From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manivannan Sadhasivam Subject: Re: [PATCH v2 2/2] arm64: dts: Add Mediatek X20 Development Board support Date: Wed, 18 Jul 2018 22:13:04 +0530 Message-ID: <20180718164304.GA4902@Mani-XPS-13-9360> References: <20180605163442.4812-1-manivannan.sadhasivam@linaro.org> <20180605163442.4812-3-manivannan.sadhasivam@linaro.org> <20180717140453.GA19076@mani> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Matthias Brugger Cc: robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, taiten.peng@linaro.org, daniel.thompson@linaro.org, amit.kucheria@linaro.org, manivannanece23@gmail.com List-Id: devicetree@vger.kernel.org Hi Matthias, On Wed, Jul 18, 2018 at 05:07:38PM +0200, Matthias Brugger wrote: > > > On 17/07/18 16:04, Manivannan Sadhasivam wrote: > > Hi Matthias, > > > > On Mon, Jul 16, 2018 at 03:24:44PM +0200, Matthias Brugger wrote: > >> Hi Manivanna, > >> > >> On 05/06/18 18:34, Manivannan Sadhasivam wrote: > >>> Add initial device tree support for Mediatek X20 Development Board > >>> based on MT6797 Deca core SoC. This board is one of the 96Boards > >>> Consumer Edition platform. > >>> > >>> Signed-off-by: Manivannan Sadhasivam > >>> --- > >>> arch/arm64/boot/dts/mediatek/Makefile | 1 + > >>> .../boot/dts/mediatek/mt6797-x20-dev.dts | 33 +++++++++++++++++++ > >>> 2 files changed, 34 insertions(+) > >>> create mode 100644 arch/arm64/boot/dts/mediatek/mt6797-x20-dev.dts > >>> > >>> diff --git a/arch/arm64/boot/dts/mediatek/Makefile b/arch/arm64/boot/dts/mediatek/Makefile > >>> index ac17f60f998c..5b7fd6ad96e4 100644 > >>> --- a/arch/arm64/boot/dts/mediatek/Makefile > >>> +++ b/arch/arm64/boot/dts/mediatek/Makefile > >>> @@ -3,5 +3,6 @@ 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) += mt6797-evb.dtb > >>> +dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-x20-dev.dtb > >>> dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-rfb1.dtb > >>> dtb-$(CONFIG_ARCH_MEDIATEK) += mt8173-evb.dtb > >>> diff --git a/arch/arm64/boot/dts/mediatek/mt6797-x20-dev.dts b/arch/arm64/boot/dts/mediatek/mt6797-x20-dev.dts > >>> new file mode 100644 > >>> index 000000000000..2c09ca95d9e2 > >>> --- /dev/null > >>> +++ b/arch/arm64/boot/dts/mediatek/mt6797-x20-dev.dts > >>> @@ -0,0 +1,33 @@ > >>> +// SPDX-License-Identifier: GPL-2.0 > >>> +/* > >>> + * Device Tree Source for MediaTek X20 Development Board > >>> + * > >>> + * Copyright (C) 2018, Linaro Ltd. > >>> + * > >>> + */ > >>> + > >>> +/dts-v1/; > >>> + > >>> +#include "mt6797.dtsi" > >>> + > >>> +/ { > >>> + model = "Mediatek X20 Development Board"; > >>> + compatible = "archermind,mt6797-x20-dev", "mediatek,mt6797"; > >>> + > >>> + aliases { > >>> + serial0 = &uart1; > >>> + }; > >> > >> Sorry for the late answer. > >> Why did you use uart1 instead of uart0? > >> I know that uart0 is used by the bootloader, but because of their exotic flash > >> procedure I find it quite useful to see this messages in my serial connection. > >> Of course you can only use 921600 baudrate then. > >> > > > > The reason is, most of the Mezzanine boards use USB to UART bridge on the > > UART1 port available on the Low Speed Expansion header. Additionally, the > > convention followed by most of the Consumer Edition 96Boards is to use UART1 > > as the debug serial port. That's why eventhough the bootloader is using UART0, > > I forced the kernel to use UART1. > > > > Sounds reasonable, I don't have this 96 boards adapter and I forgot about it. > That's fine :) > >>> + > >>> + memory@40000000 { > >>> + device_type = "memory"; > >>> + reg = <0 0x40000000 0 0x1e605000>; > >> > >> How comes this strange number for the memory size? > >> > > > > Actually, the memory size is extracted from the downstream kernel [1]. > > > > Hm, Archermind "Helio X20 Development Board Hardware Manual" talks about 2GB > LPDDR3-SDRAM. Would you mind to check if that is actually true? > Yes, it is 2GB. Shall I change the size to 0x80000000? Thanks, Mani > >> BTW do you know the differences between the EVB board and the x20 one? > >> I used the evb dts for booting up to now. > >> > > > > Sorry, I don't know the difference between both boards! > > Sure, no problem :) > > Regards, > Matthias > > > > > Thanks, > > Mani > > > > [1] https://github.com/helio-x20/linux/blob/helio-x20/arch/arm64/boot/dts/amt6797_64_open.dts#L8 > > > >> Best regards, > >> Matthias > >> > >>> + }; > >>> + > >>> + chosen { > >>> + stdout-path = "serial0:115200n8"; > >>> + }; > >>> +}; > >>> + > >>> +&uart1 { > >>> + status = "okay"; > >>> +}; > >>>