From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 2/2] iio: adc: ti_am335x_tscadc: Improve accuracy of measurement Date: Mon, 3 Dec 2018 07:01:17 +0000 Message-ID: <20181203070117.GI6009@dell> References: <20181119064236.28902-1-vigneshr@ti.com> <20181119064236.28902-3-vigneshr@ti.com> <20181128091432.GT4272@dell> <20181201150400.09706f47@archlinux> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20181201150400.09706f47@archlinux> Sender: linux-kernel-owner@vger.kernel.org To: Jonathan Cameron Cc: Vignesh R , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org On Sat, 01 Dec 2018, Jonathan Cameron wrote: > On Wed, 28 Nov 2018 09:14:32 +0000 > Lee Jones wrote: > > > 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 > > > I'll leave this for v2 given changes in the first patch. > > My assumption is at the moment that both will go through mfd. > Shout Lee if you have other plans. I'm fine with that. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog