Re: [PATCH 4/5] riscv: dts: add initial canmv-k230 and k230-evb dts

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 03/03/2024 14:26, Yangyu Chen wrote:
> Add initial dts for CanMV-K230 and K230-EVB powered by Canaan Kendryte
> K230 SoC [1].
> 
> Some key considerations:
> - Only enable BigCore which is 1.6GHz RV64GCBV
> 
> Since is there cache coherence between two cores remains a mystery since
> they have a dedicated L2 Cache. And the factory SDK uses it for other OS
> by default.
> 
> Meanwhile, although docs from Canaan said 1.6GHz Core with Vector is
> CPU1, the csr.mhartid of this core is 0.
> 
> - Support for "zba" "zbb" "zbc" "zbs" are tested by hand
> 
> The user manual of C908 from T-Head does not document it specifically.
> It just said it supports B extension V1.0-rc1. [2]
> 
> - Support for "zicbom" is tested by hand
> 
> Have tested with some out-of-tree drivers that need DMA and they do not
> come to the dts currently.
> 
> - Cache parameters are inferred from T-Head docs [2] and Cannan docs [1]
> 
> L1i: 32KB, VIPT 4-Way set-associative, 64B Cacheline
> L1d: 32KB, VIPT 4-Way set-associative, 64B Cacheline
> L2: 256KB, PIPI 16-way set-associative, 64B Cacheline
> 
> The numbers of cache sets are calculated from these parameters.
> 
> - MMU only supports Sv39
> 
> Since T-Head docs [2] says C908 should support sv48. However, it will fail
> during the kernel probe. I also tested it by hand on M-Mode software,
> writing sv48 to satp.mode will not trap but will leave the csr unchanged.
> 
> [1] https://developer.canaan-creative.com/k230/dev/zh/00_hardware/K230_datasheet.html#chapter-1-introduction
> [2] https://occ-intl-prod.oss-ap-southeast-1.aliyuncs.com/resource//1699268369347/XuanTie-C908-UserManual.pdf
> 
> Signed-off-by: Yangyu Chen <cyy@cyyself.name>
> ---
>  arch/riscv/boot/dts/canaan/Makefile       |   2 +
>  arch/riscv/boot/dts/canaan/canmv-k230.dts |  23 ++++
>  arch/riscv/boot/dts/canaan/k230-evb.dts   |  23 ++++
>  arch/riscv/boot/dts/canaan/k230.dtsi      | 146 ++++++++++++++++++++++
>  4 files changed, 194 insertions(+)
>  create mode 100644 arch/riscv/boot/dts/canaan/canmv-k230.dts
>  create mode 100644 arch/riscv/boot/dts/canaan/k230-evb.dts
>  create mode 100644 arch/riscv/boot/dts/canaan/k230.dtsi
> 
> diff --git a/arch/riscv/boot/dts/canaan/Makefile b/arch/riscv/boot/dts/canaan/Makefile
> index 987d1f0c41f0..b4a0ec668f9a 100644
> --- a/arch/riscv/boot/dts/canaan/Makefile
> +++ b/arch/riscv/boot/dts/canaan/Makefile
> @@ -5,3 +5,5 @@ dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_bit.dtb
>  dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_dock.dtb
>  dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_go.dtb
>  dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maixduino.dtb
> +dtb-$(CONFIG_ARCH_CANAAN) += k230-evb.dtb
> +dtb-$(CONFIG_ARCH_CANAAN) += canmv-k230.dtb
> \ No newline at end of file

Please fix patch errors.

> diff --git a/arch/riscv/boot/dts/canaan/canmv-k230.dts b/arch/riscv/boot/dts/canaan/canmv-k230.dts
> new file mode 100644
> index 000000000000..09777616d30e


...

> +&uart0 {
> +	status = "okay";
> +};
> diff --git a/arch/riscv/boot/dts/canaan/k230.dtsi b/arch/riscv/boot/dts/canaan/k230.dtsi
> new file mode 100644
> index 000000000000..4317bda38142
> --- /dev/null
> +++ b/arch/riscv/boot/dts/canaan/k230.dtsi
> @@ -0,0 +1,146 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2024 Yangyu Chen <cyy@cyyself.name>
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq.h>
> +
> +/dts-v1/;
> +/ {
> +	#address-cells = <2>;
> +	#size-cells = <2>;
> +	compatible = "canaan,kendryte-k230";
> +
> +	aliases {
> +		serial0 = &uart0;
> +	};
> +
> +	cpus {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		timebase-frequency = <27000000>;
> +
> +		cpu@0 {
> +			compatible = "thead,c908", "riscv";
> +			device_type = "cpu";
> +			reg = <0>;
> +			riscv,isa = "rv64imafdcv_zba_zbb_zbc_zbs_zicbom_svpbmt";
> +			riscv,isa-base = "rv64i";
> +			riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "v", "zba", "zbb",
> +					       "zbc", "zbs", "zicbom", "zicntr", "zicsr",
> +					       "zifencei", "zihpm", "svpbmt";
> +			riscv,cbom-block-size = <64>;
> +			d-cache-block-size = <64>;
> +			d-cache-sets = <128>;
> +			d-cache-size = <32768>;
> +			i-cache-block-size = <64>;
> +			i-cache-sets = <128>;
> +			i-cache-size = <32768>;
> +			next-level-cache = <&l2_cache>;
> +			mmu-type = "riscv,sv39";
> +
> +			cpu0_intc: interrupt-controller {
> +				compatible = "riscv,cpu-intc";
> +				interrupt-controller;
> +				#interrupt-cells = <1>;
> +			};
> +		};
> +
> +		l2_cache: l2-cache {
> +			compatible = "cache";
> +			cache-block-size = <64>;
> +			cache-level = <2>;
> +			cache-size = <262144>;
> +			cache-sets = <256>;
> +			cache-unified;
> +		};
> +	};
> +
> +	soc {
> +		compatible = "simple-bus";
> +		interrupt-parent = <&plic>;
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		dma-noncoherent;
> +		ranges;
> +
> +		plic: interrupt-controller@f00000000 {
> +			compatible = "thead,c900-plic";
> +			reg = <0xf 0x00000000 0x0 0x04000000>;
> +			interrupts-extended = <&cpu0_intc 11>, <&cpu0_intc 9>;
> +			interrupt-controller;
> +			reg-names = "control";
> +			#address-cells = <0>;
> +			#interrupt-cells = <2>;
> +			riscv,ndev = <208>;
> +		};
> +
> +		clint: timer@f04000000 {
> +			compatible = "thead,c900-clint";
> +			reg = <0xf 0x04000000 0x0 0x04000000>;
> +			interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
> +		};
> +
> +		apb_clk: apb-clk-clock {

Only MMIO-nodes go to soc. Such stubs go outside.

It does not look like you tested the DTS against bindings. Please run
`make dtbs_check W=1` (see
Documentation/devicetree/bindings/writing-schema.rst or
https://www.linaro.org/blog/tips-and-tricks-for-validating-devicetree-sources-with-the-devicetree-schema/
for instructions).

> +			compatible = "fixed-clock";
> +			clock-frequency = <50000000>;
> +			clock-output-names = "apb_clk";
> +			#clock-cells = <0>;
> +		};
> +


Best regards,
Krzysztof