[PATCH v8 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux

[Wolfram Sang]

On Tue, Feb 03, 2026 at 03:01:40PM +0200, Josua Mayer wrote:
> Some hardware designs route data or control signals through a mux to
> support multiple devices on a single sdhi controller.
> 
> In particular SolidRun RZ/G2L/G2LC/V2L System on Module use a mux for
> switching between soldered eMMC and an optional microSD on a carrier
> board, e.g. for development or provisioning.
> 
> SD/SDIO/eMMC are not well suited for runtime switching between different
> cards, however boot-time selection is possible and useful - in
> particular considering dt overlays.
> 
> Add support for an optional SD/SDIO/eMMC mux defined in dt, and select
> it during probe.
> 
> Similar functionality already exists in other places, e.g. i2c-omap.
> 
> Reviewed-by: Geert Uytterhoeven <geert+renesas at glider.be>
> Signed-off-by: Josua Mayer <josua at solid-run.com>

And to confirm the obvious, no regression found on a Renesas SparrowHawk
(R-Car V4H) not using muxes:

Tested-by: Wolfram Sang <wsa+renesas at sang-engineering.com>