Re: [RFC PATCH v2 09/11] riscv: soc: Initial DTS for Allwinner D1 NeZha board

[Guo Ren <guoren@kernel.org>]

On Mon, Jun 7, 2021 at 12:26 AM Jernej Škrabec <jernej.skrabec@gmail.com> wrote:
>
> Hi!
>
> I didn't go through all details. After you fix all comments below, you should
> run "make dtbs_check" and fix all reported warnings too.
>
> Dne nedelja, 06. junij 2021 ob 11:04:07 CEST je guoren@kernel.org napisal(a):
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Add initial DTS for Allwinner D1 NeZha board having only essential
> > devices (uart, dummy, clock, reset, clint, plic, etc).
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Co-Developed-by: Liu Shaohua <liush@allwinnertech.com>
> > Signed-off-by: Liu Shaohua <liush@allwinnertech.com>
> > Cc: Anup Patel <anup.patel@wdc.com>
> > Cc: Atish Patra <atish.patra@wdc.com>
> > Cc: Christoph Hellwig <hch@lst.de>
> > Cc: Chen-Yu Tsai <wens@csie.org>
> > Cc: Drew Fustini <drew@beagleboard.org>
> > Cc: Maxime Ripard <maxime@cerno.tech>
> > Cc: Palmer Dabbelt <palmerdabbelt@google.com>
> > Cc: Wei Fu <wefu@redhat.com>
> > Cc: Wei Wu <lazyparser@gmail.com>
> > ---
> >  arch/riscv/boot/dts/Makefile                       |  1 +
> >  arch/riscv/boot/dts/allwinner/Makefile             |  2 +
> >  .../boot/dts/allwinner/allwinner-d1-nezha-kit.dts  | 29 ++++++++
> >  arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi    | 84
> > ++++++++++++++++++++++ 4 files changed, 116 insertions(+)
> >  create mode 100644 arch/riscv/boot/dts/allwinner/Makefile
> >  create mode 100644 arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
> > create mode 100644 arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
> >
> > diff --git a/arch/riscv/boot/dts/Makefile b/arch/riscv/boot/dts/Makefile
> > index fe996b8..3e7b264 100644
> > --- a/arch/riscv/boot/dts/Makefile
> > +++ b/arch/riscv/boot/dts/Makefile
> > @@ -2,5 +2,6 @@
> >  subdir-y += sifive
> >  subdir-$(CONFIG_SOC_CANAAN_K210_DTB_BUILTIN) += canaan
> >  subdir-y += microchip
> > +subdir-y += allwinner
> >
> >  obj-$(CONFIG_BUILTIN_DTB) := $(addsuffix /, $(subdir-y))
> > diff --git a/arch/riscv/boot/dts/allwinner/Makefile
> > b/arch/riscv/boot/dts/allwinner/Makefile new file mode 100644
> > index 00000000..4adbf4b
> > --- /dev/null
> > +++ b/arch/riscv/boot/dts/allwinner/Makefile
> > @@ -0,0 +1,2 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +dtb-$(CONFIG_SOC_SUNXI) += allwinner-d1-nezha-kit.dtb
> > diff --git a/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
> > b/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts new file mode
> > 100644
> > index 00000000..cd9f7c9
> > --- /dev/null
> > +++ b/arch/riscv/boot/dts/allwinner/allwinner-d1-nezha-kit.dts
>
> Board DT names are comprised of soc name and board name, in this case it would
> be "sun20i-d1-nezha-kit.dts"
>
> > @@ -0,0 +1,29 @@
> > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>
> Usually copyrights are added below spdx id.
>
> > +
> > +/dts-v1/;
> > +
> > +#include "allwinner-d1.dtsi"
> > +
> > +/ {
> > +     #address-cells = <2>;
> > +     #size-cells = <2>;
>
> This should be part of SoC level DTSI.
>
> > +     model = "Allwinner D1 NeZha Kit";
> > +     compatible = "allwinner,d1-nezha-kit";
>
> Board specific compatible string should be followed with SoC compatible, in
> this case "allwinner,sun20i-d1".  You should document it too.
>
> > +
> > +     chosen {
> > +             bootargs = "console=ttyS0,115200";
>
> Above line doesn't belong here. If anything, it should be added dynamically by
> bootloader.
After discussion, we still want to keep a default value here.
Sometimes we could boot with jtag and parse dtb is hard for gdbinit
script.

