Re: [PATCH 24/25] riscv: add Metanoia MT2824 SoC and MT5824 EVB support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 06/11/2026 10:30, Benoît Monin wrote:
> Add the device tree for the Metanoia MT2824, a dual-core Andes
> AX45MP-based SoC, and for the MT5824 evaluation board.
> 
> The SoC device tree describes the CPUs and their L2 cache, the PLIC,
> PLICSW and PLMT, the reset controller, the reboot controller, the
> watchdog, two UARTs, the QSPI and eight SPI controllers, the DWC
> MSHC MMC controller, and the USB2 controller.
> 
> The MT5824 EVB enables the watchdog, the two UARTs, the MMC
> controller, the QSPI port with its SPI-NOR flash, the first three SPI
> controllers, and the USB controller.
> 
> Originally-by: Jun Chang <jun.chang@metanoia-comm.com>
> Signed-off-by: Benoît Monin <benoit.monin@bootlin.com>
> ---
>  arch/riscv/boot/dts/Makefile                |   1 +
>  arch/riscv/boot/dts/metanoia/Makefile       |   2 +
>  arch/riscv/boot/dts/metanoia/mt2824.dtsi    | 330 ++++++++++++++++++++++++++++
>  arch/riscv/boot/dts/metanoia/mt5824-evb.dts |  81 +++++++
>  4 files changed, 414 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/Makefile b/arch/riscv/boot/dts/Makefile
> index 69d8751fb17c..8e1e987ea089 100644
> --- a/arch/riscv/boot/dts/Makefile
> +++ b/arch/riscv/boot/dts/Makefile
> @@ -4,6 +4,7 @@ subdir-y += andes
>  subdir-y += anlogic
>  subdir-y += canaan
>  subdir-y += eswin
> +subdir-y += metanoia
>  subdir-y += microchip
>  subdir-y += renesas
>  subdir-y += sifive
> diff --git a/arch/riscv/boot/dts/metanoia/Makefile b/arch/riscv/boot/dts/metanoia/Makefile
> new file mode 100644
> index 000000000000..7a685798d5a4
> --- /dev/null
> +++ b/arch/riscv/boot/dts/metanoia/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +dtb-$(CONFIG_ARCH_METANOIA) += mt5824-evb.dtb
> diff --git a/arch/riscv/boot/dts/metanoia/mt2824.dtsi b/arch/riscv/boot/dts/metanoia/mt2824.dtsi
> new file mode 100644
> index 000000000000..5f73c6d3760b
> --- /dev/null
> +++ b/arch/riscv/boot/dts/metanoia/mt2824.dtsi
> @@ -0,0 +1,330 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (C) 2026 Metanoia Communications Inc.. All rights reserved.
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq.h>
> +
> +/ {
> +	#address-cells = <0x02>;
> +	#size-cells = <0x02>;
> +	compatible = "metanoia,mt2824";
> +
> +	cpus: cpus {
> +		#address-cells = <0x01>;
> +		#size-cells = <0x00>;
> +		timebase-frequency = <20000000>;
> +
> +		cpu0: cpu@0 {
> +			device_type = "cpu";
> +			reg = <0x00>;
> +			compatible = "andestech,ax45mp", "riscv";
> +			riscv,isa-base = "rv64i";
> +			riscv,isa-extensions = "i", "m", "a", "f", "d", "c",
> +					       "zicntr", "zicsr", "zifencei",
> +					       "zihpm", "xandespmu";
> +			mmu-type = "riscv,sv39";
> +			clock-frequency = <900000000>;
> +			i-cache-size = <0x8000>;
> +			i-cache-sets = <0x100>;
> +			i-cache-line-size = <0x40>;
> +			i-cache-block-size = <0x40>;
> +			d-cache-size = <0x8000>;
> +			d-cache-sets = <0x80>;
> +			d-cache-line-size = <0x40>;
> +			d-cache-block-size = <0x40>;
> +			next-level-cache = <&l2_cache>;
> +
> +			cpu0intc: interrupt-controller {
> +				#interrupt-cells = <0x01>;
> +				interrupt-controller;
> +				compatible = "andestech,cpu-intc", "riscv,cpu-intc";
