From 4e870b513e3641bf7184174ac10e79e28b39f544 Mon Sep 17 00:00:00 2001
From: Hugo Karlsson <huggek@klattorp.se>
Date: Sun, 8 Nov 2026 14:02:32 +0100
Subject: [PATCH] overlays: Add geekworm-x120x overlay

The Geekworm X120x UPS boards for the Raspberry Pi 5 are currently set
up with two separate overlays:

  dtoverlay=i2c-sensor,max17040
  dtoverlay=gpio-charger,gpio=6,...

Nothing tells the fuel gauge that the charger supplies it, so the
battery cannot report whether it is charging. Add one overlay that
creates both nodes and links them with power-supplies.

The overlay and this description were written with help from Claude
Code (claude-opus-5-5) and tested on a Raspberry Pi 5 with an X1202.

Signed-off-by: Hugo Karlsson <huggek@klattorp.se>
---
 arch/arm/boot/dts/overlays/Makefile           |  1 +
 arch/arm/boot/dts/overlays/README             |  9 ++++
 .../dts/overlays/geekworm-x120x-overlay.dts   | 44 +++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/geekworm-x120x-overlay.dts

diff --git a/arch/arm/boot/dts/overlays/Makefile b/arch/arm/boot/dts/overlays/Makefile
index 688e3f786b7365..020213c7936d6e 100644
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -75,6 +75,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	fe-pi-audio.dtbo \
 	fsm-demo.dtbo \
 	gc9a01.dtbo \
+	geekworm-x120x.dtbo \
 	ghost-amp.dtbo \
 	goodix.dtbo \
 	googlevoicehat-soundcard.dtbo \
diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
index 9f7578b8a9e83a..5f35ee995124b8 100644
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -1561,6 +1561,15 @@ Params: speed                   Display SPI bus speed
         debug                   Debug output level {0-7}
 
 
+Name:   geekworm-x120x
+Info:   Geekworm X120x UPS boards for the Raspberry Pi 5, such as the X1202
+        and X1206. Adds the MAX17040-compatible fuel gauge at I2C address
+        0x36 and a gpio-charger for the GPIO that reports input power, and
+        links the two so the battery can report whether it is charging.
+Load:   dtoverlay=geekworm-x120x,<param>=<val>
+Params: gpio                    GPIO that reports input power (default 6)
+
+
 Name:   ghost-amp
 Info:   An overlay for the Ghost amplifier.
 Load:   dtoverlay=ghost-amp,<param>=<val>
diff --git a/arch/arm/boot/dts/overlays/geekworm-x120x-overlay.dts b/arch/arm/boot/dts/overlays/geekworm-x120x-overlay.dts
new file mode 100644
index 00000000000000..c408468b8a02b7
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/geekworm-x120x-overlay.dts
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Definitions for Geekworm X120x UPS boards such as the X1202 and X1206:
+// a MAX17040-compatible fuel gauge on I2C plus a GPIO that reports input
+// power, linked so the battery knows its charger.
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+	compatible = "brcm,bcm2712";
+
+	fragment@0 {
+		target-path = "/";
+		__overlay__ {
+			x120x_charger: charger {
+				compatible = "gpio-charger";
+				gpios = <&gpio 6 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>;
+				charger-type = "mains";
+				status = "okay";
+			};
+		};
+	};
+
+	fragment@1 {
+		target = <&i2c_arm>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "okay";
+
+			x120x_battery: fuel-gauge@36 {
+				compatible = "maxim,max17040";
+				reg = <0x36>;
+				power-supplies = <&x120x_charger>;
+				status = "okay";
+			};
+		};
+	};
+
+	__overrides__ {
+		gpio = <&x120x_charger>,"gpios:4";
+	};
+};