[PATCH 0/5] arm64: mediatek: Add initial MT6895 and Xiaomi Poco X4 GT support

[PATCH 0/5] arm64: mediatek: Add initial MT6895 and Xiaomi Poco X4 GT support

[Alexander Letuchiy]

This series adds initial support for the MediaTek MT6895 (Dimensity
8100) SoC and the Xiaomi xaga board, sold as Xiaomi Poco X4 GT, Redmi
Note 11T Pro/Pro+ and Redmi K50i. It is enough to boot to an initramfs
with a serial console.

Bootloader dependency
---------------------
This was tested with a modified LK bootloader that is not public.
The stock LK cannot boot this DT, as its Android fixups expect nodes
that are not present here.

The DT relies on the bootloader to:

 - update the /memory node
 - add all firmware carveouts to /reserved-memory
 - pass the command line from the boot image

The carveout addresses are therefore not listed in the DT, as the
bootloader allocates some of them dynamically. I can describe the
fixed ones in the DT if that is preferred.

Testing
-------
Tested on a Poco X4 GT with 8 GiB of RAM, using a minimal config and a
script in the initramfs. The results were:

 - All 8 CPUs come up and match the DT (A55 on 0-3, A78 on 4-7), and
   CPUs 1-7 can be taken offline and brought back through PSCI.
 - The redistributor is found for each CPU, and timer interrupts reach
   every CPU.
 - UART0 output works at 921600 baud, and its TX interrupt fires on the
   expected line.
 - About 7 GiB of RAM was written and verified with no errors, with the
   carveouts added by the bootloader.
 - The ramoops driver probes, and the console log survives a watchdog
   reset. The last 30 lines were clean in the final run.

UART1 is disabled and was not tested. Only a minimal config was tested
on the device, not defconfig.

dt_binding_check, dtbs_check report no issues. checkpatch reports only
the "does MAINTAINERS need updating?" warning for the new files,
which are already covered by the existing F: pattern.

Tool use
--------
The commit messages, this cover letter and the test script were
drafted with Claude Code (Claude Opus 5.5). I reviewed them
and tested the result on the device.

Based on next-20261102.

Alexander Letuchiy (5):
  dt-bindings: arm: mediatek: Add MT6895 and Xiaomi Poco X4 GT
  dt-bindings: serial: mediatek,uart: Add compatible for MT6895
  dt-bindings: watchdog: mediatek,mtk-wdt: Add compatible for MT6895
  arm64: dts: mediatek: Add MT6895 SoC
  arm64: dts: mediatek: Add Xiaomi Poco X4 GT

 .../devicetree/bindings/arm/mediatek.yaml     |   4 +
 .../bindings/serial/mediatek,uart.yaml        |   1 +
 .../bindings/watchdog/mediatek,mtk-wdt.yaml   |   1 +
 arch/arm64/boot/dts/mediatek/Makefile         |   1 +
 .../boot/dts/mediatek/mt6895-xiaomi-xaga.dts  |  46 +++++
 arch/arm64/boot/dts/mediatek/mt6895.dtsi      | 166 ++++++++++++++++++
 6 files changed, 219 insertions(+)
 create mode 100644 arch/arm64/boot/dts/mediatek/mt6895-xiaomi-xaga.dts
 create mode 100644 arch/arm64/boot/dts/mediatek/mt6895.dtsi

-- 
2.56.0

[PATCH 1/5] dt-bindings: arm: mediatek: Add MT6895 and Xiaomi Poco X4 GT

[Alexander Letuchiy]

Add the compatible for the MediaTek MT6895 (Dimensity 8100) SoC, along
with the Xiaomi xaga board based on it, which is sold as Xiaomi Poco
X4 GT, Redmi Note 11T Pro/Pro+ and Redmi K50i.

Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>
---
 Documentation/devicetree/bindings/arm/mediatek.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/mediatek.yaml b/Documentation/devicetree/bindings/arm/mediatek.yaml
index 180e6e4948e7..28180ed0e815 100644
--- a/Documentation/devicetree/bindings/arm/mediatek.yaml
+++ b/Documentation/devicetree/bindings/arm/mediatek.yaml
@@ -72,6 +72,10 @@ properties:
               - archermind,mt6797-x20-dev
               - mediatek,mt6797-evb
           - const: mediatek,mt6797
+      - items:
+          - enum:
+              - xiaomi,xaga
+          - const: mediatek,mt6895
       - items:
           - enum:
               - bananapi,bpi-r64
-- 
2.56.0

[PATCH 2/5] dt-bindings: serial: mediatek,uart: Add compatible for MT6895

[Alexander Letuchiy]

Add a compatible string for the UART of the MediaTek MT6895 (Dimensity
8100) SoC. It works with the existing driver through the
mediatek,mt6577-uart fallback.

Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>
---
 Documentation/devicetree/bindings/serial/mediatek,uart.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/serial/mediatek,uart.yaml b/Documentation/devicetree/bindings/serial/mediatek,uart.yaml
index 5bd8a8853ae0..a3969cfdea7e 100644
--- a/Documentation/devicetree/bindings/serial/mediatek,uart.yaml
+++ b/Documentation/devicetree/bindings/serial/mediatek,uart.yaml
@@ -35,6 +35,7 @@ properties:
               - mediatek,mt6795-uart
               - mediatek,mt6797-uart
               - mediatek,mt6893-uart
+              - mediatek,mt6895-uart
               - mediatek,mt7622-uart
               - mediatek,mt7623-uart
               - mediatek,mt7629-uart
-- 
2.56.0

[PATCH 3/5] dt-bindings: watchdog: mediatek,mtk-wdt: Add compatible for MT6895

[Alexander Letuchiy]

Add a compatible string for the watchdog of the MediaTek MT6895
(Dimensity 8100) SoC, which uses mediatek,mt6589-wdt as its fallback.

Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>
---
 Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
index f9b725592c27..cac7d9ae98dd 100644
--- a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
@@ -38,6 +38,7 @@ properties:
               - mediatek,mt6572-wdt
               - mediatek,mt6582-wdt
               - mediatek,mt6797-wdt
+              - mediatek,mt6895-wdt
               - mediatek,mt7622-wdt
               - mediatek,mt7623-wdt
               - mediatek,mt7629-wdt
-- 
2.56.0

Re: [PATCH 3/5] dt-bindings: watchdog: mediatek,mtk-wdt: Add compatible for MT6895

[Roman Vivchar]

Hi,

On Thursday, November 5th, 2026 at 11:07 PM, Alexander Letuchiy <asalde.le1@gmail.com> wrote:

> Add a compatible string for the watchdog of the MediaTek MT6895
> (Dimensity 8100) SoC, which uses mediatek,mt6589-wdt as its fallback.
> 
> Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>

Does mt6895 actually share the same reset layout as mt6589? Given the
generation leap between these, the former is very unlikely to use
the same resets.

Best regards,
Roman

> ---
>  Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> index f9b725592c27..cac7d9ae98dd 100644
> --- a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> @@ -38,6 +38,7 @@ properties:
>                - mediatek,mt6572-wdt
>                - mediatek,mt6582-wdt
>                - mediatek,mt6797-wdt
> +              - mediatek,mt6895-wdt
>                - mediatek,mt7622-wdt
>                - mediatek,mt7623-wdt
>                - mediatek,mt7629-wdt
> --
> 2.56.0
> 
> 
>

Re: [PATCH 3/5] dt-bindings: watchdog: mediatek,mtk-wdt: Add compatible for MT6895

[Alexander Letuchiy]

Hi Roman,

Thanks for looking.

On Thu, Nov 5, 2026 at 11:50 PM, Roman Vivchar wrote:
> Does mt6895 actually share the same reset layout as mt6589? Given the
> generation leap between these, the former is very unlikely to use
> the same resets.

