From mboxrd@z Thu Jan 1 00:00:00 1970 From: Karl Beldan Subject: Re: [PATCH] ARM: dts: da850: Add basic DTS for the L138/C6748 Dev Kit Date: Thu, 4 Aug 2016 21:03:26 +0000 Message-ID: <20160804210326.GE15013@gobelin> References: <20160804144332.4841-1-kbeldan@baylibre.com> <20160804182902.GA22499@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160804182902.GA22499@rob-hp-laptop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Rob Herring Cc: Mark Rutland , devicetree@vger.kernel.org, karl.beldan+oss@gmail.com, Kevin Hilman , Russell King , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Thu, Aug 04, 2016 at 01:29:02PM -0500, Rob Herring wrote: > On Thu, Aug 04, 2016 at 02:43:32PM +0000, Karl Beldan wrote: > > The LCDK is the successor to the late Hawkboard and has the same machine > > number. > > Among the differences are the flash (16bits vs 8bits) and some pins > > (MMC, LEDs, buttons, some external connectors), however the main > > components remain the same (eth. PHY, Audio Codec, Video decoder and > > DAC) except for the main PMIC, different and hard-wired on the LCDK (the > > LDOs and DCDCs are always ON). > > A DT-only boot with this addition gives functional uart, reboot via > > watchdog, rtc, ethernet and MMC (I added the CD gpio for the MMC > > although davinci_mmc doesn't call yet the mmc core OF facilities). > > > > Signed-off-by: Karl Beldan > > --- > > Documentation/devicetree/bindings/arm/davinci.txt | 4 ++ > > arch/arm/boot/dts/Makefile | 1 + > > arch/arm/boot/dts/omapl138-lcdk.dts | 71 +++++++++++++++++++++++ > > arch/arm/mach-davinci/da8xx-dt.c | 1 + > > 4 files changed, 77 insertions(+) > > create mode 100644 arch/arm/boot/dts/omapl138-lcdk.dts > > > > diff --git a/Documentation/devicetree/bindings/arm/davinci.txt b/Documentation/devicetree/bindings/arm/davinci.txt > > index cfaeda4..1482c74 100644 > > --- a/Documentation/devicetree/bindings/arm/davinci.txt > > +++ b/Documentation/devicetree/bindings/arm/davinci.txt > > @@ -5,6 +5,10 @@ DA850/OMAP-L138/AM18x Evaluation Module (EVM) board > > Required root node properties: > > - compatible = "ti,da850-evm", "ti,da850"; > > > > +DA850/OMAP-L138/AM18x L138/C6748 Development Kit (LCDK) board > > +Required root node properties: > > + - compatible = "ti,omapl138-lcdk", "ti,da850"; > > + > > EnBW AM1808 based CMC board > > Required root node properties: > > - compatible = "enbw,cmc", "ti,da850; > > diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile > > index 414b427..da3f69b 100644 > > --- a/arch/arm/boot/dts/Makefile > > +++ b/arch/arm/boot/dts/Makefile > > @@ -105,6 +105,7 @@ dtb-$(CONFIG_ARCH_BERLIN) += \ > > dtb-$(CONFIG_ARCH_BRCMSTB) += \ > > bcm7445-bcm97445svmb.dtb > > dtb-$(CONFIG_ARCH_DAVINCI) += \ > > + omapl138-lcdk.dtb \ > > da850-enbw-cmc.dtb \ > > da850-evm.dtb > > dtb-$(CONFIG_ARCH_DIGICOLOR) += \ > > diff --git a/arch/arm/boot/dts/omapl138-lcdk.dts b/arch/arm/boot/dts/omapl138-lcdk.dts > > new file mode 100644 > > index 0000000..fad3b6d > > --- /dev/null > > +++ b/arch/arm/boot/dts/omapl138-lcdk.dts > > @@ -0,0 +1,71 @@ > > +/* > > + * Copyright (c) 2016 BayLibre, Inc. > > + * > > + * Licensed under GPLv2 or later. > > + */ > > +/dts-v1/; > > +#include "da850.dtsi" > > +#include > > + > > +/ { > > + model = "DA850/AM1808/OMAP-L138 LCDK"; > > + compatible = "ti,omapl138-lcdk", "ti,da850"; > > + > > + aliases { > > + serial2 = &serial2; > > + }; > > + > > + chosen { > > + bootargs = "console=ttyS2,115200n8 earlycon"; > > You don't need console with stdout-path set. And really, earlycon should > not be the default. > Ok for earlycon. For the console, I thought likewise .. until I _struggled_ to understand why the console was disappearing under my feet. It seemed even stranger when I started looking at the codepath because drivers/of/base.c would properly add_preferred_console as expected after the corresponding UART was added. But the reality was there, without it the console was not like stdout-path. Among the commits that could instill doubt as to whether stdout-path rules is f64255b5072d: "The assumption that at least 1 preferred console will be registered when the stdout-path property is set is invalid, which can result in _no_ consoles.", though it didn't answer my question. I started looking whether tty0 was not getting in the way and in the end I came up with setting console. But you seem affirmative. Karl