From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Cousson, Benoit" Subject: Re: How to handle named resources with DT? Date: Tue, 9 Aug 2011 18:57:20 +0200 Message-ID: <4E4166F0.9050401@ti.com> References: <4E40FC88.5090403@ti.com> <20110809162907.GA630@manju-WNB7PBC4801-0006> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110809162907.GA630@manju-WNB7PBC4801-0006> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "G, Manjunath Kondaiah" Cc: "Hilman, Kevin" , Paul Walmsley , "devicetree-discuss@lists.ozlabs.org" , "Nayak, Rajendra" , Grant Likely , linux-omap , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org Hi Manju, On 8/9/2011 6:29 PM, G, Manjunath Kondaiah wrote: > Hi Benoit, > > On Tue, Aug 09, 2011 at 11:23:20AM +0200, Cousson, Benoit wrote: >> Hi Grant, >> >> Trying to bind hwmod informations with DT, I'm facing a little limitation. >> A bunch of drivers are using the platform_get_resource_byname, so >> the name for the resource is needed. >> >> The name is used so far for IORESOURCE_MEM, IORESOURCE_IRQ and >> IORESOURCE_DMA types of resources. > > IORESOURCE_MEM and IORESOURCE_IRQ's are fetched from dt blob and > it will be part of pdev. Yes, but without the proper name in the resource structure. It will be then impossible to use the platform_get_resource_byname function that is currently used by a bunch of drivers. > For IORESOURCE_DMA, you can have property > "dma-channel" in dtsi file and fetch dma-channel in driver probe > through "of_property_read_u32()" api. That will not be enough to get the name. So maybe something like: dmas = <12>, "rx_req", <13>, "tx_req"; will be doable. The issue is that the name is optional so managing the multiple entries might be tricky. BTW, it's strange that a default support does not exist for dma request (and not channel). The mechanism is similar to irq line, and quite standard to many SoC AFAIK. Or maybe I missed it. > BTW, this is not required for omap since dt-hwmod binding will fetch > pdev pointer from hwmod database and it will be used "as is" without > any modification which inturn does not break any existing pm > functionality. Well for the moment... but I have some long term plan as well:-) Thanks, Benoit