the following patch was just integrated into master: commit f24262d01822bd8634e44b5aab19dafe7e04ae72 Author: Aaron Durbin adurbin@chromium.org Date: Wed Apr 10 14:59:21 2013 -0500
haswell: calibrate 24MHz clock against BCLK
On haswell ULT systems there is a 24MHz clock that continuously runs when deep package c-states are entered. The 100MHz BCLK is shut down in the lower c-states. When the package wakes back up a conversion formula needs to be applied. The 24MHz calibration is done using the internal PCODE unit.
Change-Id: I6be7702fb1de1429273724536f5af9125b98da64 Signed-off-by: Aaron Durbin adurbin@chromium.org Reviewed-on: https://gerrit.chromium.org/gerrit/48292 Tested-by: Stefan Reinauer reinauer@google.com Commit-Queue: Stefan Reinauer reinauer@google.com Reviewed-on: http://review.coreboot.org/4136 Tested-by: build bot (Jenkins) Reviewed-by: Alexandru Gagniuc mr.nuke.me@gmail.com
See http://review.coreboot.org/4136 for details.
-gerrit