gma broxton: Fill in port PLL configuration

PLL parameter selection is a much simplified version of what's done in
i915 on Linux. We just assume the error in the resulting clock of a
valid parameter tuple is always small enough. Trying to speak mathe-
matically, since the only calculated parameter M2 is given as a frac-
tion of 2^22, the error should stay below 2^-22.

As the PLLs are tied to specific DDI ports, they won't ever be shared
among ports and the allocation boils down to just configuring the PLL.

Change-Id: I206675506f1dbbb57d65bfdc308de1891ccbf61a
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/18423
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
3 files changed
tree: b76eeed11f3323131d984f59a0bd9f84d50811b2
  1. common/
  2. configs/
  3. .gitignore
  4. COPYING
  5. Makefile
  6. Makefile.inc
  7. TODO