pinvoke.net: Edit: setupapi.CM_Get

@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$
@pinvoke=http://pinvoke.net/$$$.htm

Summary: Get the "Parent" device in the current device tree

!!!!C# Signature:
 [DllImport("setupapi.dll")]
 static extern int CM_Get_Parent(
   out UInt32 pdnDevInst,
   UInt32 dnDevInst,
   int ulFlags
 );
!!!!VB Signature:
 Declare Function CM_Get_Parent Lib "setupapi.dll" (TODO) As TODO
!!!!User-Defined Types:
None.

!!!!Alternative Managed API:
Do you know one?  Please contribute it!

!!!!Notes:
DEVINST is a DWORD, not a pointer.  This matters on 64-bit platforms.

!!!!Tips & Tricks:
Please add some!

!!!!Sample Code:
 Guid DiskGUID = new Guid(GUID_DEVINTERFACE_DISK);

// We start at the "root" of the device tree and look for all
 // devices that match the interface GUID of a disk
 IntPtr h = SetupDiGetClassDevs(ref DiskGUID, 0, IntPtr.Zero, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
 if (h.ToInt32() != INVALID_HANDLE_VALUE)
 {
   bool Success = true;
   int i = 0;
   while (Success)
   {
     // create a Device Interface Data structure
     SP_DEVICE_INTERFACE_DATA dia = new SP_DEVICE_INTERFACE_DATA();
     dia.cbSize = Marshal.SizeOf(dia);

// start the enumeration 
     Success = SetupDiEnumDeviceInterfaces(h, IntPtr.Zero, ref DiskGUID, i, ref dia);
     if (Success)
     {
        // build a DevInfo Data structure
        SP_DEVINFO_DATA da = new SP_DEVINFO_DATA();
        da.cbSize = Marshal.SizeOf(da);

// build a Device Interface Detail Data structure
        SP_DEVICE_INTERFACE_DETAIL_DATA didd = new SP_DEVICE_INTERFACE_DETAIL_DATA();
        didd.cbSize = 4 + Marshal.SystemDefaultCharSize; // trust me :)

// now we can get some more detailed information
        int nRequiredSize = 0;
        int nBytes = BUFFER_SIZE;
        if (SetupDiGetDeviceInterfaceDetail(h, ref dia, ref didd, nBytes, ref nRequiredSize, ref da))
        {
          // current InstanceID is at the "USBSTOR" level, so we
          // need up "move up" one level to get to the "USB" level
          UInt32 ptrPrevious;
          CM_Get_Parent(out ptrPrevious, da.DevInst, 0);

// Now we get the InstanceID of the USB level device
          IntPtr ptrInstanceBuf = Marshal.AllocHGlobal(nBytes);
          CM_Get_Device_ID(ptrPrevious, ptrInstanceBuf, nBytes, 0);
          string InstanceID = Marshal.PtrToStringAuto(ptrInstanceBuf);

Marshal.FreeHGlobal(ptrInstanceBuf);
        }
      }
    }
    i++;
  }
  SetupDiDestroyDeviceInfoList(h);
}

Documentation: CM_Get_Parent@msdn on MSDN