add uart6/12 dts for qcs6490.

add uart6/12 dts for qcs6490.

format metadata&& add 2pin uart

add uart dtso 2 makefile.

format q6a overlay descriptions.

Author: Rjgawuie

arch/arm64/boot/dts/qcom/overlays/Makefile

@@ -7,6 +7,10 @@ dtb-$(CONFIG_ARCH_QCOM) += qcs6490-radxa-dragon-q6a-cam1-imx577.dtbo \
 	qcs6490-radxa-dragon-q6a-cam3-radxa-camera-8m-219.dtbo \
 	qcs6490-radxa-dragon-q6a-kvm.dtbo \
 	qcs6490-radxa-dragon-q6a-radxa-display-10fhd.dtbo \
+	qcs6490-radxa-dragon-q6a-uart6-flowctl.dtbo \
+	qcs6490-radxa-dragon-q6a-uart6.dtbo \
+	qcs6490-radxa-dragon-q6a-uart12-flowctl.dtbo \
+	qcs6490-radxa-dragon-q6a-uart12.dtbo \
 	qcs6490-radxa-dragon-q6a-usb-peripheral.dtbo
 
 targets += $(dtb-y)

arch/arm64/boot/dts/qcom/overlays/qcs6490-radxa-dragon-q6a-uart12-flowctl.dtso

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2025 Radxa Computer (Shenzhen) Co., Ltd.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+    metadata {
+        title = "Enable UART12 with Flow Control";
+        compatible = "radxa,dragon-q6a";
+        category = "misc";
+        exclusive = "spi12", "uart12", "i2c12";
+        description = "Enable UART12 with Flow Control. 
+On Radxa Dragon Q6A, this is pin 19(rts), 21(cts), 23(tx), 24(rx).";
+    };
+};
+
+&spi12 {
+	status = "disabled";
+};
+
+&i2c12 {
+	status = "disabled";
+};
+
+&uart12 {
+	qcom,enable-gsi-dma;
+	status = "okay";
+};

arch/arm64/boot/dts/qcom/overlays/qcs6490-radxa-dragon-q6a-uart12.dtso

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2025 Radxa Computer (Shenzhen) Co., Ltd.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+    metadata {
+        title = "Enable UART12";
+        compatible = "radxa,dragon-q6a";
+        category = "misc";
+        exclusive = "spi12", "uart12", "i2c12";
+        description = "Enable UART12. 
+On Radxa Dragon Q6A, this is pin 23(tx), 24(rx).";
+    };
+};
+
+&spi12 {
+	status = "disabled";
+};
+
+&i2c12 {
+	status = "disabled";
+};
+
+&uart12 {
+	qcom,enable-gsi-dma;
+	status = "okay";
+    pinctrl-0 = <&qup_uart12_tx>, <&qup_uart12_rx>;
+};

arch/arm64/boot/dts/qcom/overlays/qcs6490-radxa-dragon-q6a-uart6-flowctl.dtso

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2025 Radxa Computer (Shenzhen) Co., Ltd.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+    metadata {
+        title = "Enable UART6 with Flow Control";
+        compatible = "radxa,dragon-q6a";
+        category = "misc";
+        exclusive = "uart6","i2c6","spi6";
+        description = "Enable UART6 with Flow Control. 
+On Radxa Dragon Q6A, this is pin  3(cts), 5(rts),16(tx), 18(rx).";
+    };
+};
+
+&spi6 {
+	status = "disabled";
+};
+
+&i2c6 {
+	status = "disabled";
+};
+
+&uart6 {
+	qcom,enable-gsi-dma;
+	status = "okay";
+};

arch/arm64/boot/dts/qcom/overlays/qcs6490-radxa-dragon-q6a-uart6.dtso

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2025 Radxa Computer (Shenzhen) Co., Ltd.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+    metadata {
+        title = "Enable UART6";
+        compatible = "radxa,dragon-q6a";
+        category = "misc";
+        exclusive = "uart6","i2c6","spi6";
+        description = "Enable UART6. 
+On Radxa Dragon Q6A, this is pin 16(tx), 18(rx).";
+    };
+};
+
+&spi6 {
+	status = "disabled";
+};
+
+&i2c6 {
+	status = "disabled";
+};
+
+&uart6 {
+	qcom,enable-gsi-dma;
+	status = "okay";
+    pinctrl-0 = <&qup_uart6_tx>, <&qup_uart6_rx>;
+};