Re: [PATCH v2 00/11] Add Milk-V Pioneer RISC-V board support

[Palmer Dabbelt]

On Tue, 19 Sep 2023 23:33:48 PDT (-0700), unicornxw@xxxxxxxxx wrote:
> Milk-V Pioneer [1] is a developer motherboard based on SOPHON SG2042 [2]
> in a standard mATX form factor. Add minimal device
> tree files for the SG2042 SOC and the Milk-V Pioneer board.
>
> Now only support basic uart drivers to boot up into a basic console.
>
> Thanks,
> Chen
>
> ---
>
> Changes in v2:
>   The patch series is based on v6.6-rc1. You can simply review or test
>   the patches at the link [4].
>   - Improve format for comment of commitments as per input from last review.
>   - Improve format of DTS as per input from last review.
>   - Remove numa related stuff from DTS. This part is just for optimization, may
>     add it later if really needed.
>
> Previous versions:
> v1: due to it is not sent in thread, I have listed permlinks of the patchset
>     [v1-0/12] ~ [v1-12/12] here for quick reference. You can simply review or
>     test the patches at the link [3].
>
> [1]: https://milkv.io/pioneer
> [2]: https://en.sophgo.com/product/introduce/sg2042.html
> [3]: https://github.com/unicornx/linux-riscv/commits/milkv-pioneer-minimal
> [4]: https://github.com/unicornx/linux-riscv/commits/milkv-pioneer-minimal-v2
> [v1-0/12]:https://lore.kernel.org/linux-riscv/20230915070856.117514-1-wangchen20@xxxxxxxxxxx/
> [v1-1/12]:https://lore.kernel.org/linux-riscv/20230915071005.117575-1-wangchen20@xxxxxxxxxxx/
> [v1-2/12]:https://lore.kernel.org/linux-riscv/20230915071409.117692-1-wangchen20@xxxxxxxxxxx/
> [v1-3/12]:https://lore.kernel.org/linux-riscv/20230915072242.117935-1-wangchen20@xxxxxxxxxxx/
> [v1-4/12]:https://lore.kernel.org/linux-riscv/20230915072333.117991-1-wangchen20@xxxxxxxxxxx/
> [v1-5/12]:https://lore.kernel.org/linux-riscv/20230915072358.118045-1-wangchen20@xxxxxxxxxxx/
> [v1-6/12]:https://lore.kernel.org/linux-riscv/20230915072415.118100-1-wangchen20@xxxxxxxxxxx/
> [v1-7/12]:https://lore.kernel.org/linux-riscv/20230915072431.118154-1-wangchen20@xxxxxxxxxxx/
> [v1-8/12]:https://lore.kernel.org/linux-riscv/20230915072451.118209-1-wangchen20@xxxxxxxxxxx/
> [v1-9/12]:https://lore.kernel.org/linux-riscv/20230915072517.118266-1-wangchen20@xxxxxxxxxxx/
> [v1-10/12]:https://lore.kernel.org/linux-riscv/20230915072558.118325-1-wangchen20@xxxxxxxxxxx/
> [v1-11/12]:https://lore.kernel.org/linux-riscv/20230915072624.118388-1-wangchen20@xxxxxxxxxxx/
> [v1-12/12]:https://lore.kernel.org/linux-riscv/20230915072653.118448-1-wangchen20@xxxxxxxxxxx/
>
> ---
>
> Chen Wang (8):
>   riscv: Add SOPHGO SOC family Kconfig support
>   dt-bindings: vendor-prefixes: add milkv/sophgo
>   dt-bindings: riscv: add sophgo sg2042 bindings
>   dt-bindings: riscv: Add T-HEAD C920 compatibles
>   dt-bindings: interrupt-controller: Add SOPHGO's SG2042 PLIC
>   riscv: dts: add initial SOPHGO SG2042 SoC device tree
>   riscv: dts: sophgo: add Milk-V Pioneer board device tree
>   riscv: defconfig: enable SOPHGO SoC
>
> Emil Renner Berthing (2):
>   dt-bindings: serial: snps-dw-apb-uart: Add Sophgo SG2042 uarts
>   serial: 8250_dw: Add Sophgo SG2042 support
>
> Inochi Amaoto (1):
>   dt-bindings: timer: Add Sophgo sg2042 clint
>
>  .../sifive,plic-1.0.0.yaml                    |    1 +
>  .../devicetree/bindings/riscv/cpus.yaml       |    1 +
>  .../devicetree/bindings/riscv/sophgo.yaml     |   28 +
>  .../bindings/serial/snps-dw-apb-uart.yaml     |    1 +
>  .../bindings/timer/sifive,clint.yaml          |    8 +
>  .../devicetree/bindings/vendor-prefixes.yaml  |    4 +
>  MAINTAINERS                                   |    7 +
>  arch/riscv/Kconfig.socs                       |    5 +
>  arch/riscv/boot/dts/Makefile                  |    1 +
>  arch/riscv/boot/dts/sophgo/Makefile           |    3 +
>  arch/riscv/boot/dts/sophgo/sg2042-cpus.dtsi   | 1744 +++++++++++++++++
>  .../boot/dts/sophgo/sg2042-milkv-pioneer.dts  |   19 +
>  arch/riscv/boot/dts/sophgo/sg2042.dtsi        |  439 +++++
>  arch/riscv/configs/defconfig                  |    1 +
>  drivers/tty/serial/8250/8250_dw.c             |    5 +-
>  15 files changed, 2265 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/riscv/sophgo.yaml
>  create mode 100644 arch/riscv/boot/dts/sophgo/Makefile
>  create mode 100644 arch/riscv/boot/dts/sophgo/sg2042-cpus.dtsi
>  create mode 100644 arch/riscv/boot/dts/sophgo/sg2042-milkv-pioneer.dts
>  create mode 100644 arch/riscv/boot/dts/sophgo/sg2042.dtsi

Given this is the first sg2042 and it appears to have a few errata (the 
FP rounding issues and the special fence for starvation), I think we 
want to make sure we figure out how to provide that information to 
userspace.

> base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d