smartcard reader kmdf .sys with multiple device interface

Hello everybody,
I try to develop a smartcard reader USB driver.
1) evtDeviceAdd :
_ I have created an usb target device, for catch usb interrupt.
_ I call WdfDeviceInitSetFileObjectConfig (EvtDeviceFileCreate) with a fileSlot context that contains all parameter needed for a slot interface smartcard.
_ I call twice "WdfDeviceCreateDeviceInterface" ( for 2 smartcard slot interface )

2) EvtDeviceD0Entry :
_ Start interruptPipe target for catch interrupt message

3) EvtDeviceFileCreate :
_ with "FileOject" I extract fileSlot context attached to my device interface.

When I launch a smartcard tool, I can see both interface.

Now I have a problem for distinguish what is the deviceinterface affected by the usb interrupt.
For example : the interruptPipe returned me 2 bytes (value 0x50, 0x0, 0x0, 0x0 )
If value is : (value 0x50, 0x0, 0x0, 0xFF ) : Slot 1 is concerned ( devInterface0)
If value is : (value 0x50, 0x0, 0xFF, 0x0 ) : Slot 2 is concerned ( devInterface1)

In Interrupt completionRoutine, I would like to know how to communicate directly with devInterface concerned ( for change status smartcard = detected ) ?

some one could give me any tips,
if I can use a WdfIoTarget during DeviceFileCreate function that point to the WdfFileObject input parameter ?
or use an array in deviceContext that contains both wdffileObject pointer ?

deviceContext
{
WDFUSBDEVICE UsbDevice;
WDFUSBPIPE pipeRead;
WDFUSBPIPE pipeWrite;
WDFUSBPIPE pipeInterrupt;

WDFQUEUE ioctlQueue;
} DEVICE_CONTEXT;

fileSlotContext
{
PSMARTCARD_EXTENSION smartcardExtension; // for each deviceInterface
UNICODE_STRING slotInterfaceName; // Slot0, Slot1, ....
UCHAR deviceSlotNumber // 0,1, ....
}

Thanks in advance,

Best regards,

Moulefrite