From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: How to handle named resources with DT? Date: Tue, 9 Aug 2011 13:26:29 -0500 Message-ID: <4E417BD5.8080409@freescale.com> References: <4E40FC88.5090403@ti.com> <20110809162907.GA630@manju-WNB7PBC4801-0006> <4E4166F0.9050401@ti.com> <4E4172A8.3030101@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4E4172A8.3030101@ti.com> Sender: linux-omap-owner@vger.kernel.org To: "Cousson, Benoit" Cc: Grant Likely , "Hilman, Kevin" , Paul Walmsley , "G, Manjunath Kondaiah" , "devicetree-discuss@lists.ozlabs.org" , linux-omap , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On 08/09/2011 12:47 PM, Cousson, Benoit wrote: > On 8/9/2011 7:23 PM, Grant Likely wrote: >> There is no analogous mechanism for _byname in the device tree. The >> DT binding for a device must explicitly state what order the register >> ranges are in. The driver will need to be adapted. > > That seems to be a small regression for my point of view. Relying on the > order is not super safe. This is not very readable either. That's for > that exact reason that we changed our drivers to use > platform_get_resource_byname. That's probably the reason why that API is > there as well. > For the same IP, the number of entries can vary depending of the SoC > revision. > By using the _byname, we can check if the resource is there or not > without having to care about the position. You could have a named u32 property that contains the reg index, e.g.: dev { reg = <0x20000 0x200 0x24000 0x200>; foo-reg = <0>; bar-reg = <1>; }; -Scott