From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964891AbVLNT1F (ORCPT ); Wed, 14 Dec 2005 14:27:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964916AbVLNT1E (ORCPT ); Wed, 14 Dec 2005 14:27:04 -0500 Received: from smtp104.sbc.mail.mud.yahoo.com ([68.142.198.203]:39348 "HELO smtp104.sbc.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S964891AbVLNT1D (ORCPT ); Wed, 14 Dec 2005 14:27:03 -0500 From: David Brownell To: Vitaly Wool Subject: Re: [PATCH/RFC] SPI: add DMAUNSAFE analog Date: Wed, 14 Dec 2005 10:50:54 -0800 User-Agent: KMail/1.7.1 Cc: Greg KH , linux-kernel@vger.kernel.org, dpervushin@gmail.com, akpm@osdl.org, basicmark@yahoo.com, komal_shah802003@yahoo.com, stephen@streetfiresound.com, spi-devel-general@lists.sourceforge.net, Joachim_Jaeger@digi.com References: <20051212182026.4e393d5a.vwool@ru.mvista.com> <20051214171842.GB30546@kroah.com> <43A05C32.3070501@ru.mvista.com> In-Reply-To: <43A05C32.3070501@ru.mvista.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200512141050.55294.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 14 December 2005 9:53 am, Vitaly Wool wrote: > Greg KH wrote: > > >What is the speed of your SPI bus? > > > >And what are your preformance requirements? > > > > > The maximum frequency for the SPI bus is 26 MHz, WLAN driver is to work > at true 10 Mbit/sec. Some SPI flash chips are rated at 60 MHz ... there's no "official" standard placing such limits on SPI. The various IEEE 802.15.4 (ZigBee) transceivers seem to take up to 10 MHz clocks, FWIW. USB controllers, 12 MHz (surprise! they are of course full speed, 12 MHz). Sensors with A-to-D converters are often lower rate; only 100K samples per second, say, at maybe 12 bits each; more like 2 MHz. - Dave