Re: [PATCH v7 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

[Ulf Hansson]

On Wed, 28 Jan 2026 at 15:46, Josua Mayer <josua@xxxxxxxxxxxxx> wrote:
>
> Some Renesas SoC based boards mux SD and eMMC on a single sdio
> controller, exposing user control by dip switch and software control by
> gpio.
>
> Purpose is to simplify development and provisioning by selecting boot
> media at power-on, and again before starting linux.
>
> Add binding and driver support for linking a (gpio) mux to renesas sdio
> controller.
>
> Introduce generic helper functions for getting managed and selected
> mux-state objects, and switch i2c-omap and phy-can-transceiver drivers.
>
> Signed-off-by: Josua Mayer <josua@xxxxxxxxxxxxx>

This series needs to go together in some way. If you like, I can
funnel it via my mmc tree, unless someone (Wolfram for the i2c part?)
has objections to this of course.

Kind regards
Uffe

> ---
> Changes in v7:
> - picked up reviewed-tags
> - fix Kconfig change to add the missing prompt for CONFIG_MULTIPLEXER,
>   and enable it by default when COMPILE_TEST is set.
>   (Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>)
> - fix another kernel build robot warning: undocumented C struct member
> - Link to v6: https://lore.kernel.org/r/20260121-rz-sdio-mux-v6-0-38aa39527928@xxxxxxxxxxxxx
>
> Changes in v6:
> - replaced /* with /** for devm_mux_state_state function description.
> - collected review tags.
> - fixed checkpatch warnings (space-before-tab, void-return).
>   (Reported-by: Geert Uytterhoeven)
> - fixed use-after-free in mux core mux_get function.
>   (Reported-by: Geert Uytterhoeven)
> - fix mux helper error path uninitialised return code variable.
>   (Reported-by: kernel test robot <lkp@xxxxxxxxx>)
> - Link to v5: https://lore.kernel.org/r/20260118-rz-sdio-mux-v5-0-3c37e8872683@xxxxxxxxxxxxx
>
> Changes in v5:
> - implemented automatic mux deselect for devm_*_selected.
>   (Reported-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>)
> - because of semantic changes I dropped reviewed and acks from omap-i2c
>   patch (Andreas Kemnade / Wolfram Sang).
> - fix invalid return value in void function for mux helper stubs
>   (Reported-by: kernel test robot <lkp@xxxxxxxxx>)
> - Link to v4: https://lore.kernel.org/r/20251229-rz-sdio-mux-v4-0-a023e55758fe@xxxxxxxxxxxxx
>
> Changes in v4:
> - added MULTIPLEXER Kconfig help text.
> - removed "select MULTIPLEXER" from renesas sdhi Kconfig, as it is
>   not required for all devices using this driver.
> - added stubs for all symbols exported by mux core.
>   (Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>)
> - refactored mux core logic to silence ENOENT errors only on optional
>   code paths, keeping error printing unchanged otherwise.
>   (Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>)
> - picked up various reviewed- and acked-by tags
> - Link to v3: https://lore.kernel.org/r/20251210-rz-sdio-mux-v3-0-ca628db56d60@xxxxxxxxxxxxx
>
> Changes in v3:
> - updated omap-i2c and phy-can-transceiver to use new helpers.
> - created generic helper functions for getting managed optional mux-state.
>   (Reported-by: Rob Herring <robh@xxxxxxxxxx>)
> - picked up binding ack by Rob Herring.
> - replaced use of "SDIO" with "SD/SDIO/eMMC" in binding document and
>   commit descriptions.
>   (Reported-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>)
> - Link to v2: https://lore.kernel.org/r/20251201-rz-sdio-mux-v2-0-bcb581b88dd7@xxxxxxxxxxxxx
>
> Changes in v2:
> - dropped mux-controller node from dt binding example
>   (Reported-by: Conor Dooley <conor@xxxxxxxxxx>
>    Reported-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>)
> - Link to v1: https://lore.kernel.org/r/20251128-rz-sdio-mux-v1-0-1ede318d160f@xxxxxxxxxxxxx
>
> ---
> Josua Mayer (7):
>       phy: can-transceiver: rename temporary helper function to avoid conflict
>       mux: Add helper functions for getting optional and selected mux-state
>       mux: add help text for MULTIPLEXER config option
>       phy: can-transceiver: drop temporary helper getting optional mux-state
>       i2c: omap: switch to new generic helper for getting selected mux-state
>       dt-bindings: mmc: renesas,sdhi: Add mux-states property
>       mmc: host: renesas_sdhi_core: support selecting an optional mux
>
>  .../devicetree/bindings/mmc/renesas,sdhi.yaml      |   6 +
>  drivers/i2c/busses/i2c-omap.c                      |  24 +--
>  drivers/mmc/host/renesas_sdhi_core.c               |   6 +
>  drivers/mux/Kconfig                                |   8 +-
>  drivers/mux/core.c                                 | 178 +++++++++++++++++----
>  drivers/phy/phy-can-transceiver.c                  |  10 --
>  include/linux/mux/consumer.h                       | 108 ++++++++++++-
>  7 files changed, 277 insertions(+), 63 deletions(-)
> ---
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> change-id: 20251128-rz-sdio-mux-acc5137f1618
>
> Best regards,
> --
> Josua Mayer <josua@xxxxxxxxxxxxx>
>
>