Re: [PATCH 7/8] riscv: dts: openhwgroup: add CVA6 APU on Digilent Genesys 2

[Conor Dooley <conor@kernel.org>]

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On Mon, Nov 02, 2026 at 03:17:26PM +0100, marouene.boubakri@oss.nxp.com wrote:
> From: Marouene Boubakri <marouene.boubakri@oss.nxp.com>
> 
> The CVA6 APU is the FPGA SoC built around the OpenHW Group CVA6 core in
> the CVA6 repository (corev_apu/fpga, release v5.3.0). It targets the
> Digilent Genesys 2 board and provides a CLINT, a PLIC, a 16550 UART, a
> Xilinx SPI controller connected to the SD card slot and a Xilinx GPIO
> block driving the LEDs.
> 
> Describe the SoC in cva6-genesys2.dtsi, shared by the two configurations
> of the core that the FPGA platform builds, and add a board device tree
> for each of them:
> 
>   - cv64a6: rv64imafdc with the B, Zcb, Zicond and Zkn extensions,
>     Sv39, 1 GiB of DDR3
>   - cv32a6: rv32ima, Sv32, 128 MiB of DDR3
> 
> The ISA extensions follow the core configurations of CVA6 v5.3.0
> (core/include/cv64a6_imafdc_sv39_config_pkg.sv and
> cv32a6_ima_sv32_fpga_config_pkg.sv).
> 
> The platform also has a lowRISC Ethernet controller and a PULP APB
> timer. They are left out until bindings exist for them.
> 
> Signed-off-by: Marouene Boubakri <marouene.boubakri@oss.nxp.com>
> ---
>  MAINTAINERS                                   |   7 +
>  arch/riscv/boot/dts/Makefile                  |   1 +
>  arch/riscv/boot/dts/openhwgroup/Makefile      |   2 +
>  .../boot/dts/openhwgroup/cv32a6-genesys2.dts  |  29 ++++
>  .../boot/dts/openhwgroup/cv64a6-genesys2.dts  |  31 +++++
>  .../boot/dts/openhwgroup/cva6-genesys2.dtsi   | 131 ++++++++++++++++++
>  6 files changed, 201 insertions(+)
>  create mode 100644 arch/riscv/boot/dts/openhwgroup/Makefile
>  create mode 100644 arch/riscv/boot/dts/openhwgroup/cv32a6-genesys2.dts
>  create mode 100644 arch/riscv/boot/dts/openhwgroup/cv64a6-genesys2.dts
>  create mode 100644 arch/riscv/boot/dts/openhwgroup/cva6-genesys2.dtsi
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 782389bd5c..17865074a2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -23566,6 +23566,13 @@ T:	git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/
>  F:	arch/riscv/boot/dts/canaan/
>  F:	arch/riscv/boot/dts/sifive/
>  
> +RISC-V OPENHW GROUP SoC SUPPORT
> +M:	Marouene Boubakri <marouene.boubakri@oss.nxp.com>
> +L:	linux-riscv@lists.infradead.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/riscv/openhwgroup.yaml
> +F:	arch/riscv/boot/dts/openhwgroup/

There's no git tree here, are you expecting me to apply the patches for
your platform?

