Re: Question about nct6775 regarding MFD

[Guenter Roeck]

On 6/16/25 03:34, Niedermayr, BENEDIKT wrote:
> Hi folks,
>
> we are currently refactoring some parts of the
> "drivers/platform/x86/siemens/*" which has references to some
>
> Nuvoton Super-I/O chips. One of them is the nct6775.
>
> The driver in question is not implemented as MFD, even though MFD would
> have fit perfectly for it (or am I wrong?).
>
>
> My question now:
>
> Why wasn't the driver implemented as an MFD? Was MFD discussed during
> your upstreaming-related conversations?

Super-IO chips have historically not been implemented as MFD since the functionality
is well separated except for configuration register access, and that is well handled
with the various superio_enter() functions which use a multiplexed memory region
to (temporarily) request chip access. Implementing those drivers as MFD would only
add complexity with no gain or benefit.

Guenter