| Message ID | 1500912640-23927-3-git-send-email-fabrice.gasnier@st.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, 24 Jul 2017 18:10:39 +0200 Fabrice Gasnier <fabrice.gasnier@st.com> 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@st.com> 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 devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jul 24, 2017 at 06:10:39PM +0200, Fabrice Gasnier 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@st.com> > --- > 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(+) Acked-by: Rob Herring <robh@kernel.org> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 3 Aug 2017 12:01:54 -0500 Rob Herring <robh@kernel.org> wrote: > On Mon, Jul 24, 2017 at 06:10:39PM +0200, Fabrice Gasnier 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@st.com> > > --- > > 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(+) > > Acked-by: Rob Herring <robh@kernel.org> Applied to the togreg branch of iio.git and pushed out as testings. Thanks for review Rob and thanks for the patch Fabrice. Jonathan > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 {
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@st.com> --- 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(+)