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). Booster or vdd can be used, to get full ADC
performances.
Add documentation for:
- optional booster-supply that can be used on stm32h7 and stm32mp1.
- optional vdd-supply that can be used on stm32mp1 to supply analog
circuitry, selected by syscfg.
Mark these as optional, since this is a trade-off between analog
performance and power consumption.
Signed-off-by: Fabrice Gasnier <[email protected]>
---
Changes in v2:
- Rework since: "Add missing vdda-supply to STM32 ADC" series.
- Add booster-supply regulator description
- typo: input switches
---
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 93a0bd2..4c0da8c 100644
--- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
+++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
@@ -47,6 +47,12 @@ 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.
+- booster-supply: Phandle to the embedded booster regulator that can be used
+ to supply ADC analog input switches on stm32h7 and stm32mp1.
+- vdd-supply: Phandle to the vdd input voltage. It can be used to supply ADC
+ analog input switches on stm32mp1.
+- st,syscfg: Phandle to system configuration controller. It can be used to
+ control the analog circuitry on stm32mp1.
Contents of a stm32 adc child node:
-----------------------------------
--
2.7.4
On Wed, 3 Jul 2019 12:08:14 +0200
Fabrice Gasnier <[email protected]> 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). Booster or vdd can be used, to get full ADC
> performances.
>
> Add documentation for:
> - optional booster-supply that can be used on stm32h7 and stm32mp1.
> - optional vdd-supply that can be used on stm32mp1 to supply analog
> circuitry, selected by syscfg.
> Mark these as optional, since this is a trade-off between analog
> performance and power consumption.
>
> Signed-off-by: Fabrice Gasnier <[email protected]>
Seems fine to me. Applied to the togreg branch of iio.git and pushed out
as testing for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> Changes in v2:
> - Rework since: "Add missing vdda-supply to STM32 ADC" series.
> - Add booster-supply regulator description
> - typo: input switches
> ---
> 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 93a0bd2..4c0da8c 100644
> --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
> +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
> @@ -47,6 +47,12 @@ 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.
> +- booster-supply: Phandle to the embedded booster regulator that can be used
> + to supply ADC analog input switches on stm32h7 and stm32mp1.
> +- vdd-supply: Phandle to the vdd input voltage. It can be used to supply ADC
> + analog input switches on stm32mp1.
> +- st,syscfg: Phandle to system configuration controller. It can be used to
> + control the analog circuitry on stm32mp1.
>
> Contents of a stm32 adc child node:
> -----------------------------------