From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v4 00/14] DMA Engine support for AM33XX Date: Fri, 11 Jan 2013 11:40:41 +0000 Message-ID: <201301111140.41584.arnd@arndb.de> References: <1357883330-5364-1-git-send-email-mporter@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1357883330-5364-1-git-send-email-mporter-l0cyMroinI0@public.gmane.org> 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: Matt Porter Cc: Linux DaVinci Kernel List , Linux OMAP List , Russell King , Linux Documentation List , Linux MMC List , Devicetree Discuss , Mark Brown , Sekhar Nori , Linux Kernel Mailing List , Rob Herring , Vinod Koul , Dan Williams , Linux SPI Devel List , Chris Ball , Linux ARM Kernel List List-Id: linux-mmc@vger.kernel.org On Friday 11 January 2013, Matt Porter wrote: > The approach taken is similar to how OMAP DMA is being converted to > DMA Engine support. With the functional EDMA private API already > existing in mach-davinci/dma.c, we first move that to an ARM common > area so it can be shared. Adding DT and runtime PM support to the > private EDMA API implementation allows it to run on AM33xx. AM33xx > only boots using DT so we leverage Jon's generic DT DMA helpers to > register EDMA DMAC with the of_dma framework and then add support > for calling the dma_request_slave_channel() API to both the mmc > and spi drivers. I think this looks very good. What I wonder is whether we should make the non-DT parts of the dmaengine driver compile-time conditional on CONFIG_ATAGS though, so the slave drivers don't have a link-time dependency on the dmaengine driver's omap_dma_filter_fn symbol when building without ATAGS support. Arnd