From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tx2ehsobe004.messaging.microsoft.com ([65.55.88.14]:51759 "EHLO TX2EHSOBE009.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753463Ab1K2NAv (ORCPT ); Tue, 29 Nov 2011 08:00:51 -0500 Message-ID: <4ED4D611.7030701@analog.com> Date: Tue, 29 Nov 2011 13:54:41 +0100 From: Michael Hennerich Reply-To: MIME-Version: 1.0 To: Alessandro Rubini CC: "lars@metafoo.de" , "jic23@kernel.org" , "federico.vaga@gmail.com" , "linux-iio@vger.kernel.org" , "greg@kroah.com" , "device-drivers-devel@blackfin.uclinux.org" Subject: Re: ZIO wiki analysis of IIO and why it doesn't meet there requirements [was Re: Industrial Input Output analysis] References: <4ED36B93.5020703@metafoo.de> <4ED21960.1000002@kernel.org> <20111129110013.GA27762@mail.gnudd.com> In-Reply-To: <20111129110013.GA27762@mail.gnudd.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 11/29/2011 12:00 PM, Alessandro Rubini wrote: > > Hello Lars-Peter, sorry for the delay. >> We do use IIO for high speed data conversion. > May I know how high? > Hi Alessandro, Right now we use IIO to capture single work loads at 250MSPS. User space requests - let's say 1M samples, the IIO driver captures and returns data to user space. (sounds a bit similar to your use case) Hardware is a Virtex6 FPGA, microblaze softcore running Linux and the converter is a AD9467 on an FMC-LPC card. The per-sample buffer implementations in IIO are purely optional! You can build your own buffer implementation by using the INDIO_BUFFER_HARDWARE flag. For now the full rate capture is only used for hardware validation purposes. Later it is assumed that there will be data decimation inside the FPGA fabric, so that only a few MSPS sustained data is DMAed into the processor core system. Right now it's not decided whether double buffering or a larger chain is required in order to solve the producer-consumer and latency problems. But I'm pretty optimistic that there is nothing in IIO which prevents me from getting the right solution in place. Ideally there is only one subsytem, and not one targeting low-speed and another for high speed. -- Greetings, Michael -- Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368; Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin, Margaret Seif