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 <jeremy.compostella@intel.com>
Change-Id: I313acf01c534d0d32620a9dedba7cf3b304ed2ee
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66917
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Bora Guvendik <bora.guvendik@intel.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/alderlake/include/soc/vr_config.h

@@ -8,6 +8,25 @@
 #include <fsp/api.h>
 
 struct vr_config {
+#if CONFIG(SOC_INTEL_RAPTORLAKE)
+	/*
+	 * When enabled, this feature makes the SoC throttle when the power
+	 * consumption exceeds the I_TRIP threshold.
+	 *
+	 * FSPs sets a by default I_TRIP threshold adapted to the current SoC
+	 * and assuming a Voltage Regulator error accuracy of 6.5%.
+	 */
+	bool enable_fast_vmode;
+
+	/*
+	 * VR Fast Vmode I_TRIP threshold.
+	 * 0-255A in 1/4 A units. Example: 400 = 100A
+
+	 * This setting overrides the default value set by FSPs when Fast VMode
+	 * is enabled.
+	 */
+	uint16_t fast_vmode_i_trip;
+#endif
 
 	/* The below settings will take effect when this is set to 1 for that domain. */
 	bool vr_config_enable;

src/soc/intel/alderlake/vr_config.c

@@ -254,6 +254,16 @@ static const struct vr_lookup vr_config_tdc_currentlimit[] = {
 	{ PCI_DID_INTEL_ADL_S_ID_12, 35,  VR_CFG_ALL_DOMAINS_TDC_CURRENT(30, 30) },
 };
 
+static void fill_vr_fast_vmode(FSP_S_CONFIG *s_cfg,
+		int domain, const struct vr_config *chip_cfg)
+{
+#if CONFIG(SOC_INTEL_RAPTORLAKE)
+	s_cfg->EnableFastVmode[domain] = chip_cfg->enable_fast_vmode;
+	if (s_cfg->EnableFastVmode[domain])
+		s_cfg->IccLimit[domain] = chip_cfg->fast_vmode_i_trip;
+#endif
+}
+
 void fill_vr_domain_config(FSP_S_CONFIG *s_cfg,
 		int domain, const struct vr_config *chip_cfg)
 {
@@ -299,6 +309,8 @@ void fill_vr_domain_config(FSP_S_CONFIG *s_cfg,
 							domain, mch_id, tdp);
 	}
 
+	fill_vr_fast_vmode(s_cfg, domain, chip_cfg);
+
 	/* Check TdcTimeWindow and TdcCurrentLimit,
 	   Set TdcEnable and Set VR TDC Input current to root mean square */
 	if (s_cfg->TdcTimeWindow[domain] != 0 && s_cfg->TdcCurrentLimit[domain] != 0) {