From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f65.google.com ([209.85.128.65]:54000 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727382AbeK1UPc (ORCPT ); Wed, 28 Nov 2018 15:15:32 -0500 Received: by mail-wm1-f65.google.com with SMTP id y1so1749402wmi.3 for ; Wed, 28 Nov 2018 01:14:36 -0800 (PST) Date: Wed, 28 Nov 2018 09:14:32 +0000 From: Lee Jones To: Vignesh R Cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] iio: adc: ti_am335x_tscadc: Improve accuracy of measurement Message-ID: <20181128091432.GT4272@dell> References: <20181119064236.28902-1-vigneshr@ti.com> <20181119064236.28902-3-vigneshr@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <20181119064236.28902-3-vigneshr@ti.com> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On Mon, 19 Nov 2018, Vignesh R wrote: > When performing single ended measurements with TSCADC, its recommended > to set negative input (SEL_INM_SWC_3_0) of ADC step to ADC's VREFN in the > corresponding STEP_CONFIGx register. > Also, the positive(SEL_RFP_SWC_2_0) and negative(SEL_RFM_SWC_1_0) > reference voltage for ADC step needs to be set to VREFP and VREFN > respectively in STEP_CONFIGx register. > Without these changes, there may be variation of as much as ~2% in the > ADC's digital output which is bad for precise measurement. > > Signed-off-by: Vignesh R > --- > drivers/iio/adc/ti_am335x_adc.c | 5 ++++- > include/linux/mfd/ti_am335x_tscadc.h | 4 ++++ Acked-by: Lee Jones -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog