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iio: accel: Add driver for the Analog Devices ADXL345 3-axis accelero…
…meter 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.pdf Signed-off-by: Eva Rachel Retuya <[email protected]> Cc: Michael Hennerich <[email protected]> Cc: Daniel Baluta <[email protected]> Cc: Alison Schofield <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>
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/* | ||
* ADXL345 3-Axis Digital Accelerometer | ||
* | ||
* Copyright (c) 2017 Eva Rachel Retuya <[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. | ||
* | ||
* IIO driver for ADXL345 | ||
* 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or | ||
* 0x53 (ALT ADDRESS pin grounded) | ||
*/ | ||
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#include <linux/i2c.h> | ||
#include <linux/module.h> | ||
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#include <linux/iio/iio.h> | ||
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#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 | ||
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#define ADXL345_POWER_CTL_MEASURE BIT(3) | ||
#define ADXL345_POWER_CTL_STANDBY 0x00 | ||
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#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 | ||
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#define ADXL345_DEVID 0xE5 | ||
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/* | ||
* 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; | ||
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struct adxl345_data { | ||
struct i2c_client *client; | ||
u8 data_range; | ||
}; | ||
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#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), \ | ||
} | ||
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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), | ||
}; | ||
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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; | ||
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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; | ||
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*val = sign_extend32(ret, 12); | ||
return IIO_VAL_INT; | ||
case IIO_CHAN_INFO_SCALE: | ||
*val = 0; | ||
*val2 = adxl345_uscale; | ||
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return IIO_VAL_INT_PLUS_MICRO; | ||
} | ||
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return -EINVAL; | ||
} | ||
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static const struct iio_info adxl345_info = { | ||
.driver_module = THIS_MODULE, | ||
.read_raw = adxl345_read_raw, | ||
}; | ||
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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; | ||
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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; | ||
} | ||
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if (ret != ADXL345_DEVID) { | ||
dev_err(&client->dev, "Invalid device ID: %d\n", ret); | ||
return -ENODEV; | ||
} | ||
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | ||
if (!indio_dev) | ||
return -ENOMEM; | ||
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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; | ||
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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; | ||
} | ||
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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); | ||
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/* 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; | ||
} | ||
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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); | ||
} | ||
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return ret; | ||
} | ||
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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); | ||
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iio_device_unregister(indio_dev); | ||
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return i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL, | ||
ADXL345_POWER_CTL_STANDBY); | ||
} | ||
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static const struct i2c_device_id adxl345_i2c_id[] = { | ||
{ "adxl345", 0 }, | ||
{ } | ||
}; | ||
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MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id); | ||
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static struct i2c_driver adxl345_driver = { | ||
.driver = { | ||
.name = "adxl345", | ||
}, | ||
.probe = adxl345_probe, | ||
.remove = adxl345_remove, | ||
.id_table = adxl345_i2c_id, | ||
}; | ||
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module_i2c_driver(adxl345_driver); | ||
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MODULE_AUTHOR("Eva Rachel Retuya <[email protected]>"); | ||
MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer driver"); | ||
MODULE_LICENSE("GPL v2"); |