Re: [PATCH V1 0/2] arm64: dts: qcom: lemans-evk: Update SDHC storage support via overlays

[Monish Chunara <monish.chunara@oss.qualcomm.com>]

On Fri, Feb 27, 2026 at 10:07:33PM +0200, Dmitry Baryshkov wrote:
> On Fri, Feb 27, 2026 at 03:54:03PM +0530, Monish Chunara wrote:
> > This series updates the device tree configuration for the LeMans EVK
> > board to support dynamic selection between SD card and eMMC storage.
> > 
> > The LeMans EVK hardware supports either an SD card or eMMC, but the
> > interfaces are mutually exclusive as they share the same controller and
> > resources. Previously, SD card support was hardcoded in the main device
> > tree, preventing easy switching to eMMC.
> > 
> > This series refactors the SDHC configuration by:
> > 
> > 1. Moving the existing SD card configuration into a dedicated overlay.
> > 2. Adding a new overlay to support eMMC.
> > 3. Updating the common SDHC node in the SoC dtsi to include necessary
> > resources (clocks, register ranges) required by the eMMC configuration.
> > 
> > This allows the bootloader to apply the appropriate overlay based on the
> > desired storage medium.
> 
> Is there a default mode of operation / extension? If there is one,
> please define it in the base DT and override it in a single overlay
> rather than having two mutually exclusive overlays.
> 

The LeMans EVK has SD card slot onboard and eMMC support via a mezzanine card.

However, if SD card is configured to be a default case in plaform DT, some of
the properties like 'no-mmc' would conflict for eMMC use case which cannot be
deleted in an overlay file, and vice versa. To avoid such issues, definied
separate overlays for both which gets selected based on the actual connection on
the board.

Regards,
Monish