[PATCH 2/6] arm64: dts: freescale: imx8mp-verdin: Add Cortex-M7 UART_4 overlay

[Ernest Van Hoecke]

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

Verdin UART_4 can be assigned to Cortex-M7 firmware. Add an overlay
that marks the UART as reserved so Linux does not claim the port.

The overlay is also combined with the Verdin iMX8M Plus Development
Board device tree to provide a ready-to-use DTB for the non-WiFi SoM
variant. UART_4 carries Bluetooth on WiFi SoMs.

Signed-off-by: Ernest Van Hoecke <ernest.vanhoecke@xxxxxxxxxxx>
---
 arch/arm64/boot/dts/freescale/Makefile                     |  3 +++
 arch/arm64/boot/dts/freescale/imx8mp-verdin-uart4-mcu.dtso | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
index ca4fec7c1038..8b152903b4b1 100644
--- a/arch/arm64/boot/dts/freescale/Makefile
+++ b/arch/arm64/boot/dts/freescale/Makefile
@@ -734,6 +734,7 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dahlia-dsi-to-hdmi.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dahlia-panel-cap-touch-10inch-dsi.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dahlia.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dev-dsi-to-hdmi.dtb
+dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dev-uart4-mcu.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-dev.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-ivy.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-mallow.dtb
@@ -742,6 +743,7 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-yavia.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-nonwifi-zinnia.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-panel-cap-touch-10inch-dsi.dtbo
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-panel-cap-touch-7inch-dsi.dtbo
+dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-uart4-mcu.dtbo
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-wifi-dahlia-dsi-to-hdmi.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-wifi-dahlia-panel-cap-touch-10inch-dsi.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mp-verdin-wifi-dahlia.dtb
@@ -759,6 +761,7 @@ imx8mp-verdin-nonwifi-dahlia-dsi-to-hdmi-dtbs := imx8mp-verdin-nonwifi-dahlia.dt
 imx8mp-verdin-nonwifi-dahlia-panel-cap-touch-10inch-dsi-dtbs := imx8mp-verdin-nonwifi-dahlia.dtb \
 	imx8mp-verdin-panel-cap-touch-10inch-dsi.dtbo
 imx8mp-verdin-nonwifi-dev-dsi-to-hdmi-dtbs := imx8mp-verdin-nonwifi-dev.dtb imx8mp-verdin-dsi-to-hdmi.dtbo
+imx8mp-verdin-nonwifi-dev-uart4-mcu-dtbs := imx8mp-verdin-nonwifi-dev.dtb imx8mp-verdin-uart4-mcu.dtbo
 imx8mp-verdin-nonwifi-yavia-dsi-to-hdmi-dtbs := imx8mp-verdin-nonwifi-yavia.dtb imx8mp-verdin-dsi-to-hdmi.dtbo
 imx8mp-verdin-wifi-dahlia-dsi-to-hdmi-dtbs := imx8mp-verdin-wifi-dahlia.dtb imx8mp-verdin-dsi-to-hdmi.dtbo
 imx8mp-verdin-wifi-dahlia-panel-cap-touch-10inch-dsi-dtbs := imx8mp-verdin-wifi-dahlia.dtb \
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-verdin-uart4-mcu.dtso b/arch/arm64/boot/dts/freescale/imx8mp-verdin-uart4-mcu.dtso
new file mode 100644
index 000000000000..74d90b39faec
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx8mp-verdin-uart4-mcu.dtso
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Copyright (c) Toradex
+ *
+ * Verdin iMX8M Plus UART_4 for Cortex-M7
+ */
+
+/dts-v1/;
+/plugin/;
+
+/* Verdin UART_4 */
+&uart4 {
+	status = "reserved";
+};

-- 
2.43.0