On Wed, 12 Jun 2019 09:24:34 +0200 Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote: > On stm32h7 and stm32mp1, the ADC inputs are multiplexed with analog > switches which have reduced performances when their supply is below 2.7V > (vdda by default). > > Add documentation for optional vdda-supply & vdd-supply that can be used > to supply analog circuitry (controlled by syscfg bits). > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > --- > Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > index 8346bcb..3af48b9 100644 > --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt > @@ -46,6 +46,12 @@ Required properties: > Optional properties: > - A pinctrl state named "default" for each ADC channel may be defined to set > inX ADC pins in mode of operation for analog input on external pin. > +- vdda-supply: Phandle to the vdda input voltage. It can be used to supply ADC > + analog inputs switches on stm32h7 and stm32mp1. input switches > +- vdd-supply: Phandle to the vdd input voltage. It can be used to supply ADC > + analog inputs switches on stm32mp1. > +- st,syscfg: Phandle to system configuration controller. It can be used to > + control the analog circuitry on stm32h7 and stm32mp1. > > Contents of a stm32 adc child node: > -----------------------------------
