[PATCH v4 0/3] iio: adc: ti-ads112c14: continuous mode support

[David Lechner (TI)]

The TI ADS112C14 ADC has a continuous mode where it can trigger
conversions using its own clock and signals that data is ready using
the /DRDY line. This allows capturing data at higher rates since it
avoids the settling time between conversions. But it is limited to only
being able to sample one channel at a time.

Users will be able to select between continuous and single-shot mode
for buffered reads by selecting the trigger. If the "own" trigger from
the /DRDY interrupt is selected, continuous mode will be used. Or if
some other (software) trigger is selected, single-shot mode will be used
as was already implemented before this series.

Supporting open-drain /DRDY is deferred for future work. In simple cases
we have just done a `drive-open-drain` DT property for this, but on this
chip there is more than one pin (GPIO, FAULT interrupt) that could also
need to be open-drain and not all at the same time.

Signed-off-by: David Lechner (TI) <dlechner@xxxxxxxxxxxx>
---
Changes in v4:
- Check for the "interrupt-names" property instead of "interrupts" to
  detect the /DRDY interrupt so that it works on ACPI systems too.
- Add ads112c14_first_active_channel() helper instead of duplicating the
  find_first_bit() lookup.
- Use regmap_update_bits() with FIELD_PREP() instead of
  regmap_assign_bits() for the CONV_MODE field.
- Link to v3: https://patch.msgid.link/20260807-iio-adc-ti-ads112c14-continuous-mode-v3-0-76e0d30e6c6b@xxxxxxxxxxxx

Changes in v3:
- Leave DRDY interrupt always enabled.
- Link to v2: https://patch.msgid.link/20260731-iio-adc-ti-ads112c14-continuous-mode-v2-0-eb13da38e8fc@xxxxxxxxxxxx

Changes in v2:
- Split out irq and poll code paths into separate functions.
- Split refactoring into separate patch.
- Use iio_validate_scan_mask_onehot().
- Just return immediately on error in buffer_predisable().
- Don't set default trigger.
- Code style improvements.
- Fixed null pointer dereference bug when no trigger.
- Link to v1: https://patch.msgid.link/20260724-iio-adc-ti-ads112c14-continuous-mode-v1-0-9eb0b7a4f020@xxxxxxxxxxxx

---
David Lechner (TI) (3):
      iio: adc: ti-ads112c14: add DRDY interrupt support
      iio: adc: ti-ads112c14: create data read helper functions
      iio: adc: ti-ads112c14: add continuous mode support

 drivers/iio/adc/ti-ads112c14.c | 288 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 259 insertions(+), 29 deletions(-)
---
base-commit: 22359083a9e74d538ce383d5c0ee30cc20182187
change-id: 20260724-iio-adc-ti-ads112c14-continuous-mode-dd1580754609

Best regards,
--  
David Lechner (TI) <dlechner@xxxxxxxxxxxx>