Re: [PATCH v2 0/3] regulator: Add X-Powers AXP318W PMIC support

[Jerome Brunet <jbrunet@baylibre.com>]

On ven. 10 juil. 2026 at 18:19, Jerome Brunet <jbrunet@baylibre.com> wrote:

> This patch series adds support for the X-Powers AXP318W PMIC, which is
> used recently on new boards with Allwinner SoCs (the A733).
>
> The PMIC features 9 DCDC buck converters and 28 LDOs, plus the usual ADC,
> interrupts, and power key components.
> A datasheet can be found linked in this Wiki table:
> https://linux-sunxi.org/AXP_PMICs
>
> Patch 1 adds the compatible string to the binding document, and adds
> the additional input supply properties.
> Patch 2 is the MFD part, describing the regmap and all the interrupts.
> So far we support the regulator and power key devices, the ADC and
> other pieces will follow later.
> Patch 3 adds the voltage regulator rails, this part is crucial to enable
> any board using this PMIC, as we depend on those rails even for basic
> devices.
>
> There was an unclosed topic regarding the handling of LDOs output
> voltage being limited to input voltage being provided by the supply.
> Chen-Yu noted the min_dropout_uV would be a good fit for that but
> the actual minimal dropout value was unknown. I've arbitrarily picked
> 1uV because it is the minimum the framework supports. Realistically a low
> dropout regulator is bound to have some dropout. This choice
> is very likely optimistic but does the trick for now.
>
> If anyone has problems because the dropout is actually higher
> * it is arguably an HW design error
> * it is a good time to let us know what the actual dropout is :P
>

I've focused on the regulator and the comments from v1 while taking over,
assuming the rest was fine. I should not have. Please ignore this
version. I'll re-spin it.

> Changes in v2:
> * Droped _NUM_VOLTAGES macros
> * Use min_dropout_uV to limit LDO voltage to supplies
> * Add bypass mode for EDLO4/5
> * Prevent crossing 1.54V threshold for DCDC6/7/8/9
> * Link to v1: https://lore.kernel.org/r/20251021112013.2710903-1-andre.przywara@arm.com
>
> ---
> Andre Przywara (3):
>       dt-bindings: mfd: x-powers,axp152: Document AXP318W
>       mfd: axp20x: Add support for AXP318W PMIC
>       regulator: axp20x: add support for the AXP318W
>
>  .../devicetree/bindings/mfd/x-powers,axp152.yaml   |  28 +-
>  drivers/mfd/axp20x-i2c.c                           |   2 +
>  drivers/mfd/axp20x.c                               |  84 ++++++
>  drivers/regulator/axp20x-regulator.c               | 298 ++++++++++++++++++++-
>  include/linux/mfd/axp20x.h                         | 129 +++++++++
>  5 files changed, 532 insertions(+), 9 deletions(-)
> ---
> base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
> change-id: 20260710-axp318-regulator-43545ce3261f
>
> Best regards,

-- 
Jerome