From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: The way for disabling input device? Date: Tue, 15 Mar 2011 21:55:52 -0700 Message-ID: <20110316045551.GB2582@core.coreip.homeip.net> References: <4D7F2C12.5020509@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:37064 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090Ab1CPEz6 (ORCPT ); Wed, 16 Mar 2011 00:55:58 -0400 Received: by ywj3 with SMTP id 3so515833ywj.19 for ; Tue, 15 Mar 2011 21:55:57 -0700 (PDT) Content-Disposition: inline In-Reply-To: <4D7F2C12.5020509@samsung.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Joonyoung Shim Cc: linux-input@vger.kernel.org On Tue, Mar 15, 2011 at 06:06:26PM +0900, Joonyoung Shim wrote: > Hi, all. > > The many smartphones and embedded devices have LCD panel with > touchscreen. The LCD panel is turned off for power saving and > touchscreen also is disabled if there isn't user input for a while or if > user presses power key briefly. This state is such idle, not suspend. > > The framebuffer device driver of kernel supplies sysfs interface to > control blanking level of framebuffer and we can turn off LCD panel > using this sysfs at the above case. > > Currently i know there isn't the generic way for disabling input device > via user interface, so i am looking for the way for disabling > input device on kernel side for above case. > > The above case has a condition which the touchscreen is disabled if LCD > panel is turned off. The framebuffer framework of kernel has notifier > block to callback on events like hardware display blank change occured, > so the callback function disabling and enabling input device can be > called using notifier block of framebuffer. The callback function is > implemented in each touchscreen driver or can be implemented though > input core if this can be generic way for input device. > > Actually i wonder whether this approach makes sense. I know this is a > specific case but certainly necessary function in the smartphone and > embedded devices. I do not believe that we should tie the 2 together. I can come up with scenarios where you woudl want to put the keeboard/touchcsreen to sleep before turning off the display and vice versa. Thanks. -- Dmitry