> +			};
> +		};
> +
> +		cpu1: cpu@1 {
> +			device_type = "cpu";
> +			reg = <0x01>;
> +			compatible = "andestech,ax45mp", "riscv";
> +			riscv,isa-base = "rv64i";
> +			riscv,isa-extensions = "i", "m", "a", "f", "d", "c",
> +					       "zicntr", "zicsr", "zifencei",
> +					       "zihpm", "xandespmu";
> +			mmu-type = "riscv,sv39";
> +			clock-frequency = <900000000>;
> +			i-cache-size = <0x8000>;
> +			i-cache-sets = <0x100>;
> +			i-cache-line-size = <0x40>;
> +			i-cache-block-size = <0x40>;
> +			d-cache-size = <0x8000>;
> +			d-cache-sets = <0x80>;
> +			d-cache-line-size = <0x40>;
> +			d-cache-block-size = <0x40>;
> +			next-level-cache = <&l2_cache>;
> +
> +			cpu1intc: interrupt-controller {
> +				#interrupt-cells = <0x01>;
> +				interrupt-controller;
> +				compatible = "andestech,cpu-intc", "riscv,cpu-intc";
> +			};
> +		};
> +	};
> +
> +	clocks {
> +		ext_clk: ext-clk {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <20000000>;
> +			clock-output-names = "ext-clk";
> +		};
> +
> +		pclk_div4: platform-clock-div4 {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <225000000>;
> +			clock-output-names = "platform-clock-div4";
> +		};
> +
> +		pll_soc_out3: pll-soc-out3 {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <180000000>;
> +			clock-output-names = "pll-soc-out3";
> +		};
> +
> +		usb_otg_ahb_clk: clock-usb-otg-ahb {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <60000000>;
> +			clock-output-names = "otg";
> +		};
> +	};
> +
> +	soc: soc {
> +		#address-cells = <0x02>;
> +		#size-cells = <0x02>;
> +		compatible = "simple-bus";
> +		interrupt-parent = <&plic>;
> +		ranges;
> +
> +		usb0: usb@4000000 {
> +			compatible = "metanoia,mt2824-usb", "snps,dwc2";
> +			reg = <0x0 0x04000000 0x0 0x100000>;
> +			interrupts = <7 IRQ_TYPE_LEVEL_HIGH>;
> +			clocks = <&usb_otg_ahb_clk>;
> +			clock-names = "otg";
> +			dr_mode = "host";
> +			resets = <&rst 19>, <&rst 20>;
> +			reset-names = "dwc2", "dwc2-ecc";
> +			phys = <&usb2phy>;
> +			phy-names = "usb2-phy";
> +			hnp-disable;
> +			srp-disable;
> +			disable-over-current;
> +			status = "disabled";
> +		};
> +
> +		mmcsd: mmc@4100000 {
> +			compatible = "metanoia,mt2824-dwcmshc";
> +			clocks = <&pll_soc_out3>;
> +			clock-names = "core";
> +			reg = <0x0 0x04100000 0x0 0x00100000>;

Please follow coding style and dt-checkstyle.

Also 0x00100000 is 0x100000

Anywya, look at size of address space. 0x100000, right?

...

> +		reboot: reboot@10000004 {
> +			compatible = "metanoia,mt2824-reboot";
> +			reg = <0x0 0x10000004 0x0 0x08>;

Now look here - 0x8

> +		};
> +
> +		rst: reset-controller@1000000c {
> +			#reset-cells = <1>;

Random coding style.

> +			compatible = "metanoia,mt2824-reset";
> +			reg = <0x0 0x1000000c 0x0 0x04>;

and 0x4.

Do you see the problem?

Why do you pad some numbers?

> +		};
> +
> +		watchdog: watchdog@10090000 {
> +			compatible = "metanoia,mt2824-wdt", "andestech,ae350-wdt";
> +			reg = <0x0 0x10090000 0x0 0x10000>;
> +			clocks = <&ext_clk>;
> +			andestech,clock-source = <0>;
> +			timeout-sec = <10>;
> +			status = "disabled";

Why? It's always there, no?


> +
> +	usb2phy: usb2-phy {

Follow DTS coding style.


Best regards,
Krzysztof