[RFC PATCH 0/2] iio: magnetometer: add support for Melexis MLX90393

[Nikhil Gautam <nikhilgtr@gmail.com>]

Hi,

This series adds initial Industrial I/O subsystem support for the
Melexis MLX90393 3-axis magnetometer and temperature sensor.

The MLX90393 supports both I2C and SPI interfaces. This RFC
implements support for the I2C interface while keeping the driver
structure transport-independent to simplify future SPI support.

Currently supported features:

raw magnetic field measurements for X/Y/Z axes
raw temperature measurements
configurable gain/scale selection
configurable oversampling ratio
direct mode operation through the IIO subsystem
initially I2C support for this driver

The driver has been tested on Raspberry Pi 5 hardware using an
actual MLX90393 sensor connected over I2C. Raw magnetic field and
temperature values were verified through the IIO sysfs interface.

A custom transport abstraction was used instead of regmap due to
the MLX90393 command/response protocol semantics and repeated-start
transfer behavior. This approach was discussed previously on the
mailing list and seemed preferable for this device.
Link: https://lore.kernel.org/linux-iio/20260424114818.1290b029@jic23-huawei/

The implementation intentionally focuses on a minimal and reviewable
feature set for the initial RFC submission. Support for SPI,
buffered capture, triggers, interrupts and runtime PM can be added
incrementally in follow-up work.

The DT binding schema has been validated using dt_binding_check and
the driver has been checked using checkpatch.pl --strict.

Feedback on the overall driver structure, transport abstraction,
IIO ABI usage and DT binding would be appreciated.

Thanks,
Nikhil Gautam

Nikhil Gautam (2):
  dt-bindings: iio: magnetometer: add Melexis MLX90393
  iio: magnetometer: add support for Melexis MLX90393

 .../iio/magnetometer/melexis,mlx90393.yaml    |  39 +
 drivers/iio/magnetometer/Kconfig              |  10 +
 drivers/iio/magnetometer/Makefile             |   2 +
 drivers/iio/magnetometer/mlx90393.h           |  76 ++
 drivers/iio/magnetometer/mlx90393_core.c      | 724 ++++++++++++++++++
 drivers/iio/magnetometer/mlx90393_i2c.c       |  71 ++
 6 files changed, 922 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/melexis,mlx90393.yaml
 create mode 100644 drivers/iio/magnetometer/mlx90393.h
 create mode 100644 drivers/iio/magnetometer/mlx90393_core.c
 create mode 100644 drivers/iio/magnetometer/mlx90393_i2c.c

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2.39.5