Send Events from Kernel space to User Space
 

Dear Friends,

I am not clear of how to send the Push button(Simple Button connected through GPIO) event from Kernel to User space. I have gone through the code of how keyboard and touchscreen or input devices work. I found that input devices talks to input_core kernel driver and that inturn talks to evdev(Event Handler) which will send the event to the userspace which will handle by application.

I would like to know how evdev sends events to userspace? Does it uses signals to send the events?

Have a Good day,
Thank you,
Ankur.

This post explains X event processing very well.

You also might want to take a look at how the evtest utility works.