HID: wacom: generic: Send BTN_STYLUS3 when both barrel switches are set

The Wacom Pro Pen 3D includes a third barrel switch which is intended to be particularly useful in applications where one frequency uses pan, zoom, and rotate to navigate around a scene or model. The pen is compatible with the MobileStudio Pro, 2nd-gen Intuos Pro, and Cintiq Pro. When the third button is pressed, these devices set both the HID_DG_BARRELSWITCH and HID_DG_BARRELSWITCH2 usages since their HID descriptors do not include a usage specific to the button. Rather than send both BTN_STYLUS and BTN_STYLUS2 when the third button is pressed, userspace (libinput) has requested that we detect this condition and report a newly-defined BTN_STYLUS3 event instead. We could define a quirk specific to devices compatible with the Pro Pen 3D, but the liklihood of seeing both barrel switch bits set with other pens/devices is low enough to not worry about (pens mechanically prevent accidental activation of multiple switches).

JGJason Gerecke committed 9 years ago