[PATCH 3/8] ARM: dts: stm32: add vrefint support to adc2 on stm32mp15

[Olivier Moysan]

Set STM32 ADC2 as a consumer of BSEC on STM32MP15, to retrieve
vrefint calibration data saved in OTP.

During the calibration process vrefp is set to 3.3V and the data
acquired is saved to the OTP. This data is used by the ADC driver
to calculated the actual value of vrefp according to the formula:
vrefp = 3.3 x vrefint_cal / vrefint_data

The vrefint channel provides the actual value of vrefp,
which can be used to correct ADC acquisition data.

Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx>
---
 arch/arm/boot/dts/stm32mp151.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
index 40d3959964cf..5bb5dfabb747 100644
--- a/arch/arm/boot/dts/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/stm32mp151.dtsi
@@ -1113,6 +1113,8 @@ adc2: adc@100 {
 				interrupts = <1>;
 				dmas = <&dmamux1 10 0x400 0x01>;
 				dma-names = "rx";
+				nvmem-cells = <&vrefint>;
+				nvmem-cell-names = "vrefint";
 				status = "disabled";
 				channel@13 {
 					reg = <13>;
-- 
2.25.1