[PATCH v2 2/3] dt-bindings: iio: adc: stm32: add optional st,min-sample-time-nsecs
From: jic23@kernel.org (Jonathan Cameron)
Date: 2017-07-30 16:24:25
Also in:
linux-devicetree, linux-iio, lkml
On Mon, 24 Jul 2017 18:10:39 +0200 Fabrice Gasnier [off-list ref] 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 <redacted>
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
quoted hunk ↗ jump to hunk
--- 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 at 40012000 {