From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guennadi Liakhovetski Date: Tue, 17 Jul 2012 10:53:38 +0000 Subject: [PATCH/RFC 0/4] dma: Add multiplexer call-back for channel allocation Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi all As recently [1] proposed, a DMA channel multiplexer can be user to flexibly allocate DMA channels without a use of a DMAC-specific filter function. This patch set presents a possible implementation. Of the 3 patches in this series the first one is the actual proposal, the other two are an illustration, using the shdma dmaengine and the sh_mmcif mmc drivers on the sh7372 mackerel board. This is an RFC, please, comment. One extension, that seems to make sense is an addition of a multiplexer-configure call-back to actually configure the routing. It isn't needed in the shdma case, so, I didn't want to add it without real users. Something along the lines of struct dma_chan *(*route_chan)(struct dma_chan *, struct device *, enum dma_transfer_direction, const char *); perhaps? Thanks Guennadi [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/75828/focusv295 --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/