Re: [PATCH v7] gpio: virtuser: new virtual driver

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Wed, Jun 12, 2024 at 8:38 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> On Mon, Jun 10, 2024 at 4:57 PM Andy Shevchenko
> <andy.shevchenko@xxxxxxxxx> wrote:
> > Mon, Jun 10, 2024 at 03:22:32PM +0200, Bartosz Golaszewski kirjoitti:
> > > On Wed, May 29, 2024 at 11:00 PM Andy Shevchenko
> > > <andy.shevchenko@xxxxxxxxx> wrote:
> > > > Mon, May 27, 2024 at 04:40:54PM +0200, Bartosz Golaszewski kirjoitti:

...

> > > > > +static ssize_t gpio_virtuser_sysfs_emit_value_array(char *buf,
> > > > > +                                                 unsigned long *values,
> > > > > +                                                 size_t num_values)
> > > > > +{
> > > > > +     ssize_t len = 0;
> > > > > +     size_t i;
> > > > > +
> > > > > +     for (i = 0; i < num_values; i++)
> > > > > +             len += sysfs_emit_at(buf, len, "%d",
> > > > > +                                  test_bit(i, values) ? 1 : 0);
> > > > > +     return len + sysfs_emit_at(buf, len, "\n");
> > > >
> > > > Why not use %pb?
> > >
> > > Because it outputs hex? I want to output binary, can I do it?
> >
> > But why do you need that? You can also print a list of numbers of bits that
> > set (%pbl).
> >
> > We have a few ABIs in the kernel that works nice and people are familiar with
> > (CPU sets, IRQ affinity masks, etc). Why to reinvent the wheel?
>
> If I see "11001011" as output, I can immediately convert that to pins
> in my head. If I see 0xcb, I need to use a calculator.