Re: [PATCH 2/2] gpio: sch: Add interrupt support

Andy Shevchenko
2019-04-26T17:20:19Z

On Fri, Apr 26, 2019 at 7:05 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>
> On 26.04.19 16:42, Enrico Weigelt, metux IT consult wrote:
> > On 26.04.19 15:36, Jan Kiszka wrote:
> >
> >> At the same time, there are no real alternatives - to my> knowledge - for the value it brings (various bindings) to simply
> > switch> the engine.
> > Which value exactly does that collection of crude wrappers and broken
> > attempts to buypass the kernel (driving gpios via /dev/mem *facepalm*)
> > provide ?
>
> Leaving that blunt hack aside:
>
> import mraa
>
> pin = mraa.Gpio(13)
> pin.dir(mraa.DIR_OUT)
> pin.write(1)
>
> And the same goes for nodejs, java and c++.
>
> Moreover, this allows you to abstract away where "Pin 13" actually came from on
> that board if the kernel changes (BSP -> upstream...) or the extension board or
> ...

The problem here is opaque number. This has to be chip + *relative* pin number/
See this:
https://stackoverflow.com/questions/55532410/how-do-linux-gpio-numbers-get-their-values/55579640#55579640

--
With Best Regards,
Andy Shevchenko