iio: health: add MAX86150 ECG and PPG biosensor driver [LWN.net]

From:		Md Shofiqul Islam <shofiqtest-AT-gmail.com>
To:		linux-iio-AT-vger.kernel.org
Subject:		[PATCH v4 0/3] iio: health: add MAX86150 ECG and PPG biosensor driver
Date:		Tue, 23 Jun 2026 20:45:57 +0300
Message-ID:		<20260623174600.17100-1-shofiqtest@gmail.com>
Cc:		jic23-AT-kernel.org, dlechner-AT-baylibre.com, nuno.sa-AT-analog.com, andy-AT-kernel.org, robh-AT-kernel.org, krzk+dt-AT-kernel.org, conor+dt-AT-kernel.org, lars-AT-metafoo.de, devicetree-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org, Md Shofiqul Islam <shofiqtest-AT-gmail.com>
Archive-link:		Article

Changes in v4 (addressing Sashiko review of v3):

- [High] Fix optional regulator probe failure: treat -ENODEV from
  devm_regulator_get_enable_optional() as success (supply absent,
  not an error).

- [High] Align fifo_raw to ARCH_DMA_MINALIGN to satisfy DMA mapping
  requirements of I2C host controllers that use DMA for burst transfers.

- [High] Disambiguate FIFO empty vs exactly-full: when wr_ptr == rd_ptr
  with OVF_COUNTER == 0, consult the A_FULL interrupt status bit to
  determine whether the FIFO pointer wrapped to full or is truly empty.

- [High] Remove iio_trigger_get() in probe: the incremented refcount
  leaks on the error path when devm_iio_device_register() fails because
  iio_device_unregister() (and its paired iio_trigger_put()) never runs.
  Users set the trigger via the current_trigger sysfs attribute as normal.

- [High] Assert SYS_SHDN in chip_init() so the LED drivers draw no
  current while capture is inactive.  set_trigger_state() clears SHDN
  when the buffer is enabled and re-asserts it when disabled.
  read_raw() wakes and sleeps the device around each single-shot read.

- [Medium] Replace IRQF_TRIGGER_FALLING with irq_get_trigger_type() to
  honour the interrupt trigger type from the device tree; falls back to
  falling-edge if the DT does not specify one.

- [Medium] Add .validate_trigger = iio_trigger_validate_own_device to
  prevent incompatible external triggers from being attached.

- [Medium] Fix per-sample timestamp jitter: anchor timestamps to the
  A_FULL IRQ capture time.  The sample at index (A_FULL_SAMPLES - 1)
  corresponds to pf->timestamp; samples accumulated between the IRQ and
  handler execution receive future timestamps, eliminating scheduling-
  latency-dependent jitter in multi-sample drains.

Link: https://lore.kernel.org/linux-iio/20260623155556.13701-1-...
  v3 cover letter

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

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2.49.0