mb/google/cherry: Add NOR-Flash support

TEST=boot to romstage on MT8195 EVB

Change-Id: I356e6b1cba3c078bf99e056b290476c7179e8ccf
Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52872
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

src/mainboard/google/cherry/Kconfig

@@ -22,4 +22,10 @@ config MAINBOARD_DIR
 config MAINBOARD_PART_NUMBER
 	string
 	default "Cherry" if BOARD_GOOGLE_CHERRY
+
+# On MT8195 the SPI flash is actually using a SPI-NOR controller with its own bus.
+# The number here should be a virtual value as (SPI_BUS_NUMBER + 1).
+config BOOT_DEVICE_SPI_FLASH_BUS
+	int
+	default 7
 endif

src/mainboard/google/cherry/Makefile.inc

@@ -1,4 +1,5 @@
 bootblock-y += memlayout.ld
+bootblock-y += bootblock.c
 bootblock-y += chromeos.c
 
 verstage-y += memlayout.ld

src/mainboard/google/cherry/bootblock.c

@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <bootblock_common.h>
+#include <device/mmio.h>
+#include <soc/gpio.h>
+
+struct pad_func {
+	u8 pin_id;
+	u8 func;
+};
+
+#define PAD_FUNC(name, func) {PAD_##name##_ID, PAD_##name##_FUNC_##func}
+
+static void nor_set_gpio_pinmux(void)
+{
+	const struct pad_func *ptr = NULL;
+
+	/* GPIO 140 ~ 143 */
+	struct pad_func nor_pinmux[] = {
+		PAD_FUNC(SPIM2_CSB, SPINOR_CS),
+		PAD_FUNC(SPIM2_CLK, SPINOR_CK),
+		PAD_FUNC(SPIM2_MO, SPINOR_IO0),
+		PAD_FUNC(SPIM2_MI, SPINOR_IO1),
+	};
+
+	ptr = nor_pinmux;
+	for (size_t i = 0; i < ARRAY_SIZE(nor_pinmux); i++) {
+		gpio_set_pull((gpio_t){.id = ptr[i].pin_id},
+				GPIO_PULL_ENABLE, GPIO_PULL_UP);
+		gpio_set_mode((gpio_t){.id = ptr[i].pin_id}, ptr[i].func);
+	}
+}
+
+void bootblock_mainboard_init(void)
+{
+	nor_set_gpio_pinmux();
+}