From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com ([209.85.192.170]:34117 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbaBGWTx convert rfc822-to-8bit (ORCPT ); Fri, 7 Feb 2014 17:19:53 -0500 Received: by mail-pd0-f170.google.com with SMTP id p10so3703997pdj.15 for ; Fri, 07 Feb 2014 14:19:53 -0800 (PST) Date: Fri, 07 Feb 2014 14:19:59 -0800 Subject: Re: DMA sampling and IIO From: John Syn To: Mark Brown , Lars-Peter Clausen CC: , Matt Flax Message-ID: References: <52F35C5B.7080409@metafoo.de> <52F3FB6E.3070201@metafoo.de> <20140207132058.GN32298@sirena.org.uk> In-Reply-To: <20140207132058.GN32298@sirena.org.uk> 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 On 2/7/14, 5:20 AM, "Mark Brown" wrote: >On Thu, Feb 06, 2014 at 10:15:26PM +0100, Lars-Peter Clausen wrote: > >> I guess this is because it is the traditional area where I2S is used >>and nobody >> cared so far about using it somewhere else in the context of the Linux >>kernel. >> Not having to have a extra layer of abstraction in the middle between >>ALSA/ASoC >> and the I2S peripheral driver helped to keep things simple. > >Plus many of the uses actually found that the audio APIs were doing >useful things for them anyway - the DMA bit is reasonably useful way of >transferring continuous streams of data and nothing much cares if that >data is actually audio or not so long as the application on top doesn't >mind. Hi Mark, That is interesting. The ADE7878 transmits the measurements as 16 sequential measurements (Voltage A, Voltage B, Voltage C, Current A, etc) and uses a frame to denote a new set of measurements. Can the audio API cope with 16 channels and how do I prevent any modification (equalization, etc) to the measurement data? Also, is it possible to break out these measurements into separate buffers (Voltage A buffer, Voltage B buffer, etc)? I guess I would access these measurement in the same way as an audio application like aplay? What I donšt like about this solution is the possibility of missing samples. In an audio app, this isnšt so critical, but in my app this would be a big problem. Regards, John >