The vendor kernel for this SoC binds the watchdog with the same
compatible list ("mediatek,mt6895-wdt", "mediatek,mt6589-wdt") at the
same address, and its register definitions are identical to mtk_wdt.c.

The TOPRGU reset layout is the one thing I can't confirm, as I found no
reset table for MT6895 there. This series does not use it: the DT has
no #reset-cells and no consumers. If reset lines are needed later, I
will add a dedicated mt6895_data to the driver.

I also tested the watchdog on the device: while userspace keeps
kicking it, the system stays up, and once the kicks stop the watchdog
resets the board after the timeout.

Best regards,
Alexander

[PATCH 4/5] arm64: dts: mediatek: Add MT6895 SoC

[Alexander Letuchiy]

Add initial support for the MediaTek MT6895 (Dimensity 8100) SoC, which
has four Cortex-A55 and four Cortex-A78 cores.

Describe the CPUs, PSCI, the GICv3 interrupt controller, the architected
timer, two UARTs and the watchdog. There is no clock controller driver
for this SoC yet, so both UART clocks use a fixed 26 MHz clock.

Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>
---
 arch/arm64/boot/dts/mediatek/mt6895.dtsi | 166 +++++++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 arch/arm64/boot/dts/mediatek/mt6895.dtsi

diff --git a/arch/arm64/boot/dts/mediatek/mt6895.dtsi b/arch/arm64/boot/dts/mediatek/mt6895.dtsi
new file mode 100644
index 000000000000..c80f30da7bf9
--- /dev/null
+++ b/arch/arm64/boot/dts/mediatek/mt6895.dtsi
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	compatible = "mediatek,mt6895";
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu-map {
+			cluster0 {
+				core0 {
+					cpu = <&cpu0>;
+				};
+
+				core1 {
+					cpu = <&cpu1>;
+				};
+
+				core2 {
+					cpu = <&cpu2>;
+				};
+
+				core3 {
+					cpu = <&cpu3>;
+				};
+
+				core4 {
+					cpu = <&cpu4>;
+				};
+
+				core5 {
+					cpu = <&cpu5>;
+				};
+
+				core6 {
+					cpu = <&cpu6>;
+				};
+
+				core7 {
+					cpu = <&cpu7>;
+				};
+			};
+		};
+
+		cpu0: cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a55";
+			reg = <0x0>;
+			enable-method = "psci";
+		};
+
+		cpu1: cpu@100 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a55";
+			reg = <0x100>;
+			enable-method = "psci";
+		};
+
+		cpu2: cpu@200 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a55";
+			reg = <0x200>;
+			enable-method = "psci";
+		};
+
+		cpu3: cpu@300 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a55";
+			reg = <0x300>;
+			enable-method = "psci";
+		};
+
+		cpu4: cpu@400 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a78";
+			reg = <0x400>;
+			enable-method = "psci";
+		};
+
+		cpu5: cpu@500 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a78";
+			reg = <0x500>;
+			enable-method = "psci";
+		};
+
+		cpu6: cpu@600 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a78";
+			reg = <0x600>;
+			enable-method = "psci";
+		};
+
+		cpu7: cpu@700 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a78";
+			reg = <0x700>;
+			enable-method = "psci";
+		};
+	};
+
+	clk26m: clock-26m {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <26000000>;
+		clock-output-names = "clk26m";
+	};
+
+	psci {
+		compatible = "arm,psci-1.0";
+		method = "smc";
+	};
+
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW 0>,
+			     <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW 0>,
+			     <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW 0>,
+			     <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW 0>;
+	};
+
+	soc {
+		compatible = "simple-bus";
+		ranges;
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		gic: interrupt-controller@c000000 {
+			compatible = "arm,gic-v3";
+			reg = <0 0x0c000000 0 0x40000>,
+			      <0 0x0c040000 0 0x200000>;
+			#interrupt-cells = <4>;
+			interrupt-controller;
+			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH 0>;
+		};
+
+		uart0: serial@11001000 {
+			compatible = "mediatek,mt6895-uart", "mediatek,mt6577-uart";
+			reg = <0 0x11001000 0 0x1000>;
+			interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH 0>;
+			clocks = <&clk26m>, <&clk26m>;
+			clock-names = "baud", "bus";
+			status = "disabled";
+		};
+
+		uart1: serial@11002000 {
+			compatible = "mediatek,mt6895-uart", "mediatek,mt6577-uart";
+			reg = <0 0x11002000 0 0x1000>;
+			interrupts = <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH 0>;
+			clocks = <&clk26m>, <&clk26m>;
+			clock-names = "baud", "bus";
+			status = "disabled";
+		};
+
+		watchdog: watchdog@1c007000 {
+			compatible = "mediatek,mt6895-wdt", "mediatek,mt6589-wdt";
+			reg = <0 0x1c007000 0 0x100>;
+		};
+	};
+};
-- 
2.56.0

