Message-ID: <d299493d8fec0f34f527942f2cdedf15f2136c9a.camel@mediatek.com>
Subject: Re: [PATCH v7 2/3] arm64: dts: mediatek: add basic mt7986a support
From:   Sam Shih <sam.shih@mediatek.com>
To:     Matthias Brugger <matthias.bgg@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        "Enric Balletbo i Serra" <enric.balletbo@collabora.com>,
        Fabien Parent <fparent@baylibre.com>,
        Seiya Wang <seiya.wang@mediatek.com>,
        Sean Wang <sean.wang@mediatek.com>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>
CC:     John Crispin <john@phrozen.org>, Ryder Lee <Ryder.Lee@mediatek.com>
Date:   Tue, 16 Nov 2021 09:39:49 +0800
In-Reply-To: <d411aec5-efa8-c71d-8179-54ff52c17039@gmail.com>
References: <20211018114009.13350-1-sam.shih@mediatek.com>
         <20211018114009.13350-3-sam.shih@mediatek.com>
         <d411aec5-efa8-c71d-8179-54ff52c17039@gmail.com>
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi,

On Mon, 2021-11-15 at 17:27 +0100, Matthias Brugger wrote:
> Hi,
> 
> On 18/10/2021 13:40, Sam Shih wrote:
> > Add basic chip support for Mediatek mt7986a, include
> > basic uart nodes, rng node and watchdog node.
> > 
> > Add cpu node, timer node, gic node, psci and reserved-memory node
> > for ARM Trusted Firmware.
> > 
> 
> What is the exact difference between mt7986a and mt7986b? Right now,
> it's only 
> the compatible, for that it makes no sense to split them.
> 

The difference between mt7986a and mt7986b is pinout which described
in our pinctrl patch series 
https://lore.kernel.org/all/20211022124036.5291-3-sam.shih@mediatek.com/

You are right, in this "basic SoC support" patch series, only show
compatible differences

> It would be good to see what the exact differences are, so that we
> can see if it 
> makes sense to have one of the alternatives:
> 1) use a common mt7986.dtsi which get included by mt7986[a,b].dtsi
> 2) Use on mt7986.dtsi and only add one mt7986a.dtsi or mt7986b.dtsi
> which has 
> add-ons.
> 

In this case, can we use solution (1) to create a generic mt7986.dtsi
in this patch series, and add mt7986[a,b].dtsi to the dts part of the
pinctrl patch series to separate the difference nodes?

> > Signed-off-by: Sam Shih <sam.shih@mediatek.com>
> > 
> > ---
> > v7: added memory node back to dts
> > v6: removed clock and pinctrl node, to separate basic part into a
> > single
> >      patch series
> > 
> > Original thread:
> > 
https://urldefense.com/v3/__https://lore.kernel.org/all/20211004124155.1404-1-sam.shih@mediatek.com/__;!!CTRNKA9wMg0ARbw!xCEW0lwTKx4k272sWASoi90y_yRyQdAx0oNJC-jSAIWnIEkprJD-gAc1ugCvo0ex$
> >  
> > 
> > v5: follow reviewr's comment: removed clock freqency node in timer
> > due to
> >      we have set CNTFRQ_EL0 in ATF firmware, and also corrected
> > GICD range
> > v4: added missing gic register bases, and fixed range of GICR
> > v3: used the stdout-path instead of console=ttyS0
> > v2: modified clock and uart node due to clock driver updated
> > ---
> >   arch/arm64/boot/dts/mediatek/Makefile        |   1 +
> >   arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts |  38 +++++
> >   arch/arm64/boot/dts/mediatek/mt7986a.dtsi    | 149
> > +++++++++++++++++++
> >   3 files changed, 188 insertions(+)
> >   create mode 100644 arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
> >   create mode 100644 arch/arm64/boot/dts/mediatek/mt7986a.dtsi
> > 
> > diff --git a/arch/arm64/boot/dts/mediatek/Makefile
> > b/arch/arm64/boot/dts/mediatek/Makefile
> > index 4f68ebed2e31..e6c3a73b9e4a 100644
> > --- a/arch/arm64/boot/dts/mediatek/Makefile
> > +++ b/arch/arm64/boot/dts/mediatek/Makefile
> > @@ -7,6 +7,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-evb.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-x20-dev.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-rfb1.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-bananapi-bpi-r64.dtb
> > +dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-rfb.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8167-pumpkin.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-elm.dtb
> >   dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-elm-hana.dtb
> > diff --git a/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
> > b/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
> > new file mode 100644
> > index 000000000000..ca074cf8e578
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
> > @@ -0,0 +1,38 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > +/*
> > + * Copyright (C) 2021 MediaTek Inc.
> > + * Author: Sam.Shih <sam.shih@mediatek.com>
> > + */
> > +
> > +/dts-v1/;
> > +#include "mt7986a.dtsi"
> > +
> > +/ {
> > +	model = "MediaTek MT7986a RFB";
> > +	compatible = "mediatek,mt7986a-rfb";
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +		bootargs = "earlycon=uart8250,mmio32,0x11002000
> > swiotlb=512";
> 
> We normally don't add earlycon parameter to the normal bootargs, as
> it's only 
> for debugging. Also what do we need the swiotlb? Are there any
> limitation in the 
> HW that makes us need it?
> 

Thank you for your suggestion, as far as I know, it should not have
hardware limitations. This bootargs is just inherent from mt7622-
rfb.dts, I will delete it and test again on our development board.

