Re: [RFC PATCH] gpio: uapi: v2 proposal

From: Bartosz Golaszewski
Date: Thu Jun 04 2020 - 08:06:49 EST


År., 27 maj 2020 o 07:58 Linus Walleij <linus.walleij@xxxxxxxxxx> napisaÅ(a):
>
> On Mon, May 25, 2020 at 4:19 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
> > > > +struct gpioline_config {
> > > > + __u8 default_values[GPIOLINES_MAX];
> > >
> > > So 32 bytes
> > >
> >
> > Actually that one is 64 bytes, which is the same as v1, i.e. GPIOLINES_MAX
> > is the same as GPIOHANDLES_MAX - just renamed.
> >
> > On the subject of values, is there any reason to use a byte for each line
> > rather value than a bit?
>
> Not really, other than making things simple for userspace.
>

I'm in favor of using bits here. I think we can rely on libgpiod to
make things simple for user-space, the kernel interface can be as
brief as possible.

Bart