Re: [PATCH 2/2] iio: adc: ti_am335x_tscadc: Improve accuracy of measurement

From: Jonathan Cameron
Date: Sat Dec 01 2018 - 10:04:18 EST


On Wed, 28 Nov 2018 09:14:32 +0000
Lee Jones <lee.jones@xxxxxxxxxx> 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 <vigneshr@xxxxxx>
> > ---
> > drivers/iio/adc/ti_am335x_adc.c | 5 ++++-
>
> > include/linux/mfd/ti_am335x_tscadc.h | 4 ++++
>
> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
>
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.

Jonathan