Commit c6236075 authored by Eva Rachel Retuya's avatar Eva Rachel Retuya Committed by Jonathan Cameron

iio: accel: Add driver for the Analog Devices ADXL345 3-axis accelerometer

Add basic IIO support for the Analog Devices ADXL345 3-axis accelerometer.
The datasheet can be found here:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdfSigned-off-by: default avatarEva Rachel Retuya <eraretuya@gmail.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Cc: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 48458b0c
......@@ -5,6 +5,17 @@
menu "Accelerometers"
config ADXL345
tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
depends on I2C
help
Say Y here if you want to build support for the Analog Devices
ADXL345 3-axis digital accelerometer.
To compile this driver as a module, choose M here: the
module will be called adxl345.
config BMA180
tristate "Bosch BMA180/BMA250 3-Axis Accelerometer Driver"
depends on I2C
......
......@@ -3,6 +3,7 @@
#
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_ADXL345) += adxl345.o
obj-$(CONFIG_BMA180) += bma180.o
obj-$(CONFIG_BMA220) += bma220_spi.o
obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
......
/*
* ADXL345 3-Axis Digital Accelerometer
*
* Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
*
* 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.
*
* IIO driver for ADXL345
* 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or
* 0x53 (ALT ADDRESS pin grounded)
*/
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#define ADXL345_REG_DEVID 0x00
#define ADXL345_REG_POWER_CTL 0x2D
#define ADXL345_REG_DATA_FORMAT 0x31
#define ADXL345_REG_DATAX0 0x32
#define ADXL345_REG_DATAY0 0x34
#define ADXL345_REG_DATAZ0 0x36
#define ADXL345_POWER_CTL_MEASURE BIT(3)
#define ADXL345_POWER_CTL_STANDBY 0x00
#define ADXL345_DATA_FORMAT_FULL_RES BIT(3) /* Up to 13-bits resolution */
#define ADXL345_DATA_FORMAT_2G 0
#define ADXL345_DATA_FORMAT_4G 1
#define ADXL345_DATA_FORMAT_8G 2
#define ADXL345_DATA_FORMAT_16G 3
#define ADXL345_DEVID 0xE5
/*
* In full-resolution mode, scale factor is maintained at ~4 mg/LSB
* in all g ranges.
*
* At +/- 16g with 13-bit resolution, scale is computed as:
* (16 + 16) * 9.81 / (2^13 - 1) = 0.0383
*/
static const int adxl345_uscale = 38300;
struct adxl345_data {
struct i2c_client *client;
u8 data_range;
};
#define ADXL345_CHANNEL(reg, axis) { \
.type = IIO_ACCEL, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.address = reg, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec adxl345_channels[] = {
ADXL345_CHANNEL(ADXL345_REG_DATAX0, X),
ADXL345_CHANNEL(ADXL345_REG_DATAY0, Y),
ADXL345_CHANNEL(ADXL345_REG_DATAZ0, Z),
};
static int adxl345_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct adxl345_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
/*
* Data is stored in adjacent registers:
* ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
* and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
*/
ret = i2c_smbus_read_word_data(data->client, chan->address);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 12);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = adxl345_uscale;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static const struct iio_info adxl345_info = {
.driver_module = THIS_MODULE,
.read_raw = adxl345_read_raw,
};
static int adxl345_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct adxl345_data *data;
struct iio_dev *indio_dev;
int ret;
ret = i2c_smbus_read_byte_data(client, ADXL345_REG_DEVID);
if (ret < 0) {
dev_err(&client->dev, "Error reading device ID: %d\n", ret);
return ret;
}
if (ret != ADXL345_DEVID) {
dev_err(&client->dev, "Invalid device ID: %d\n", ret);
return -ENODEV;
}
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
/* Enable full-resolution mode */
data->data_range = ADXL345_DATA_FORMAT_FULL_RES;
ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_DATA_FORMAT,
data->data_range);
if (ret < 0) {
dev_err(&client->dev, "Failed to set data range: %d\n", ret);
return ret;
}
indio_dev->dev.parent = &client->dev;
indio_dev->name = id->name;
indio_dev->info = &adxl345_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = adxl345_channels;
indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
/* Enable measurement mode */
ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
ADXL345_POWER_CTL_MEASURE);
if (ret < 0) {
dev_err(&client->dev, "Failed to enable measurement mode: %d\n",
ret);
return ret;
}
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "iio_device_register failed: %d\n", ret);
i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
ADXL345_POWER_CTL_STANDBY);
}
return ret;
}
static int adxl345_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct adxl345_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
return i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
ADXL345_POWER_CTL_STANDBY);
}
static const struct i2c_device_id adxl345_i2c_id[] = {
{ "adxl345", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id);
static struct i2c_driver adxl345_driver = {
.driver = {
.name = "adxl345",
},
.probe = adxl345_probe,
.remove = adxl345_remove,
.id_table = adxl345_i2c_id,
};
module_i2c_driver(adxl345_driver);
MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer driver");
MODULE_LICENSE("GPL v2");
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