Re: [PATCH v2 4/7] riscv: dts: sophgo: Separate common devices from cv1800b soc

From: Conor Dooley
Date: Fri Oct 13 2023 - 05:08:34 EST

Yo,

On Mon, Oct 09, 2023 at 07:26:35PM +0800, Inochi Amaoto wrote:
> Move the cpu and the common peripherals of CV181x and CV180x to new file.
>
> Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxxxx>
> ---
> arch/riscv/boot/dts/sophgo/cv1800b.dtsi | 95 +------------------
> .../dts/sophgo/{cv1800b.dtsi => cv180x.dtsi} | 19 +---
> 2 files changed, 2 insertions(+), 112 deletions(-)
> copy arch/riscv/boot/dts/sophgo/{cv1800b.dtsi => cv180x.dtsi} (80%)
>
> diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
> index df40e87ee063..0904154f9829 100644
> --- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
> +++ b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
> @@ -3,106 +3,13 @@
> * Copyright (C) 2023 Jisheng Zhang <jszhang@xxxxxxxxxx>
> */
>
> -#include <dt-bindings/interrupt-controller/irq.h>
> +#include "cv180x.dtsi"
>
> / {
> compatible = "sophgo,cv1800b";
> - #address-cells = <1>;
> - #size-cells = <1>;
> -
> - 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;
> - #address-cells = <0>;
> - #interrupt-cells = <1>;
> - };
> - };
> - };
> -
> - osc: oscillator {
> - compatible = "fixed-clock";
> - clock-output-names = "osc_25m";
> - #clock-cells = <0>;
> - };
>
> soc {
> - compatible = "simple-bus";
> interrupt-parent = <&plic>;
> - #address-cells = <1>;
> - #size-cells = <1>;
> - dma-noncoherent;
> - ranges;
> -
> - uart0: serial@4140000 {
> - compatible = "snps,dw-apb-uart";
> - reg = <0x04140000 0x100>;
> - interrupts = <44 IRQ_TYPE_LEVEL_HIGH>;
> - clocks = <&osc>;
> - reg-shift = <2>;
> - reg-io-width = <4>;
> - status = "disabled";
> - };
> -
> - uart1: serial@4150000 {
> - compatible = "snps,dw-apb-uart";
> - reg = <0x04150000 0x100>;
> - interrupts = <45 IRQ_TYPE_LEVEL_HIGH>;
> - clocks = <&osc>;
> - reg-shift = <2>;
> - reg-io-width = <4>;
> - status = "disabled";
> - };
> -
> - uart2: serial@4160000 {
> - compatible = "snps,dw-apb-uart";
> - reg = <0x04160000 0x100>;
> - interrupts = <46 IRQ_TYPE_LEVEL_HIGH>;
> - clocks = <&osc>;
> - reg-shift = <2>;
> - reg-io-width = <4>;
> - status = "disabled";
> - };
> -
> - uart3: serial@4170000 {
> - compatible = "snps,dw-apb-uart";
> - reg = <0x04170000 0x100>;
> - interrupts = <47 IRQ_TYPE_LEVEL_HIGH>;
> - clocks = <&osc>;
> - reg-shift = <2>;
> - reg-io-width = <4>;
> - status = "disabled";
> - };
> -
> - uart4: serial@41c0000 {
> - compatible = "snps,dw-apb-uart";
> - reg = <0x041c0000 0x100>;
> - interrupts = <48 IRQ_TYPE_LEVEL_HIGH>;
> - clocks = <&osc>;
> - reg-shift = <2>;
> - reg-io-width = <4>;
> - status = "disabled";
> - };
>
> plic: interrupt-controller@70000000 {
> compatible = "sophgo,cv1800b-plic", "thead,c900-plic";
> diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv180x.dtsi
> similarity index 80%
> copy from arch/riscv/boot/dts/sophgo/cv1800b.dtsi
> copy to arch/riscv/boot/dts/sophgo/cv180x.dtsi
> index df40e87ee063..ffaf51724c98 100644

Firstly, this form of diff really threw me, I was quite confused for a
few minutes. A copy plus a pair of diffs doesn't really make much sense,
when the operation being carried is an extraction of some nodes to a
different file.

> --- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
> +++ b/arch/riscv/boot/dts/sophgo/cv180x.dtsi
> @@ -1,12 +1,12 @@
> // SPDX-License-Identifier: (GPL-2.0 OR MIT)
> /*
> * Copyright (C) 2023 Jisheng Zhang <jszhang@xxxxxxxxxx>
> + * Copyright (C) 2023 Inochi Amaoto <inochiama@xxxxxxxxxxx>

Also, is moving around some bits of hw description really a
copyrightable change?