> +
>  RISC-V PMU DRIVERS
>  M:	Atish Patra <atish.patra@linux.dev>
>  R:	Anup Patel <anup@brainfault.org>
> diff --git a/arch/riscv/boot/dts/Makefile b/arch/riscv/boot/dts/Makefile
> index 69d8751fb1..305a93ad6f 100644
> --- a/arch/riscv/boot/dts/Makefile
> +++ b/arch/riscv/boot/dts/Makefile
> @@ -5,6 +5,7 @@ subdir-y += anlogic
>  subdir-y += canaan
>  subdir-y += eswin
>  subdir-y += microchip
> +subdir-y += openhwgroup
>  subdir-y += renesas
>  subdir-y += sifive
>  subdir-y += sophgo
> diff --git a/arch/riscv/boot/dts/openhwgroup/Makefile b/arch/riscv/boot/dts/openhwgroup/Makefile
> new file mode 100644
> index 0000000000..a75a5863b7
> --- /dev/null
> +++ b/arch/riscv/boot/dts/openhwgroup/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +dtb-$(CONFIG_ARCH_OPENHWGROUP) += cv32a6-genesys2.dtb cv64a6-genesys2.dtb
> diff --git a/arch/riscv/boot/dts/openhwgroup/cv32a6-genesys2.dts b/arch/riscv/boot/dts/openhwgroup/cv32a6-genesys2.dts
> new file mode 100644
> index 0000000000..83d0286171
> --- /dev/null
> +++ b/arch/riscv/boot/dts/openhwgroup/cv32a6-genesys2.dts
> @@ -0,0 +1,29 @@
> +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> +/*
> + * Copyright 2026 NXP
> + *
> + * OpenHW Group CVA6 APU, 32-bit core (cv32a6), on the Digilent Genesys 2.
> + */
> +
> +/dts-v1/;
> +
> +#include "cva6-genesys2.dtsi"
> +
> +/ {
> +	model = "OpenHW Group CVA6 cv32a6 on Digilent Genesys 2";
> +	compatible = "openhwgroup,cv32a6-genesys2", "openhwgroup,cva6-apu";
> +
> +	memory@80000000 {
> +		device_type = "memory";
> +		/* 128 MiB of DDR3, as configured for this core by the FPGA build */
> +		reg = <0x0 0x80000000 0x0 0x8000000>;
> +	};
> +};
> +
> +&cpu0 {
> +	compatible = "openhwgroup,cv32a6", "riscv";
> +	riscv,isa-base = "rv32i";
> +	riscv,isa-extensions = "i", "m", "a", "zicntr", "zicsr", "zifencei",
> +			       "zihpm";
> +	mmu-type = "riscv,sv32";
> +};
> diff --git a/arch/riscv/boot/dts/openhwgroup/cv64a6-genesys2.dts b/arch/riscv/boot/dts/openhwgroup/cv64a6-genesys2.dts
> new file mode 100644
> index 0000000000..8fe653b35c
> --- /dev/null
> +++ b/arch/riscv/boot/dts/openhwgroup/cv64a6-genesys2.dts
> @@ -0,0 +1,31 @@
> +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> +/*
> + * Copyright 2026 NXP
> + *
> + * OpenHW Group CVA6 APU, 64-bit core (cv64a6), on the Digilent Genesys 2.
> + */
> +
> +/dts-v1/;
> +
> +#include "cva6-genesys2.dtsi"
> +
> +/ {
> +	model = "OpenHW Group CVA6 cv64a6 on Digilent Genesys 2";
> +	compatible = "openhwgroup,cv64a6-genesys2", "openhwgroup,cva6-apu";

As I mentioned, these need to change.

> +
> +	memory@80000000 {
> +		device_type = "memory";
> +		/* 1 GiB of DDR3, as configured for this core by the FPGA build */
> +		reg = <0x0 0x80000000 0x0 0x40000000>;
> +	};
> +};
> +
> +&cpu0 {
> +	compatible = "openhwgroup,cv64a6", "riscv";
> +	riscv,isa-base = "rv64i";
> +	riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "b", "zba",
> +			       "zbb", "zbc", "zbkb", "zbkc", "zbkx", "zbs",
> +			       "zca", "zcb", "zcd", "zicntr", "zicond", "zicsr",
> +			       "zifencei", "zihpm", "zknd", "zkne", "zknh";
> +	mmu-type = "riscv,sv39";
> +};
> diff --git a/arch/riscv/boot/dts/openhwgroup/cva6-genesys2.dtsi b/arch/riscv/boot/dts/openhwgroup/cva6-genesys2.dtsi
> new file mode 100644
> index 0000000000..95978274a7
> --- /dev/null
> +++ b/arch/riscv/boot/dts/openhwgroup/cva6-genesys2.dtsi
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> +/*
> + * Copyright 2026 NXP
> + *
> + * OpenHW Group CVA6 APU on the Digilent Genesys 2 FPGA board.
> + *
> + * The SoC description is shared between the 32-bit (cv32a6) and the
> + * 64-bit (cv64a6) configurations of the CVA6 core. The core specific
> + * properties and the memory size are set in the board .dts files.
> + */
> +
> +/ {
> +	#address-cells = <2>;
> +	#size-cells = <2>;
> +
> +	aliases {
> +		serial0 = &uart0;
> +	};
> +
> +	chosen {
> +		stdout-path = "serial0:115200n8";
> +	};

As I understand it, these should always be at the board level, but given
this is a pure FPGA design there's gonna be some oddness and I think
that's okay.


