I had this working several months ago.
With recent sups and kernel rebuilds, it doesn't.
Here's what I have:

0) From boot prompt, probe-scsi does detetct the scanner correctly

1) With an almost generic kernel build, I added the line
 ss*     at scsibus? target ? lun ?              # SCSI scanners

and rebuilt kernel.

2) On reboot, I get this message :

Jul 28 11:12:49  /netbsd: scsibus0 targ 5 lun 0: <HP, C5110A, 3638> SCSI
2 3/processor fixed not configured

and the previously used utilities from PINT don't find the scanner.

HELP!

Clarence Wilkerson