Subject: [PATCH v3 08/11] arm64: dts: ti: k3-am62-verdin: Reserve UART_4 for Cortex-M4F

From: Vitor Soares <[email-masked]>
Date: Fri, 22 May 2026 17:11:12 +0100

From: Vitor Soares <[email-masked]>

Add a device tree overlay reserving AM62 MCU_UART0 (Verdin UART_4) for
use by the Cortex-M4F co-processor as its debug UART.

Assisted-by: Claude:claude-sonnet-4.6
Signed-off-by: Vitor Soares <[email-masked]>
---
 arch/arm64/boot/dts/ti/Makefile                     |  4 ++++
 .../boot/dts/ti/k3-am625-verdin-uart4-mcu.dtso      | 13 +++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 arch/arm64/boot/dts/ti/k3-am625-verdin-uart4-mcu.dtso

diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
index a1083c0b2502..31c9bc1d48b1 100644
--- a/arch/arm64/boot/dts/ti/Makefile
+++ b/arch/arm64/boot/dts/ti/Makefile
@@ -44,6 +44,7 @@ dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-nonwifi-zinnia.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-panel-cap-touch-10inch-dsi.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-panel-cap-touch-10inch-lvds.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-panel-cap-touch-7inch-dsi.dtbo
+dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-uart4-mcu.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-dahlia-dsi-to-hdmi.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-dahlia-panel-cap-touch-10inch-dsi.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-dahlia.dtb
@@ -230,6 +231,8 @@ k3-am625-verdin-wifi-dev-nau8822-btl-dtbs := k3-am625-verdin-wifi-dev.dtb \
 k3-am625-verdin-wifi-dev-panel-cap-touch-7inch-dsi-dtbs := \
 	k3-am625-verdin-wifi-dev.dtb \
 	k3-am625-verdin-panel-cap-touch-7inch-dsi.dtbo
+k3-am625-verdin-wifi-dev-uart4-mcu-dtbs := k3-am625-verdin-wifi-dev.dtb \
+	k3-am625-verdin-uart4-mcu.dtbo
 k3-am625-verdin-wifi-mallow-panel-cap-touch-10inch-lvds-dtbs := \
 	k3-am625-verdin-wifi-mallow.dtb \
 	k3-am625-verdin-panel-cap-touch-10inch-lvds.dtbo
@@ -337,6 +340,7 @@ dtb- += k3-am625-beagleplay-csi2-ov5640.dtb \
 	k3-am625-verdin-wifi-dev-dsi-to-lvds-panel-cap-touch-10inch.dtb \
 	k3-am625-verdin-wifi-dev-nau8822-btl.dtb \
 	k3-am625-verdin-wifi-dev-panel-cap-touch-7inch-dsi.dtb \
+	k3-am625-verdin-wifi-dev-uart4-mcu.dtb \
 	k3-am625-verdin-wifi-mallow-panel-cap-touch-10inch-lvds.dtb \
 	k3-am62-lp-sk-hdmi-audio.dtb \
 	k3-am62-lp-sk-nand.dtb \
diff --git a/arch/arm64/boot/dts/ti/k3-am625-verdin-uart4-mcu.dtso b/arch/arm64/boot/dts/ti/k3-am625-verdin-uart4-mcu.dtso
new file mode 100644
index 000000000000..e263809cdf74
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am625-verdin-uart4-mcu.dtso
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Copyright (c) Toradex
+ *
+ * Verdin AM62 Cortex-M4F debug UART
+ */
+
+/dts-v1/;
+/plugin/;
+
+&mcu_uart0 {
+	status = "reserved";
+};
-- 
2.54.0