From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: Deprecating of_platform, the path from here... Date: Thu, 10 Dec 2009 13:47:33 -0700 Message-ID: References: <20091209.161550.168794100.davem@davemloft.net> <20091209.162121.256573183.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091209.162121.256573183.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: David Miller Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org, jk-mnsaURCQ41sdnm+yROfE0A@public.gmane.org List-Id: devicetree@vger.kernel.org Hi David, On Wed, Dec 9, 2009 at 5:21 PM, David Miller wrote: > From: David Miller > Date: Wed, 09 Dec 2009 16:15:50 -0800 (PST) > >> From: Grant Likely >> Date: Wed, 9 Dec 2009 15:06:29 -0700 >> >>> 1) of_platform will be deprecated in preference of the platform bus. >> >> What a shame, it's one of the cleanest driver probing models >> in the tree. > > And BTW, have you folks who "decided" this considered at all the fact > that it is much easier to describe represent platform devices using > of OF devices rather than the other way around? Yup. I also think of_platform is a cleaner implementation than platform, but the fact remains that there are far more platform drivers than there are of_platform. So, as nice as of_platform is, it still does pretty much exactly the same job as platform. I'd rather see of_platform features migrated to platform than creating drivers with dual registrations to be used on both OF and non-OF platforms. Trying to go the other way around (deprecate platform and encouraging of_platform instead) I don't think will gain much traction; whereas I think bringing of_platform features into platform will be an easier sell. I'm trying to be pragmatic here. > The platform device pdata mechanism requires data structure changes > and is not dynamically extensible, whereas OF devices are > fundamentally so. > > I don't like the idea to get rid of of_platform devices at all. There are no plans to actually remove of_platform. I certainly don't plan to try and force SPARC to switch from of_platform to platform bus. But on PowerPC (and probably Microblaze) the plan is to move away from of_platform for all the reasons discussed, and I'm not be bringing of_platform over as I work on ARM support. > OF devices are really clean, much like netlink messages, where > arbitrary named attributes can be added or removed without any data > structure changes at all. No argument here. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.