From mboxrd@z Thu Jan 1 00:00:00 1970 From: Markus Niebel Subject: Input: ads7846 - sampling logic issues with AD7873 Date: Tue, 29 May 2012 12:47:26 +0200 Message-ID: <4FC4A93E.9040305@tqsc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Return-path: Received: from smtprelay01.ispgateway.de ([80.67.31.28]:49647 "EHLO smtprelay01.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751271Ab2E2Kvb (ORCPT ); Tue, 29 May 2012 06:51:31 -0400 Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-input@vger.kernel.org Cc: michael.hennerich@analog.com, dmitry.torokhov@gmail.com Hi, we use the AD7873 controller with internal reference. The current implementation for AD7873 in the ads7846 driver forces the vref to switch off after every sample. So measurements especially in the edge of the screen become unreliable due to the settling time for the internal reference (I guess). Is there a special reason to override the "keep_vref_of" setting of the platform data for the AD7873 in ads7846_setup_spi_msg? We did already some tests and found out, that leaving vref on makes out system usable with AD7873. Markus