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Message-ID: <4e6469e5-0f6c-4150-4709-7459597f06cc@linaro.org>
Date:   Wed, 19 Apr 2023 09:48:34 +0200
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Subject: Re: [RFC PATCH 2/2] arm64: dts: add support for C3 based Amlogic
 AW409
Content-Language: en-US
To:     =Xianwei Zhao <xianwei.zhao@amlogic.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
References: <20230419073834.972273-1-xianwei.zhao@amlogic.com>
 <20230419073834.972273-3-xianwei.zhao@amlogic.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230419073834.972273-3-xianwei.zhao@amlogic.com>
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On 19/04/2023 09:38, =Xianwei Zhao wrote:
> From: Xianwei Zhao <xianwei.zhao@amlogic.com>
> 
> Amlogic C3 is an advanced edge AI processor designed for smart IP camera
> applications.
> 
> Add basic support for the C3 based Amlogic AW409 board, which describes
> the following components: CPU, GIC, IRQ, Timer, UART. It's capable of
> booting up into the serial console.
> 
> Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
> ---
>  arch/arm64/boot/dts/amlogic/Makefile          |  1 +
>  .../amlogic/amlogic-c3-c302x-aw409-256m.dts   | 30 +++++++
>  arch/arm64/boot/dts/amlogic/amlogic-c3.dtsi   | 87 +++++++++++++++++++
>  3 files changed, 118 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/amlogic/amlogic-c3-c302x-aw409-256m.dts
>  create mode 100644 arch/arm64/boot/dts/amlogic/amlogic-c3.dtsi
> 
> diff --git a/arch/arm64/boot/dts/amlogic/Makefile b/arch/arm64/boot/dts/amlogic/Makefile
> index cd1c5b04890a..d2b5d0d750bc 100644
> --- a/arch/arm64/boot/dts/amlogic/Makefile
> +++ b/arch/arm64/boot/dts/amlogic/Makefile
> @@ -74,3 +74,4 @@ dtb-$(CONFIG_ARCH_MESON) += meson-sm1-odroid-hc4.dtb
>  dtb-$(CONFIG_ARCH_MESON) += meson-sm1-sei610.dtb
>  dtb-$(CONFIG_ARCH_MESON) += meson-sm1-x96-air-gbit.dtb
>  dtb-$(CONFIG_ARCH_MESON) += meson-sm1-x96-air.dtb
> +dtb-$(CONFIG_ARCH_AMLIPC) += amlogic-c3-c302x-aw409-256m.dtb
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-c3-c302x-aw409-256m.dts b/arch/arm64/boot/dts/amlogic/amlogic-c3-c302x-aw409-256m.dts
> new file mode 100644
> index 000000000000..38ca98a32181
> --- /dev/null
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-c3-c302x-aw409-256m.dts
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2021 Amlogic, Inc. All rights reserved.
> + */
> +
> +/dts-v1/;
> +
> +#include "amlogic-c3.dtsi"
> +
> +/ {
> +	model = "Amlogic C302 aw409 Development Board";
> +	compatible = "amlogic,aw409", "amlogic,c3";

Undocumented compatibles. Run checkpatch and fix all warnings. Anyway, I
am not sure this warrants separate architecture. Isn't C3 standard Meson
SoC?

> +	interrupt-parent = <&gic>;
> +	#address-cells = <2>;
> +	#size-cells = <2>;
> +
> +	aliases {
> +		serial0 = &uart_B;
> +	};
> +
> +	memory@0 {
> +		device_type = "memory";
> +		reg = <0x0 0x0 0x0 0x10000000>;
> +	};
> +

Drop stray blank lines.

> +};
> +
> +&uart_B {
> +	status = "okay";
> +};
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-c3.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-c3.dtsi
> new file mode 100644
> index 000000000000..c69072ac57f5
> --- /dev/null
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-c3.dtsi
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2021 Amlogic, Inc. All rights reserved.
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +#include <dt-bindings/gpio/gpio.h>
> +
> +/ {
> +	cpus {
> +		#address-cells = <2>;
> +		#size-cells = <0>;
> +
> +		cpu0: cpu@0 {
> +			device_type = "cpu";
> +			compatible = "arm,cortex-a35";
> +			reg = <0x0 0x0>;
> +			enable-method = "psci";
> +		};
> +
> +		cpu1: cpu@1 {
> +			device_type = "cpu";
> +			compatible = "arm,cortex-a35";
> +			reg = <0x0 0x1>;
> +			enable-method = "psci";
> +		};
> +

Everywhere...

> +	};
> +
> +	timer {
> +		compatible = "arm,armv8-timer";
> +		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;
> +	};
> +
> +	psci {
> +		compatible = "arm,psci-1.0";
> +		method = "smc";
> +	};
> +
> +	xtal: xtal-clk {
> +		compatible = "fixed-clock";
> +		clock-frequency = <24000000>;
> +		clock-output-names = "xtal";
> +		#clock-cells = <0>;
> +	};
> +
> +	soc {
> +		compatible = "simple-bus";
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		ranges;
> +
> +		gic: interrupt-controller@fff01000 {
> +			compatible = "arm,gic-400";
> +			#interrupt-cells = <3>;
> +			#address-cells = <0>;
> +			interrupt-controller;
> +			reg = <0x0 0xfff01000 0 0x1000>,
> +			      <0x0 0xfff02000 0 0x2000>,
> +			      <0x0 0xfff04000 0 0x2000>,
> +			      <0x0 0xfff06000 0 0x2000>;
> +			interrupts = <GIC_PPI 9 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>;
> +		};
> +
> +		apb4: apb4@fe000000 {

Node names should be generic.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

> +			compatible = "simple-bus";
> +			reg = <0x0 0xfe000000 0x0 0x480000>;
> +			#address-cells = <2>;
> +			#size-cells = <2>;
> +			ranges = <0x0 0x0 0x0 0xfe000000 0x0 0x480000>;
> +
> +			uart_B: serial@7a000 {

lowercase for labels

> +				compatible = "amlogic,meson-g12a-uart";

So this is just meson? Drop new ARCH, no need for it. Anyway, you need
SoC specific compatible.

Best regards,
Krzysztof