AnsweredAssumed Answered

BF548 GPIO debounce possible?

Question asked by MarkBishop on Jun 20, 2013
Latest reply on Jul 25, 2013 by Aaronwu

I have some GPIOs that are exported to user space in /sys/class/gpio/gpioXX.

 

At certain times when the transition from a low to high state they see a signal like this:

         /

        /

   /\  /

  /  \/

/

/

 

The number inside the /value file is a 1, however, poll() and epoll() don't get triggered so my system thinks there is a 0 inside /value.  Is there a way I can debounce the GPIO input in the kernel?  Or if it is already being debounced, any idea where the debounce source code is located at?  Or maybe I need to debounce poll/epoll?  Suggestions?

 

I have found the fs/eventpoll.c and fs/select.c and have started walking through the code there to better understand how they work.

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