xpg-fusion — hwmon driver for the XPG Fusion 1600W Titanium PSU

Linux kernel DKMS module. Reads PSU telemetry (Delta Electronics, GPS-1600AB, VID 0x125F / PID 0x7900) and exports it via hwmon (lm_sensors / sensors).

Read-only: the module sends PMBus read commands only (0xDF FULLPACKAGE, 0x96 POUT, 0x99/0x9A/0xDC MFR strings). No writes. Tested with kernel 7.0.0-34-generic (Ubuntu 26.04).

Channels

hwmon	Value	Unit	Label
in1	AC input voltage	mV	AC Input
in2	+12V	mV	+12V
in3	+5V	mV	+5V
in4	+3.3V	mV	+3.3V
in5	−12V (magnitude)	mV	-12V
curr1	AC input current	mA	IIN
curr2-7	+12V1..+12V6 current	mA	+12V1..6
curr8-11	−12V, +5V, +3.3V, +12V total current	mA	-12V, +5V, +3.3V, +12V
power1	Output power (DC)	µW	DC Output
power2	Input power (AC)	µW	AC Input
temp1	GaN temperature	m°C	PSU GaN
fan1	Fan speed	RPM	PSU Fan

Extra sysfs attributes (hwmonX/): efficiency_percent (the PSU's claimed efficiency — without XPG Prime's marketing corrections), model, firmware_version.

Build and installation

sudo ./xpg-fusion-dkms-build.sh      # dkms add + build
sudo ./xpg-fusion-dkms-install.sh    # dkms install + udevadm trigger

The module is picked up by udev automatically via the usb:v125Fp7900... alias (plug in the PSU — the module loads). If the PSU is already connected at install time, the script runs udevadm trigger.

Uninstall: dkms remove xpg-fusion/1.0 --all (or sudo rmmod xpg-fusion for a temporary one). After removal, the userspace script (xpg_fusion/xpg_fusion_monitor.py) can open the device again.

Module parameters

• interval_sec (default 1) — polling interval in seconds (1..60). modprobe xpg-fusion interval_sec=2.

Known behavior

• While the module is bound, XPG Prime / pyusb cannot open the device (-EBUSY). This is normal behavior (exclusive driver-core claim).
• If the PSU is lost (AC power off, unplugged): polling fails, the driver logs one dev_err ("PSU contact lost") and sysfs reads return an error (-ESHUTDOWN) until the device answers again — on recovery a "PSU contact restored" message is logged and values resume. The kernel is not blocked; polling keeps running at the fixed interval.
• The response is validated: command echo + PEC (CRC-8). The MCU silently drops commands with a bad PEC — the module reports this as -EPROTO.
• −12V is exported with a positive sign, label "-12V" (dual-polarity rail).
• usb_reset_device is NOT called automatically (the PSU is not a harmless device; if needed — manual usb_reset_device from userspace, or v2 with an opt-in parameter).

Transfer structure (briefly)

HID Feature Report ID 7, exactly 257 bytes, wValue=0x0307: SET_REPORT [0]=07 [1]=00 [2]=command [255]=PEC → 50 ms → GET_REPORT (257 bytes: [2]=echo, [3..]=data, [255]=PEC) → 30 ms. Values are Linear11 with a non-standard Delta packing (see xpg_fusion.c, function l11_scaled). The FULLPACKAGE field map is in xpg_decode_full().