From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] of: support an enumerated-bus compatible value Date: Tue, 3 Jul 2012 15:42:42 +0100 Message-ID: <20120703144242.GE25995@sirena.org.uk> References: <4FF1C567.4060809@wwwdotorg.org> <4FF1D8F9.9040005@firmworks.com> <4FF1DDBD.9050106@wwwdotorg.org> <4FF1EA1A.9030307@firmworks.com> <4FF1F955.6030204@wwwdotorg.org> <6BC22F77-77D7-45DF-821A-6CA2DBADEA59@kernel.crashing.org> <4FF22031.3060206@wwwdotorg.org> <20120703104720.GB25995@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Segher Boessenkool Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: devicetree@vger.kernel.org On Tue, Jul 03, 2012 at 04:00:37PM +0200, Segher Boessenkool wrote: > So you *can* address the device, you just don't want to show that > in the device tree (I don't blame you, it's quite impossible to > design a sane addressing scheme for this, all this stuff is so > ad-hoc). I see. You could make it the kid of a GPIO controller > node, but then what if it is controlled by two (or more!) GPIO > controllers? Yes, exactly - there's a bunch of random incoming signals which aren't reliably going to fit in with the tree structure (and of course we do already have a GPIO binding which isn't anything like the bus you're suggesting above). > There is still no reason for the fake bus node to have a "compatible" > property though. What could it possibly mean? "This bus does not > exist at all but you access it in bla bla bla way"? That just doesn't > make sense. It doesn't exist, you do not access it, it has no > programming model, it has no "compatible" property. Well, as everyone keeps saying this seems to be a limitation of the current device tree rather than something that's actually sensible in and of itself.