From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com ([134.134.136.20]:5658 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751586AbaG1LJq (ORCPT ); Mon, 28 Jul 2014 07:09:46 -0400 Message-ID: <57688.163.33.229.63.1406545747.squirrel@linux.intel.com> In-Reply-To: <53D12208.9030500@metafoo.de> References: <61739.163.33.230.161.1406207197.squirrel@linux.intel.com> <53D12208.9030500@metafoo.de> Date: Mon, 28 Jul 2014 11:09:07 -0000 (GMT) Subject: Re: IIO for PCIe-DMA ADC From: "Krzysztof Sywula" To: "Lars-Peter Clausen" Cc: "Krzysztof Sywula" , linux-iio@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org Lars, I have few more questions, would love if you could answer. - ADC I have uses max 4KHz sampling frequency, SoC CPU is 533MHz; will IIO cope? - are there any other ADCs in IIO framework that use your DMA-extension? - I would like to use dw_dmac DMA driver, I hope both, IIO and your DMA-extension will honour that - what is the status of upstreaming DMA-extension? Are you commited to any dates? - is there any out of the box set of tests for IIO/DMA-extension? Thanks, Krzysztof Sywula > On 07/24/2014 03:06 PM, Krzysztof Sywula wrote: >> Hi there, I’m designing a PCIe driver for DMA enabled ADC. Is IIO >> handling >> such a combo? I'm based on kernel 3.8.7. >> >> Website: >> http://wiki.analog.com/software/linux/docs/iio/iio >> says "However typical DMA operated devices such as ones connected to a >> high speed synchronous serial (McBSP, SPORT) or high speed synchronous >> parallel (EPI, PPI) or FPGA peripherals are also subject to this >> subsystem." >> >> which is not clear enough for me to answer that question. > > > Hi, > > The current upstream version of IIO does not have built-in support for > DMA, > but you can always create your custom buffer implementation that handles > the > DMA. > > There is a out of tree generic DMA[0] and DMAengine[1] support for IIO. > This > is both scheduled for mainline submission, but obviously will not be > available in a 3.8.7 kernel. > > - Lars > > [0] > https://github.com/analogdevicesinc/linux/blob/xcomm_zynq/drivers/iio/industrialio-dmabuf.c > [1] > https://github.com/analogdevicesinc/linux/blob/xcomm_zynq/drivers/iio/industrialio-dmaengine.c > >