[Loop timeline]

Well, the easiest thing would probably be to use a TimelineMax instead of a TimelineLite because it supports the "repeat" property:

var tl = new TimelineMax({repeat:2});

...

And you can even set a repeatDelay, and/or set it to yoyo (back and forth). 

 

But to answer your question, if you're using TimelineLite, you could use an onComplete to then restart() the timeline:

var tl = new TimelineLite({onComplete:function() {
    this.restart();
});

Does that help?

Thanks for posting this response. I just used it on one of my projects.