From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Breton M. Saunders" <bms20@brettnet.eu>
Subject: HID input dealing with multiple collections?
Date: Mon, 09 Sep 2013 13:56:52 +0100
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Hello,

   I've written a USB device which supports multiple input devices:
     * A touch surface digitizer (following Microsoft's specification)
     * A pen surface digitizer
     * A mouse emulator

   In windows each of these interfaces are exposed as a separate top 
level collection, e.g.:
   Usage_Page(Generic Desktop)
   Usage(Mouse)
   Collection(Application)
        ...
   End_Collection
   Usage_Page(Digitzer)
   Usage(Touch_Screen)
   Collection(Application)
      ...
   End_Collection
   Usage(Digitizer)
   Usage(Pen)
   Collection(Application)
      ...
   End_Collection

   Now this descriptor works well in Windows; all reporting channels are 
exposed correctly as hid devices and mouse/multitouch/pen input all 
works correctly as expected.  In linux, however, this is not the case.  
What I see is that if I drop out the touch/pen functionality then the 
mouse support works correctly.  Likewise, if I drop any pair of other 
top level collections such that I have exactly one top level collection 
the system works correctly.

   Am I missing something here - as in: Have I made an error in my usage 
of top level collections, or is linux-input's hid support incapable of 
dealing with multiple top level collections?

   Thanks in advance for any advice on this!

-bms20