Dell's documentation on the Latitude 7280[1] says that "<Fn> + <H> [toggles] the battery charge LED to a hard drive activity indicator." However, Dell support told me this functionality is only supported on Windows when using the latest Intel HID Event Filter driver,[2] despite the documentation making it appear like a hardware feature. Dell support claims this feature is not supported by any other OS. My guess is that support for this could be added to the dell_wmi driver with appropriate information. I'm happy to help as possible to collect this information as possible as an owner of a Latitude 7280 with access to Dell support. 1. http://www.dell.com/support/article/us/en/19/SLN305113/dell-latitude-7280-visual-and-led-guide 2. http://dell.to/2s0u29o