soc/intel/alderlake: Add provision to override Rcomp settings

Add function to allow overriding the RcompResistor and
RcompTarget UPDs from mainboard if required.

Mainboard users can pass required rcomp from memory.c file.

Refactor ddr_config structure to take out rcomp related variable
outside for all memory type to override if required.

BUG=b:182772421
TEST=Able to override the default RcompResistor and RcompTarget
values.

Change-Id: Ie8528bbf0517728534d47f9adaabfc9a2c469609
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51683
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/mainboard/intel/adlrvp/memory.c

@@ -8,18 +8,19 @@
 static const struct mb_cfg ddr4_mem_config = {
 	.type = MEM_TYPE_DDR4,
 
+	.rcomp = {
+		/* Baseboard uses only 100ohm Rcomp resistor */
+		.resistor = 100,
+
+		/* Baseboard Rcomp target values */
+		.targets = {40, 30, 33, 33, 30},
+	},
+
 	.ect = true, /* Early Command Training */
 
 	.UserBd = BOARD_TYPE_MOBILE,
 
 	.ddr_config = {
-
-		/* Baseboard uses only 100ohm Rcomp resistor */
-		.rcomp_resistor = 100,
-
-		/* Baseboard Rcomp target values */
-		.rcomp_targets = {40, 30, 33, 33, 30},
-
 		.dq_pins_interleaved = false,
 	},
 };
@@ -143,17 +144,19 @@ static const struct mb_cfg lp5_mem_config = {
 static const struct mb_cfg ddr5_mem_config = {
 	.type = MEM_TYPE_DDR5,
 
+	.rcomp = {
+		/* Baseboard uses only 100ohm Rcomp resistor */
+		.resistor = 100,
+
+		/* Baseboard Rcomp target values */
+		.targets = {50, 30, 30, 30, 27},
+	},
+
 	.ect = true, /* Early Command Training */
 
 	.UserBd = BOARD_TYPE_MOBILE,
 
 	.ddr_config = {
-		/* Baseboard uses only 100ohm Rcomp resistor */
-		.rcomp_resistor = 100,
-
-		/* Baseboard Rcomp target values */
-		.rcomp_targets = {50, 30, 30, 30, 27},
-
 		.dq_pins_interleaved = false,
 	}
 };

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

@@ -19,13 +19,6 @@ enum mem_type {
 struct mem_ddr_config {
 	/* Dqs Pins Interleaved Setting. Enable/Disable Control */
 	bool dq_pins_interleaved;
-	/*
-	 * Rcomp resistor value. This values represents the resistance in
-	 * ohms of the rcomp resistor attached to the DDR_COMP pin on the SoC.
-	 */
-	uint16_t rcomp_resistor;
-	/* Rcomp target values. */
-	uint16_t rcomp_targets[5];
 };
 
 struct lpx_dq {
@@ -64,9 +57,22 @@ struct mem_lp5x_config {
 	uint8_t ccc_config;
 };
 
+struct rcomp {
+	/*
+	 * Rcomp resistor value. This values represents the resistance in
+	 * ohms of the rcomp resistor attached to the DDR_COMP pin on the SoC.
+	 *
+	 * Note: If mainboard users don't want to override rcomp related settings
+	 * then associated rcomp UPDs will have its default value.
+	 */
+	uint16_t resistor;
+	/* Rcomp target values. */
+	uint16_t targets[5];
+};
+
 struct mb_cfg {
 	enum mem_type type;
-
+	struct rcomp rcomp;
 	union {
 		/*
 		 * DQ CPU<>DRAM map:

src/soc/intel/alderlake/meminit.c

@@ -14,6 +14,17 @@
 #define DDR5_PHYSICAL_CH_WIDTH		32
 #define DDR5_CHANNELS			CHANNEL_COUNT(DDR5_PHYSICAL_CH_WIDTH)
 
+static void set_rcomp_config(FSP_M_CONFIG *mem_cfg, const struct mb_cfg *mb_cfg)
+{
+	if (mb_cfg->rcomp.resistor != 0)
+		mem_cfg->RcompResistor = mb_cfg->rcomp.resistor;
+
+	for (size_t i = 0; i < ARRAY_SIZE(mem_cfg->RcompTarget); i++) {
+		if (mb_cfg->rcomp.targets[i] != 0)
+			mem_cfg->RcompTarget[i] = mb_cfg->rcomp.targets[i];
+	}
+}
+
 static void meminit_lp4x(FSP_M_CONFIG *mem_cfg)
 {
 	mem_cfg->DqPinsInterleaved = 0;
@@ -28,8 +39,6 @@ static void meminit_lp5x(FSP_M_CONFIG *mem_cfg, const struct mem_lp5x_config *lp
 static void meminit_ddr(FSP_M_CONFIG *mem_cfg, const struct mem_ddr_config *ddr_config)
 {
 	mem_cfg->DqPinsInterleaved = ddr_config->dq_pins_interleaved;
-	mem_cfg->RcompResistor = ddr_config->rcomp_resistor;
-	memcpy(mem_cfg->RcompTarget, ddr_config->rcomp_targets, sizeof(mem_cfg->RcompTarget));
 }
 
 static const struct soc_mem_cfg soc_mem_cfg[] = {
@@ -215,6 +224,7 @@ void memcfg_init(FSP_M_CONFIG *mem_cfg, const struct mb_cfg *mb_cfg,
 
 	mem_cfg->ECT = mb_cfg->ect;
 	mem_cfg->UserBd = mb_cfg->UserBd;
+	set_rcomp_config(mem_cfg, mb_cfg);
 
 	switch (mb_cfg->type) {
 	case MEM_TYPE_DDR4: