From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Suloev Subject: Re: [PATCH 7/7] ARM: dts: sun7i: Add dts file for the A20-linova1-7 HMI Date: Sat, 5 May 2018 00:59:07 +0300 Message-ID: <644bcd2f-3479-3f3c-3aef-9db3d565c133@orpaltech.com> References: <1521662593-25468-1-git-send-email-giulio.benetti@micronovasrl.com> <1521662593-25468-7-git-send-email-giulio.benetti@micronovasrl.com> <20180322180508.my64gobhh5rc2x2m@flea> <8ef3b259-03b4-6987-286e-36ff627a8b76@micronovasrl.com> <20180424084137.7xfwji2gcibxavvt@flea> <03a02abb-e95c-b4ec-748f-907c0af67969@micronovasrl.com> <20180425184016.xktppxw7egddr7li@flea> <42feccc9-1d09-9ff2-3ccc-1dea63bacfb6@micronovasrl.com> <839d2560-0250-9b3a-8019-4e83d9e931e2@micronovasrl.com> <20180504080652.dniwaqqhbeuknp7y@flea> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Giulio Benetti Cc: Maxime Ripard , devicetree@vger.kernel.org, David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Chen-Yu Tsai , Thierry Reding , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org Hi, Giulio, On 05/05/2018 12:52 AM, Giulio Benetti wrote: > Hi Maxime! > > Il 04/05/2018 10:06, Maxime Ripard ha scritto: >> Hi, >> >> On Wed, May 02, 2018 at 06:41:34PM +0200, Giulio Benetti wrote: >>>>> You don't have to handcode the fragments anymore with the new syntax, >>>>> and U-Boot makes it really trivial to use if you use the FIT image >>>>> format to have multiple overlays bundled in the same image. You can >>>>> choose to apply them dynamically, for example based on an EEPROM or >>>>> some other metric to see which combination you have. >>>> >>>> Ah, this is interesting. I'm going to experiment with that. >>>> >>> >>> I'm struggling against this, I don't really know how to proceed, >>> except keeping monolithic dts files including other dtsi files. >>> >>> About dt-overlays I've tried to look around lot of time, >>> but the only thing I've found is this: >>> https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/tree/arch/arm/boot/dts?h=topic/renesas-overlays >>> >>> >>> where they use .dtso tagging them as "/plugin/;" >>> and compile all .dtso found in dts folder. >>> Then they obtain .dtbo files that should be the dt-overlays we have >>> spoken >>> about right? >> >> Yes. You don't have to do that though, you can just rely on dtc to >> compile them, outside of the linux build system. >> >>> What I can't understand is if there's a real standard at this time to >>> follow, because on renesas-driver they use their way to handle all >>> .dtso >>> files, but on mainline there seems to be nothing about that. >> >> I'm not sure what you mean here. It's just fragments of device tree, >> that have to be compiled using dtc, that's it. You can use the Linux >> build system infrastructure to do that, or you can build your own >> simpler one. That's really up to you. See for example >> https://github.com/NextThingCo/CHIP-dt-overlays/blob/master/Makefile >> >> (even though the overlays themselves use the legacy syntax and >> shouldn't really be used an examples) > > Everything works now! > Thank you very much! > I've setted up a Repo on Github to give an example on how make it work > with no pain: > https://github.com/micronovasrl/linova-dtoverlays > > At the moment it's a mess all around, but it's working and give an > idea on how to make it work. Though I'm going to clean it up well as a > base for linova dtoverlays. > > Ah, btw, can you confirm me that base dts file must be compiled > outside kernel with: > dtc -@ .... > Otherwise as in-tree dts with make dtbs "-@" argument is not passed. > Right? > > Thank you a lot for your help and time again! > > Best regards! > I'd highly recommend you to look at Armbian overlay support: it is easy and elegant. https://github.com/armbian/build/blob/master/patch/kernel/sunxi-next/add-overlay-compilation-support.patch https://github.com/armbian/build/blob/master/patch/kernel/sunxi-next/add-sunxi-overlays.patch Sergey