mb/google/dedede: Remove pad termination for RAM_STRAP_4

The stuffed resistor straps are weaker compared to the internal pull-up.
This can cause the GPIO to read '1' always. Remove the internal pull-up.
Also read the GPIO only on the boards where the board version is
populated.

BUG=b:154301008
TEST=Build and boot the mainboard.

Change-Id: Ib640211b9f50dfb0174a570eda1625bacbebb855
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40531
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/mainboard/google/dedede/variants/waddledee/memory.c b/src/mainboard/google/dedede/variants/waddledee/memory.c
new file mode 100644
index 000000000000..d1e8af2c5904
--- /dev/null
+++ b/src/mainboard/google/dedede/variants/waddledee/memory.c
@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <baseboard/variants.h>
+#include <baseboard/gpio.h>
+#include <ec/google/chromeec/ec.h>
+#include <gpio.h>
+
+bool variant_mem_is_half_populated(void)
+{
+	uint32_t board_ver;
+
+	/* On boards where board version is populated, ram strap is also populated */
+	if (!google_chromeec_get_board_version(&board_ver))
+		return !gpio_get(GPIO_MEM_CH_SEL);
+
+	return false;
+}