From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mugunthan V N Subject: Re: [PATCH v2 0/3] increase TSCADC clock to 24MHz and fix ti,charge-delay to represent in nS Date: Fri, 25 Nov 2016 10:27:09 +0530 Message-ID: <71482721-fd60-65b2-d601-f1698ce5fa0a@ti.com> References: <20161110163515.27598-1-mugunthanvnm@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: Received: from lelnx194.ext.ti.com ([198.47.27.80]:18255 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751237AbcKYE5W (ORCPT ); Thu, 24 Nov 2016 23:57:22 -0500 In-Reply-To: <20161110163515.27598-1-mugunthanvnm@ti.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-input@vger.kernel.org Cc: Dmitry Torokhov , Jonathan Cameron , Rob Herring , Mark Rutland , Lee Jones , Sekhar Nori , Vignesh R , devicetree@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Hi Dmitry Torokhov, On Thursday 10 November 2016 10:05 PM, Mugunthan V N wrote: > This patch series enables ADC to be clocked at 24MHz as the > TI AM335x ADC driver has already adopted to use DMA to transfer > ADC samples. Now ADC can generated upto 800K Samples per second > with the patch [1] on AM335x BBB and AM437x GP EVM. > > when ADC ref clock is set at 24MHz, I am seeing some issue with > touch screen pointer as the pointer jumps to random locations > with free draw application. The issue is due to increase in ADC > clock and charge delay for the touchscreen ADC line duration > reduced. > > So the notation of ti,charge-delay in terms of ADC clock is > wrong, it has to be represented in time and driver has to convert > the charge delay time to ADC clocks based on what ADC clock > frequency is set. > > Measured the performance with the iio_generic_buffer with the > patch [2] applied > > Verified the touch screen on AM335x GP EVM and AM335x BBB LCD7 > cape with [3] dts for display and touch screen to work. > Since there are acks from DT and MFD maintainers, can you pull the patch series if you do not have any more comments. Regards Mugunthan V N