From c84f22405085d91cd5f0c5b967318371c07904ba Mon Sep 17 00:00:00 2001 From: David Jander Date: Wed, 18 Mar 2026 11:51:17 +0100 Subject: [PATCH] ARM: dts: stm32: stm32mp15x-mecio1-io: Enable internal ADC reference Switch the ADC reference supply from the general 3.3V rail to the internal 2.5V VREFBUF regulator. The ADC circuits on this board are designed for the internal 2.5V reference. Without this change, all ADC measurement values are incorrect. Fixes: 8267753c891c ("ARM: dts: stm32: Add MECIO1 and MECT1S board variants") Co-developed-by: Oleksij Rempel Signed-off-by: David Jander Signed-off-by: Oleksij Rempel Cc: Link: https://lore.kernel.org/r/20260318105123.819807-2-o.rempel@pengutronix.de Signed-off-by: Alexandre Torgue --- arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi b/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi index 915ba2526f45..1ce01bac9814 100644 --- a/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi +++ b/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi @@ -95,7 +95,7 @@ &adc { pinctrl-names = "default"; vdd-supply = <&v3v3>; vdda-supply = <&v3v3>; - vref-supply = <&v3v3>; + vref-supply = <&vrefbuf>; status = "okay"; }; @@ -412,6 +412,13 @@ &usbphyc_port1 { phy-supply = <&v3v3>; }; +&vrefbuf { + regulator-min-microvolt = <2500000>; + regulator-max-microvolt = <2500000>; + vdda-supply = <&v3v3>; + status = "okay"; +}; + &pinctrl { adc12_pins_mecsbc: adc12-ain-mecsbc-0 { pins {