ARM64: zynqmp: Force certain bootmode for SPL

ZynqMP provides an option to overwrite bootmode setting which
can change SPL behavior.
For example: boot SPL via JTAG and then SPL loads images from SD.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv8/zynqmp/Kconfig b/arch/arm/cpu/armv8/zynqmp/Kconfig
index e703991..1eedb39 100644
--- a/arch/arm/cpu/armv8/zynqmp/Kconfig
+++ b/arch/arm/cpu/armv8/zynqmp/Kconfig
@@ -47,5 +47,53 @@
 config SYS_MALLOC_F_LEN
 	default 0x600
 
+config SPL_ZYNQMP_ALT_BOOTMODE_ENABLED
+	bool "Overwrite SPL bootmode"
+	depends on SPL
+	help
+	  Overwrite bootmode selected via boot mode pins to tell SPL what should
+	  be the next boot device.
+
+config SPL_ZYNQMP_ALT_BOOTMODE
+	hex
+	default 0x0 if JTAG_MODE
+	default 0x1 if QSPI_MODE_24BIT
+	default 0x2 if QSPI_MODE_32BIT
+	default 0x3 if SD_MODE
+	default 0x4 if NAND_MODE
+	default 0x5 if SD_MODE1
+	default 0x6 if EMMC_MODE
+	default 0x7 if USB_MODE
+
+choice
+	prompt "Boot mode"
+	depends on ZYNQMP_ALT_BOOTMODE_ENABLED
+	default JTAG
+
+config JTAG_MODE
+	bool "JTAG_MODE"
+
+config QSPI_MODE_24BIT
+	bool "QSPI_MODE_24BIT"
+
+config QSPI_MODE_32BIT
+	bool "QSPI_MODE_32BIT"
+
+config SD_MODE
+	bool "SD_MODE"
+
+config SD_MODE1
+	bool "SD_MODE1"
+
+config NAND_MODE
+	bool "NAND_MODE"
+
+config EMMC_MODE
+	bool "EMMC_MODE"
+
+config USB_MODE
+	bool "USB"
+
+endchoice
 
 endif
diff --git a/arch/arm/cpu/armv8/zynqmp/spl.c b/arch/arm/cpu/armv8/zynqmp/spl.c
index 867d2b2..4b6fdc2 100644
--- a/arch/arm/cpu/armv8/zynqmp/spl.c
+++ b/arch/arm/cpu/armv8/zynqmp/spl.c
@@ -48,6 +48,13 @@
 	u32 reg = 0;
 	u8 bootmode;
 
+#if defined(CONFIG_SPL_ZYNQMP_ALT_BOOTMODE_ENABLED)
+	/* Change default boot mode at run-time */
+	writel(BOOT_MODE_USE_ALT |
+	       CONFIG_SPL_ZYNQMP_ALT_BOOTMODE << BOOT_MODE_ALT_SHIFT,
+	       &crlapb_base->boot_mode);
+#endif
+
 	reg = readl(&crlapb_base->boot_mode);
 	bootmode = reg & BOOT_MODES_MASK;