From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH v2] input: Extend matrix-keypad device tree binding Date: Fri, 11 Jan 2013 09:13:43 -0800 Message-ID: <20130111171343.GE11224@core.coreip.homeip.net> References: <1357868492-16023-1-git-send-email-sjg@chromium.org> <50F0473F.404@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <50F0473F.404@wwwdotorg.org> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Warren Cc: Simon Glass , LKML , Roland Stigge , Vincent Palatin , linux-doc@vger.kernel.org, Wolfram Sang , Felipe Balbi , Luigi Semenzato , Rob Herring , linux-input@vger.kernel.org, Stephen Warren , Sourav Poddar , Alban Bedel , devicetree-discuss@lists.ozlabs.org, Laxman Dewangan List-Id: devicetree@vger.kernel.org On Fri, Jan 11, 2013 at 10:09:19AM -0700, Stephen Warren wrote: > On 01/10/2013 06:41 PM, Simon Glass wrote: > > Some matrix keypad drivers can support different numbers of rows and > > columns. Add a generic binding for these. > > > > Implementation note: > > > > In order to implement this binding in the kernel, we will need to modify > > matrix_keypad_() to look up the number of rows and cols in > > the keymap. Perhaps this could be done by passing 0 for these parameters? > > Many of the parameters can already be set to NULL. Ick. > > Reviewed-by: Stephen Warren > > Note that the Tegra bindings are based on matrix-keypad.txt, and > recently added the following properties: > > > - nvidia,kbc-row-pins: The KBC pins which are configured as row. This is an > > array of pin numbers which is used as rows. > > - nvidia,kbc-col-pins: The KBC pins which are configured as column. This is an > > array of pin numbers which is used as column. > > Those both define the number of rows/columns (indirectly via the > property lengths) *and* define which pins are used for the rows/columns. > How will this influence/interact-with any changes you're planning to the > core matrix keymap parsing code; would Tegra require your "new" > keypad,num-rows/keypad,num-columns properties even though the > information is redundant, or will the Tegra driver have some way of > passing this information to the core? Even if we decide to move lookup of keypad,num-rows/keypad,num-columns into matrix-keypad code we will still allow callers to override DT data, like we do with platform keymaps. Thanks. -- Dmitry