[PATCH RFC v6 0/5] iio: add Open Sensor Fusion IIO driver

[Jinseob Kim <kimjinseob88@gmail.com>]

Open Sensor Fusion (OSF) devices expose a UART/serdev host interface
for a sensor aggregation hub.  This RFC adds a Linux IIO driver that
parses OSF frames and creates IIO devices at runtime from capability
reports provided by the device firmware.

When the corresponding capabilities are reported, the driver exposes
accelerometer, gyroscope, magnetometer, and temperature data as IIO
devices named osf-accel, osf-gyro, osf-magn, and osf-temp.

This remains RFC while the binding, protocol subset, runtime discovery
model, and driver-facing ABI are reviewed.

Changes in v6:
- Reworked the series as a 5-patch standalone RFC.
- Folded the previous transport and IIO registration split into one
  final driver patch to avoid Kconfig and Makefile churn.
- Addressed binding feedback with generic host interface wording,
  mandatory capability reporting, runtime discovery wording, no
  Linux-specific binding language, and no fixed regulator provider in
  the example.
- Added progressive MAINTAINERS coverage as files are introduced.
- Removed patch-split wording from Kconfig and introduced Kconfig and
  Makefile entries in final form.
- Applied style cleanups including loop-local variables, unused include
  cleanup, and a probe-local device pointer.
- Used designated initializers and guard/scoped_guard where useful.
- Kept the stream parser from discarding unauthenticated frame_len on
  failed decode.
- Synchronized IIO buffer pushes with
  iio_device_try_claim_buffer_mode() and release.
- Replaced iio_push_to_buffers_with_ts_unaligned() with local zeroed
  scan storage and iio_push_to_buffers_with_ts().

Validation summary:
- git diff --check: pass.
- checkpatch --strict: pass, 0 errors, 0 warnings, 0 checks.
- dt_binding_check: pass with dtschema 2026.4.
- make KBUILD_MODPOST_WARN=1 W=1 M=drivers/iio/opensensorfusion:
  pass, no compiler warnings.
- Local stream parser corruption/resync harness: pass.
- Static IIO scan layout and padding checks: pass.
- Raspberry Pi hardware/runtime smoke testing is pending for this v6
  candidate.

Jinseob Kim (5):
  dt-bindings: iio: add Open Sensor Fusion device
  Documentation: iio: add Open Sensor Fusion driver overview
  iio: osf: add protocol decoding
  iio: osf: add authenticated stream parser
  iio: osf: add UART IIO driver

 .../bindings/iio/opensensorfusion,osf.yaml    |  54 +++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 Documentation/iio/index.rst                   |   1 +
 Documentation/iio/open-sensor-fusion.rst      |  72 ++++
 MAINTAINERS                                   |  14 +
 drivers/iio/Kconfig                           |   1 +
 drivers/iio/Makefile                          |   1 +
 drivers/iio/opensensorfusion/Kconfig          |  16 +
 drivers/iio/opensensorfusion/Makefile         |   6 +
 drivers/iio/opensensorfusion/osf_core.c       | 291 +++++++++++++++++
 drivers/iio/opensensorfusion/osf_core.h       |  70 ++++
 drivers/iio/opensensorfusion/osf_iio.c        | 308 ++++++++++++++++++
 drivers/iio/opensensorfusion/osf_iio.h        |  22 ++
 drivers/iio/opensensorfusion/osf_protocol.c   | 258 +++++++++++++++
 drivers/iio/opensensorfusion/osf_protocol.h   |  97 ++++++
 drivers/iio/opensensorfusion/osf_serdev.c     | 114 +++++++
 drivers/iio/opensensorfusion/osf_stream.c     | 189 +++++++++++
 drivers/iio/opensensorfusion/osf_stream.h     |  31 ++
 18 files changed, 1547 insertions(+)


base-commit: ab5fce87a778cb780a05984a2ca448f2b41aafbf
-- 
2.43.0