Re: [PATCH v2 05/18] gpiolib: cdev: support GPIO_GET_LINE_IOCTL and GPIOLINE_GET_VALUES_IOCTL

From: Bartosz Golaszewski
Date: Tue Aug 04 2020 - 13:47:57 EST


On Tue, Aug 4, 2020 at 1:01 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>

[snip]

>
> > Also: I just started going through the patches - nice idea with the
> > GPIO attributes, I really like it. Although I need to give it a longer
> > thought tomorrow - I'm wondering if we can maybe unify them and the
> > flags.
> >
>
> I had an earlier draft that did just that - and that is partially why
> the loop is last in wins - I was using slot 0 as the default flags.
> But the default flags cover a lot of use cases, including all of v1, and
> it was simple and cheap to provide a default - and it simplified the
> initial port of libgpiod to v2...
>

If porting libgpiod to v2 is the only concern then I wouldn't stress
about it. At the same time I'm wondering - is there any use-case where
we wouldn't need the flags attribute for at least some lines? Because
if it's always required than maybe having a default isn't that bad.

Bartosz