Re: [PATCH 0/3] pinctrl: single: bit-per-mux DT flexibility, probe robustness, and consistent pinconf offsets

Andrew Jeffery
2026-01-07T23:44:27Z

Hi Billy,

On Mon, 2025-12-22 at 20:04 +0800, Billy Tsai wrote:
> This series updates pinctrl-single to behave more predictably on
> bit-per-mux platforms by making its DT interface more flexible, its probe
> path more tolerant of pre-reserved resources, and its pin configuration
> register addressing consistent with pinmux.

Can you provide some more context here? For instance, this is motivated
by the AST2700 - can you talk a bit more about why its design needs
these changes?

> It extends the driver to accept a per-pin <pin_index func_sel> style
> description for bit-per-mux users while keeping the existing
> pinctrl-single,bits binding as the preferred input when available. It also
> relaxes probe failure when the I/O memory region cannot be reserved
> exclusively, allowing initialization to proceed with a warning on systems
> where that region is already reserved.
>

Can you unpack what's going on here in the context of the target soc?

Andrew

> Finally, it aligns pinconf register
> offset computation with the pinmux logic so that both muxing and pin
> configuration access the same register offsets, avoiding incorrect pinconf
> operations on bit-per-mux configurations.
>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
> Billy Tsai (3):
>       pinctrl: single: add per-pin binding support for bit-per-mux
>       pinctrl: single: Allow probe to continue if mem region busy
>       pinctrl: single: unify pinconf offset mapping with pinmux
>
>  drivers/pinctrl/pinctrl-single.c | 150 ++++++++++++++++++++++++++++-----------
>  1 file changed, 110 insertions(+), 40 deletions(-)
> ---
> base-commit: dd9b004b7ff3289fb7bae35130c0a5c0537266af
> change-id: 20251222-upstream_pinctrl_single-99e8df1fe2b9
>
> Best regards,