Re: [PATCH] pinctrl: cherryview: Add quirk with custom translation of ACPI GPIO numbers

Michał Stanek
2020-02-08T18:43:41Z

> >
> > Hi Mika,
> >
> > The previous patches from Dmitry handled IRQ numbering, here we have a
> > similar issue with GPIO to pin translation - hardcoded values in FW
> > which do not agree with the (non-consecutive) numbering in newer
> > kernels.
>
> Hmm, so instead of passing GpioIo/GpioInt resources to devices the
> firmware uses some hard-coded Linux GPIO numbering scheme? Would you
> able to share the exact firmware description where this happens?

Actually it is a GPIO offset in ACPI tables for Braswell that was
hardcoded in the old firmware to match the previous (consecutive)
Linux GPIO numbering.

> > > What GPIO(s) we are talking about and how does it show up to the user?
> >
> > As an example, the issue manifests itself when you run 'crossystem
> > wpsw_cur'. On my Kefka it incorrectly reports the value as 1 instead
> > of 0 when the write protect screw is removed.
>
> Is it poking GPIOs directly through sysfs relying the Linux GPIO
> numbering (which can change and is fragile anyway)?

I believe so, yes.