Add support for the LTM8054 voltage regulator

From:		Romain Gantois <romain.gantois-AT-bootlin.com>
To:		Liam Girdwood <lgirdwood-AT-gmail.com>, Mark Brown <broonie-AT-kernel.org>, Rob Herring <robh-AT-kernel.org>, Krzysztof Kozlowski <krzk+dt-AT-kernel.org>, Conor Dooley <conor+dt-AT-kernel.org>, Jonathan Cameron <jic23-AT-kernel.org>, David Lechner <dlechner-AT-baylibre.com>, Nuno Sá <nuno.sa-AT-analog.com>, Andy Shevchenko <andy-AT-kernel.org>
Subject:		[PATCH v2 0/5] Add support for the LTM8054 voltage regulator
Date:		Thu, 25 Sep 2025 14:37:32 +0200
Message-ID:		<20250925-ltm8054-driver-v2-0-bb61a401a0dc@bootlin.com>
Cc:		Hans de Goede <hansg-AT-kernel.org>, Thomas Petazzoni <thomas.petazzoni-AT-bootlin.com>, linux-kernel-AT-vger.kernel.org, devicetree-AT-vger.kernel.org, linux-iio-AT-vger.kernel.org, Romain Gantois <romain.gantois-AT-bootlin.com>
Archive-link:		Article

Hello everyone,

These patches depend on the following series from Hans de Goede:

iio: processed channel handling fixes + Intel Dollar Cove TI PMIC ADC driver
(v4) https://lore.kernel.org/all/20250811155453.31525-1-hansg@...

This is version two of my series which adds initial support of the Linear
Technology LTM8054 voltage regulator. The driver supports a fixed voltage and a
tunable output current limit using a DAC-controlled pin.

I'd say that the only unusual part of this series is the usage of the IIO
consumer API in a regulator driver. I think this makes sense here, since
the regulator driver has to access a DAC to read/set the output current
limit.

Since the regulator driver writes microvolts and the IIO consumer API takes
millivolts, the reads and writes to the CTL DAC have to be scaled by a
factor of 1000. Scaled reads are already supported in IIO, but scaled
writes are not, which is why I've implemented them in patch 2/4.

Please let me know what you think.

Thanks,

Romain

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
---
Changes in v2:
- Refactored iio_convert_processed_to_raw() to match what was done in Hans'
  series.
- Added unit tests for IIO division.
- Fixed coding style issues and removed unnecessary casts.
- Link to v1: https://lore.kernel.org/r/20250916-ltm8054-driver-v1-0-fd...

---
Romain Gantois (5):
      regulator: dt-bindings: Add Linear Technology LTM8054 regulator
      iio: add processed write API
      Add kunit tests for iio_divide_by_value()
      regulator: Support the LTM8054 voltage regulator
      regulator: ltm8054: Support output current limit control

 .../devicetree/bindings/regulator/adi,ltm8054.yaml |  73 +++++++
 MAINTAINERS                                        |   6 +
 drivers/iio/inkern.c                               | 120 +++++++++++
 drivers/iio/test/Kconfig                           |  12 ++
 drivers/iio/test/Makefile                          |   1 +
 drivers/iio/test/iio-test-divide.c                 | 212 +++++++++++++++++++
 drivers/regulator/Kconfig                          |   9 +
 drivers/regulator/Makefile                         |   1 +
 drivers/regulator/ltm8054-regulator.c              | 235 +++++++++++++++++++++
 include/linux/iio/consumer.h                       |  36 ++++
 10 files changed, 705 insertions(+)
---
base-commit: bd89f4b281945a63659687ef5c70c4442d7e4940
change-id: 20250728-ltm8054-driver-11cfa4741065

Best regards,
-- 
Romain Gantois <romain.gantois@bootlin.com>