From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out-247.synserver.de ([212.40.185.247]:1051 "EHLO smtp-out-243.synserver.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751295AbaG1LsO (ORCPT ); Mon, 28 Jul 2014 07:48:14 -0400 Message-ID: <53D63879.5050709@metafoo.de> Date: Mon, 28 Jul 2014 13:48:09 +0200 From: Lars-Peter Clausen MIME-Version: 1.0 To: Krzysztof Sywula CC: linux-iio@vger.kernel.org Subject: Re: IIO for PCIe-DMA ADC References: <61739.163.33.230.161.1406207197.squirrel@linux.intel.com> <53D12208.9030500@metafoo.de> <57688.163.33.229.63.1406545747.squirrel@linux.intel.com> In-Reply-To: <57688.163.33.229.63.1406545747.squirrel@linux.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 07/28/2014 01:09 PM, Krzysztof Sywula wrote: > 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? That's more of a hardware issue and less of a IIO framework issue. But I think 4kHz is something that's even without DMA possible to archive without problems. > - are there any other ADCs in IIO framework that use your DMA-extension? Not at this point. > - I would like to use dw_dmac DMA driver, I hope both, IIO and your > DMA-extension will honour that If the dw_dmac driver is compliant with the DMAengine API it will work out of the box. > - what is the status of upstreaming DMA-extension? Are you commited to any > dates? soon ;) The plan is to at least send the kernel parts after the next merge window has closed. > - is there any out of the box set of tests for IIO/DMA-extension? The userspace API is backwards compatible so you can use the same tools that can be used to test other IIO applications. - Lars > > 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 >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >