[PATCH 4/4] arm64: dts: freescale: imx95-toradex-smarc: Add Cortex-M7 SER0 overlay

[Ernest Van Hoecke]

From: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>

SMARC SER0 can be assigned to Cortex-M7 firmware. Add an overlay that
reserves LPUART2 so Linux does not claim the port. On the Development
Board this removes the Linux RS485 port on SER0, while the console on
SER1 (LPUART1) remains available. Firmware must configure the UART and
its pads for the intended MCU application.

The overlay is also combined with the Toradex SMARC iMX95 Development
Board device tree to provide a ready-to-use DTB.

Signed-off-by: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
---
 arch/arm64/boot/dts/freescale/Makefile                     |  4 ++++
 .../boot/dts/freescale/imx95-toradex-smarc-ser0-mcu.dtso   | 14 ++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
index b17fd5b067de..489da1fb0012 100644
--- a/arch/arm64/boot/dts/freescale/Makefile
+++ b/arch/arm64/boot/dts/freescale/Makefile
@@ -957,7 +957,9 @@ dtb-$(CONFIG_ARCH_MXC) += imx95-aquila-clover.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-aquila-dev-uart4-mcu.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-aquila-dev.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-aquila-uart4-mcu.dtbo
+dtb-$(CONFIG_ARCH_MXC) += imx95-toradex-smarc-dev-ser0-mcu.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-toradex-smarc-dev.dtb
+dtb-$(CONFIG_ARCH_MXC) += imx95-toradex-smarc-ser0-mcu.dtbo
 dtb-$(CONFIG_ARCH_MXC) += imx95-tqma9596la-mba95xxca.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-tqma9596sa-mb-smarc-2.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-var-dart-sonata.dtb
@@ -980,6 +982,8 @@ dtb-$(CONFIG_ARCH_MXC) += imx95-verdin-wifi-zinnia.dtb
 
 imx95-aquila-dev-uart4-mcu-dtbs := imx95-aquila-dev.dtb imx95-aquila-uart4-mcu.dtbo
 
+imx95-toradex-smarc-dev-ser0-mcu-dtbs := imx95-toradex-smarc-dev.dtb imx95-toradex-smarc-ser0-mcu.dtbo
+
 imx95-verdin-wifi-dev-nau8822-btl-dtbs := imx95-verdin-wifi-dev.dtb imx95-verdin-dev-nau8822-btl.dtbo
 imx95-verdin-wifi-dev-uart4-mcu-dtbs := imx95-verdin-wifi-dev.dtb imx95-verdin-uart4-mcu.dtbo
 
diff --git a/arch/arm64/boot/dts/freescale/imx95-toradex-smarc-ser0-mcu.dtso b/arch/arm64/boot/dts/freescale/imx95-toradex-smarc-ser0-mcu.dtso
new file mode 100644
index 000000000000..cbc58f1af41d
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx95-toradex-smarc-ser0-mcu.dtso
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Copyright (c) Toradex
+ *
+ * Toradex SMARC iMX95 SER0 for Cortex-M7
+ */
+
+/dts-v1/;
+/plugin/;
+
+/* SMARC SER0 */
+&lpuart2 {
+	status = "reserved";
+};

-- 
2.43.0