mb/google/rex: Add memory init

Add memory init with placeholder to fill in required memory
configuration parameters. DQ map and Rcomp can be auto probed by
the FSP-M hence, kept it as default.

BUG=b:224325352
TEST=util/abuild/abuild -p none -t google/rex -a -c max
Able to boot till FSP-M/MRC using MTL simics.

Signed-off-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I5baa87411c28a20602eb5a7077f00664ccab3ade
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64850
Reviewed-by: Tarun Tuli <taruntuli@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 39 insertions, 0 deletions

diff --git a/src/mainboard/google/rex/variants/baseboard/include/baseboard/variants.h b/src/mainboard/google/rex/variants/baseboard/include/baseboard/variants.h
index c2dbe5401d..6fd64c9246 100644
--- a/src/mainboard/google/rex/variants/baseboard/include/baseboard/variants.h
+++ b/src/mainboard/google/rex/variants/baseboard/include/baseboard/variants.h
@@ -4,6 +4,7 @@
 #define __BASEBOARD_VARIANTS_H__
 
 #include <soc/gpio.h>
+#include <soc/meminit.h>
 #include <stdint.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
@@ -15,4 +16,9 @@ const struct pad_config *variant_gpio_table(size_t *num);
 const struct pad_config *variant_early_gpio_table(size_t *num);
 const struct pad_config *variant_romstage_gpio_table(size_t *num);
 
+const struct mb_cfg *variant_memory_params(void);
+void variant_get_spd_info(struct mem_spd *spd_info);
+int variant_memory_sku(void);
+bool variant_is_half_populated(void);
+
 #endif /*__BASEBOARD_VARIANTS_H__ */
diff --git a/src/mainboard/google/rex/variants/baseboard/rex/Makefile.inc b/src/mainboard/google/rex/variants/baseboard/rex/Makefile.inc
index 6c29346470..7d1f88652d 100644
--- a/src/mainboard/google/rex/variants/baseboard/rex/Makefile.inc
+++ b/src/mainboard/google/rex/variants/baseboard/rex/Makefile.inc
@@ -1,5 +1,6 @@
 bootblock-y += gpio.c
 
 romstage-y += gpio.c
+romstage-y += memory.c
 
 ramstage-y += gpio.c
diff --git a/src/mainboard/google/rex/variants/baseboard/rex/memory.c b/src/mainboard/google/rex/variants/baseboard/rex/memory.c
new file mode 100644
index 0000000000..0fb80e94af
--- /dev/null
+++ b/src/mainboard/google/rex/variants/baseboard/rex/memory.c
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+#include <gpio.h>
+
+static const struct mb_cfg baseboard_memcfg = {
+	.type = MEM_TYPE_LP5X,
+	/* TODO: Add Memory configuration */
+	.ect = 1, /* Enable Early Command Training */
+};
+
+const struct mb_cfg *__weak variant_memory_params(void)
+{
+	return &baseboard_memcfg;
+}
+
+int __weak variant_memory_sku(void)
+{
+	return 0;
+}
+
+bool __weak variant_is_half_populated(void)
+{
+	return 0;
+}
+
+void __weak variant_get_spd_info(struct mem_spd *spd_info)
+{
+	spd_info->topo = MEM_TOPO_MEMORY_DOWN;
+	spd_info->cbfs_index = variant_memory_sku();
+}