I ported Manu Abraham’s Mantis driver from his tree (revision 3c897a20ff8b) to the latest v4l-dvb tree (revision 28f8b0ebd224). I also ported the previous remote control support as an additional patch. The Mantis driver patch for the v4l-dvb tree is available here and the additional remote control patch is available here. Since I only have Mantis VP-2033, I don’t know whether the support for other Mantis cards work. At least mine works fine.
Manu has done some big changes to the Mantis driver since the revision 3c897a20ff8b, but I could not view any channels with those changes. Until it gets fixed, I’ll stick to the revision 3c897a20ff8b.