From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755179AbcGEOY0 (ORCPT ); Tue, 5 Jul 2016 10:24:26 -0400 Received: from mail-pa0-f67.google.com ([209.85.220.67]:36500 "EHLO mail-pa0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbcGEOYX (ORCPT ); Tue, 5 Jul 2016 10:24:23 -0400 Subject: Re: portable device tree connector -- problem statement To: Mark Brown References: <577ACE0D.9050700@gmail.com> <20160705083152.GM6247@sirena.org.uk> Cc: Pantelis Antoniou , Rob Herring , david@gibson.dropbear.id.au, stephen.boyd@linaro.org, grant.likely@secretlab.ca, Mark Rutland , mporter@konsulko.com, Koen Kooi , Guenter Roeck , marex@denx.de, Wolfram Sang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, panto@antoniou-consulting.com From: Frank Rowand Message-ID: <577BC30C.10105@gmail.com> Date: Tue, 5 Jul 2016 07:24:12 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20160705083152.GM6247@sirena.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/05/16 01:31, Mark Brown wrote: > On Mon, Jul 04, 2016 at 01:58:53PM -0700, Frank Rowand wrote: > >> On the other hand, I have no previous detailed knowledge of the beagle >> family. > > This is in no way specific to the BeagleBones, there's plenty of other > boards out there with similar setups like the Raspberry Pi and its > derivatives. Yes, absolutely. I'm just picking on the beaglebones because that is what Pantelis has recently used for examples. (He has mentioned other connector types and expansion boards in his presentations.) And we need to think beyond beaglebone, pi, arduino, and grove type of connectors. Some other connectors that are obvious are pci and possibly usb. >> - for bones with the same pinout: >> - the pins are routed to different function blocks on the >> SOC because different bones may have different SOCs? >> - the different functional blocks are compatible or not? > > This is the general case, there will be a substantial level of > compatibility between different base boards by virtue of the pinouts > being the same but obviously there will be some variation in the > specifics (and even where that exists it may not be enough to be visible > at the DT level for the most part). That said there will doubtless be > some plug in modules that want to rely on the specifics of a given base > board rather than remain compatible with general users of the interface. >