Re: [PATCH v8 6/6] iio: imu: st_lsm6dsx: Add support for rotation sensor

[David Lechner]

On 3/17/26 10:04 AM, Francesco Lavra wrote:
> Some IMU chips in the LSM6DSX family have sensor fusion features that
> combine data from the accelerometer and gyroscope. One of these features
> generates rotation vector data and makes it available in the hardware
> FIFO as a quaternion (more specifically, the X, Y and Z components of the
> quaternion vector, expressed as 16-bit half-precision floating-point
> numbers).
> 
> Add support for a new sensor instance that allows receiving sensor fusion
> data, by defining a new struct st_lsm6dsx_fusion_settings (which contains
> chip-specific details for the sensor fusion functionality), and adding this
> struct as a new field in struct st_lsm6dsx_settings. In st_lsm6dsx_core.c,
> populate this new struct for the LSM6DSV and LSM6DSV16X chips, and add the
> logic to initialize an additional IIO device if this struct is populated
> for the hardware type being probed.
> Note: a new IIO device is being defined (as opposed to adding channels to
> an existing device) because the rate at which sensor fusion data is
> generated may not match the data rate from any of the existing devices.
> 
> Tested on LSMDSV16X.
> 
We should mention that this depends on [1] to get the correct sizing
of the buffer in userspace.

[1]: https://lore.kernel.org/linux-iio/20260307-iio-fix-timestamp-alignment-v2-4-d1d48fbadbbf@xxxxxxxxxxxx/