[PATCH 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[PATCH 0/2] arm64: dts: mt7981/openwrt-one: UART labels and console

[bryan]

This series makes two small updates for MT7981:

- Patch 1/2: Add stable labels (uart0, uart1, uart2) in the SoC dtsi so
  that board dts files can reference them directly.
- Patch 2/2: Update the OpenWrt One board dts to define serial0 alias,
  configure chosen stdout-path, and set correct UART current-speed.

Both patches were build-tested (dtbs) and boot-tested: 
mainline Image+DTB built and loaded via U-Boot on MT7981 hardware,
with serial console output verified.

Thanks,
Bryan

---

Bryan Hinton (2):
  arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes
  arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200

 .../arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts | 13 +++++++++++++
 arch/arm64/boot/dts/mediatek/mt7981b.dtsi           |  6 +++---
 2 files changed, 16 insertions(+), 3 deletions(-)


base-commit: 1522b530ac3e2dadd75ccb351b88d3c7c4cf584e
-- 
2.51.0

[PATCH 1/2] arm64: dts: mediatek: mt7981b: add labels for UART0/1/2 nodes

[bryan]

Add stable labels (uart0, uart1, uart2) to the MT7981B SoC UART nodes so
board DTS files can reference them directly. This change is purely
cosmetic and introduces no functional differences.

Verification: Built dtbs and boot-tested mainline Image+DTB via U-Boot on
MT7981B hardware; decompiled DT shows the uart0 label present and the
serial0 alias (or absolute path) resolves to serial@11002000.

Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>
---
 arch/arm64/boot/dts/mediatek/mt7981b.dtsi | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
index 5cbea9cd411f..4ee7fb83000d 100644
--- a/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt7981b.dtsi
@@ -94,7 +94,7 @@ pwm@10048000 {
 			#pwm-cells = <2>;
 		};
 
-		serial@11002000 {
+		uart0: serial@11002000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11002000 0 0x100>;
 			interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>;
@@ -105,7 +105,7 @@ serial@11002000 {
 			status = "disabled";
 		};
 
-		serial@11003000 {
+		uart1: serial@11003000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11003000 0 0x100>;
 			interrupts = <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>;
@@ -116,7 +116,7 @@ serial@11003000 {
 			status = "disabled";
 		};
 
-		serial@11004000 {
+		uart2: serial@11004000 {
 			compatible = "mediatek,mt7981-uart", "mediatek,mt6577-uart";
 			reg = <0 0x11004000 0 0x100>;
 			interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
-- 
2.51.0

[PATCH 2/2] arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200

[bryan]

Use the new uart0 label for the console and make the speed explicit by
adding current-speed = <115200>. This keeps the DTS OS-agnostic: no
bootargs or distribution-specific properties are added.

Verification: Boot-tested with mainline Image+DTB via U-Boot on OpenWrt
One (MT7981B). Serial console active at 115200 baud, and DTB decompile
confirms serial0 alias and stdout-path set correctly.

Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>
---
 .../arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
index 4f6cbb491287..1d2c3a21019c 100644
--- a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
@@ -8,8 +8,21 @@ / {
 	compatible = "openwrt,one", "mediatek,mt7981b";
 	model = "OpenWrt One";
 
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
 	memory@40000000 {
 		reg = <0 0x40000000 0 0x40000000>;
 		device_type = "memory";
 	};
 };
+
+&uart0 {
+	status = "okay";
+	current-speed = <115200>; /* 0x1c200 */
+};
-- 
2.51.0

Re: [PATCH 2/2] arm64: dts: mediatek: mt7981b: OpenWrt One: set console UART to 115200

[Daniel Golle]

On Fri, Sep 19, 2025 at 07:06:12PM -0500, bryan@bryanhinton.com wrote:
> Use the new uart0 label for the console and make the speed explicit by
> adding current-speed = <115200>. This keeps the DTS OS-agnostic: no
> bootargs or distribution-specific properties are added.
> 
> Verification: Boot-tested with mainline Image+DTB via U-Boot on OpenWrt
> One (MT7981B). Serial console active at 115200 baud, and DTB decompile
> confirms serial0 alias and stdout-path set correctly.
> 
> Signed-off-by: Bryan Hinton <bryan@bryanhinton.com>

Reviewed-by: Daniel Golle <daniel@makrotopia.org>

See comment below
> ---
>  .../arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
> index 4f6cbb491287..1d2c3a21019c 100644
> --- a/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
> +++ b/arch/arm64/boot/dts/mediatek/mt7981b-openwrt-one.dts
> @@ -8,8 +8,21 @@ / {
>  	compatible = "openwrt,one", "mediatek,mt7981b";
>  	model = "OpenWrt One";
>  
> +	aliases {
> +		serial0 = &uart0;
> +	};
> +
> +	chosen {
> +		stdout-path = "serial0:115200n8";
> +	};
> +
>  	memory@40000000 {
>  		reg = <0 0x40000000 0 0x40000000>;
>  		device_type = "memory";
>  	};
>  };
> +
> +&uart0 {
> +	status = "okay";
> +	current-speed = <115200>; /* 0x1c200 */

The comment with the hex value should be removed. There is no need for it.

> +};
> -- 
> 2.51.0
> 
>