[PATCH 0/3] iio: adc: add LTC2499 features support

This series adds LTC2499 support on top of the existing LTC2497 driver.

It includes:
- a small binding title correction for LTC2499,
- the LTC2499 internal temperature channel,
- the LTC2499 2x conversion speed mode exposed via sampling_frequency.

Validation performed on Raspberry Pi 4 hardware with a DC1012A-A board:
- temperature raw/scale/offset read correctly,
- voltage channels remain sane after temperature reads,
- sampling_frequency 1x/2x switching works,
- pyadi-iio LTC2499 validation passed.

Changes in v2:
- guard against regulator_get_voltage() returning 0 in the temperature offset path,
- replace LTC2499 two-byte stack command buffers with a DMA-safe buffer,
- use ABSOLUTE_ZERO_MILLICELSIUS and standard SI unit multipliers,
- make channel-count handling explicit,
- clean up includes and iterator usage,
- update conversion-state handling for interrupted waits,
- clarify conversion-time rounding and LTC2499 configuration behavior.

Andrei Stancovici (3):
  dt-bindings: iio: adc: lltc,ltc2497: add LTC2499 to title
  iio: adc: ltc2497: add LTC2499 internal temperature channel
  iio: adc: ltc2497: add 2x conversion speed mode

 .../bindings/iio/adc/lltc,ltc2497.yaml        |   2 +-
 drivers/iio/adc/ltc2497-core.c                | 234 +++++++++++++++++-
 drivers/iio/adc/ltc2497.c                     |  41 +++
 drivers/iio/adc/ltc2497.h                     |  46 +++-
 4 files changed, 310 insertions(+), 13 deletions(-)

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2.43.0