>
> > +             stdout-path = &serial0;
> > +     };
> > +
> > +     memory@40000000 {
> > +             device_type = "memory";
> > +             reg = <0x0 0x40000000 0x0 0x20000000>;
> > +     };
>
> Ditto for whole memory node.
Ditto

>
> > +
> > +     soc {
> > +     };
>
> There is no point having empty nodes.
>
> > +};
> > +
> > +&serial0 {
> > +     status = "okay";
> > +};
> > diff --git a/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
> > b/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi new file mode 100644
> > index 00000000..11cd938
> > --- /dev/null
> > +++ b/arch/riscv/boot/dts/allwinner/allwinner-d1.dtsi
>
> Current naming approach for Allwinner SoC level DTSI is "sun20i-d1.dtsi".
>
> > @@ -0,0 +1,84 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
>
> > +
> > +/dts-v1/;
> > +
> > +/ {
> > +     #address-cells = <2>;
> > +     #size-cells = <2>;
>
> Since all peripherals and memory are below 4 GiB, why have 64-bit addresses
> and sizes? It just clutters DT.
>
> > +     model = "Allwinner D1 Soc";
> > +     compatible = "allwinner,d1-nezha-kit";
>
> Compatible and model don't belong to SoC level DTSI.
>
> > +
> > +     chosen {
> > +     };
>
> Remove empty node.
>
> > +
> > +     cpus {
> > +             #address-cells = <1>;
> > +             #size-cells = <0>;
> > +             timebase-frequency = <2400000>;
> > +             cpu@0 {
> > +                     device_type = "cpu";
> > +                     reg = <0>;
> > +                     status = "okay";
> > +                     compatible = "riscv";
> > +                     riscv,isa = "rv64imafdcv";
> > +                     mmu-type = "riscv,sv39";
> > +                     cpu0_intc: interrupt-controller {
> > +                             #interrupt-cells = <1>;
> > +                             compatible = "riscv,cpu-intc";
> > +                             interrupt-controller;
> > +                     };
> > +             };
> > +     };
> > +
> > +     soc {
> > +             #address-cells = <2>;
> > +             #size-cells = <2>;
> > +             compatible = "simple-bus";
> > +             ranges;
> > +
> > +             reset: reset-sample {
> > +                     compatible = "thead,reset-sample";
> > +                     plic-delegate = <0x0 0x101ffffc>;
> > +             };
> > +
> > +             clint: clint@14000000 {
> > +                     compatible = "riscv,clint0";
> > +                     interrupts-extended = <
> > +                             &cpu0_intc  3 &cpu0_intc  7
> > +                             >;
> > +                     reg = <0x0 0x14000000 0x0 0x04000000>;
> > +                     clint,has-no-64bit-mmio;
> > +             };
> > +
> > +             plic: interrupt-controller@10000000 {
> > +                     #interrupt-cells = <1>;
> > +                     compatible = "riscv,plic0";
> > +                     interrupt-controller;
> > +                     interrupts-extended = <
> > +                             &cpu0_intc  0xffffffff &cpu0_intc  9
> > +                             >;
> > +                     reg = <0x0 0x10000000 0x0 0x04000000>;
> > +                     reg-names = "control";
> > +                     riscv,max-priority = <7>;
> > +                     riscv,ndev = <200>;
> > +             };
> > +
> > +             dummy_apb: apb-clock {
> > +                     compatible = "fixed-clock";
> > +                     clock-frequency = <24000000>;
> > +                     clock-output-names = "dummy_apb";
> > +                     #clock-cells = <0>;
> > +             };
> > +
> > +             serial0: serial@2500000 {
>
> This should be uart0 and board should have alias for it. Check ARM based
> Allwinner DTs.
>
> Best regards,
> Jernej
>
> > +                     compatible = "snps,dw-apb-uart";
> > +                     reg = <0x0 0x02500000 0x0 0x400>;
> > +                     reg-io-width = <4>;
> > +                     reg-shift = <2>;
> > +                     interrupt-parent = <&plic>;
> > +                     interrupts = <18>;
> > +                     clocks = <&dummy_apb>;
> > +                     status = "disabled";
> > +             };
> > +     };
> > +};
>
>
>
>


-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

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