Jiri Kosina explained in the mailing list pull request that the HID changes for Linux 3.15 present a substantial clean-up to the generic and transport layers, but there's also some exciting end-user changes:
- A new HID driver has been added, the CP2112. This new driver supports the Silicon Labs CP2112 chip as a "Single-Chip HID USB to SMBus Master Bridge."
- The Sony HID driver now supports the Dualshock 4 controller as found with the PlayStation 4 game console. The Dualshock 4 controller is Bluetooth-based and from an initial look-over it seems this Linux driver support for 3.15 is in good standing for this new game controller.
- Support for the Windows 8.1 Multi-Touch protocol.
- Other small fixes and also new device IDs have been added.