[PATCH v5 0/4] BMI270: Add support for step counter and motion events

[Gustavo Silva <gustavograzs@gmail.com>]

This series adds support for step counter and motion events using
interrupts in the BMI270 driver.

The step counter can be enabled, disabled, and configured with a
watermark, all from userspace.

Any-motion and no-motion events are generated by detecting changes
in acceleration on each axis.

Signed-off-by: Gustavo Silva <gustavograzs@gmail.com>
---
Sorry for the delay in sending v5.
As a reminder, patches 1 and 2 were already accepted in v3.

Changes in v5:
- BMI270_G_MACRO_M_S_2 -> BMI270_G_MICRO_M_S_2
- Add patch #4: ABI documentation for the exposed sysfs attributes
Link to v4: https://lore.kernel.org/r/20250711-bmi270-events-v4-3-53ec7da35046@gmail.com

Changes in v4:
- Reworked the threshold for the any-motion event so that threshold *
  accel_scale is given in m/s^2, in accordance with the ABI
  Also the range of available values for the threshold is now determined
  dynamically based on the value of the accelerometer scale
- Fixed alignment and styling of some statements and macros
- Simplified the return statement in the bmi270_read_event_config()
  function by returning the boolean expression directly
- Link to v3: https://lore.kernel.org/r/20250616-bmi270-events-v3-0-16e37588604f@gmail.com

Changes in v3:
- Avoid the usage of set_mask_bits() macro on 16-bit integers,
  use the bitwise operators instead
- Fix indentation, alignment and style issues
- Link to v2: https://lore.kernel.org/r/20250605-bmi270-events-v2-0-8b2c07d0c213@gmail.com

Changes in v2:
- Reduce the scope of mutex lock when clearing the step counter
- Change the type of the 'steps_enabled' variable from int to bool
- Add a new DMA safe variable to the device's private data to access the
  feature registers
- Remove unnecessary mutex lock
- Fix a build error found by the kernel test robot by initializing a
  local variable in the `bmi270_update_feature_reg()` function
- Remove dead code in the `bmi270_write_event_config()` function
- Add macro definitions and corresponding datasheet references for
  relevant constants: step counter maximum value, step counter factor,
  and threshold upper limit
- Remove the event bitmask from the device's private data. Read the
  registers directly to retrieve this information instead
- Use IIO_UNMOD_EVENT_CODE instead of IIO_MOD_EVENT_CODE where
  appropriate
- Fix shadowed error codes
- Change motion event to be enabled on a per-axis basis
- Create pseudo channel of type accel_x&y&z for the no-motion event
- Change no-motion event type to IIO_EV_TYPE_ROC
- Link to v1: https://lore.kernel.org/r/20250424-bmi270-events-v1-0-a6c722673e5f@gmail.com

---
Gustavo Silva (2):
  iio: imu: bmi270: add support for motion events
  iio: ABI: document accel and roc event attributes

 Documentation/ABI/testing/sysfs-bus-iio |  40 +++
 drivers/iio/imu/bmi270/bmi270_core.c    | 384 ++++++++++++++++++++++--
 2 files changed, 404 insertions(+), 20 deletions(-)


base-commit: 91812d3843409c235f336f32f1c37ddc790f1e03
-- 
2.51.0