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authorFabrice Gasnier <fabrice.gasnier@st.com>2017-07-24 19:10:39 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2017-08-09 16:11:57 +0300
commitbc8e1f5b21b1b816173937747b0e9c6db76c19b2 (patch)
tree73617759f9cc83f3de2edce0586bc6f1d00b1ffe /Documentation/devicetree/bindings/iio
parent0d0d4d21a09981e65b2bd386c999e8c0ecc6444e (diff)
downloadlinux-bc8e1f5b21b1b816173937747b0e9c6db76c19b2.tar.xz
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>
Diffstat (limited to 'Documentation/devicetree/bindings/iio')
-rw-r--r--Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
index 8310073f14e1..48bfcaa3ffcd 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 {