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

[Linus Walleij]

On Thu, Dec 9, 2021 at 9:26 AM Zev Weiss <zweiss at equinix.com> 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.

Yours,
Linus Walleij