dt-bindings: iio: adc: stm32: add optional st,min-sample-time-nsecs

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>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Fabrice Gasnier 2017-07-24 18:10:39 +02:00 committed by Jonathan Cameron
parent 0d0d4d21a0
commit bc8e1f5b21

View file

@ -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 {