On Mon, 24 Jul 2017 18:10:39 +0200 Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote: > STM32 ADC allows each channel to be sampled with a different sampling > time. There's an application note that deals with this: 'How to get > the best ADC accuracy in STM32...' It basically depends on analog input > signal electrical properties (depends on board). > > Add optional 'st,min-sample-time-nsecs' property so this can be tuned > in dt. > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> This ideally wants a devicetree review so I'm going to sit on it for a few days longer. Looks fine to me as does the implementation patch. Give me a kick in a week or so if we have seen no progress on this. I will be travelling from next weekend and access may be a little intermittent for up to two weeks. Thanks, Jonathan > --- > Changes in v2: > - Use 'st,min-sample-time-nsecs' instead of 'min-sample-time'. > --- > Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > index 8310073..48bfcaa3 100644 > --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > @@ -74,6 +74,11 @@ Optional properties: > * can be 6, 8, 10 or 12 on stm32f4 > * can be 8, 10, 12, 14 or 16 on stm32h7 > Default is maximum resolution if unset. > +- st,min-sample-time-nsecs: Minimum sampling time in nanoseconds. > + Depending on hardware (board) e.g. high/low analog input source impedance, > + fine tune of ADC sampling time may be recommended. > + This can be either one value or an array that matches 'st,adc-channels' list, > + to set sample time resp. for all channels, or independently for each channel. > > Example: > adc: adc@40012000 { -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html