[M] Change in coreboot[main]: mb/google/rex/var/screebo: Set Baseline Power Limit

[Subrata Banik (Code Review)]

Subrata Banik has submitted this change. ( https://review.coreboot.org/c/coreboot/+/78661?usp=email )

Change subject: mb/google/rex/var/screebo: Set Baseline Power Limit
......................................................................

mb/google/rex/var/screebo: Set Baseline Power Limit

This patch allows google/rex mainboard to choose between "Performance"
(PL_PERFORMANCE) and "Baseline" (PL_BASELINE) power limits (PLs).

This is important for platform to meet balance between power and
performance.

The OEM design google/screebo selects baseline power limit to maintain
the balance performance in lower power.

BUG=b:307237761
TEST=Able to build and boot google/screebo.

w/o this patch:

screebo4es-rev1 ~ # cbmem -c -1 | grep "CPU PL"
[INFO ]  CPU PL1 = 15 Watts
[INFO ]  CPU PL2 = 57 Watts
[INFO ]  CPU PL4 = 114 Watts

w/ this patch:

screebo4es-rev1 ~ # cbmem -c -1 | grep "CPU PL"
[INFO ]  CPU PL1 = 15 Watts
[INFO ]  CPU PL2 = 40 Watts
[INFO ]  CPU PL4 = 84 Watts

Change-Id: I43debc5442ae9c01851652beba676ffc102ca27d
Signed-off-by: Subrata Banik 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78661
Tested-by: build bot (Jenkins) 
Reviewed-by: Kapil Porwal 
Reviewed-by: Eric Lai 
---
M src/mainboard/google/rex/Kconfig
M src/mainboard/google/rex/variants/baseboard/rex/ramstage.c
M src/mainboard/google/rex/variants/screebo/overridetree.cb
3 files changed, 63 insertions(+), 0 deletions(-)

Approvals:
  Eric Lai: Looks good to me, approved
  Kapil Porwal: Looks good to me, approved
  build bot (Jenkins): Verified

diff --git a/src/mainboard/google/rex/Kconfig b/src/mainboard/google/rex/Kconfig
index e781f08..c162a44 100644
--- a/src/mainboard/google/rex/Kconfig
+++ b/src/mainboard/google/rex/Kconfig
@@ -238,4 +238,17 @@
 config HAVE_SLP_S0_GATE
    def_bool n

+choice
+	prompt "Choose desired processor power limits (PLs)"
+	default PL_BASELINE if BOARD_GOOGLE_MODEL_SCREEBO
+	default PL_PERFORMANCE
+
+config PL_PERFORMANCE
+	bool "Performance: Maximum PLs for maximum performance"
+
+config PL_BASELINE
+	bool "Baseline: Baseline PLs for balanced performance at lower power"
+
+endchoice
+
 endif # BOARD_GOOGLE_REX_COMMON
diff --git a/src/mainboard/google/rex/variants/baseboard/rex/ramstage.c b/src/mainboard/google/rex/variants/baseboard/rex/ramstage.c
index d2adaae..02bdca5d 100644
--- a/src/mainboard/google/rex/variants/baseboard/rex/ramstage.c
+++ b/src/mainboard/google/rex/variants/baseboard/rex/ramstage.c
@@ -10,6 +10,7 @@
  * pl2_min (milliWatts), pl2_max (milliWatts), pl4 (milliWatts)
  * Following values are for performance config as per document #640982
  */
+#if CONFIG(PL_PERFORMANCE)
 const struct cpu_tdp_power_limits performance_efficient_limits[] = {
    {
    	.mch_id = PCI_DID_INTEL_MTL_P_ID_2,
@@ -51,6 +52,49 @@
    	.pl4_power = 64000
    },
 };
+#else
+const struct cpu_tdp_power_limits performance_efficient_limits[] = {
+	{
+		.mch_id = PCI_DID_INTEL_MTL_P_ID_2,
+		.cpu_tdp = 15,
+		.pl1_min_power = 10000,
+		.pl1_max_power = 15000,
+		.pl2_min_power = 40000,
+		.pl2_max_power = 40000,
+		.pl4_power = 84000
+	},
+	{
+		.mch_id = PCI_DID_INTEL_MTL_P_ID_5,
+		.cpu_tdp = 15,
+		.pl1_min_power = 10000,
+		.pl1_max_power = 15000,
+		.pl2_min_power = 40000,
+		.pl2_max_power = 40000,
+		.pl4_power = 84000
+	},
+};
+
+const struct cpu_tdp_power_limits power_optimized_limits[] = {
+	{
+		.mch_id = PCI_DID_INTEL_MTL_P_ID_2,
+		.cpu_tdp = 15,
+		.pl1_min_power = 10000,
+		.pl1_max_power = 15000,
+		.pl2_min_power = 40000,
+		.pl2_max_power = 40000,
+		.pl4_power = 47000
+	},
+	{
+		.mch_id = PCI_DID_INTEL_MTL_P_ID_5,
+		.cpu_tdp = 15,
+		.pl1_min_power = 10000,
+		.pl1_max_power = 15000,
+		.pl2_min_power = 40000,
+		.pl2_max_power = 40000,
+		.pl4_power = 47000
+	},
+};
+#endif

void variant_devtree_update(void)
 {
diff --git a/src/mainboard/google/rex/variants/screebo/overridetree.cb b/src/mainboard/google/rex/variants/screebo/overridetree.cb
index 06f7b9b..0d69aca 100644
--- a/src/mainboard/google/rex/variants/screebo/overridetree.cb
+++ b/src/mainboard/google/rex/variants/screebo/overridetree.cb
@@ -34,6 +34,12 @@

chip soc/intel/meteorlake

+	register "power_limits_config[MTL_P_282_242_CORE]" = "{
+		.tdp_pl1_override = 15,
+		.tdp_pl2_override = 40,
+		.tdp_pl4 = 84,
+	}"
+
    register "usb2_ports[0]" = "USB2_PORT_TYPE_C(OC1)"	# USB2_C1
    register "usb2_ports[1]" = "USB2_PORT_TYPE_C(OC0)"	# USB2_C0
    register "usb2_ports[2]" = "USB2_PORT_MID(OC2)"	# Type-A Port A1