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diff --git a/arch/arm64/boot/dts/marvell/ac5x-rd-carrier.dtsi b/arch/arm64/boot/dts/marvell/ac5x-rd-carrier.dtsi
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+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (C) 2023 Marvell International Ltd.
+ *
+ * Device tree for the AC5X RD Type 7 Com Express carrier board,
+ * This specific board in external mode (see below) only maintains
+ * a PCIe link with the COM Express CPU module, which does not
+ * require any special DTS definitions.
+ *
+ * AC5X RD can either work as you would expect, as a complete standalone
+ * box using the internal CPU, or you can move the switch on the back of
+ * the box to "external" mode, and connect via an external cable a kit
+ * which would allow it to use an external CPU COM Express module,
+ * mounted on top of an interposer kit.
+ *
+ * So in this case, once the switch is set to external mode as explained above,
+ * the AC5X RD becomes part of the carrier solution.
+ * This is a development/reference solution, not a full commercial solution,
+ * hence it was designed with the flexibility to be configured in different
+ * modes of operation.
+ *
+ * When the board boots in the external CPU mode, the internal CPU is disabled,
+ * and only the switch portion of the SOC acts as a PCIe end-point, Hence there
+ * is no need to describe this internal (disabled CPU) in the device tree.
+ *
+ * There is no CPU booting in this mode on the carrier,
+ * only on the COM Express CPU module.
+ */
+
+/ {
+	model = "Marvell Armada AC5X RD COM EXPRESS type 7 carrier board";
+	compatible = "marvell,rd-ac5x-carrier";
+
+};