Good news to write is, that Sensable shows people sourcecode for their 2.4 Linux PHANToM driver. That means, everybody can sort out, how things work and use the know-how in their 2.6 driver.
This is exactly the thing, I've done. I have a 2.6 driver based on real basis, not rtc hack and ready to submit upstream :), whoooo, except the fact, that I'll probably rewrite it to standard force feedback layer before sumbit #2, as Dmitry Torokhov suggests.
The world becomes nice.