From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonyoung Shim Subject: The way for disabling input device? Date: Tue, 15 Mar 2011 18:06:26 +0900 Message-ID: <4D7F2C12.5020509@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7BIT Return-path: Received: from mailout2.samsung.com ([203.254.224.25]:32100 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499Ab1COJSV (ORCPT ); Tue, 15 Mar 2011 05:18:21 -0400 Received: from epmmp2 (mailout2.samsung.com [203.254.224.25]) by mailout2.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LI300LQQDAQTY40@mailout2.samsung.com> for linux-input@vger.kernel.org; Tue, 15 Mar 2011 18:06:26 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LI300LW2DAQ50@mmp2.samsung.com> for linux-input@vger.kernel.org; Tue, 15 Mar 2011 18:06:26 +0900 (KST) Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-input@vger.kernel.org Cc: Dmitry Torokhov 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. Thanks.