You'll always need *something* the poll the input device
. However you implement that is up to you, though. If you're okay with reacting to the barest random brushes, you can simply poll it and react to the first thing that comes up (random Google link that is completely random and I haven't actually read:
https://www.linuxjournal.com/article/6429). Just keep in mind that "one touch == *multiple* evdev events" with a touchscreen, it's less straightforward than a keyboard where you basically only get keydown/keyup/keyrep & sync events.
But if you need to react to only some *specific* things, you'll either have to decode it yourself (it's actually fairly straightforward, we've had people doing it in shell over in Kobo-land), or rely on something that does it for you (f.g., evtest).