[PATCH v3 0/3] iio: health: add MAX86150 ECG and PPG biosensor driver

[Md Shofiqul Islam <shofiqtest@gmail.com>]

The MAX86150 (Maxim/Analog Devices) combines two PPG optical channels
(Red/IR LED) and one ECG biopotential channel in a single I2C device.

Changes since v2 (addressing Sashiko review):
 - Move FIFO read buffer from stack to struct field (DMA-safe for I2C host
   controllers that use DMA for burst reads)
 - Remove redundant devm iio_trigger_put action; the IIO core calls
   iio_trigger_put(indio_dev->trig) in iio_dev_release()
 - Remove IIO_CHAN_INFO_SCALE from info_mask_separate until hardware scale
   factors (PPG nA/LSB and ECG uV/LSB) are implemented with register
   readback in a follow-up
 - Reconstruct per-sample timestamps from IRQ capture time (pf->timestamp)
   and the configured sample period (10 ms at 100 Hz) so buffered samples
   carry accurate, evenly-spaced timestamps instead of all sharing the
   drain-loop clock reading
 - Switch to devm_regulator_get_enable_optional() for vdd-supply and
   leds-supply so probing succeeds on boards with fixed (non-DT) rails
 - Zero data->buf at the start of each FIFO drain iteration to prevent
   padding bytes from leaking previous sample data when fewer than 3
   channels are active
 - Flush FIFO (reset wr_ptr, rd_ptr, ovf_counter) in set_trigger_state()
   before enabling the interrupt so capture starts with a clean FIFO
 - Fix file permissions: both new files are 100644

Changes since v1 (addressing Joshua Crofts and Krzysztof Kozlowski review):
 - Split into 3 patches: DT binding / driver+Kconfig+Makefile / MAINTAINERS
 - Add MAINTAINERS entry

Md Shofiqul Islam (3):
  dt-bindings: iio: health: add maxim,max86150
  iio: health: add MAX86150 ECG and PPG biosensor driver
  MAINTAINERS: add entry for MAX86150 IIO health driver

 .../bindings/iio/health/maxim,max86150.yaml   |  67 +++
 MAINTAINERS                                   |   7 +
 drivers/iio/health/Kconfig                    |  19 +
 drivers/iio/health/Makefile                   |   1 +
 drivers/iio/health/max86150.c                 | 651 ++++++++++++++++++
 5 files changed, 745 insertions(+)

-- 
2.43.0