Re: Need help with libgpiod gpiod_line_request_both_edges_events()

[Bartosz Gołaszewski <bartekgola@xxxxxxxxx>]

2018-03-06 2:05 GMT+01:00 Timur Tabi <timur@xxxxxxxxxxxxxx>:
> I'm trying to test event handling with a loopback GPIO.  I have two
> GPIOs, 37 and 38.  On my board, they are wired together.  I set 37 to
> output and 38 to input.  If I write 1 to 37, I read a 1 from 38.  Same
> thing with 0.
>
> So I'm trying to test GPIO interrupts now.  I have this code:
>
>         ret = gpiod_line_request_both_edges_events(input, NULL);
>
> This function immediately returns with -1.  While debugging it, it
> appears that the code in core.c is expecting the GPIO to be configured
> as output.  Is that correct?  If so, that doesn't make any sense.  I'm
> trying to receive an event when a GPIO transitions from 0 to 1 (or 1
> to 0) on input.
>
> I missing be missing something fundamental.
>
> --
> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
> Technologies, Inc.  Qualcomm Technologies, Inc. is a member of the
> Code Aurora Forum, a Linux Foundation Collaborative Project.

What is the error code (errno) after this function fails? Could you
share some code?

-- 
Best regards,
Bartosz Golaszewski
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