Battery level reporting for HID devices

configname: CONFIG_HID_BATTERY_STRENGTH

Linux Kernel Configuration
└─>Device Drivers
└─>HID support
└─>Power supply class support
└─>Power supply class support
└─>Battery level reporting for HID devices
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option adds support of reporting battery strength (for HID devices
that support this feature) through power_supply class so that userspace
tools, such as upower, can display it.