Re: [PATCH v2 1/7] riscv: dts: sophgo: cv18xx: Move RiscV-specific part into SoCs' .dtsi files

[Krzysztof Kozlowski <krzk@kernel.org>]

On 12/02/2025 18:44, Alexander Sverdlin wrote:
> Hi 
> 
> On Wed, 2025-02-12 at 17:46 +0100, Krzysztof Kozlowski wrote:
>>>>> Make the peripheral device tree re-usable on ARM64 platform by moving CPU
>>>>> core and interrupt controllers' parts into the respective per-SoC .dtsi
>>>>> files.
>>>>>
>>>>> Add SOC_PERIPHERAL_IRQ() macro which explicitly maps peripheral nubering
>>>>> into "plic" interrupt-controller numbering.
>>>>>
>>>>> Have a nice refactoring side-effect that "plic" and "clint" "compatible"
>>>>> property is not specified outside of the corresponding device itself.
>>>>>
>>>>> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
>>>>> ---
>>>>> Changelog:
>>>>> v2:
>>>>> - instead of carving out peripherals' part, carve out ARCH-specifics (CPU
>>>>> core, interrupt controllers) and spread them among 3 SoC .dtsi files which
>>>>> included cv18xx.dtsi;
>>>>> - define a label for the "soc" node and use it in the newly introduced DTs;
>>>>>
>>>>>  arch/riscv/boot/dts/sophgo/cv1800b.dtsi    | 64 ++++++++++++---
>>>>>  arch/riscv/boot/dts/sophgo/cv1812h.dtsi    | 64 ++++++++++++---
>>>>>  arch/riscv/boot/dts/sophgo/cv181x.dtsi     |  2 +-
>>>>>  arch/riscv/boot/dts/sophgo/cv18xx-cpu.dtsi | 57 ++++++++++++++
>>>>>  arch/riscv/boot/dts/sophgo/cv18xx.dtsi     | 91 ++++++----------------
>>>>>  arch/riscv/boot/dts/sophgo/sg2002.dtsi     | 64 ++++++++++++---
>>>>>  6 files changed, 240 insertions(+), 102 deletions(-)
>>>>>  create mode 100644 arch/riscv/boot/dts/sophgo/cv18xx-cpu.dtsi
>>>>>
>>>>> diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>>>> index aa1f5df100f0..eef2884b36f9 100644
>>>>> --- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>>>> +++ b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>>>> @@ -3,6 +3,8 @@
>>>>>   * Copyright (C) 2023 Jisheng Zhang <jszhang@kernel.org>
>>>>>   */
>>>>>  
>>>>> +#define SOC_PERIPHERAL_IRQ(nr)	((nr) + 16)
>>>>> +
>>>>>  #include <dt-bindings/pinctrl/pinctrl-cv1800b.h>
>>>>>  #include "cv18xx.dtsi"
>>>>>  
>>>>> @@ -14,22 +16,62 @@ memory@80000000 {
>>>>>  		reg = <0x80000000 0x4000000>;
>>>>>  	};
>>>>>  
>>>>
>>>>> -	soc {
>>>>> -		pinctrl: pinctrl@3001000 {
>>>>> -			compatible = "sophgo,cv1800b-pinctrl";
>>>>> -			reg = <0x03001000 0x1000>,
>>>>> -			      <0x05027000 0x1000>;
>>>>> -			reg-names = "sys", "rtc";
>>>>
>>>>
>>>>> +	cpus: cpus {
>>>>> +		#address-cells = <1>;
>>>>> +		#size-cells = <0>;
>>>>> +		timebase-frequency = <25000000>;
>>>>> +
>>>>> +		cpu0: cpu@0 {
>>>>> +			compatible = "thead,c906", "riscv";
>>>>> +			device_type = "cpu";
>>>>> +			reg = <0>;
>>>>> +			d-cache-block-size = <64>;
>>>>> +			d-cache-sets = <512>;
>>>>> +			d-cache-size = <65536>;
>>>>> +			i-cache-block-size = <64>;
>>>>> +			i-cache-sets = <128>;
>>>>> +			i-cache-size = <32768>;
>>>>> +			mmu-type = "riscv,sv39";
>>>>> +			riscv,isa = "rv64imafdc";
>>>>> +			riscv,isa-base = "rv64i";
>>>>> +			riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "zicntr", "zicsr",
>>>>> +					       "zifencei", "zihpm";
>>>>> +
>>>>> +			cpu0_intc: interrupt-controller {
>>>>> +				compatible = "riscv,cpu-intc";
>>>>> +				interrupt-controller;
>>>>> +				#interrupt-cells = <1>;
>>>>> +			};
>>>>>  		};
>>>>>  	};
>>>>>  };
>>>>
>>>> Make all soc definition include the common cpu file. 
>>>> Not just copy it.
>>>
>>> I was acting according to Krzysztof's suggestion:
>>> https://lore.kernel.org/soc/d3ba0ea5-0491-42d5-a18e-64cf21df696c@kernel.org/
>>>
>>> Krzysztof, I can name the file cv18xx-cpu-intc.dtsi and pack CPU core + interrupt
>>> controllers into it. Would it make sense?
>>
>>
>> I don't understand the original suggestion.
> 
> This is the snippet in question:
> 
> ---[ cut ]---
> #define SOC_PERIPHERAL_IRQ(nr)	((nr) + 16)
> 
> / {
> 	cpus: cpus {
> 		#address-cells = <1>;
> 		#size-cells = <0>;
> 		timebase-frequency = <25000000>;
> 
> 		cpu0: cpu@0 {
> 			compatible = "thead,c906", "riscv";
> 			device_type = "cpu";
> 			reg = <0>;
> 			d-cache-block-size = <64>;
> 			d-cache-sets = <512>;
> 			d-cache-size = <65536>;
> 			i-cache-block-size = <64>;
> 			i-cache-sets = <128>;
> 			i-cache-size = <32768>;
> 			mmu-type = "riscv,sv39";
> 			riscv,isa = "rv64imafdc";
> 			riscv,isa-base = "rv64i";
> 			riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "zicntr", "zicsr",
> 					       "zifencei", "zihpm";
> 
> 			cpu0_intc: interrupt-controller {
> 				compatible = "riscv,cpu-intc";
> 				interrupt-controller;
> 				#interrupt-cells = <1>;
> 			};
> 		};
> 	};
> };
> 
> &soc {
> 	interrupt-parent = <&plic>;
> 	dma-noncoherent;
> 
> 	plic: interrupt-controller@70000000 {
> 		reg = <0x70000000 0x4000000>;
> 		interrupts-extended = <&cpu0_intc 11>, <&cpu0_intc 9>;
> 		interrupt-controller;
> 		#address-cells = <0>;
> 		#interrupt-cells = <2>;
> 		riscv,ndev = <101>;
> 	};
> 
> 	clint: timer@74000000 {
> 		reg = <0x74000000 0x10000>;
> 		interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
> 	};
> };
> ---[ cut ]---
> 
> Inochi's proposal is to put it into separate cv18xx-cpu-intc.dtsi and
> include the latter in 3 other SoC-specific .dtsis. In v2 I've just
> duplicated the above snippet 3 times (refer to diffstat above).
> 
> What are your thoughts? In Renesas everything is duplicated, I believe.
> Sophgo outsources much smaller snippets into .dtsi (refer to cv181x.dtsi). 

If it represents some shared design/part, then it feels good.
Best regards,
Krzysztof

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