} EZUSB_DRIVER_VERSION, *PEZUSB_DRIVER_VERSION;

#ifdef DRIVER

typedef struct _RING_BUFFER
{
   PUCHAR      inPtr;
   PUCHAR      outPtr;
   ULONG       totalSize;
   ULONG       currentSize;
   KSPIN_LOCK	spinLock;
   PUCHAR      buffer;
} RING_BUFFER, *PRING_BUFFER;

PRING_BUFFER
AllocRingBuffer(
   ULONG    Size
   );

VOID
FreeRingBuffer(
   PRING_BUFFER   ringBuffer
   );

ULONG
ReadRingBuffer(
   PRING_BUFFER   ringBuffer,
   PUCHAR         readBuffer,
   ULONG          numberOfBytesToRead
   );
   
ULONG
WriteRingBuffer(
   PRING_BUFFER   ringBuffer,
   PUCHAR         writeBuffer,
   ULONG          numberOfBytesToWrite
   );

typedef struct _EZUSB_FIRMWARE
{
   // tag contains a string to identify the start of the firmware
   // image in the driver binary.  Another utilty can then be used
   // to replace the firmware image inthe driver without requiring
   // a recompile
   UCHAR tag[10];
   ULONG size;
   UCHAR firmware[];
} EZUSB_FIRMWARE, *PEZUSB_FIRMWARE;

// 
// this is the default number of IRP's to queue for streaming ISO
// data.
//
#define DEFAULT_ISO_BUFFER_COUNT 2

//
// Default number of frames of ISO data transferred by a single ISO
// URB/IRP
//
#define DEFAULT_ISO_FRAMES_PER_BUFFER 10

typedef struct _ISO_STREAM_OBJECT ISO_STREAM_OBJECT, *PISO_STREAM_OBJECT;

typedef struct _ISO_TRANSFER_OBJECT
{
   ULONG Frame;
   PISO_STREAM_OBJECT StreamObject;
   PURB Urb;
   PIRP Irp;
   KEVENT Done;
} ISO_TRANSFER_OBJECT, *PISO_TRANSFER_OBJECT;

typedef struct _ISO_STREAM_OBJECT
{
   PDEVICE_OBJECT DeviceObject;
   ULONG PacketSize;
   ULONG NumPackets;
   PUSBD_PIPE_INFORMATION PipeInfo;
   PVOID TransferBuffer;
   ULONG TransferBufferLength;
   PVOID IsoDescriptorBuffer;
   ULONG FramesPerBuffer;
   ULONG BufferCount;
   ULONG PendingTransfers;
   PRING_BUFFER DataRingBuffer;
   PRING_BUFFER DescriptorRingBuffer;
   PISO_TRANSFER_OBJECT TransferObject;
} ISO_STREAM_OBJECT, *PISO_STREAM_OBJECT;


#define Ezusb_NAME_MAX  64




//
// This is an unused structure in this driver, but is provided here
// so when you extend the driver to deal with USB pipes, you may wish
// to use this structure as an example or model.
//
typedef struct _EZUSB_PIPE {
   ULONG Mode;
   ULONG Option;
   ULONG Param1;
   ULONG Param2;
   WCHAR Name[Ezusb_NAME_MAX];
   PUSBD_PIPE_INFORMATION PipeInfo;
} EZUSB_PIPE, *PEZUSB_PIPE;


/*
// The interface number on this device that this driver expects to use
// This would be in the bInterfaceNumber field of the Interface Descriptor, hence
// this device driver would need to know this value.
*/
#define SAMPLE_INTERFACE_NBR 0x00


//
// A structure representing the instance information associated with
// this particular device.
//
typedef struct _DEVICE_EXTENSION
{

   // physical device object
   PDEVICE_OBJECT PhysicalDeviceObject;        

   // Device object we call when submitting Urbs/Irps to the USB stack
   PDEVICE_OBJECT		StackDeviceObject;		

   // Indicates that we have recieved a STOP message
   BOOLEAN Stopped;

   // Indicates the device needs to be cleaned up (ie., some configuration
   // has occurred and needs to be torn down).
   BOOLEAN NeedCleanup;

   // configuration handle for the configuration the
   // device is currently in
   USBD_CONFIGURATION_HANDLE ConfigurationHandle;

   // ptr to the USB device descriptor
   // for this device
   PUSB_DEVICE_DESCRIPTOR DeviceDescriptor;

   // we support up to one interface
   PUSBD_INTERFACE_INFORMATION Interface;

   // the number of device handles currently open to the device object.
   // Gets incremented by Create and decremented by Close
   ULONG                OpenHandles;

   // Name buffer for our named Functional device object link
   WCHAR DeviceLinkNameBuffer[Ezusb_NAME_MAX];

   // This member is used to store the URB status of the
   // most recently failed URB.  If a USB transfer fails, a caller
   // can use IOCTL_EZUSB_GET_LAST_ERROR to retrieve this value.
   // There's only room for one, so you better get it quick (or at
   // least before the next URB failure occurs).
   USBD_STATUS LastFailedUrbStatus;