> +
> +	cpus {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		/* The CLINT mtime counter runs at half the core clock */
> +		timebase-frequency = <25000000>;
> +
> +		cpu0: cpu@0 {
> +			device_type = "cpu";
> +			reg = <0>;
> +			clock-frequency = <50000000>;
> +			tlb-split;
> +
> +			cpu0_intc: interrupt-controller {
> +				#interrupt-cells = <1>;
> +				interrupt-controller;
> +				compatible = "riscv,cpu-intc";
> +			};
> +		};
> +	};
> +
> +	/* Peripheral clock, the same as the core clock */

Sounds like you're then missing a clocks property in your cpu?

> +	clk50: clock-50mhz {
> +		compatible = "fixed-clock";
> +		#clock-cells = <0>;
> +		clock-frequency = <50000000>;
> +		clock-output-names = "clk50";
> +	};

Is this genuinely a fixed clock, or an output of a clocking-wizard
instance (or similar)?

Cheers,
Conor.

> +
> +	leds {
> +		compatible = "gpio-leds";
> +
> +		led-0 {
> +			gpios = <&gpio0 1 0>;
> +			linux,default-trigger = "heartbeat";
> +		};
> +	};
> +
> +	soc {
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		compatible = "simple-bus";
> +		ranges;
> +
> +		clint: clint@2000000 {
> +			compatible = "openhwgroup,cva6-clint", "sifive,clint0";
> +			reg = <0x0 0x2000000 0x0 0xc0000>;
> +			interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
> +		};
> +
> +		plic: interrupt-controller@c000000 {
> +			compatible = "openhwgroup,cva6-plic", "sifive,plic-1.0.0";
> +			reg = <0x0 0xc000000 0x0 0x4000000>;
> +			#address-cells = <0>;
> +			#interrupt-cells = <1>;
> +			interrupt-controller;
> +			interrupts-extended = <&cpu0_intc 11>, <&cpu0_intc 9>;
> +			riscv,ndev = <30>;
> +		};
> +
> +		uart0: serial@10000000 {
> +			compatible = "ns16550a";
> +			reg = <0x0 0x10000000 0x0 0x1000>;
> +			clock-frequency = <50000000>;
> +			interrupt-parent = <&plic>;
> +			interrupts = <1>;
> +			/* Registers are 32-bit wide and 32-bit aligned */
> +			reg-shift = <2>;
> +			reg-io-width = <4>;
> +		};
> +
> +		spi0: spi@20000000 {
> +			compatible = "xlnx,xps-spi-2.00.a";
> +			reg = <0x0 0x20000000 0x0 0x1000>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			interrupt-parent = <&plic>;
> +			interrupts = <2>;
> +			xlnx,num-ss-bits = <1>;
> +			xlnx,num-transfer-bits = <8>;
> +
> +			mmc@0 {
> +				compatible = "mmc-spi-slot";
> +				reg = <0>;
> +				spi-max-frequency = <12500000>;
> +				voltage-ranges = <3300 3300>;
> +				disable-wp;
> +			};
> +		};
> +
> +		gpio0: gpio@40000000 {
> +			compatible = "xlnx,xps-gpio-1.00.a";
> +			reg = <0x0 0x40000000 0x0 0x10000>;
> +			clocks = <&clk50>;
> +			#gpio-cells = <2>;
> +			gpio-controller;
> +			xlnx,all-inputs = <0>;
> +			xlnx,all-inputs-2 = <0>;
> +			xlnx,dout-default = <0>;
> +			xlnx,dout-default-2 = <0>;
> +			xlnx,gpio-width = <8>;
> +			xlnx,gpio2-width = <8>;
> +			xlnx,interrupt-present = <0>;
> +			xlnx,is-dual = <1>;
> +			xlnx,tri-default = <0xffffffff>;
> +			xlnx,tri-default-2 = <0xffffffff>;
> +		};
> +	};
> +};
> -- 
> 2.43.0
> 

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