Re: [PATCH v3 7/9] dt-bindings: arm: stm32: Switch st,stm32mp23/25-syscfg into simple-mfd

On 8/27/26 3:07 PM, Krzysztof Kozlowski wrote:

On Sat, Aug 22, 2026 at 09:46:40AM +0200, Marek Vasut wrote:

quoted

The st,stm32mp23-syscfg and st,stm32mp25-syscfg can have subnodes, which
represent the USB 2.0 FEMTO-PHY. Turn the syscfg into "simple-mfd" so the
PHYs would get populated by the OS.

Sashiko comment is partially valid - you change the ABI in incompatible
way, by requiring a new compatible. Commit msg should briefly explain
the impact, e.g. that there is no impact because phy was not
implemented by Linux and was not described in the binding.

OTOH, adding simple-mfd means children have no dependency on the parent,
so this should be considered or even explicitly mentioned in commit msg
(parent clock is irrelevant to child, right?)

OTOH2, you have now patchset dependency which is nowwhere explained.
Merging constraints are the most important part of cover letter so must
be clearly stated. IMO, should be stated also here, because many
maintainers do not read cover letters. Or just decouple dependencies
with using 'compatibles' pattern (see Qualcomm msm/mdss display
bindings).

I wonder, wouldn't it be better to write a driver which binds to 
st,stm32mp25-syscfg , handles the SYSCFG clock, and does some 
of_platform_populate() to bring up the PHYs (DT subnodes) ?

I think that would resolve the ABI break problem, since we wouldn't need 
the simple-mfd compatible anymore. And it would also correctly handle 
the SYSCFG clock.

What do you think ?