Using 11.0-CURRENT on a macbook, -r 270176, on boot I found catting /dev/apt showed no output when i touched the trackpad.

If I kldunload atp and load it again, then (confusingly) the wsp0 device is created instead. I can cat that fine, and see data from the trackpad's movements.

I think either wsp(4) or ums(4) is interfering with the priority for devd.conf when attaching devices. As I understand it, atp(4) obsoletes wsp(4). So I worked around this by changing the priorities such that atp(4) attaches before ums(4), and I commented out wsp(4) entirely:

notify 120 {
        match "system" "DEVFS";
        match "subsystem" "CDEV";
        match "type" "CREATE";
        match "cdev" "atp[0-9]+";

        action "/etc/rc.d/moused quietstart $cdev";
};

notify 100 {
        match "system" "DEVFS";
        match "subsystem" "CDEV";
        match "type" "CREATE";
        match "cdev" "ums[0-9]+";

        action "/etc/rc.d/moused quietstart $cdev";
};

#notify 110 {
#       match "system" "DEVFS";
#       match "subsystem" "CDEV";
#       match "type" "CREATE";
#       match "cdev" "wsp[0-9]+";

#       action "/etc/rc.d/moused quietstart $cdev";
#};

I'm not sure what's the proper thing to do. My guess is that wsp(4) ought to be removed entirely, if atp(4) includes its supported models.