[PATCH 5/5] arm64: dts: mediatek: Add Xiaomi Poco X4 GT

[Alexander Letuchiy]

Add a device tree for the Xiaomi xaga board, which is sold as Xiaomi
Poco X4 GT, Redmi Note 11T Pro/Pro+ and Redmi K50i. It enables a serial
console on UART0.

The DT only describes the memory that Linux itself uses, which is the
ramoops region. The bootloader updates the /memory node and adds the
firmware carveouts to /reserved-memory, so their addresses are not
hardcoded here. This DT must not be booted with a bootloader that does
not do this, as Linux would then use memory owned by the firmware.

The ramoops zone sizes place the console zone at the offset where the
bootloader expects to find it.

Signed-off-by: Alexander Letuchiy <asalde.le1@gmail.com>
---
 arch/arm64/boot/dts/mediatek/Makefile         |  1 +
 .../boot/dts/mediatek/mt6895-xiaomi-xaga.dts  | 46 +++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 arch/arm64/boot/dts/mediatek/mt6895-xiaomi-xaga.dts

diff --git a/arch/arm64/boot/dts/mediatek/Makefile b/arch/arm64/boot/dts/mediatek/Makefile
index a86fb313b1a9..d73489149ab5 100644
--- a/arch/arm64/boot/dts/mediatek/Makefile
+++ b/arch/arm64/boot/dts/mediatek/Makefile
@@ -6,6 +6,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += mt6795-evb.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt6795-sony-xperia-m5.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-evb.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-x20-dev.dtb
+dtb-$(CONFIG_ARCH_MEDIATEK) += mt6895-xiaomi-xaga.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-rfb1.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-bananapi-bpi-r64.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7981b-cudy-wr3000-v1.dtb
diff --git a/arch/arm64/boot/dts/mediatek/mt6895-xiaomi-xaga.dts b/arch/arm64/boot/dts/mediatek/mt6895-xiaomi-xaga.dts
new file mode 100644
index 000000000000..f53425c536c3
--- /dev/null
+++ b/arch/arm64/boot/dts/mediatek/mt6895-xiaomi-xaga.dts
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+/dts-v1/;
+#include "mt6895.dtsi"
+
+/ {
+	model = "Xiaomi Poco X4 GT";
+	compatible = "xiaomi,xaga", "mediatek,mt6895";
+	chassis-type = "handset";
+
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:921600n8";
+	};
+
+	memory@40000000 {
+		device_type = "memory";
+		/* The size is updated by the bootloader. */
+		reg = <0x0 0x40000000 0x2 0x0>;
+	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		/* The firmware carveouts are added by the bootloader. */
+
+		ramoops@48090000 {
+			compatible = "ramoops";
+			reg = <0 0x48090000 0 0xe0000>;
+			no-map;
+			record-size = <0x10000>;
+			console-size = <0x40000>;
+			ftrace-size = <0x10000>;
+			pmsg-size = <0x10000>;
+		};
+	};
+};
+
+&uart0 {
+	status = "okay";
+};
-- 
2.56.0