From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v2] Input: matrix-keypad - support binary column select gpios Date: Wed, 20 Feb 2013 14:09:03 -0700 Message-ID: <51253B6F.10202@wwwdotorg.org> References: <1359462324-7233-1-git-send-email-agust@denx.de> <1361388475-23705-1-git-send-email-agust@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]:51138 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935519Ab3BTVJH (ORCPT ); Wed, 20 Feb 2013 16:09:07 -0500 In-Reply-To: <1361388475-23705-1-git-send-email-agust@denx.de> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Anatolij Gustschin Cc: linux-input@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Dmitry Torokhov On 02/20/2013 12:27 PM, Anatolij Gustschin wrote: > On hardware with limited gpios one column select gpio can select > two different rows when using some additional hardware logic: > high value selects one row, low value selects another row. Add > support for such matrix keyboards and document device tree > bindings used to describe them. > > Since half of the columns is always not selected, interrupts won't be > generated for press events on these columns. To generate interrupts > for not selected columns we need to periodicaly switch to these columns > in order to catch the potential press events. This is done by additional > work function. > diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > +- col-gpios-binary: specify that high and low states of a column gpio > + select two different rows (boards with limited gpios > + could support this by additional hardware logic) 1 GPIO and 2 columns is essentially a special case with a 1->2 line decoder. Do the binding definition and code work fine if you have e.g. 3 GPIOs, and a 3->8 decoder in order to support 8 columns?