protocol MyCollectionViewCellDelegate {
    func didLongPressCell()
}

class MyCollectionViewCell:UICollectionViewCell {

    var delegate:MyCollectionViewCellDelegate?

    func longPressAction() {
        if let del = self.delegate {
            del.didLongPressCell
        }
    }

}

class MyViewController:UIViewController, MyCollectionViewCellDelegate {

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! MyCollectionViewCell
        cell.delegate = self
        return cell
    }

    func didLongPressCell() {
        // do what you want with the event from the cell here
    }

}