soc/intel/meteorlake: Hook up SaGvFreq, SaGvGear upds

Hook the SaGvFreq, SaGvGear upds so that mainboard can change the
settings via devicetree. Meteor Lake supports 4 SaGv work points and it
can dynamically scale the work point based on memory bandwidth
utilization. Dynamic gearing technology allows the Memory Controller to
run at 1:1, 1:2 or 1:4 ratio of DRAM speed. The gear ratio is the ratio
of DRAM speed to Memory Controller Clock.

BUG=b:282164577
TEST=Verified the settings on google/rex using debug FSP logs.

Signed-off-by: Bora Guvendik <bora.guvendik@intel.com>
Change-Id: I37169880af4019675374594e90735b5d7d0873b8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75290
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/meteorlake/chip.h

@@ -18,6 +18,8 @@
 #include <soc/usb.h>
 #include <stdint.h>
 
+#define MAX_SAGV_POINTS 4
+
 /* Types of different SKUs */
 enum soc_intel_meteorlake_power_limits {
 	MTL_P_282_CORE,
@@ -375,6 +377,15 @@ struct soc_intel_meteorlake_config {
 	uint8_t energy_perf_pref_value;
 
 	bool disable_vmx;
+
+	/*
+	 * SAGV Frequency per point in Mhz. 0 is Auto, otherwise holds the
+	 * frequency value expressed as an integer. For example: 1867
+	 */
+	uint16_t sagv_freq_mhz[MAX_SAGV_POINTS];
+
+	/* Gear Selection for SAGV points. 0: Auto, 1: Gear 1, 2: Gear 2, 4: Gear 4 */
+	uint8_t sagv_gear[MAX_SAGV_POINTS];
 };
 
 typedef struct soc_intel_meteorlake_config config_t;

src/soc/intel/meteorlake/romstage/fsp_params.c

@@ -123,7 +123,10 @@ static void fill_fspm_igd_params(FSP_M_CONFIG *m_cfg,
 static void fill_fspm_mrc_params(FSP_M_CONFIG *m_cfg,
 		const struct soc_intel_meteorlake_config *config)
 {
+	unsigned int i;
+
 	m_cfg->SaGv = config->sagv;
+
 	if (m_cfg->SaGv) {
 		/*
 		 * Set SaGv work points after reviewing the power and performance impact
@@ -134,6 +137,11 @@ static void fill_fspm_mrc_params(FSP_M_CONFIG *m_cfg,
 			m_cfg->SaGvWpMask = config->sagv_wp_bitmap;
 		else
 			m_cfg->SaGvWpMask = SAGV_POINTS_0_1_2_3;
+
+		for  (i = 0; i < HOB_MAX_SAGV_POINTS; i++) {
+			m_cfg->SaGvFreq[i] = config->sagv_freq_mhz[i];
+			m_cfg->SaGvGear[i] = config->sagv_gear[i];
+		}
 	}
 
 	m_cfg->RMT = config->rmt;