Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751995Ab2KLKxz (ORCPT ); Mon, 12 Nov 2012 05:53:55 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:39852 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750988Ab2KLKxx convert rfc822-to-8bit (ORCPT ); Mon, 12 Nov 2012 05:53:53 -0500 Content-Type: text/plain; charset=US-ASCII Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: Re: [RFC] Device Tree Overlays Proposal (Was Re: capebus moving omap_devices to mach-omap2) From: Koen Kooi In-Reply-To: Date: Mon, 12 Nov 2012 11:53:49 +0100 Cc: Stephen Warren , Pantelis Antoniou , Rob Herring , Deepak Saxena , Benjamin Herrenschmidt , Scott Wood , Tony Lindgren , Kevin Hilman , Matt Porter , linux-kernel , Felipe Balbi , Russ Dill , linux-omap@vger.kernel.org, devicetree-discuss@lists.ozlabs.org Content-Transfer-Encoding: 7BIT Message-Id: <89EFC1DF-4471-49C4-9483-C67C57C73986@dominion.thruhere.net> References: <50999145.2070306@wwwdotorg.org> <509D9089.7020407@wwwdotorg.org> To: Grant Likely X-Mailer: Apple Mail (2.1499) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2400 Lines: 50 Op 10 nov. 2012, om 00:40 heeft Grant Likely het volgende geschreven: > On Fri, Nov 9, 2012 at 11:23 PM, Stephen Warren wrote: >> On 11/09/2012 09:28 AM, Grant Likely wrote: >>> On Tue, Nov 6, 2012 at 10:37 PM, Stephen Warren wrote: >> ... >>>> I do rather suspect this use-case is quite common. NVIDIA certainly has >>>> a bunch of development boards with pluggable >>>> PMIC/audio/WiFi/display/..., and I believe there's some ability to >>>> re-use the pluggable components with a variety of base-boards. >>>> >>>> Given people within NVIDIA started talking about this recently, I asked >>>> them to enumerate all the boards we have that support pluggable >>>> components, and how common it is that some boards support being plugged >>>> into different main boards. I don't know when that enumeration will >>>> complete (or even start) but hopefully I can provide some feedback on >>>> how common the use-case is for us once it's done. >>> >>> From your perspective, is it important to use the exact same .dtb >>> overlays for those add-on boards, or is it okay to have a separate >>> build of the overlay for each base tree? >> >> I certainly think it'd be extremely beneficial to use the exact same >> child board .dtb with arbitrary base boards. >> >> Consider something like the Arduino shield connector format, which I >> /believe/ has been re-used across a wide variety of Arduino boards and >> other compatible or imitation boards. Now consider a vendor of an >> Arduino shield. The shield vendor probably wants to publish a single >> .dtb file that works for users irrespective of which board they're using >> it with. >> >> (Well, I'm not sure that Arduino can run Linux; perhaps that's why you >> picked BeagleBone capes for your document!) > > Correct, the Arduino is only an AVR with a tiny amount of ram. No Linux there. > > However, Arduino shields are a good example of a use case. I think > there are even some Arduino shield compatible Linux boards out there. A good example of those would be the Rascal Micro: http://rascalmicro.com/ regards, Koen-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/