From mboxrd@z Thu Jan 1 00:00:00 1970 From: s.hauer@pengutronix.de (Sascha Hauer) Date: Tue, 17 Aug 2010 08:47:34 +0200 Subject: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support In-Reply-To: <20100817043612.GA9631@jasper.tkos.co.il> References: <1281956870-12463-1-git-send-email-s.hauer@pengutronix.de> <1281956870-12463-4-git-send-email-s.hauer@pengutronix.de> <20100816141540.GQ27749@pengutronix.de> <20100817043612.GA9631@jasper.tkos.co.il> Message-ID: <20100817064734.GS27749@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Aug 17, 2010 at 07:36:12AM +0300, Baruch Siach wrote: > Hi Sascha, > > On Mon, Aug 16, 2010 at 04:15:40PM +0200, Sascha Hauer wrote: > > On Mon, Aug 16, 2010 at 02:21:06PM +0200, Linus Walleij wrote: > > > 2010/8/16 Sascha Hauer : > > > > The SDMA engine is a scatter/gather DMA engine which is implemented > > > > as a seperate coprocessor. SDMA needs its own firmware which is > > > > requested using the standard request_firmware mechanism. The firmware > > > > has different entry points for each peripheral type, so drivers > > > > have to pass the peripheral type to the DMA engine which in turn > > > > picks the correct firmware entry point from a table contained in > > > > the firmware image itself. > > > > > > Quite fun, if the spec for the microcode is open this opens up > > > for dynamic firmware generation for specific DMA jobs does it > > > not? > > > > Unfortunately the specs are not open, so we are sticked to the binary > > microcode from Freescale. I'm pretty sure though that the SDMA engine > > could do at least a device_prep_dma_xor operation. > > Chapter 38 in the i.MX25 Reference Manual seems to include almost everything > there is to know about the SDMA. Isn't this enough for writing custom SDMA > microcodes? Unfortunately not, the assembler is missing. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |