mb/google/dedede: Add GPIO stubs

Add stubbed out GPIO configuration and perform GPIO initialization
during bootblock and ramstage.

BUG=b:144768001
TEST=Build Test

Change-Id: I1397b6a433e5046650f64f7eb9a84c51eb0c7441
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38278
Reviewed-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/dedede/Kconfig

@@ -32,4 +32,8 @@ config UART_FOR_CONSOLE
 	int
 	default 2
 
+config VARIANT_DIR
+	string
+	default "dedede" if BOARD_GOOGLE_DEDEDE
+
 endif #BOARD_GOOGLE_BASEBOARD_DEDEDE

src/mainboard/google/dedede/Makefile.inc

@@ -4,3 +4,7 @@ ramstage-y += mainboard.c
 
 subdirs-y += variants/baseboard
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/baseboard/include
+
+VARIANT_DIR:=$(call strip_quotes,$(CONFIG_VARIANT_DIR))
+subdirs-y += variants/$(VARIANT_DIR)
+CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/$(VARIANT_DIR)/include

src/mainboard/google/dedede/bootblock.c

@@ -6,9 +6,14 @@
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
+#include <baseboard/variants.h>
 #include <bootblock_common.h>
 
 void bootblock_mainboard_init(void)
 {
-	/* TODO: Perform mainboard initialization */
+	const struct pad_config *pads;
+	size_t num;
+
+	pads = variant_early_gpio_table(&num);
+	gpio_configure_pads(pads, num);
 }

src/mainboard/google/dedede/mainboard.c

@@ -6,11 +6,16 @@
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
+#include <baseboard/variants.h>
 #include <device/device.h>
 
 static void mainboard_init(void *chip_info)
 {
-	/* TODO: Perform mainboard initialization */
+	const struct pad_config *pads;
+	size_t num;
+
+	pads = variant_gpio_table(&num);
+	gpio_configure_pads(pads, num);
 }
 
 static void mainboard_enable(struct device *dev)

src/mainboard/google/dedede/variants/baseboard/Makefile.inc

@@ -0,0 +1,5 @@
+bootblock-y += gpio.c
+
+ramstage-y += gpio.c
+
+smm-y += gpio.c

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

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2020 The coreboot project Authors.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+#include <commonlib/helpers.h>
+
+/* Pad configuration in ramstage*/
+static const struct pad_config gpio_table[] = {
+	/* ToDo: Fill gpio configuration */
+};
+
+/* Early pad configuration in bootblock */
+static const struct pad_config early_gpio_table[] = {
+	/* ToDo: Fill early gpio configuration */
+};
+
+const struct pad_config *__weak variant_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(gpio_table);
+	return gpio_table;
+}
+
+const struct pad_config *__weak variant_early_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(early_gpio_table);
+	return early_gpio_table;
+}

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

@@ -12,4 +12,10 @@
 #include <soc/gpio.h>
 #include <stdint.h>
 
+/* The next set of functions return the gpio table and fill in the number of
+ * entries for each table. */
+
+const struct pad_config *variant_gpio_table(size_t *num);
+const struct pad_config *variant_early_gpio_table(size_t *num);
+
 #endif /*__BASEBOARD_VARIANTS_H__ */

src/mainboard/google/dedede/variants/dedede/include/variant/gpio.h

@@ -0,0 +1,14 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2020 The coreboot project Authors.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef MAINBOARD_GPIO_H
+#define MAINBOARD_GPIO_H
+
+#include <baseboard/gpio.h>
+
+#endif /* MAINBOARD_GPIO_H */