overlays: rpi-max14001-pmb-overlay.dts: Add MAX14001PMB example overlay

The MAX14001 is a configurable, isolated 10-bit ADC for multi-range binary
inputs. Besides the ADC readings, the MAX14001 offers more features, like
a binary comparator, a filtered reading that can provide the average of
the last 2, 4, or 8 ADC readings, and an inrush comparator that triggers
the inrush current. There is also a fault feature that can diagnose seven
possible fault conditions. And an option to select an external or internal
ADC voltage reference.

The MAX14001PMB provides the hardware to evaluate the MAX14001 to measure
two channels of data, line voltage and load current.

Signed-off-by: Marilene Andrade Garcia <[email protected]>

Author: MarileneGarcia

arch/arm/boot/dts/overlays/Makefile

@@ -309,6 +309,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	rpi-ltc2991.dtbo \
 	rpi-ltc4162.dtbo \
 	rpi-ltc6952.dtbo \
+	rpi-max14001-pmb.dtbo \
 	rpi-max14830-i2c.dtbo \
 	rpi-max14830-spi.dtbo \
 	rpi-max31335.dtbo \

arch/arm/boot/dts/overlays/rpi-max14001-pmb-overlay.dts

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Overlay for the MAX14001 ADC
+ *
+ * Copyright (c) 2025 Marilene Andrade Garcia <[email protected]>
+ *
+ * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX14001-MAX14002.pdf
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	compatible = "brcm,bcm2712";
+};
+
+&{/} {
+	vdd: fixedregulator@0 {
+		compatible = "regulator-fixed";
+		regulator-name = "Isolated DC-DC Power Supply Input Voltage";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		regulator-always-on;
+		status = "okay";
+	};
+
+	vddl: fixedregulator@1 {
+		compatible = "regulator-fixed";
+		regulator-name = "Logic Power Supply Voltage";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		regulator-always-on;
+		status = "okay";
+	};
+
+	vrefin: fixedregulator@2 {
+		compatible = "regulator-fixed";
+		regulator-name = "Reference Input Range Voltage";
+		regulator-min-microvolt = <1250000>;
+		regulator-max-microvolt = <1250000>;
+		regulator-boot-on;
+		regulator-always-on;
+		status = "okay";
+	};
+};
+
+&spi0 {
+    status = "okay";
+	max14001_u51: max14001@0 {
+		compatible = "adi,max14001";
+		reg = <0x0>;
+		spi-max-frequency = <5000000>;
+		vdd-supply = <&vdd>;
+		vddl-supply = <&vddl>;
+		vrefin-supply = <&vrefin>;
+		status = "okay";
+	};
+	max14001_u11: max14001@1 {
+		compatible = "adi,max14001";
+		reg = <0x1>;
+		spi-max-frequency = <5000000>;
+		vdd-supply = <&vdd>;
+		vddl-supply = <&vddl>;
+		vrefin-supply = <&vrefin>;
+		status = "okay";
+	};
+};
+
+&spidev0 {
+	status = "disabled";
+};
+
+&spidev1 {
+	status = "disabled";
+};