   // use counter for the device.  Gets incremented when the driver receives
   // a request and gets decremented when a request s completed.
   LONG usage;

   // this ev gets set when it is ok to remove the device
	KEVENT evRemove;

   // TRUE if we're trying to remove this device
   BOOLEAN removing;

   BOOLEAN StopIsoStream;

   PRING_BUFFER DataRingBuffer;
   PRING_BUFFER DescriptorRingBuffer;

} DEVICE_EXTENSION, *PDEVICE_EXTENSION;


#if DBG

#define Ezusb_KdPrint(_x_) DbgPrint("Ezusb.SYS: "); \
                             DbgPrint _x_ ;
#define TRAP() DbgBreakPoint()
#else
#define Ezusb_KdPrint(_x_)
#define TRAP()
#endif


NTSTATUS
Ezusb_Dispatch(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP           Irp
    );

VOID
Ezusb_Unload(
    IN PDRIVER_OBJECT DriverObject
    );

NTSTATUS
Ezusb_StartDevice(
    IN  PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
Ezusb_StopDevice(
    IN  PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
Ezusb_RemoveDevice(
    IN  PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
Ezusb_CallUSBD(
    IN PDEVICE_OBJECT DeviceObject,
    IN PURB Urb
    );

NTSTATUS
Ezusb_PnPAddDevice(
    IN PDRIVER_OBJECT DriverObject,
    IN PDEVICE_OBJECT PhysicalDeviceObject
    );

NTSTATUS
Ezusb_CreateDeviceObject(
    IN PDRIVER_OBJECT DriverObject,
    IN PDEVICE_OBJECT *DeviceObject,
    LONG Instance
    );

NTSTATUS
Ezusb_ConfigureDevice(
    IN  PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
Ezusb_Create(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    );

NTSTATUS
Ezusb_Close(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    );

NTSTATUS
Ezusb_Read_Write(
   IN  PDEVICE_OBJECT DeviceObject,
   IN  PIRP Irp
   );

NTSTATUS
Ezusb_ProcessIOCTL(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    );

NTSTATUS
Ezusb_SelectInterfaces(
    IN PDEVICE_OBJECT DeviceObject,
    IN PUSB_CONFIGURATION_DESCRIPTOR ConfigurationDescriptor,
    IN PUSBD_INTERFACE_INFORMATION Interface
    );

NTSTATUS
Ezusb_ResetPipe(
   IN PDEVICE_OBJECT DeviceObject,
   IN ULONG PipeNum
   );

NTSTATUS
Ezusb_AbortPipe(
    IN PDEVICE_OBJECT DeviceObject,
    IN USBD_PIPE_HANDLE PipeHandle
    );

ULONG
Ezusb_GetCurrentFrameNumber(
    IN PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
Ezusb_Read_Write_Direct(
    IN  PDEVICE_OBJECT DeviceObject,
    IN  PIRP Irp,
    IN  BOOLEAN Read
    );

ULONG
Ezusb_DownloadTest(
    IN PDEVICE_OBJECT DeviceObject,
    IN PVENDOR_REQUEST_IN pVendorRequest
    );

NTSTATUS
Ezusb_ResetParentPort(
    IN IN PDEVICE_OBJECT DeviceObject
    );

VOID
Ezusb_Cleanup(
    PDEVICE_OBJECT DeviceObject
    );

ULONG
Ezusb_GetDeviceDescriptor(
    IN PDEVICE_OBJECT DeviceObject,
    PVOID             pvOutputBuffer
    );

ULONG
Ezusb_GetConfigDescriptor(
    IN PDEVICE_OBJECT DeviceObject,
    PVOID             pvOutputBuffer,
    ULONG             ulngth
    );

ULONG
Ezusb_VendorRequest(
    IN PDEVICE_OBJECT DeviceObject,
    PVENDOR_REQUEST_IN pVendorRequest
    );

ULONG
Ezusb_GetCurrentConfig(
    IN PDEVICE_OBJECT DeviceObject,
    IN PVENDOR_REQUEST_IN pVendorRequest
    );

ULONG
Ezusb_GetCurrentInterface(
    IN PDEVICE_OBJECT DeviceObject,
    IN PVENDOR_REQUEST_IN pVendorRequest
    );

PUSB_CONFIGURATION_DESCRIPTOR
GetConfigDescriptor(
    IN PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
ConfigureDevice(
    IN  PDEVICE_OBJECT DeviceObject
    );

NTSTATUS
SetInterface(
   IN PDEVICE_OBJECT DeviceObject,
   IN UCHAR InterfaceNumber,
   IN UCHAR AlternateSetting
   );

ULONG
Ezusb_GetStringDescriptor(
    IN PDEVICE_OBJECT DeviceObject,
    UCHAR             Index,