Re: [PATCH 1/7] selftests: gpio: rework and simplify test implementation

From: Kent Gibson
Date: Sun Jan 03 2021 - 20:53:28 EST


On Sun, Jan 03, 2021 at 05:10:10PM +0200, Andy Shevchenko wrote:
> On Sun, Jan 3, 2021 at 4:17 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> > On Sun, Jan 03, 2021 at 12:20:26AM +0200, Andy Shevchenko wrote:
> > > On Sat, Jan 2, 2021 at 4:32 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
[snip]
>
> ...
>
> > > > + local platform=`cat $SYSFS/kernel/debug/gpio | grep "$chip:" | tr -d ',' | awk '{print $5}'`
> > >
> > > Besides useless use of cat (and tr + awk can be simplified) why are
> >
> > What do you suggest for the tr/awk simplification?
>
> You have `awk`, you can easily switch the entire pipeline to a little
> awk scriptlet.
>

Baah, the number that I'm after is in the $SYSFS/kernel/debug/gpio that I
was pulling the platform from, so I can just pull it directly from there.

No need to go hunting through the file system for the base file - the
range of GPIOs assigned to the chip is right there.

In this example it is the 508:

# e.g. gpiochip0: GPIOs 508-511, parent: platform/gpio-mockup.0, gpio-mockup-A:

So I'll use that - unless it is unreliable for some reason?

Cheers,
Kent.