From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4027DC433FE for ; Sun, 13 Dec 2020 12:17:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7A84206B7 for ; Sun, 13 Dec 2020 12:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406194AbgLMMRA (ORCPT ); Sun, 13 Dec 2020 07:17:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:33558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405806AbgLMMRA (ORCPT ); Sun, 13 Dec 2020 07:17:00 -0500 Received: from archlinux (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A787D206B7; Sun, 13 Dec 2020 12:16:18 +0000 (UTC) Date: Sun, 13 Dec 2020 12:16:15 +0000 From: Jonathan Cameron To: Peter Rosin Cc: Linus Walleij , linux-iio , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler Subject: Re: [PATCH] iio: afe: iio-rescale: Support processed channels Message-ID: <20201213121615.55a86f77@archlinux> In-Reply-To: <435ebb1b-431c-fdeb-023e-39c6f6102e22@axentia.se> References: <20201101232211.1194304-1-linus.walleij@linaro.org> <435ebb1b-431c-fdeb-023e-39c6f6102e22@axentia.se> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, 13 Dec 2020 00:22:17 +0100 Peter Rosin wrote: > On 2020-12-12 13:26, Linus Walleij wrote: > > On Mon, Nov 2, 2020 at 12:22 AM Linus Walleij wrote: > > > >> It happens that an ADC will only provide raw or processed > >> voltage conversion channels. (adc/ab8500-gpadc.c). > >> On the Samsung GT-I9070 this is used for a light sensor > >> and current sense amplifier so we need to think of something. > >> > >> The idea is to allow processed channels and scale them > >> with 1/1 and then the rescaler can modify the result > >> on top. > >> > >> Cc: Peter Rosin > >> Signed-off-by: Linus Walleij > > > > Did we reach any conclusion on this? I really need to use > > the rescaler on an ADC that only handles processed channels... > > > > I'm sorry that I can't make this ADC disappear :D > > Hi! > > My conclusion was that the patch is buggy since it presents inconsistent > information. That needs to be fixed one way or the other. If the offending > information cannot be filtered out for some reason, I don't know what to > do. Details in my previous comment [1]. BTW, I still do not know the answer > to the .read_avail question at the end of that message, and I don't have > time to dig into it. Sorry. Unless I'm missing something, I think it presents no information unless we strangely have a driver providing read_avail for _RAW but only _PROCESSED channels which is a bug. I'm not that bothered about missing information in this particular, somewhat obscure, corner case. So I think we should take the patch as it stands. It's missed the merge window now anyway unfortunately. So Peter, I would suggest we take this and perhaps revisit to tidy up loose corners when we all have more time. Thanks, Jonathan > > Cheers, > Peter > > [1] https://lore.kernel.org/linux-iio/320464d8-659c-01de-0e08-34e4c744ef16@axentia.se/