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Message-ID: <dfa99943-3bca-ec6d-7152-fc6465181a08@sholland.org>
Date:   Thu, 18 May 2023 22:55:21 -0500
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Subject: Re: [PATCH v4 08/10] riscv: dts: bouffalolab: add Sipeed M1s SoM and
 Dock devicetree
Content-Language: en-US
To:     Jisheng Zhang <jszhang@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
        devicetree@vger.kernel.org, linux-serial@vger.kernel.org,
        Palmer Dabbelt <palmer@rivosinc.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>
References: <20230518152244.2178-1-jszhang@kernel.org>
 <20230518152244.2178-9-jszhang@kernel.org>
From:   Samuel Holland <samuel@sholland.org>
In-Reply-To: <20230518152244.2178-9-jszhang@kernel.org>
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Precedence: bulk

Hi Jisheng,

On 5/18/23 10:22, Jisheng Zhang wrote:
> Sipeed manufactures a M1s system-on-module and dock board, add basic
> support for them.
> 
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
> ---
>  arch/riscv/boot/dts/Makefile                  |  1 +
>  arch/riscv/boot/dts/bouffalolab/Makefile      |  2 ++
>  .../dts/bouffalolab/bl808-sipeed-m1s-dock.dts | 25 +++++++++++++++++++
>  .../dts/bouffalolab/bl808-sipeed-m1s.dtsi     | 21 ++++++++++++++++
>  4 files changed, 49 insertions(+)
>  create mode 100644 arch/riscv/boot/dts/bouffalolab/Makefile
>  create mode 100644 arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s-dock.dts
>  create mode 100644 arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s.dtsi
> 
> diff --git a/arch/riscv/boot/dts/Makefile b/arch/riscv/boot/dts/Makefile
> index f0d9f89054f8..133e6c38c9b0 100644
> --- a/arch/riscv/boot/dts/Makefile
> +++ b/arch/riscv/boot/dts/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  subdir-y += allwinner
> +subdir-y += bouffalolab
>  subdir-y += sifive
>  subdir-y += starfive
>  subdir-y += canaan
> diff --git a/arch/riscv/boot/dts/bouffalolab/Makefile b/arch/riscv/boot/dts/bouffalolab/Makefile
> new file mode 100644
> index 000000000000..5419964e892d
> --- /dev/null
> +++ b/arch/riscv/boot/dts/bouffalolab/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +dtb-$(CONFIG_SOC_BOUFFALOLAB) += bl808-sipeed-m1s-dock.dtb
> diff --git a/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s-dock.dts b/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s-dock.dts
> new file mode 100644
> index 000000000000..aa6cf909cd4d
> --- /dev/null
> +++ b/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s-dock.dts
> @@ -0,0 +1,25 @@
> +// SPDX-License-Identifier: (GPL-2.0+ or MIT)
> +/*
> + * Copyright (C) 2022 Jisheng Zhang <jszhang@kernel.org>
> + */
> +
> +/dts-v1/;
> +
> +#include "bl808-sipeed-m1s.dtsi"
> +
> +/ {
> +	model = "Sipeed M1s Dock";
> +	compatible = "sipeed,m1s-dock", "sipeed,m1s", "bouffalolab,bl808";
> +
> +	aliases {
> +		serial3 = &uart3;
> +	};
> +
> +	chosen {
> +		stdout-path = "serial3:2000000n8";
> +	};
> +};
> +
> +&uart3 {
> +	status = "okay";
> +};
> diff --git a/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s.dtsi b/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s.dtsi
> new file mode 100644
> index 000000000000..5026de768534
> --- /dev/null
> +++ b/arch/riscv/boot/dts/bouffalolab/bl808-sipeed-m1s.dtsi
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: (GPL-2.0+ or MIT)
> +/*
> + * Copyright (C) 2022 Jisheng Zhang <jszhang@kernel.org>
> + */
> +
> +/dts-v1/;
> +
> +#include "bl808.dtsi"
> +
> +/ {
> +	compatible = "sipeed,m1s", "bouffalolab,bl808";
> +
> +	memory@50000000 {
> +		device_type = "memory";
> +		reg = <0x50000000 0x04000000>;
> +	};

Especially since the SoC contains three heterogeneous CPUs, the firmware
may want to divide the PSRAM among them, so I do not think it is a good
idea to define this statically. (Or would all of the DTs contain this
same node, and then use reserved-memory nodes to cover the other CPUs'
allocations?)

Regards,
Samuel

> +};
> +
> +&xtal {
> +	clock-frequency = <40000000>;
> +};