Subject: Re: [PATCH v2 2/2] arm64: dts: Add Mediatek SoC MT2712 and evaluation
 board dts and Makefile
To: YT Shen <yt.shen@mediatek.com>
References: <1496230773-22633-1-git-send-email-yt.shen@mediatek.com>
 <1496230773-22633-3-git-send-email-yt.shen@mediatek.com>
 <d1be42ad-0b79-8487-1590-711b0e86d2ca@arm.com>
 <1497015668.29586.26.camel@mtksdaap41>
Cc: Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Mars Cheng <mars.cheng@mediatek.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com,
        hongkun.cao@mediatek.com
From: Marc Zyngier <marc.zyngier@arm.com>
Organization: ARM Ltd
Message-ID: <43283159-8ad0-d2e6-2375-cb3562e55344@arm.com>
Date: Fri, 9 Jun 2017 14:50:56 +0100
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On 09/06/17 14:41, YT Shen wrote:
> On Wed, 2017-05-31 at 13:38 +0100, Marc Zyngier wrote:
>> On 31/05/17 12:39, YT Shen wrote:
>>> This adds basic chip support for Mediatek 2712
>>>
>>> Signed-off-by: YT Shen <yt.shen@mediatek.com>
>>> ---
>>>  arch/arm64/boot/dts/mediatek/Makefile       |   1 +
>>>  arch/arm64/boot/dts/mediatek/mt2712-evb.dts |  39 +++++++
>>>  arch/arm64/boot/dts/mediatek/mt2712e.dtsi   | 166 ++++++++++++++++++++++++++++
>>>  3 files changed, 206 insertions(+)
>>>  create mode 100644 arch/arm64/boot/dts/mediatek/mt2712-evb.dts
>>>  create mode 100644 arch/arm64/boot/dts/mediatek/mt2712e.dtsi
>>>
>>> diff --git a/arch/arm64/boot/dts/mediatek/Makefile b/arch/arm64/boot/dts/mediatek/Makefile
>>> index 9fbfd32..fcc0604 100644
>>> --- a/arch/arm64/boot/dts/mediatek/Makefile
>>> +++ b/arch/arm64/boot/dts/mediatek/Makefile
>>> @@ -1,3 +1,4 @@
>>> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt2712-evb.dtb
>>>  dtb-$(CONFIG_ARCH_MEDIATEK) += mt6755-evb.dtb
>>>  dtb-$(CONFIG_ARCH_MEDIATEK) += mt6795-evb.dtb
>>>  dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-evb.dtb
>>> diff --git a/arch/arm64/boot/dts/mediatek/mt2712-evb.dts b/arch/arm64/boot/dts/mediatek/mt2712-evb.dts
>>> new file mode 100644
>>> index 0000000..e526c0f
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/mediatek/mt2712-evb.dts
>>> @@ -0,0 +1,39 @@
>>> +/*
>>> + * Copyright (c) 2017 MediaTek Inc.
>>> + * Author: YT Shen <yt.shen@mediatek.com>
>>> + *
>>> + * SPDX-License-Identifier: (GPL-2.0 OR MIT)
>>> + */
>>> +
>>> +/dts-v1/;
>>> +#include "mt2712e.dtsi"
>>> +
>>> +/ {
>>> +	model = "MediaTek MT2712 evaluation board";
>>> +	compatible = "mediatek,mt2712-evb", "mediatek,mt2712";
>>> +
>>> +	aliases {
>>> +		serial0 = &uart0;
>>> +		serial1 = &uart1;
>>> +		serial2 = &uart2;
>>> +		serial3 = &uart3;
>>> +		serial4 = &uart4;
>>> +		serial5 = &uart5;
>>> +	};
>>> +
>>> +	memory@40000000 {
>>> +		device_type = "memory";
>>> +		reg = <0 0x40000000 0 0x80000000>;
>>> +	};
>>> +
>>> +	chosen {
>>> +		stdout-path = "serial0:921600n8";
>>> +		linux,initrd-start = <0x45000000>;
>>> +		linux,initrd-end   = <0x4a000000>;
>>> +	};
>>> +};
>>> +
>>> +&uart0 {
>>> +	status = "okay";
>>> +};
>>> +
>>> diff --git a/arch/arm64/boot/dts/mediatek/mt2712e.dtsi b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
>>> new file mode 100644
>>> index 0000000..6df0da9
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
>>> @@ -0,0 +1,166 @@
>>> +/*
>>> + * Copyright (c) 2017 MediaTek Inc.
>>> + * Author: YT Shen <yt.shen@mediatek.com>
>>> + *
>>> + * SPDX-License-Identifier: (GPL-2.0 OR MIT)
>>> + */
>>> +
>>> +#include <dt-bindings/interrupt-controller/irq.h>
>>> +#include <dt-bindings/interrupt-controller/arm-gic.h>
>>> +
>>> +/ {
>>> +	compatible = "mediatek,mt2712";
>>> +	interrupt-parent = <&sysirq>;
>>> +	#address-cells = <2>;
>>> +	#size-cells = <2>;
>>> +
>>> +	cpus {
>>> +		#address-cells = <1>;
>>> +		#size-cells = <0>;
>>> +
>>> +		cpu-map {
>>> +			cluster0 {
>>> +				core0 {
>>> +					cpu = <&cpu0>;
>>> +				};
>>> +				core1 {
>>> +					cpu = <&cpu1>;
>>> +				};
>>> +			};
>>> +
>>> +			cluster1 {
>>> +				core0 {
>>> +					cpu = <&cpu2>;
>>> +				};
>>> +			};
>>> +		};
>>> +
>>> +		cpu0: cpu@0 {
>>> +			device_type = "cpu";
>>> +			compatible = "arm,cortex-a35";
>>> +			reg = <0x000>;
>>> +		};
>>> +
>>> +		cpu1: cpu@1 {
>>> +			device_type = "cpu";
>>> +			compatible = "arm,cortex-a35";
>>> +			reg = <0x001>;
>>> +			enable-method = "psci";
>>> +		};
>>> +
>>> +		cpu2: cpu@200 {
>>> +			device_type = "cpu";
>>> +			compatible = "arm,cortex-a72";
>>> +			reg = <0x200>;
>>> +			enable-method = "psci";
>>> +		};
>>> +	};
>>> +
>>> +	psci {
>>> +		compatible = "arm,psci-0.2";
>>> +		method = "smc";
>>> +	};
>>> +
>>> +	uart_clk: dummy26m {
>>> +		compatible = "fixed-clock";
>>> +		clock-frequency = <26000000>;
>>> +		#clock-cells = <0>;
>>> +	};
>>> +
>>> +	timer {
>>> +		compatible = "arm,armv8-timer";
>>> +		interrupt-parent = <&gic>;
>>> +		interrupts = <GIC_PPI 13
>>> +			      (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
>>
>> Why 6? I only count 3 cores...
> OK, will change to GIC_CPU_MASK_RAW(0x13)
> 
> Sorry for the late reply.
>>
>>> +			     <GIC_PPI 14
>>> +			      (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
>>> +			     <GIC_PPI 11
>>> +			      (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
>>> +			     <GIC_PPI 10
>>> +			      (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>;
>>> +	};
>>> +
>>> +	soc {
>>> +		#address-cells = <2>;
>>> +		#size-cells = <2>;
>>> +		compatible = "simple-bus";
>>> +		ranges;
>>> +
>>> +		uart5: serial@1000f000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x1000f000 0 0x400>;
>>> +			interrupts = <GIC_SPI 127 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +
>>> +		sysirq: interrupt-controller@10220a80 {
>>> +			compatible = "mediatek,mt2712-sysirq",
>>> +				     "mediatek,mt6577-sysirq";
>>> +			interrupt-controller;
>>> +			#interrupt-cells = <3>;
>>> +			interrupt-parent = <&gic>;
>>> +			reg = <0 0x10220a80 0 0x40>;
>>> +		};
>>> +
>>> +		gic: interrupt-controller@10510000 {
>>> +			compatible = "arm,gic-400";
>>> +			#interrupt-cells = <3>;
>>> +			interrupt-parent = <&gic>;
>>> +			interrupt-controller;
>>> +			reg = <0 0x10510000 0 0x1000>,
>>> +			      <0 0x10520000 0 0x1000>,
>>
>> If that's truly a GIC400, then the above is wrong (the CPU interface is
>> spread over 8kB).
>>
>> I also suspect that the first 4kB are aliased over
>> 0x10520000:0x1052f000, and the second over 0x10530000:0x1053f000 (in the
>> true SBSA tradition). If that's the case, then the size is actually 128kB.
> The chip information at hand is not enough for me to answer this
> question, if I have further document will check this part.
> 
>>
>>> +			      <0 0x10540000 0 0x2000>,
>>> +			      <0 0x10560000 0 0x2000>;
>>
>> Please check GICV as well, which probably behaves the same way.
> The reg entry I changed to 
>   reg = <0 0x10510000 0 0x1000>,
>         <0 0x10520000 0 0x20000>,
>         <0 0x10540000 0 0x20000>,
>         <0 0x10560000 0 0x20000>;
>   is that correct?

