Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751986Ab0HQEgk (ORCPT ); Tue, 17 Aug 2010 00:36:40 -0400 Received: from tango.tkos.co.il ([62.219.50.35]:50088 "EHLO tango.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321Ab0HQEgj (ORCPT ); Tue, 17 Aug 2010 00:36:39 -0400 Date: Tue, 17 Aug 2010 07:36:12 +0300 From: Baruch Siach To: Sascha Hauer Cc: Linus Walleij , Dan Williams , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100816141540.GQ27749@pengutronix.de> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1653 Lines: 36 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? baruch -- ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il - -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/