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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=unavailable 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 54CF0C433B4 for ; Sat, 8 May 2021 15:58:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37B80611BE for ; Sat, 8 May 2021 15:58:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229579AbhEHP7t (ORCPT ); Sat, 8 May 2021 11:59:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:47010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229500AbhEHP7t (ORCPT ); Sat, 8 May 2021 11:59:49 -0400 Received: from jic23-huawei (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 DE5C660FE9; Sat, 8 May 2021 15:58:45 +0000 (UTC) Date: Sat, 8 May 2021 16:59:44 +0100 From: Jonathan Cameron To: Peter Rosin Cc: Krzysztof Kozlowski , Lars-Peter Clausen , Rob Herring , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dt-bindings: iio: afe: current-sense-shunt: add io-channel-cells Message-ID: <20210508165944.2e3d8d91@jic23-huawei> In-Reply-To: <0e68ca18-7d8c-12ab-59b1-56404b29be77@axentia.se> References: <20210506150637.35288-1-krzysztof.kozlowski@canonical.com> <0e68ca18-7d8c-12ab-59b1-56404b29be77@axentia.se> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; 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: devicetree@vger.kernel.org On Sat, 8 May 2021 00:44:58 +0200 Peter Rosin wrote: > Hi! > > On 2021-05-06 17:06, Krzysztof Kozlowski wrote: > > The current-sense-shunt is an IIO provider thus can be referenced by IIO > > consumers (via "io-channels" property in consumer device node). > > Such provider is required to describe number of cells used in phandle > > lookup with "io-channel-cells" property. This also fixes dtbs_check > > warnings like: > > > > arch/arm/boot/dts/s5pv210-fascinate4g.dt.yaml: current-sense-shunt: > > '#io-channel-cells' does not match any of the regexes: 'pinctrl-[0-9]+' > > > > Fixes: ce66e52b6c16 ("dt-bindings:iio:afe:current-sense-shunt: txt to yaml conversion.") > > Signed-off-by: Krzysztof Kozlowski > > --- > > .../devicetree/bindings/iio/afe/current-sense-shunt.yaml | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml b/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml > > index 90439a8dc785..05166d8a3124 100644 > > --- a/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml > > +++ b/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml > > @@ -24,12 +24,16 @@ properties: > > description: | > > Channel node of a voltage io-channel. > > > > + "#io-channel-cells": > > + const: 0 > > + > > shunt-resistor-micro-ohms: > > description: The shunt resistance. > > > > required: > > - compatible > > - io-channels > > + - "#io-channel-cells" > > - shunt-resistor-micro-ohms > > I know I'm listed as maintainer and all, but I have not kept up with the yaml > conversion. Sorry. So, given that I might very well fundamentally misunderstand > something, it does not sound correct that #io-channel-cells is now "required". > I regard it as optional, and only needed if some other in-kernel driver is > consuming the sensed current. What am I missing? > Agreed. This should be optional and I have deliberately not introduced it into all the bindings that could in theory support being used as providers. So far I've not pushed it out in a blanket fashion into existing bindings even as optional. > Also, whatever is done in this binding should preferably also be done in the > two "sister" afe bindings, i.e. current-sense-amplifier and voltage-divider. This particular case is squashing an error, so whilst I'm happy to have those gain the binding addition, I would like to see them in a separate patch as less likely they'd get back ported. If Kryysztof is fine with me just dropping the required I can pick up this patch. Thanks, Jonathan > > Cheers, > Peter > > > additionalProperties: false > > @@ -57,6 +61,7 @@ examples: > > sysi { > > compatible = "current-sense-shunt"; > > io-channels = <&tiadc 0>; > > + #io-channel-cells = <0>; > > > > /* Divide the voltage by 3300000/1000000 (or 3.3) for the current. */ > > shunt-resistor-micro-ohms = <3300000>; > >