Touchpad Driver on Guix System

Device Information

• Device Name: DELL0A1D:00
• HID ID: 0018:04F3:3146
• Connection: I2C (not USB)
• Path: /sys/bus/i2c/devices/i2c-DELL0A1D:00/

Driver Information

• Kernel Module: i2c_hid_acpi
• Driver Type: I2C HID over ACPI
• Lower Driver: hid-multitouch

How It Works

1. The touchpad connects via I2C (not USB) - that’s why it doesn’t appear in lsusb
2. ACPI firmware enumerates it on I2C bus DELL0A1D:00
3. i2c_hid_acpi driver binds to it automatically via ACPI
4. The HID reports are converted to standard input events by hid-multitouch

Kernel Parameters

No specific kernel parameters - the device is automatically detected via ACPI.

Verification Commands

# Check the I2C device
cat /sys/bus/i2c/devices/i2c-DELL0A1D:00/name

# Check what driver is attached
ls -la /sys/bus/i2c/devices/i2c-DELL0A1D:00/driver

# Check HID device
cat /sys/class/hidraw/hidraw0/device/uevent

# List input devices
cat /proc/bus/input/devices

Related Kernel Config

CONFIG_I2C_HID_ACPI=m         # I2C HID over ACPI driver
CONFIG_HID_MULTITOUCH=m      # Multitouch HID driver

Notes

• The touchpad appears on I2C address 0x15 typically
• It uses the HID (Human Interface Device) protocol over I2C
• The same driver (i2c_hid_acpi) is used for many laptop touchpads and touchscreens