From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from service87.mimecast.com ([91.220.42.44]:47910 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756131Ab3G2Nhk convert rfc822-to-8bit (ORCPT ); Mon, 29 Jul 2013 09:37:40 -0400 Message-ID: <1375105055.10990.14.camel@hornet> Subject: Re: [PATCH 1/2] mmc: add Device Tree properties for UHS modes From: Pawel Moll Date: Mon, 29 Jul 2013 14:37:35 +0100 In-Reply-To: References: <51F2ADA2.2030503@wwwdotorg.org> <51F2EBD4.1060603@wwwdotorg.org> <1375095053.3340.7.camel@hornet> <1375098159.3340.29.camel@hornet> <1375103234.10990.8.camel@hornet> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: devicetree-owner@vger.kernel.org To: Guennadi Liakhovetski Cc: Stephen Warren , "linux-sh@vger.kernel.org" , "linux-mmc@vger.kernel.org" , Magnus Damm , Chris Ball , "devicetree@vger.kernel.org" , Simon Horman , Ian Campbell , Mark Rutland , "rob.herring@calxeda.com" List-ID: On Mon, 2013-07-29 at 14:30 +0100, Guennadi Liakhovetski wrote: > Yes, this is also a possibility, but it seems only a little bit better. > Why should a DT node on SoC vN have a compatible string with SoC vK for > some random for an abstract user absolutely unrelated SoC version?... And > that vK would be different for different devices... So on SoC v5 MMC can > be compatible with with v1, sound with v2, camera with v3... Don't you > think it would look like a mess? It won't be SoC v5 MMC then. It will be just MMC vX. SoC v6 will still have MMC vX, but SoC v7 already MMC vY (where, most likely, Y=X+1). I appreciate the fact that the SoC datasheets don't always explicitly mention the IP revision, but it's still there. Also, quite often the differences don't lie in the IP itself (it costs a lot of money to license a new version of eg. MMC host controller from Synopsys), but in the glue logic/adaptation layer etc. But in such case it probably should be described in the tree itself. Which gets us to square one :-) Pawel PS. Of course MMC vY may be just a superset of vX, so then it will be compatible with "MMC vY", "MMC vX".