From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [PATCH v3 1/7] dmaengine: of_dma: Support for DMA routers Date: Tue, 31 Mar 2015 19:48:03 +0300 Message-ID: <551ACFC3.5020003@ti.com> References: <1427459213-14611-1-git-send-email-peter.ujfalusi@ti.com> <1427459213-14611-2-git-send-email-peter.ujfalusi@ti.com> <201503280244.46961.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <201503280244.46961.arnd@arndb.de> Sender: linux-omap-owner@vger.kernel.org To: Arnd Bergmann Cc: vinod.koul@intel.com, tony@atomide.com, linux@arm.linux.org.uk, grant.likely@linaro.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, robh+dt@kernel.org, nm@ti.com List-Id: devicetree@vger.kernel.org On 03/28/2015 03:44 AM, Arnd Bergmann wrote: > On Friday 27 March 2015, Peter Ujfalusi wrote: >> +Required property: >> +- dma-device: phandle of the DMA controller. The router is= modifying >> + the DMA requests for this controller. >=20 > This property seems rather specific to the case at hand, I would expe= ct that > one might also see routers like this that are connected to more than = one > dma-device, so maybe make it a list? Yeah, it is intentional from my part. In dra7xx family we actually have two DMA controllers: sDMA and eDMA. T= hey both have identical crossbar up front but you can not choose the DMA re= quest to be routed to either eDMA or sDMA. They are always routed to both and= in the crossbar you select which signal goes to which DMA request of the given controller. At the moment I was not aware of different designs (current and future)= , but it might be possible that a design you described might surface at some = point. =46or sure, the list will complicate things quite a bit it might requir= e different API and callbacks at the end. I need to think about this how = it is going to work best. > It might also be better to name this as 'dma-controllers' or 'dma-mas= ters', > as it is not entirely obvious (without referencing the binding docume= nt) > whether a dma device refers to the slave or the master. I think the 'dma-masters' sounds much better. PS: I'm out of office this week so do not expect v4 before mid next wee= k. --=20 P=E9ter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html