mb/google/brya: Override memory ID to 0 for nivviks and nereid P0

In the nivviks and nereid pre-proto builds, the memory straps used
don't match those generated by spd_tools. Each pre-proto build only
supports a single memory part, and each of these parts should have ID 0
(see CB:61443). Therefore, for nivviks and nereid board ID 0, hard code
the memory IDs to 0 instead of reading them from the memory strap pins.
From P1 onwards, the memory straps will be assigned based on the IDs
generated by spd_tools.

BUG=b:197479026
TEST=Build test nivviks and nereid

Signed-off-by: Reka Norman <rekanorman@google.com>
Change-Id: Ic0c6f3f22d7a94f9eed44e736308e5ac4157163d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61496
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kangheui Won <khwon@chromium.org>

src/mainboard/google/brya/variants/nereid/Makefile.inc

@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 bootblock-y += gpio.c
+
 romstage-y += gpio.c
+romstage-y += memory.c
+
 ramstage-y += gpio.c

src/mainboard/google/brya/variants/nereid/memory.c

@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/variants.h>
+#include <boardid.h>
+#include <gpio.h>
+
+int variant_memory_sku(void)
+{
+	/*
+	 * The memory straps in the P0 build don't match those generated by
+	 * spd_tools, so override the memory ID to 0.
+	 */
+	if (board_id() == 0)
+		return 0;
+
+	/*
+	 * Memory configuration board straps
+	 * GPIO_MEM_CONFIG_0	GPP_E1
+	 * GPIO_MEM_CONFIG_1	GPP_E2
+	 * GPIO_MEM_CONFIG_2	GPP_E3
+	 */
+	gpio_t spd_gpios[] = {
+		GPP_E1,
+		GPP_E2,
+		GPP_E3,
+	};
+
+	return gpio_base2_value(spd_gpios, ARRAY_SIZE(spd_gpios));
+}

src/mainboard/google/brya/variants/nivviks/Makefile.inc

@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 bootblock-y += gpio.c
+
 romstage-y += gpio.c
+romstage-y += memory.c
+
 ramstage-y += gpio.c

src/mainboard/google/brya/variants/nivviks/memory.c

@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/variants.h>
+#include <boardid.h>
+#include <gpio.h>
+
+int variant_memory_sku(void)
+{
+	/*
+	 * The memory straps in the P0 build don't match those generated by
+	 * spd_tools, so override the memory ID to 0.
+	 */
+	if (board_id() == 0)
+		return 0;
+
+	/*
+	 * Memory configuration board straps
+	 * GPIO_MEM_CONFIG_0	GPP_E1
+	 * GPIO_MEM_CONFIG_1	GPP_E2
+	 * GPIO_MEM_CONFIG_2	GPP_E3
+	 */
+	gpio_t spd_gpios[] = {
+		GPP_E1,
+		GPP_E2,
+		GPP_E3,
+	};
+
+	return gpio_base2_value(spd_gpios, ARRAY_SIZE(spd_gpios));
+}