https://bugzilla.kernel.org/show_bug.cgi?id=54381
--- Comment #15 from Andrew Stubbs ams@codesourcery.com --- I fixed the problem now! (At least, for my own needs.)
The patch turns out to be very simple.
1. Disregard the mode setting (why does the PPLL care?)
2. Allow a little leeway in the frequency matching. I've allowed 10%, but another figure might be better.
I'll attach the patch in a moment. I'm not sure it's suitable for upstream without being configurable though?