From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752314AbcDVMjP (ORCPT ); Fri, 22 Apr 2016 08:39:15 -0400 Received: from 7of9.schinagl.nl ([88.159.158.68]:40446 "EHLO 7of9.schinagl.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbcDVMjO (ORCPT ); Fri, 22 Apr 2016 08:39:14 -0400 Subject: Re: [PATCH 5/6] leds: pca963x: Inform the output that it is inverted To: Rob Herring References: <1461051650-18824-1-git-send-email-oliver@schinagl.nl> <1461051650-18824-6-git-send-email-oliver@schinagl.nl> <20160421150750.GA3116@rob-hp-laptop> Cc: Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Richard Purdie , Jacek Anaszewski , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org From: Olliver Schinagl Message-ID: <571A1B60.3020804@schinagl.nl> Date: Fri, 22 Apr 2016 14:38:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160421150750.GA3116@rob-hp-laptop> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Rob, On 21-04-16 17:07, Rob Herring wrote: > On Tue, Apr 19, 2016 at 09:40:49AM +0200, Olliver Schinagl wrote: >> When leds are connected in a totem-pole configuration, they can be >> connected either in a active-high, or active-low manor. The driver >> currently always assumes active-high. This patch adds the >> 'nxp,inverted-out' boolean property to tell the driver that the leds >> are driven active-low, or rather, that the behavior is inverted to what >> is normally expected. > How do I know what is normally expected? fair point, and in fact, you don't. The text is bad here. > >> Signed-off-by: Olliver Schinagl >> --- >> Documentation/devicetree/bindings/leds/pca963x.txt | 1 + >> drivers/leds/leds-pca963x.c | 20 +++++++++++++------- >> include/linux/platform_data/leds-pca963x.h | 1 + >> 3 files changed, 15 insertions(+), 7 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/leds/pca963x.txt b/Documentation/devicetree/bindings/leds/pca963x.txt >> index dafbe99..7b23725 100644 >> --- a/Documentation/devicetree/bindings/leds/pca963x.txt >> +++ b/Documentation/devicetree/bindings/leds/pca963x.txt >> @@ -6,6 +6,7 @@ Required properties: >> Optional properties: >> - nxp,totem-pole : use totem pole (push-pull) instead of open-drain (pca9632 defaults >> to open-drain, newer chips to totem pole) >> + nxp,inverted-out: the connected leds are active-low, default to active-high > Just state what mode you want: nxp,active-low But that's not what happens, which is why my text is bad :) It depends on how the board is wired and if it is push-pull or open-drain. Though this goes beyond my electronics knowledge. So I'll reduce the text to say exactly what we mean, inverted output (or not). Unless you can explain that it would be unrelated and it is actually active-high/low. I'll be more than happy to oblige. Olliver > > Rob