[M] Change in coreboot[master]: soc/intel/alderlake: Support Raptor Lake VR Fast VMODE

[Jérémy Compostella (Code Review)]

Attention is currently required from: Anil Kumar K, Cliff Huang, Jérémy Compostella, Selma Bensaid, Paul Menzel, Tim Wawrzynczak.

Hello Zhixing Ma, Bora Guvendik, build bot (Jenkins), Anil Kumar K, Cliff Huang, Selma Bensaid, Tim Wawrzynczak,

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

https://review.coreboot.org/c/coreboot/+/66917

to look at the new patch set (#7).

Change subject: soc/intel/alderlake: Support Raptor Lake VR Fast VMODE
......................................................................

soc/intel/alderlake: Support Raptor Lake VR Fast VMODE

RaptorLake introduces the support of the Voltage Regulator Fast Vmode
feature. When enabled, it makes the SoC throttle when the current
exceeds the I_TRIP threshold. This threshold should be between
Iccmax.app and Iccmax and take into account the specification of the
Voltage Regulator of the system.

This change provides a mean to:
1. Enable the feature via the `vr_config->enable_fast_vmode'. If no
   I_TRIP value is supplied FSPs picks an adapted I_TRIP value for
   the current SoC assuming a Voltage Regulator error accuracy of
   6.5%.
2. Set the I_TRIP threshold via the `vr_config->fast_vmode_i_trip'
   field.

These new fields are considered independent from the other `vr_config'
fields so that the board configuration does not have to unnecessarily
supply other VR settings to enable Fast VMode.

Information about the Fast VMode Feature can be found in the following
Intel documents:
- 627270 ADL and RPL Processor Family Core and Uncore BIOS
  Specification
- 724220 RaptorLake Platform Fast V-Mode
- 686872 RaptorLake Lake U P H Platform

BUG=b:243120082
BRANCH=firmware-brya-14505.B
TEST=Read I_TRIP from the Pcode and verify consistency with
     a few `enable_fast_vmode' and `fast_vmode_i_trip' settings.

Signed-off-by: Jeremy Compostella 
Change-Id: I313acf01c534d0d32620a9dedba7cf3b304ed2ee
---
M src/soc/intel/alderlake/include/soc/vr_config.h
M src/soc/intel/alderlake/vr_config.c
2 files changed, 71 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/17/66917/7