | ||
y1 = (data->a0 << 10) + a1 * padc; | ||
|
||
/* compensated pressure with 4 fractional bits */ | ||
pcomp = (y1 + ((data->b2 * (int) tadc) >> 1)) >> 9; | ||
|
||
kpa = pcomp * (115 - 50) / 1023 + (50 << 4); | ||
*val = kpa >> 4; | ||
*val2 = (kpa & 15) * (1000000 >> 4); | ||
done: | ||
mutex_unlock(&data->lock); | ||
return ret; | ||
} | ||
|
||
static int mpl115_read_temp(struct mpl115_data *data) | ||
{ | ||
int ret; | ||
|
||
mutex_lock(&data->lock); | ||
ret = mpl115_request(data); | ||
if (ret < 0) | ||
goto done; | ||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_TADC); | ||
done: | ||
mutex_unlock(&data->lock); | ||
return ret; | ||
} | ||
|
||
static int mpl115_read_raw(struct iio_dev *indio_dev, | ||
struct iio_chan_spec const *chan, | ||
int *val, int *val2, long mask) | ||
{ | ||
struct mpl115_data *data = iio_priv(indio_dev); | ||
int ret; | ||
|
||
switch (mask) { | ||
case IIO_CHAN_INFO_PROCESSED: | ||
ret = mpl115_comp_pressure(data, val, val2); | ||
if (ret < 0) | ||
return ret; | ||
return IIO_VAL_INT_PLUS_MICRO; | ||
case IIO_CHAN_INFO_RAW: | ||
/* temperature -5.35 C / LSB, 472 LSB is 25 C */ | ||
ret = mpl115_read_temp(data); | ||
if (ret < 0) | ||
return ret; | ||
*val = ret >> 6; | ||
return IIO_VAL_INT; | ||
case IIO_CHAN_INFO_OFFSET: | ||
*val = 605; | ||
*val2 = 750000; | ||
return IIO_VAL_INT_PLUS_MICRO; | ||
case IIO_CHAN_INFO_SCALE: | ||
*val = -186; | ||
*val2 = 915888; | ||
return IIO_VAL_INT_PLUS_MICRO; | ||
} | ||
return -EINVAL; | ||
} | ||
|
||
static const struct iio_chan_spec mpl115_channels[] = { | ||
{ | ||
.type = IIO_PRESSURE, | ||
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), | ||
}, | ||
{ | ||
.type = IIO_TEMP, | ||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | ||
BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), | ||
}, | ||
}; | ||
|
||
static const struct iio_info mpl115_info = { | ||
.read_raw = &mpl115_read_raw, | ||
.driver_module = THIS_MODULE, | ||
}; | ||
|
||
static int mpl115_probe(struct i2c_client *client, | ||
const struct i2c_device_id *id) | ||
{ | ||
struct mpl115_data *data; | ||
struct iio_dev *indio_dev; | ||
int ret; | ||
|
||
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) | ||
return -ENODEV; | ||
|
||
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | ||
if (!indio_dev) | ||
return -ENOMEM; | ||
|
||
data = iio_priv(indio_dev); | ||
data->client = client; | ||
mutex_init(&data->lock); | ||
|
||
i2c_set_clientdata(client, indio_dev); | ||
indio_dev->info = &mpl115_info; | ||
indio_dev->name = id->name; | ||
indio_dev->dev.parent = &client->dev; | ||
indio_dev->modes = INDIO_DIRECT_MODE; | ||
indio_dev->channels = mpl115_channels; | ||
indio_dev->num_channels = ARRAY_SIZE(mpl115_channels); | ||
|
||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_A0); | ||
if (ret < 0) | ||
return ret; | ||
data->a0 = ret; | ||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_B1); | ||
if (ret < 0) | ||
return ret; | ||
data->b1 = ret; | ||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_B2); | ||
if (ret < 0) | ||
return ret; | ||
data->b2 = ret; | ||
ret = i2c_smbus_read_word_swapped(data->client, MPL115_C12); | ||
if (ret < 0) | ||
return ret; | ||
data->c12 = ret; | ||
|
||
return devm_iio_device_register(&client->dev, indio_dev); | ||
} | ||
|
||
static const struct i2c_device_id mpl115_id[] = { | ||
{ "mpl115", 0 }, | ||
{ } | ||
}; | ||
MODULE_DEVICE_TABLE(i2c, mpl115_id); | ||
|
||
static struct i2c_driver mpl115_driver = { | ||
.driver = { | ||
.name = "mpl115", | ||
}, | ||
.probe = mpl115_probe, | ||
.id_table = mpl115_id, | ||
}; | ||
module_i2c_driver(mpl115_driver); | ||
|
||
MODULE_AUTHOR("Peter Meerwald <[email protected]>"); | ||
MODULE_DESCRIPTION("Freescale MPL115 pressure/temperature driver"); | ||
MODULE_LICENSE("GPL"); |