> 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 comments below > Signed-off-by: Eva Rachel Retuya <eraretuya@xxxxxxxxx> > Cc: Michael Hennerich <michael.hennerich@xxxxxxxxxx> > Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx> > Cc: Alison Schofield <amsfield22@xxxxxxxxx> > --- > Note that this sensor is already supported in input/misc/adxl34x. This IIO > driver only supports read_raw on x, y and z axes in full-resolution mode. > > drivers/iio/accel/Kconfig | 10 +++ > drivers/iio/accel/Makefile | 1 + > drivers/iio/accel/adxl345.c | 173 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 184 insertions(+) > create mode 100644 drivers/iio/accel/adxl345.c > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index ea295fe..b73f403 100644 > --- a/drivers/iio/accel/Kconfig > +++ b/drivers/iio/accel/Kconfig > @@ -5,6 +5,16 @@ > > menu "Accelerometers" > > +config ADXL345 > + tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver" > + 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 > diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile > index 69fe8ed..618488d 100644 > --- a/drivers/iio/accel/Makefile > +++ b/drivers/iio/accel/Makefile > @@ -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 > diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345.c > new file mode 100644 > index 0000000..54ea601 > --- /dev/null > +++ b/drivers/iio/accel/adxl345.c > @@ -0,0 +1,173 @@ > +/* > + * ADXL345 3-Axis Digital Accelerometer > + * > + * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@xxxxxxxxx> > + * > + * 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) buffered mode would be useful in order to get consistent measurements of all three axis at once > + */ > + > +#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) maybe state in comment that FULL_RES is 12 bit > +#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 > + > +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), \ haven't checked but likely we need _SCALE to present the correct unit of measurement > +} > + > +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 > + */ there is no data ready? we might get old data? > + ret = i2c_smbus_read_word_data(data->client, chan->address); > + drop newline > + if (ret < 0) > + return ret; > + > + *val = sign_extend32(le16_to_cpu(ret), 12); le16_to_cpu() not needed, I2C read_word_data does it for you > + return IIO_VAL_INT; > + } > + > + 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; > + } > + > + return iio_device_register(indio_dev); stop measurement mode if registration fails > +} > + > +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@xxxxxxxxx>"); > +MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer driver"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald-Stadler +43-664-2444418 (mobile) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
