Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752522AbcKYE5b (ORCPT ); Thu, 24 Nov 2016 23:57:31 -0500 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 Subject: Re: [PATCH v2 0/3] increase TSCADC clock to 24MHz and fix ti,charge-delay to represent in nS To: References: <20161110163515.27598-1-mugunthanvnm@ti.com> CC: Dmitry Torokhov , Jonathan Cameron , Rob Herring , Mark Rutland , Lee Jones , Sekhar Nori , Vignesh R , , , From: Mugunthan V N Message-ID: <71482721-fd60-65b2-d601-f1698ce5fa0a@ti.com> Date: Fri, 25 Nov 2016 10:27:09 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161110163515.27598-1-mugunthanvnm@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1175 Lines: 31 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