Only you (or whoever integrated GIC400 on the platform) can know that.
I'd say that it is likely to be correct based on what's below, but
that's only an educated guess.

> 
> The platform boot to shell successfully.  The boot message shows
> additional different two lines:
> ...
> [    0.000000] GIC: Adjusting CPU interface base to 0x000000001052f000
> [    0.000000] GIC: Using split EOI/Deactivate mode
> ...

Seems OK to me.

>>
>>> +			interrupts = <GIC_PPI 9
>>> +				(GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_HIGH)>;
>>
>> Same thing here with 6 CPUs.
> Will change to GIC_CPU_MASK_RAW(0x13)
> 
>>
>>> +		};
>>> +
>>> +		uart0: serial@11002000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x11002000 0 0x400>;
>>> +			interrupts = <GIC_SPI 91 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +
>>> +		uart1: serial@11003000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x11003000 0 0x400>;
>>> +			interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +
>>> +		uart2: serial@11004000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x11004000 0 0x400>;
>>> +			interrupts = <GIC_SPI 93 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +
>>> +		uart3: serial@11005000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x11005000 0 0x400>;
>>> +			interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +
>>> +		uart4: serial@11019000 {
>>> +			compatible = "mediatek,mt2712-uart",
>>> +				     "mediatek,mt6577-uart";
>>> +			reg = <0 0x11019000 0 0x400>;
>>> +			interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_LOW>;
>>> +			clocks = <&uart_clk>;
>>> +			status = "disabled";
>>> +		};
>>> +	};
>>> +};
>>> +
>>>
>>
>> No PMU wired on this system?
> After checking, there is a PMU on the system, but not verified yet.
> And the plan for this patch series does not include PMU, is it
> necessary?

Well, it is an important part of the system, and given that it comes
directly with the CPU cores, it'd be good to have it. But as always,
that's up to you.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...