From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCH v3 0/2] dmaengine: core/omap-dma: Support for port window Date: Wed, 30 Nov 2016 08:54:28 +0530 Message-ID: <20161130032428.GZ6408@localhost> References: <20161129142342.30949-1-peter.ujfalusi@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20161129142342.30949-1-peter.ujfalusi@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Peter Ujfalusi Cc: dan.j.williams@intel.com, tony@atomide.com, linux@armlinux.org.uk, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, arnd@arndb.de List-Id: linux-omap@vger.kernel.org On Tue, Nov 29, 2016 at 04:23:40PM +0200, Peter Ujfalusi wrote: > Hi, > > Changes since v2: > - the src/dst_port_window_size is in words, not in bytes (comment updated) > - correct the port_window based configuration in the omap-dma driver > > Changes since v1: > - Make sure that the one frame covers the port_window (burst = port_window) > - added comment to explain the double indexed setup to cover the port_window > - Simplifications for the code mentioned by Russell and Vinod > > Cover letter from v1: > > as I'm trying to convert the remaining OMAP driver to use DMAengine instead of > the legacy omap-dma API I have encountered with the > drivers/usb/musb/tusb6010_omap.c driver. > > The TUSB6010 is connected via NOR FLASH interface and it's register space is > mapped in the GPMC memory area. In OMAP SoCs we have support for external DMA > request lines and the TUSB6010 is using those as well. > > With asynchronous access the DMA needs to read/write within the FIFO 'window' in > incremental address mode to read/write data. > The constant addressing only works in synchronous mode. > > Since the DMA is driven by external DMA requests, the asynchronous mode is also > slave DMA operation, but currently the port window can not be 'swiped' as the > DMAengine only supports single register/address on the slave side. > > This series will add support in dma_slave_config to specify the port side window > size and the second patch implements the setup needs in omap-dma driver for such > a transfer. Applied both, thanks -- ~Vinod