Re: [PATCH v2 5/8] pinctrl: nuvoton: Add driver for WPCM450

[Jonathan Neuschäfer]

On Fri, Dec 10, 2021 at 02:41:45AM +0100, Linus Walleij wrote:
> On Thu, Dec 9, 2021 at 9:26 AM Zev Weiss <zweiss@xxxxxxxxxxx> wrote:
> > On Wed, Dec 08, 2021 at 05:58:30AM PST, Jonathan Neuschäfer wrote:
> 
> > >> BIT()
> > >
> > >I'll use it, but in this case, I think it doesn't simplify much the
> > >whole expression all that much. Is there perhaps a macro that
> > >constructs a continuous bitmask of N bits, perhaps additionally
> > >left-shifted by M bits?
> > >
> > >Maybe somewhere in the bitmap_* API...
> > >
> >
> > There's GENMASK(), though it takes a high bit and low bit rather than a
> > bit position and count, so it'd require a small bit of arithmetic, e.g.
> >
> >   lastbit = gpio->first_irq_bit + gpio->num_irqs - 1;
> >   ours = GENMASK(lastbit, gpio->first_irq_bit);
> >
> > or a manual shift:
> >
> >   ours = GENMASK(gpio->num_irqs - 1, 0) << gpio->first_irq_bit;
> 
> I think this can be handled with FIELD_PREP() from
> <linux/bitfield.h>? Some examples at the top of the
> header.

Thank you both!

Best regards,
Jonathan

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