Re: [PATCH 1/2] gpiolib: Add for_each_gpio_suffix() helper

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Stefan,

On Wed, Aug 14, 2019 at 3:17 PM Stefan Roese <sr@xxxxxxx> wrote:
> On 14.08.19 10:48, Linus Walleij wrote:
> > On Mon, Aug 12, 2019 at 1:18 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> >> On Sat, Aug 10, 2019 at 10:27 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> >>> On Thu, Aug 8, 2019 at 3:25 PM Stefan Roese <sr@xxxxxxx> wrote:
> >>>> Add a helper macro to enable the interation over all supported GPIO
> >>>> suffixes (currently "gpios" & "gpio"). This will be used by the serial
> >>>> mctrl code to check, if a GPIO property exists before requesting it.
> >>>>
> >>>> Signed-off-by: Stefan Roese <sr@xxxxxxx>
> >>>> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> >>>> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> >>>> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> >>>> Cc: Pavel Machek <pavel@xxxxxxx>
> >>>> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> >>>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >>>
> >>> I really like this patch, it makes things so much more readable.
> >>
> >> Do we really need to spread this *-gpio" legacy support all over the kernel?
> >
> > Not really :/
> >
> > Isn't it possible to use something like gpiod_count(dev, "foo") to
> > check for any GPIOs instead?
>
> Good idea. I can rework my patch to use gpiod_count() to check if the
> GPIO exists before requesting it. This way, we're not spreading the
> legacy "-gpio" support any more.
>
> But I'm unsure, if I should change the string malloc (kasprintf) to the
> fixed length string on the stack as I've done in this patch version.

Would that work for the mctrl-gpio case?
The issue is that there exist GPIOs (found by index), but they don't match
the passed con_id.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds