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

From: Lee Jones
Date: Wed Nov 28 2018 - 04:14:40 EST


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>

--
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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