From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753149AbdIEV03 (ORCPT ); Tue, 5 Sep 2017 17:26:29 -0400 Received: from relay9.flbmail.info ([12.139.121.104]:42989 "EHLO relay9.flbmail.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752625AbdIEV00 (ORCPT ); Tue, 5 Sep 2017 17:26:26 -0400 X-Greylist: delayed 517 seconds by postgrey-1.27 at vger.kernel.org; Tue, 05 Sep 2017 17:26:26 EDT X-Spam-Flag: NO X-Spam-Score: 0.913 Date: Tue, 5 Sep 2017 17:16:29 -0400 (EDT) From: Dimitry Ishenko To: linux-kernel@vger.kernel.org Message-ID: <563777.534131504646189349.JavaMail.root@webmail> In-Reply-To: <27958492.533931504646096353.JavaMail.root@webmail> Subject: [PATCH v12 1/5] Input: goodix - add sysfs interface to dump config MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [207.98.208.110] X-Mailer: Zimbra 5.0.10_GA_2609.UBUNTU8 (ZimbraWebClient - SAF3 (Linux)/5.0.10_GA_2609.UBUNTU8) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Saturday, September 10, 2016 at 2:00:06 PM UTC-4, Irina Tirdea wrote: > > Goodix devices have a configuration information register area that > specifies various parameters for the device. ... > > Export a sysfs interface that would allow reading the configuration > information. ... > > This sysfs interface will be exported only if the gpio pins are properly > initialized from ACPI/DT. ... Irina, why the requirement for INT/RST gpio pins? The config info is available by simply reading from the config register (0x8047) and IIUIC does not require presence of INT/RST pins. So, it can be exported even without those pins. Likewise, config writing support currently present in the kernel (which I believe you are responsible for [thank you!]) also for some reason mandates presence of INT/RST. However, it is simply done by writing to the aforementioned config register (0x8047). I have 2 similar devices (Pipo X8 and X9) with GT911 chips that have different configs. Neither device has the RST pin defined. I was able to successfully read the config from one device and write it to the other. So, it seems the INT/RST requirement is not necessary for config reading/writing support. Or did I miss something. Thank you. Dimitry NB: I am not subscribed to the list. Please CC me directly with any replies.