mb/google/dedede: Add smihandler stub

Add stub implementation of smihandler.

BUG=b:144768001
TEST=Build test.

Change-Id: I7ab25888812bfb4578915e342b14355ccd15f5cc
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38280
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/dedede/Makefile.inc

@@ -2,6 +2,8 @@ bootblock-y += bootblock.c
 
 ramstage-y += mainboard.c
 
+smm-$(CONFIG_HAVE_SMI_HANDLER) += smihandler.c
+
 subdirs-y += variants/baseboard
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/baseboard/include
 

src/mainboard/google/dedede/smihandler.c

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2020 The coreboot project Authors.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <baseboard/variants.h>
+#include <cpu/x86/smm.h>
+#include <intelblocks/smihandler.h>
+
+void mainboard_smi_gpi_handler(const struct gpi_status *sts)
+{
+}
+
+void mainboard_smi_sleep(u8 slp_typ)
+{
+	const struct pad_config *pads;
+	size_t num;
+
+	pads = variant_sleep_gpio_table(&num);
+	gpio_configure_pads(pads, num);
+}
+
+int mainboard_smi_apmc(u8 apmc)
+{
+	return 0;
+}

src/mainboard/google/dedede/variants/baseboard/gpio.c

@@ -31,3 +31,13 @@ const struct pad_config *__weak variant_early_gpio_table(size_t *num)
 	*num = ARRAY_SIZE(early_gpio_table);
 	return early_gpio_table;
 }
+
+/* GPIO settings before entering sleep. */
+static const struct pad_config sleep_gpio_table[] = {
+};
+
+const struct pad_config *__weak variant_sleep_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(sleep_gpio_table);
+	return sleep_gpio_table;
+}

src/mainboard/google/dedede/variants/baseboard/include/baseboard/variants.h

@@ -17,5 +17,6 @@
 
 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_sleep_gpio_table(size_t *num);
 
 #endif /*__BASEBOARD_VARIANTS_H__ */