> Regards,
> Matthias
> 
> > +	};
> > +
> > +	memory {
> > +		reg = <0 0x40000000 0 0x40000000>;
> > +	};
> > +};
> > +
> > +&uart0 {
> > +	status = "okay";
> > +};
> > +
> > +&uart1 {
> > +	status = "okay";
> > +};
> > +
> > +&uart2 {
> > +	status = "okay";
> > +};
> > diff --git a/arch/arm64/boot/dts/mediatek/mt7986a.dtsi
> > b/arch/arm64/boot/dts/mediatek/mt7986a.dtsi
> > new file mode 100644
> > index 000000000000..75912bcf6c9c
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/mediatek/mt7986a.dtsi
> > @@ -0,0 +1,149 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > +/*
> > + * Copyright (C) 2021 MediaTek Inc.
> > + * Author: Sam.Shih <sam.shih@mediatek.com>
> > + */
> > +
> > +#include <dt-bindings/interrupt-controller/irq.h>
> > +#include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +/ {
> > +	compatible = "mediatek,mt7986a";
> > +	interrupt-parent = <&gic>;
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	system_clk: dummy40m {
> > +		compatible = "fixed-clock";
> > +		clock-frequency = <40000000>;
> > +		#clock-cells = <0>;
> > +	};
> > +
> > +	cpus {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		cpu0: cpu@0 {
> > +			device_type = "cpu";
> > +			compatible = "arm,cortex-a53";
> > +			enable-method = "psci";
> > +			reg = <0x0>;
> > +			#cooling-cells = <2>;
> > +		};
> > +
> > +		cpu1: cpu@1 {
> > +			device_type = "cpu";
> > +			compatible = "arm,cortex-a53";
> > +			enable-method = "psci";
> > +			reg = <0x1>;
> > +			#cooling-cells = <2>;
> > +		};
> > +
> > +		cpu2: cpu@2 {
> > +			device_type = "cpu";
> > +			compatible = "arm,cortex-a53";
> > +			enable-method = "psci";
> > +			reg = <0x2>;
> > +			#cooling-cells = <2>;
> > +		};
> > +
> > +		cpu3: cpu@3 {
> > +			device_type = "cpu";
> > +			enable-method = "psci";
> > +			compatible = "arm,cortex-a53";
> > +			reg = <0x3>;
> > +			#cooling-cells = <2>;
> > +		};
> > +	};
> > +
> > +	psci {
> > +		compatible  = "arm,psci-0.2";
> > +		method      = "smc";
> > +	};
> > +
> > +	reserved-memory {
> > +		#address-cells = <2>;
> > +		#size-cells = <2>;
> > +		ranges;
> > +		/* 192 KiB reserved for ARM Trusted Firmware (BL31) */
> > +		secmon_reserved: secmon@43000000 {
> > +			reg = <0 0x43000000 0 0x30000>;
> > +			no-map;
> > +		};
> > +	};
> > +
> > +	timer {
> > +		compatible = "arm,armv8-timer";
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
> > +			     <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
> > +			     <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
> > +			     <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
> > +	};
> > +
> > +	soc {
> > +		#address-cells = <2>;
> > +		#size-cells = <2>;
> > +		compatible = "simple-bus";
> > +		ranges;
> > +
> > +		gic: interrupt-controller@c000000 {
> > +			compatible = "arm,gic-v3";
> > +			#interrupt-cells = <3>;
> > +			interrupt-parent = <&gic>;
> > +			interrupt-controller;
> > +			reg = <0 0x0c000000 0 0x10000>,  /* GICD */
> > +			      <0 0x0c080000 0 0x80000>,  /* GICR */
> > +			      <0 0x0c400000 0 0x2000>,   /* GICC */
> > +			      <0 0x0c410000 0 0x1000>,   /* GICH */
> > +			      <0 0x0c420000 0 0x2000>;   /* GICV */
> > +			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
> > +		};
> > +
> > +		watchdog: watchdog@1001c000 {
> > +			compatible = "mediatek,mt7986-wdt",
> > +				     "mediatek,mt6589-wdt";
> > +			reg = <0 0x1001c000 0 0x1000>;
> > +			interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
> > +			#reset-cells = <1>;
> > +			status = "disabled";
> > +		};
> > +
> > +		trng: trng@1020f000 {
> > +			compatible = "mediatek,mt7986-rng",
> > +				     "mediatek,mt7623-rng";
> > +			reg = <0 0x1020f000 0 0x100>;
> > +			clocks = <&system_clk>;
> > +			clock-names = "rng";
> > +			status = "disabled";
> > +		};
> > +
> > +		uart0: serial@11002000 {
> > +			compatible = "mediatek,mt7986-uart",
> > +				     "mediatek,mt6577-uart";
> > +			reg = <0 0x11002000 0 0x400>;
> > +			interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>;
> > +			clocks = <&system_clk>;
> > +			status = "disabled";
> > +		};
> > +
> > +		uart1: serial@11003000 {
> > +			compatible = "mediatek,mt7986-uart",
> > +				     "mediatek,mt6577-uart";
> > +			reg = <0 0x11003000 0 0x400>;
> > +			interrupts = <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>;
> > +			clocks = <&system_clk>;
> > +			status = "disabled";
> > +		};
> > +
> > +		uart2: serial@11004000 {
> > +			compatible = "mediatek,mt7986-uart",
> > +				     "mediatek,mt6577-uart";
> > +			reg = <0 0x11004000 0 0x400>;
> > +			interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
> > +			clocks = <&system_clk>;
> > +			status = "disabled";
> > +		};
> > +
> > +	};
> > +
> > +};
> > 

Regards,
Sam