• David Brownell's avatar
    usb gadget: new "CDC Composite" gadget driver · 19e20680
    David Brownell authored
    This is a simple example of a composite gadget, combining two
    Communications Class Device (CDC) functions:  ECM and ACM.
    
    This provides a clear example of how the composite gadget framework
    is intended to work.  It's surprising that MS-Windows (or at least,
    XP and previous) won't "just work" with something this simple...
    
    One /proc/bus/usb/devices listing looks like:
    
      T:  Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 46 Spd=480 MxCh= 0
      D:  Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
      P:  Vendor=0525 ProdID=a4aa Rev= 3.01
      S:  Manufacturer=Linux 2.6.26-rc6-pnut with net2280
      S:  Product=CDC Composite Gadget
      C:* #Ifs= 4 Cfg#= 1 Atr=c0 MxPwr=  2mA
      I:* If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=06 Prot=00 Driver=cdc_ether
      E:  Ad=83(I) Atr=03(Int.) MxPS=  16 Ivl=32ms
      I:  If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
      I:* If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
      E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      I:* If#= 2 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=cdc_acm
      E:  Ad=86(I) Atr=03(Int.) MxPS=   8 Ivl=32ms
      I:* If#= 3 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_acm
      E:  Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
      E:  Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
    
    Not all USB peripheral controller hardware can support this driver.
    All the highspeed-capable peripheral controllers with drivers now in
    the mainline kernel seem to support this, as does omap_udc.  But
    many full speed controllers don't have enough endpoints, or (as with
    the PXA controllers) don't support altsettings.
    
    Lightly tested.
    Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    19e20680
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