[PATCH 0/2] New driver for ams AS5600 Position Sensor

[Aditya Dutt <duttaditya18@gmail.com>]

This patch series adds support for the ams AS5600 Position Sensor.

The AS5600 is a Hall-based rotary magnetic position sensor using
planar sensors that convert the magnetic field component perpendicular
to the surface of the chip into a voltage, or a numerical value
available through i2c.

The driver registers the chip as an IIO_ANGL device.
It also exposes the raw registers through debugfs for further configuration.

Datasheet: https://ams-osram.com/products/sensor-solutions/position-sensors/ams-as5600-position-sensor
Co-developed-by: Frank Zago <frank@zago.net> 
Signed-off-by: Frank Zago <frank@zago.net>
Signed-off-by: Aditya Dutt <duttaditya18@gmail.com>
---

This patch is based on the work done by Frank Zago:
v2: https://lore.kernel.org/all/20211225175353.4254-1-frank@zago.net/
v1: https://lore.kernel.org/all/20211216202651.120172-1-frank@zago.net/

I have done the changes suggested by Jonathan Cameron in the follow-ups.

I picked this up because there has been no progress on this since 2021 and
Frank Zago has previously stated he isn't trying to upstream his drivers:
https://lore.kernel.org/all/e052d872-6de2-42f4-8b36-d1e2f8359624@zago.net/

Currently, I have not added support for:
- OUT (PWM)
- PGO (GPIO used for OTP)
- DIR (GPIO used for clockwise/anti-clockwise detection)

I have tested this on a Beaglebone Black with as5600 support compiled as a
kernel module (m) as well as in-kernel (y).

changes since Frank Zago's v2:
- direct register access in debugfs is now raw register access without any
  mappings as suggested by Jonathan Cameron
- added device tree support and bindings
- in as5600_probe(), reading ZPOS and MPOS should be a word not a byte
- removed "Read then write" behavior in as5600_reg_access_write() since
  register access is now raw, reading and manipulating the correct bits and
  writing is now the duty of userspace.
- changed "Datasheet" links to the product page instead of the direct PDF
  since the PDF links are not stable


Aditya Dutt (2):
  dt-bindings: iio: position: Add ams AS5600 Position Sensor
  iio: position: Add support for ams AS5600 angle sensor

 .../bindings/iio/position/ams,as5600.yaml     |  42 ++
 Documentation/iio/as5600.rst                  |  84 ++++
 Documentation/iio/index.rst                   |   1 +
 MAINTAINERS                                   |   8 +
 drivers/iio/position/Kconfig                  |  10 +
 drivers/iio/position/Makefile                 |   1 +
 drivers/iio/position/as5600.c                 | 373 ++++++++++++++++++
 7 files changed, 519 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/position/ams,as5600.yaml
 create mode 100644 Documentation/iio/as5600.rst
 create mode 100644 drivers/iio/position/as5600.c

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2.34.1