soc/intel/tigerlake: add common routine for DDR init

Add a common routine meminit_ddr() that calls the appropriate meminit
routine based on whether the memory type requested is LPDDR4x or DDR4.

BUG=b:161772961
TEST='emerge-volteer coreboot chromeos-bootimage' and verify that
volteer still boots. NOTE that this only tests the lpddr4 side
of the implementation. I do not have a DDR4 board to test this on.

Change-Id: Ib2039eb89211efc48d10897eb679d05f567ae5a1
Signed-off-by: Nick Vaccaro <nvaccaro@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44249
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Ravishankar Sarawadi <ravishankar.sarawadi@intel.com>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

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

@@ -21,6 +21,11 @@ enum mem_topology {
 	MIXED,		/* CH0 = MD, CH1 = SODIMM (only for DDR4). */
 };
 
+enum ddr_memtype {
+	MEMTYPE_DDR4,		/* Uses DDR4 memory */
+	MEMTYPE_LPDDR4X,	/* Uses LPDDR4x memory */
+};
+
 enum md_spd_loc {
 	/* Read SPD from pointer provided to memory location. */
 	SPD_MEMPTR,
@@ -127,9 +132,24 @@ struct mb_ddr4_cfg {
 	uint8_t ect;
 };
 
+/* DDR Memory Information - Supports DDR4 and LPDDR4x */
+struct ddr_memory_cfg {
+	enum ddr_memtype mem_type;
+	union {
+		const struct mb_ddr4_cfg *ddr4_cfg;
+		const struct lpddr4x_cfg *lpddr4_cfg;
+	};
+};
+
+/* Initialize LPDDR4x memory configurations */
 void meminit_lpddr4x(FSP_M_CONFIG *mem_cfg, const struct lpddr4x_cfg *board_cfg,
 			const struct spd_info *spd, bool half_populated);
+
 /* Initialize DDR4 memory configurations */
 void meminit_ddr4(FSP_M_CONFIG *mem_cfg, const struct mb_ddr4_cfg *board_cfg,
 			const struct spd_info *spd, const bool half_populated);
+
+/* Determine which DDR memory is used and call appropriate init routine */
+void meminit_ddr(FSP_M_CONFIG *mem_cfg, const struct ddr_memory_cfg *board_cfg,
+			const struct spd_info *info, bool half_populated);
 #endif /* _SOC_TIGERLAKE_MEMINIT_H_ */

src/soc/intel/tigerlake/meminit.c

@@ -435,3 +435,20 @@ void meminit_ddr4(FSP_M_CONFIG *mem_cfg, const struct mb_ddr4_cfg *board_cfg,
 		}
 	}
 }
+
+void meminit_ddr(FSP_M_CONFIG *mem_cfg, const struct ddr_memory_cfg *board_cfg,
+			const struct spd_info *info, bool half_populated)
+{
+	switch (board_cfg->mem_type) {
+	case MEMTYPE_DDR4:
+		meminit_ddr4(mem_cfg, board_cfg->ddr4_cfg, info,
+				half_populated);
+		break;
+	case MEMTYPE_LPDDR4X:
+		meminit_lpddr4x(mem_cfg, board_cfg->lpddr4_cfg, info,
+				half_populated);
+		break;
+	default:
+		die("Unsupported memory type = %d!\n", board_cfg->mem_type);
+	}
+}