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 <20240312-basic_dt-v1-3-7f11df3a0896@amlogic.com>
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From: Jerome Brunet <jbrunet@baylibre.com>
To: xianwei.zhao@amlogic.com
Cc: Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski
 <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>,
 Neil Armstrong <neil.armstrong@linaro.org>, Martin Blumenstingl
 <martin.blumenstingl@googlemail.com>, Jerome Brunet
 <jbrunet@baylibre.com>, Kevin Hilman <khilman@baylibre.com>,
 devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org
Subject: Re: [PATCH 3/4] arm64: dts: add support for A4 based Amlogic BA400
Date: Tue, 12 Mar 2024 10:55:46 +0100
In-reply-to: <20240312-basic_dt-v1-3-7f11df3a0896@amlogic.com>
Message-ID: <1jsf0vephv.fsf@starbuckisacylon.baylibre.com>
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On Tue 12 Mar 2024 at 17:18, Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org> wrote:

> From: Xianwei Zhao <xianwei.zhao@amlogic.com>
>
> Amlogic A4 is an application processor designed for smart audio
> and IoT applications.
>
> Add basic support for the A4 based Amlogic BA400 board, which describes
> the following components: CPU, GIC, IRQ, Timer and UART.
> These are capable of booting up into the serial console.
>
> Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
> ---
>  arch/arm64/boot/dts/amlogic/Makefile               |  1 +
>  .../boot/dts/amlogic/amlogic-a4-a113l2-ba400.dts   | 43 ++++++++++
>  arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi        | 99 ++++++++++++++++++++++
>  3 files changed, 143 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/Makefile b/arch/arm64/boot/dts/amlogic/Makefile
> index 1ab160bf928a..9a50ec11bb8d 100644
> --- a/arch/arm64/boot/dts/amlogic/Makefile
> +++ b/arch/arm64/boot/dts/amlogic/Makefile
> @@ -1,4 +1,5 @@
>  # SPDX-License-Identifier: GPL-2.0
> +dtb-$(CONFIG_ARCH_MESON) += amlogic-a4-a113l2-ba400.dtb
>  dtb-$(CONFIG_ARCH_MESON) += amlogic-c3-c302x-aw409.dtb
>  dtb-$(CONFIG_ARCH_MESON) += amlogic-t7-a311d2-an400.dtb
>  dtb-$(CONFIG_ARCH_MESON) += amlogic-t7-a311d2-khadas-vim4.dtb
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-a4-a113l2-ba400.dts b/arch/arm64/boot/dts/amlogic/amlogic-a4-a113l2-ba400.dts
> new file mode 100644
> index 000000000000..60f9f23858c6
> --- /dev/null
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-a4-a113l2-ba400.dts
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
> + */
> +
> +/dts-v1/;
> +
> +#include "amlogic-a4.dtsi"

Could you describe how the a4 and a5 differs from each other ?
The description given in the commit description is the same.

Beside the a53 vs a55, I'm not seeing much of a difference.
Admittedly, there is not much yet but I wonder if a4 and a5 should have
a common dtsi.

> +
> +/ {
> +	model = "Amlogic A113L2 ba400 Development Board";
> +	compatible = "amlogic,ba400","amlogic,a4";
> +	interrupt-parent = <&gic>;
> +	#address-cells = <2>;
> +	#size-cells = <2>;
> +
> +	aliases {
> +		serial0 = &uart_b;
> +	};
> +
> +	memory@0 {
> +		device_type = "memory";
> +		reg = <0x0 0x0 0x0 0x40000000>;
> +	};
> +
> +	reserved-memory {
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		ranges;
> +
> +		/* 52 MiB reserved for ARM Trusted Firmware */

That's a lot of memory to blindly reserve.
Any chance we can stop doing that and have u-boot amend reserved memory
zone based on the actual needs of the device ?

> +		secmon_reserved:linux,secmon {
> +			compatible = "shared-dma-pool";
> +			no-map;
> +			alignment = <0x0 0x400000>;
> +			reg = <0x0 0x05000000 0x0 0x3400000>;
> +		};
> +	};
> +};
> +
> +&uart_b {
> +	status = "okay";
> +};
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi
> new file mode 100644
> index 000000000000..7e8745010b52
> --- /dev/null
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi
> @@ -0,0 +1,99 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2024 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-a53";
> +			reg = <0x0 0x0>;
> +			enable-method = "psci";
> +		};
> +
> +		cpu1: cpu@1 {
> +			device_type = "cpu";
> +			compatible = "arm,cortex-a53";
> +			reg = <0x0 0x1>;
> +			enable-method = "psci";
> +		};
> +
> +		cpu2: cpu@2 {
> +			device_type = "cpu";
> +			compatible = "arm,cortex-a53";
> +			reg = <0x0 0x2>;
> +			enable-method = "psci";
> +		};
> +
> +		cpu3: cpu@3 {
> +			device_type = "cpu";
> +			compatible = "arm,cortex-a53";
> +			reg = <0x0 0x3>;
> +			enable-method = "psci";
> +		};
> +	};
> +
> +	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-0.2";

Really ? still on the that old version ?

> +		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)>;
> +		};
> +
> +		apb@fe000000 {
> +			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 {
> +				compatible = "amlogic,meson-s4-uart",
> +					     "amlogic,meson-ao-uart";
> +				reg = <0x0 0x7a000 0x0 0x18>;
> +				interrupts = <GIC_SPI 169 IRQ_TYPE_EDGE_RISING>;
> +				clocks = <&xtal>, <&xtal>, <&xtal>;
> +				clock-names = "xtal", "pclk", "baud";
> +				status = "disabled";
> +			};
> +		};
> +	};
> +};


-- 
Jerome