Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758427Ab3GZJ3X (ORCPT ); Fri, 26 Jul 2013 05:29:23 -0400 Received: from mail.free-electrons.com ([94.23.35.102]:36590 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755017Ab3GZJ3T (ORCPT ); Fri, 26 Jul 2013 05:29:19 -0400 Message-ID: <51F2400B.1060701@free-electrons.com> Date: Fri, 26 Jul 2013 11:23:23 +0200 From: Alexandre Belloni Organization: Free Electrons User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: Marek Vasut CC: Lars-Peter Clausen , Hector Palacios , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, jic23@kernel.org, fabio.estevam@freescale.com, Thomas Petazzoni Subject: Re: [PATCH v3 2/5] ARM: dts: add reference voltage property for MXS LRADC References: <1374501843-19651-1-git-send-email-hector.palacios@digi.com> <1374501843-19651-3-git-send-email-hector.palacios@digi.com> <51ED7B47.2090104@metafoo.de> <201307230006.53434.marex@denx.de> In-Reply-To: <201307230006.53434.marex@denx.de> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1594 Lines: 37 On 23/07/2013 00:06, Marek Vasut wrote: > Dear Lars-Peter Clausen, > >> On 07/22/2013 04:04 PM, Hector Palacios wrote: >>> Some LRADC channels have fixed pre-dividers so they can measure >>> different voltages at full scale. The reference voltage allows to >>> expose a scaling attribute through the IIO sysfs so that a user can >>> compute the real voltage out of a measured sample value. >> I've said before that I'm not convinced that this is the right way to >> implement this. And considering what Thomas said here >> http://www.mail-archive.com/devicetree-discuss@lists.ozlabs.org/msg36691.ht >> ml I guess I'm not alone with that opinion. >> >> - Lars > He's talking about different versions of the IP block, this is the same IP > block, just connected to different inputs. I don't have any strong opinion on that and I'm certainly not an expert but thinking about that, I feel this is different from the discussion Thomas had. Those are reference voltages and describe how the IP block is connected whereas what Thomas was describing is supporting multiple versions of an IP block by describing heaps of registers in the DT. It may look ugly here because you have a lot of channels but I find that quite acceptable. Regards, -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/