From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Cousson, Benoit" Subject: Re: [RFC PATCH 1/2] of: Add generic device tree DMA helpers Date: Thu, 23 Feb 2012 16:57:18 +0100 Message-ID: <4F4661DE.90704@ti.com> References: <4F22DEF2.5000807@ti.com> <4F44CA82.9060906@atmel.com> <4F460EF2.9010000@ti.com> <4F46609C.8080907@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4F46609C.8080907@atmel.com> Sender: linux-omap-owner@vger.kernel.org To: Nicolas Ferre Cc: Grant Likely , Rob Herring , Stephen Warren , Thomas Abraham , "devicetree-discuss@lists.ozlabs.org" , linux-omap , "linux-arm-kernel@lists.infradead.org" , Jean-Christophe PLAGNIOL-VILLARD , Ludovic Desroches List-Id: devicetree@vger.kernel.org On 2/23/2012 4:51 PM, Nicolas Ferre wrote: > On 02/23/2012 11:03 AM, Cousson, Benoit : >> Salut Nico, > > Coucou Benoit ;-) > >> On 2/22/2012 11:59 AM, Nicolas Ferre wrote: >>> On 01/27/2012 06:29 PM, Cousson, Benoit : >>>> Add some basic helpers to retrieve a DMA controller device_node >>>> and the DMA request line number. >>>> >>>> For legacy reason another API will export the DMA request number >>>> into a Linux resource of type IORESOURCE_DMA. >>>> This API is usable only on system with an unique DMA controller. >>> >>> Hi, >>> >>> I followed that discussion and I like very much the biding that Benoit >>> is proposing. It will help me a lot with my current work on Atmel DMA >>> controller. >>> >>> If I understand correctly, some rework is needed before it can be >>> integrated in a stable git tree (I mean before we can base our work on >>> top of it). So, in the meantime, what should I do to help and make >>> things go forward? to be quite frank, I would be interested to have a >>> working DMA enabled device soon ;-) >> >> Me too, but unfortunately, I was busy trying to add irq_domain and >> fixing issues with SPARSE_IRQ on OMAP :-( > > Been there, loved that ;-) > >>> Do you think that 3.4 is out of reach? >> >> Maybe not, from the comments, it looks like we should add a .xlate >> callback to allow any custom parsing of the DMA nodes attributes. >> >> I'll be more than happy, if you can finalize that patch :-) > > I will try to figure out what I can understand from the irq mechanism of > .xlate and try to see if I can implement it on top of your patch. In fact that dma code is a big copy/paste of the of/gpio one and gpio was already managing .xlate function. I removed it because I thought it was useless for the DMA :-) You might just have to copy the original code... > I will keep you informed... Thanks for the help, Benoit