[coreboot-gerrit] Change in ...coreboot[master]: soc/intel/cannonlake: fix use of legacy 8254 timer

[Matt DeVillier (Code Review)]

Hello Aaron Durbin, Subrata Banik, Jeremy Soller, build bot (Jenkins), Nico Huber, Furquan Shaikh,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/33512

to look at the new patch set (#8).

Change subject: soc/intel/cannonlake: fix use of legacy 8254 timer
......................................................................

soc/intel/cannonlake: fix use of legacy 8254 timer

FSP sets the use of the 8254 timer via the Enable8254ClockGating
UPD, which defaults to enabled, overriding what is set by coreboot.
Per the FSP integration guide, this UPD needs to be disabled when
a legacy OS is booted (ie, when SeaBIOS is used as the payload).

Add a Kconfig option to set the UPD properly based on payload
selection, and remove the existing coreboot code in lpc.c since
it is either ineffective or being overridden by FSP.

Test: build/boot out-of-tree WHL board with both SeaBIOS and
Tianocore, ensure 8254 timer usage set correctly for each.

Signed-off-by: Matt DeVillier 
Change-Id: I0e888bf754cb72093f14fc02f39bddcd6d288203
---
M src/soc/intel/cannonlake/Kconfig
M src/soc/intel/cannonlake/chip.h
M src/soc/intel/cannonlake/fsp_params.c
M src/soc/intel/cannonlake/lpc.c
4 files changed, 12 insertions(+), 13 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/12/33512/8