Re: [PATCH 0/7] Documentation: gpio: add character device userspace API documentation

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Wed, Jan 10, 2024 at 10:16 AM Vegard Nossum <vegard.nossum@xxxxxxxxxx> wrote:
> On 10/01/2024 00:45, Kent Gibson wrote:
> > On Tue, Jan 09, 2024 at 10:00:26PM +0200, Andy Shevchenko wrote:
> >> On Tue, Jan 9, 2024 at 4:00 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> >>
> >> May we actually state in the documentation that sysfs is subject to
> >> remove at some point?
> >
> > So formally define what "deprecated" means?
> > Is that covered in the higher level documentation somewhere?
> > If so I'm more than happy to provide a reference.
>
> We have a few files that may be relevant here, that I'm aware of:
>
> 1) https://docs.kernel.org/admin-guide/sysfs-rules.html
>
> documents some general assumptions that userspace can make about the
> stability of sysfs and its files
>
> 2) https://docs.kernel.org/admin-guide/abi.html
>
> This is the public-facing, somewhat machine-readable repository of what
> is supposed to be the kernel's ABI/API, including "obsolete" and
> "removed" interfaces.
>
> 3) Documentation/ABI/README
>
> describes the process of deprecating an interface

Yes and GPIO currently is under obsolete section with also this:

"This ABI is deprecated and will be removed after 2020. It is replaced
with the GPIO character device."

https://docs.kernel.org/admin-guide/abi-obsolete.html#symbols-under-sys-class

So, proposed cleanup series should probably rely on this documentation
among other existing descriptions of sysfs GPIO.

-- 
With Best Regards,
Andy Shevchenko