Apple Magic Trackpad v1 Battery Support for Linux Kernel

 
This repository contains a kernel patch to enable battery reporting for the Apple Magic Trackpad v1 (A1339).
 

Development Transparency

In compliance with evolving community standards regarding AI-assisted development:

• AI Assistance: Claude AI was used for initial code boilerplate and HID descriptor analysis.
• Human Verification: All logic, Report IDs (0x47), and power_supply structures have been manually verified via debugfs and hidraw traces.
• Maintainer: [Damiano Gragnaniello]

The Problem

While newer Magic Trackpad 2 models have native battery support in the hid-magicmouse driver, the original v1 (Bluetooth, AA batteries) was excluded. Users couldn't see the battery percentage in GNOME/KDE settings or upower.
 

The Solution

The patch adds:

• Detection of Device ID 0x030e.
• Parsing of Report ID 0x47, which carries the battery level.
• Registration of a power_supply interface.
   

Hardware Validation (Real Data)

Validated on Linux Mint with Kernel 6.17. Raw HID Descriptor analysis:

• Feature Report (71): GenericDeviceControls.BatteryStrength
• Logical Range: 0 - 100
• Report Size: 8 bits
   

# Capture from /sys/kernel/debug/hid/*/rdesc  
FEATURE(71)[FEATURE]  
  Usage(1) GenericDeviceControls.BatteryStrength  
  Logical Minimum(0)  
  Logical Maximum(100)

## How to Test and Apply

### 1. Manual Compilation (The "Quick" Way)
If you want to test the module without recompiling the entire kernel:
1. Ensure you have kernel headers installed: `sudo apt install linux-headers-$(uname -r)`
2. Download `hid-magicmouse.c` from this repo.
3. Use a standard `Makefile` to build the `.ko` (kernel object) file.
4. Unload the current driver and load yours:
   ```bash
   sudo rmmod hid_magicmouse
   sudo insmod hid-magicmouse.ko

### 2. Official Patching (Recommended)
If you are a developer or want to include this in a custom build:
1. Clone the Linux kernel source.
2. Apply the patch: git am 0001-HID-magicmouse-add-battery-reporting-for-Magic-Track.patch
3. Rebuild the hid-magicmouse module.

### Stability & Safety
Stability Test: This code has been stress-tested for 7 days on Linux Mint (Cinnamon) without system
freezes or kernel panics.

Disclaimer: Always back up your data before loading experimental kernel modules.
Use dmesg -w to monitor system logs during the first load.