Re: [PATCH 1/3] dt-bindings: iio: adc: stm32: add analog switches supply control

From: Jonathan Cameron
Date: Sun Jun 16 2019 - 11:17:49 EST


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:
> -----------------------------------