Re: [PATCH v2 1/3] regulator: qcom_smd-regulator: fix PM2250 supply parent mappings

[Dmitry Baryshkov]

On Mon, Jul 20, 2026 at 04:25:04PM +0530, Rakesh Kota wrote:
> The rpm_pm2250_regulators table hardcodes supply parent name strings
> in the regulator descriptor, causing the Linux regulator framework to
> look up and vote on parent supplies from APPS. This is both unnecessary
> and incorrect for RPM-managed regulators.
> 
> On RPM-based platforms, the parent-child supply relationships are
> managed entirely by the RPM firmware. The RPM ensures that parent
> rails are maintained at the correct voltage with appropriate headroom,
> based on all active child rail votes across all subsystems. No explicit
> parent supply vote from APPS is required.
> 
> Furthermore, the supply rail connections to PMIC pins are fixed in
> hardware. The previously hardcoded supply name strings were inaccurate
> and did not reflect the actual physical pin connections on PM2250-based
> platforms. The correct supply relationships are to be described in the
> Device Tree, not hardcoded in the driver.

Last phrase is incorrect. The driver can hardcode parent supplies (and
it has been doing it correctly for all other PMICs).

> 
> To avoid unnecessary APPS-side parent supply access while still
> allowing correct hardware topology to be described in DT, set the
> supply name field to NULL in the regulator descriptor.

Why is this touching only PM2250? Should we drop all parent votes?

> 
> Signed-off-by: Rakesh Kota <rakesh.kota@xxxxxxxxxxxxxxxx>
> ---
>  drivers/regulator/qcom_smd-regulator.c | 52 +++++++++++++++++-----------------
>  1 file changed, 26 insertions(+), 26 deletions(-)
> 

-- 
With best wishes
Dmitry