From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relaygw2-2.mclink.it ([213.21.178.137]:48710 "EHLO relaygw2-2.mclink.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbaBFVQk (ORCPT ); Thu, 6 Feb 2014 16:16:40 -0500 Received: from [195.110.128.82] (HELO smtpoutgw1.mclink.it) by relaygw2-2.mclink.it (CommuniGate Pro SMTP 6.0.4) with ESMTP id 11575438 for linux-iio@vger.kernel.org; Thu, 06 Feb 2014 22:16:38 +0100 Date: Thu, 6 Feb 2014 22:16:37 +0100 From: Alessandro Rubini To: lars@metafoo.de Cc: john3909@gmail.com, linux-iio@vger.kernel.org, broonie@kernel.org, flatmax@flatmax.org Subject: Re: DMA sampling and IIO Message-ID: <20140206211637.GA14525@mail.gnudd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <52F3F84F.5040001@metafoo.de> References: <52F3F84F.5040001@metafoo.de> <52F35C5B.7080409@metafoo.de> <20140206205327.GA11958@mail.gnudd.com> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org >> ZIO already supports dma. And mmaping the buffer from user space. It >> is in the design since inception, and in the code since Feb 2012 (git >> log says). > > I know. And I did study the ZIO DMA code (among other things), > before I implemented the IIO DMA code. As you might remember from > our last discussion, my preference is to add the features that are > in ZIO but not in IIO to IIO and then ditch ZIO instead of having > two frameworks for the class of devices. I remember. And we both know that the class of devices that ZIO already supports cannot be supported by IIO, unless many incompatible changes are made (sub-nanosecond timestamps, symmetric input and output, hot-swap of buffer and trigger type, ...). I'm happy all accelerometers have the same interface to user space, this is definitely useful. But that's clearly not the same class of devices. > and then ditch ZIO How can you "ditch" something you don't use? Or is your employer currently using zio while helping iio catch up? Our users will not stop using it, despite your desire, because it already serves them pretty well: 100MS ADC, with DMA and mmap, all sysfs-based, completely run-time configurable, and v2.6.24..v3.12 (13 untested yet). /alessandro