From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v1 04/12] input: matrix-keypad: push/pull, separate polarity Date: Fri, 21 Jun 2013 15:34:01 -0600 Message-ID: <51C4C6C9.6030000@wwwdotorg.org> References: <1371838198-7327-1-git-send-email-gsi@denx.de> <1371838198-7327-5-git-send-email-gsi@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from avon.wwwdotorg.org ([70.85.31.133]:35778 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945979Ab3FUVeE (ORCPT ); Fri, 21 Jun 2013 17:34:04 -0400 In-Reply-To: <1371838198-7327-5-git-send-email-gsi@denx.de> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Gerhard Sittig Cc: Dmitry Torokhov , linux-input@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Chao Xie , Eric Miao , Detlev Zundel , Sekhar Nori , Marek Vasut , Ralf Baechle On 06/21/2013 12:09 PM, Gerhard Sittig wrote: > extend the device tree adjustable hardware configuration: > - allow for differing polarity of the row and column GPIO pins > - optionally fully drive column output pins instead of the former > unconditional open collector emulation approach > diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > +- row-gpios-activelow: row GPIO pins are active low > +- col-gpios-activelow: column GPIO pins are active low > - gpio-activelow: row pins as well as column pins are active low > + (provided for backward compatibility, and useful > + for matrix layouts of identical polarity for > + rows and columns) Those should all come from the existing GPIO flags, and may even differ for each GPIO. > +- col-gpios-pushpull: fully drive the column selection pins in either > + direction (high and low signals), the default > + behaviour is to actively drive low signals and > + be passive otherwise (emulates an open collector > + output driver) We don't actually have GPIO flags defined for pushpull-vs-open-collector etc. Perhaps we should do so. Then, we wouldn't need to invent custom properties to represent that in this binding. From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Fri, 21 Jun 2013 15:34:01 -0600 Subject: [PATCH v1 04/12] input: matrix-keypad: push/pull, separate polarity In-Reply-To: <1371838198-7327-5-git-send-email-gsi@denx.de> References: <1371838198-7327-1-git-send-email-gsi@denx.de> <1371838198-7327-5-git-send-email-gsi@denx.de> Message-ID: <51C4C6C9.6030000@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/21/2013 12:09 PM, Gerhard Sittig wrote: > extend the device tree adjustable hardware configuration: > - allow for differing polarity of the row and column GPIO pins > - optionally fully drive column output pins instead of the former > unconditional open collector emulation approach > diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > +- row-gpios-activelow: row GPIO pins are active low > +- col-gpios-activelow: column GPIO pins are active low > - gpio-activelow: row pins as well as column pins are active low > + (provided for backward compatibility, and useful > + for matrix layouts of identical polarity for > + rows and columns) Those should all come from the existing GPIO flags, and may even differ for each GPIO. > +- col-gpios-pushpull: fully drive the column selection pins in either > + direction (high and low signals), the default > + behaviour is to actively drive low signals and > + be passive otherwise (emulates an open collector > + output driver) We don't actually have GPIO flags defined for pushpull-vs-open-collector etc. Perhaps we should do so. Then, we wouldn't need to invent custom properties to represent that in this binding.