arm64: zynqmp: Add u-boot command to boot into recovery image

To boot into the firmware recovery tool, the user currently
needs to press a button on the board while powering the
system up. To simplify this process, a U-Boot command
was added to allow booting directly into the recovery tool.

For example:
ZynqMP> zynqmp reboot <multiboot offset in hex>

Co-develop-by: Prasad Kummari <prasad.kummari@amd.com>
Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Co-develop-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20240827115529.2931334-1-prasad.kummari@amd.com
diff --git a/arch/arm/mach-zynqmp/zynqmp.c b/arch/arm/mach-zynqmp/zynqmp.c
index bf39c54..3b4d9c6 100644
--- a/arch/arm/mach-zynqmp/zynqmp.c
+++ b/arch/arm/mach-zynqmp/zynqmp.c
@@ -340,6 +340,30 @@
 	return CMD_RET_SUCCESS;
 }
 
+static int do_zynqmp_reboot(struct cmd_tbl *cmdtp, int flag,
+			    int argc, char * const argv[])
+{
+	u32 multiboot;
+	int ret;
+
+	if (argc != cmdtp->maxargs)
+		return CMD_RET_USAGE;
+
+	multiboot = hextoul(argv[2], NULL);
+
+	ret = zynqmp_mmio_write(0xFFCA0010, 0xfff, multiboot);
+	if (ret != 0) {
+		printf("Failed: mmio write\n");
+		return ret;
+	}
+
+	/* issue soft reset */
+	writel(CRL_APB_SOFT_RESET_CTRL_MASK, &crlapb_base->soft_reset);
+
+	/* never get here */
+	return CMD_RET_SUCCESS;
+}
+
 static struct cmd_tbl cmd_zynqmp_sub[] = {
 	U_BOOT_CMD_MKENT(secure, 5, 0, do_zynqmp_verify_secure, "", ""),
 	U_BOOT_CMD_MKENT(pmufw, 4, 0, do_zynqmp_pmufw, "", ""),
@@ -348,6 +372,7 @@
 	U_BOOT_CMD_MKENT(aes, 9, 0, do_zynqmp_aes, "", ""),
 	U_BOOT_CMD_MKENT(rsa, 7, 0, do_zynqmp_rsa, "", ""),
 	U_BOOT_CMD_MKENT(sha3, 5, 0, do_zynqmp_sha3, "", ""),
+	U_BOOT_CMD_MKENT(reboot, 3, 0, do_zynqmp_reboot, "", ""),
 #ifdef CONFIG_DEFINE_TCM_OCM_MMAP
 	U_BOOT_CMD_MKENT(tcminit, 3, 0, do_zynqmp_tcm_init, "", ""),
 #endif
@@ -387,6 +412,7 @@
 	"                            long at address $src. Optional key_addr\n"
 	"                            can be specified if user key needs to\n"
 	"                            be used for decryption\n"
+	"zynqmp reboot multiboot - soft reboot to multiboot offset\n"
 	"zynqmp mmio_read address - read from address\n"
 	"zynqmp mmio_write address mask value - write value after masking to\n"
 	"					address\n"