When using the XBox Wireless Controller Elite 2 over Bluetooth,
the device exports the paddle on the back of the device as a single
bitfield value of usage "Assign Selection".
The kernel doesn't process those usages properly and report KEY_UNKNOWN
for it.
SDL doesn't know how to interprete that KEY_UNKNOWN and thus ignores the
paddles.
Given that over USB the kernel uses BTN_TRIGGER_HAPPY[5-8], we
can tweak the report descriptor to make the kernel interprete it properly:
- we need an application collection of gamepad (so we have to close the
current Consumer Control one)
- we need to change the usage to be buttons from 0x15 to 0x18
Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-7-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