> */
>
> #include <dt-bindings/interrupt-controller/irq.h>
>
> / {
> - compatible = "sophgo,cv1800b";
> #address-cells = <1>;
> #size-cells = <1>;
>
> @@ -48,7 +48,6 @@ osc: oscillator {
>
> soc {
> compatible = "simple-bus";
> - interrupt-parent = <&plic>;
> #address-cells = <1>;
> #size-cells = <1>;
> dma-noncoherent;
> @@ -103,21 +102,5 @@ uart4: serial@41c0000 {
> reg-io-width = <4>;
> status = "disabled";
> };
> -
> - plic: interrupt-controller@70000000 {
> - compatible = "sophgo,cv1800b-plic", "thead,c900-plic";
> - 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 {
> - compatible = "sophgo,cv1800b-clint", "thead,c900-clint";
> - reg = <0x74000000 0x10000>;
> - interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
> - };
> };
> };

What I wanted to comment on was this though - it seems that both the
cv1800b and the cv1812h have identical plic and clint nodes, other than
their compatibles? If that is the case, why create a cv1800b and a
cv1812h specific file containing entirely new nodes, when overriding the
compatible would be sufficient? Doubly so if the other SoCs in the
cv18xx series are going to have identical layouts.

I gave it a quick test locally with the below diff applied on top of
this series - although I didn't make sure that I didn't re-order the
plic & clint nodes, I just wanted to demonstrate what I had done.

Cheers,
Conor.

-- 8< --

diff --git a/arch/riscv/boot/dts/sophgo/cv1800b-milkv-duo.dts b/arch/riscv/boot/dts/sophgo/cv1800b-milkv-duo.dts
index 3af9e34b3bc7..a9d809a49e7a 100644
--- a/arch/riscv/boot/dts/sophgo/cv1800b-milkv-duo.dts
+++ b/arch/riscv/boot/dts/sophgo/cv1800b-milkv-duo.dts
@@ -5,7 +5,7 @@

/dts-v1/;

-#include "cv1800b.dtsi"
+#include "cv180x.dtsi"

/ {
model = "Milk-V Duo";
diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
index 0904154f9829..e69de29bb2d1 100644
--- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
+++ b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
@@ -1,30 +0,0 @@
-// SPDX-License-Identifier: (GPL-2.0 OR MIT)
-/*
- * Copyright (C) 2023 Jisheng Zhang <jszhang@xxxxxxxxxx>
- */
-
-#include "cv180x.dtsi"
-
-/ {
- compatible = "sophgo,cv1800b";
-
- soc {
- interrupt-parent = <&plic>;
-
- plic: interrupt-controller@70000000 {
- compatible = "sophgo,cv1800b-plic", "thead,c900-plic";
- 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 {
- compatible = "sophgo,cv1800b-clint", "thead,c900-clint";
- reg = <0x74000000 0x10000>;
- interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
- };
- };
-};
diff --git a/arch/riscv/boot/dts/sophgo/cv180x.dtsi b/arch/riscv/boot/dts/sophgo/cv180x.dtsi
index 64ffb23d3626..1a2c44ba4de9 100644
--- a/arch/riscv/boot/dts/sophgo/cv180x.dtsi
+++ b/arch/riscv/boot/dts/sophgo/cv180x.dtsi
@@ -48,6 +48,7 @@ osc: oscillator {

soc {
compatible = "simple-bus";
+ interrupt-parent = <&plic>;
#address-cells = <1>;
#size-cells = <1>;
dma-noncoherent;
@@ -174,5 +175,21 @@ uart4: serial@41c0000 {
reg-io-width = <4>;
status = "disabled";
};
+
+ plic: interrupt-controller@70000000 {
+ compatible = "sophgo,cv1800b-plic", "thead,c900-plic";
+ 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 {
+ compatible = "sophgo,cv1800b-clint", "thead,c900-clint";
+ reg = <0x74000000 0x10000>;
+ interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
+ };
};
};
diff --git a/arch/riscv/boot/dts/sophgo/cv1812h.dtsi b/arch/riscv/boot/dts/sophgo/cv1812h.dtsi
index 3864d34b0100..c0a8d3290cc8 100644
--- a/arch/riscv/boot/dts/sophgo/cv1812h.dtsi
+++ b/arch/riscv/boot/dts/sophgo/cv1812h.dtsi
@@ -15,22 +15,13 @@ memory@80000000 {
};

soc {
- interrupt-parent = <&plic>;

plic: interrupt-controller@70000000 {
compatible = "sophgo,cv1812h-plic", "thead,c900-plic";
- 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 {
compatible = "sophgo,cv1812h-clint", "thead,c900-clint";
- reg = <0x74000000 0x10000>;
- interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
};
};
};

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