diff --git a/reactos/drivers/wdm/audio/backpln/portcls/PortWavePci.cpp b/reactos/drivers/wdm/audio/backpln/portcls/PortWavePci.cpp
deleted file mode 100644
index 9721b52739a..00000000000
--- a/reactos/drivers/wdm/audio/backpln/portcls/PortWavePci.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
-    ReactOS Operating System
-    Port Class API / IPort Implementation
-
-    by Andrew Greenwood
-*/
-
-#include "private.h"
-
-NTSTATUS
-IPortWavePci::NewMasterDmaChannel(
-    OUT PDMACHANNEL* DmaChannel,
-    IN  PUNKNOWN OuterUnknown,
-    IN  POOL_TYPE PoolType,
-    IN  PRESOURCELIST ResourceList OPTIONAL,
-    IN  BOOL ScatterGather,
-    IN  BOOL Dma32BitAddresses,
-    IN  BOOL Dma64BitAddresses,
-    IN  DMA_WIDTH DmaWidth,
-    IN  DMA_SPEED DmaSpeed,
-    IN  ULONG MaximumLength,
-    IN  ULONG DmaPort)
-{
-    return STATUS_UNSUCCESSFUL;
-}
-
-VOID
-IPortWavePci::Notify(
-    IN  PSERVICEGROUP ServiceGroup)
-{
-}
diff --git a/reactos/drivers/wdm/audio/backpln/portcls/dma_slave.c b/reactos/drivers/wdm/audio/backpln/portcls/dma_slave.c
index eb81969c692..7e37c5d70c3 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/dma_slave.c
+++ b/reactos/drivers/wdm/audio/backpln/portcls/dma_slave.c
@@ -1,7 +1,7 @@
 /*
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS Kernel Streaming
- * FILE:            drivers/wdm/audio/backpln/portcls/dma_slave.c
+ * FILE:            drivers/wdm/audio/backpln/portcls/dma_Init.c
  * PURPOSE:         portcls dma support object
  * PROGRAMMER:      Johannes Anderwald
  */
@@ -11,7 +11,7 @@
 
 typedef struct
 {
-    IDmaChannelSlaveVtbl *lpVtbl;
+    IDmaChannelInitVtbl *lpVtbl;
 
     LONG ref;
 
@@ -36,10 +36,7 @@ typedef struct
     PMDL Mdl;
     BOOLEAN WriteToDevice;
 
-}IDmaChannelSlaveImpl;
-
-const GUID IID_IDmaChannel;
-
+}IDmaChannelInitImpl;
 
 //---------------------------------------------------------------
 // IUnknown methods
@@ -48,12 +45,12 @@ const GUID IID_IDmaChannel;
 
 NTSTATUS
 NTAPI
-IDmaChannelSlave_fnQueryInterface(
-    IDmaChannelSlave * iface,
+IDmaChannelInit_fnQueryInterface(
+    IDmaChannelInit * iface,
     IN  REFIID refiid,
     OUT PVOID* Output)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
     if (IsEqualGUIDAligned(refiid, &IID_IUnknown) ||
         IsEqualGUIDAligned(refiid, &IID_IDmaChannel) ||
@@ -63,32 +60,32 @@ IDmaChannelSlave_fnQueryInterface(
         InterlockedIncrement(&This->ref);
         return STATUS_SUCCESS;
     }
-
+    DPRINT1("No interface!!!\n");
     return STATUS_UNSUCCESSFUL;
 }
 
 ULONG
-STDMETHODCALLTYPE
-IDmaChannelSlave_fnAddRef(
-    IDmaChannelSlave * iface)
+NTAPI
+IDmaChannelInit_fnAddRef(
+    IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_AddRef: This %p\n", This);
+    DPRINT("IDmaChannelInit_AddRef: This %p\n", This);
 
     return InterlockedIncrement(&This->ref);
 }
 
 ULONG
-STDMETHODCALLTYPE
-IDmaChannelSlave_fnRelease(
-    IDmaChannelSlave* iface)
+NTAPI
+IDmaChannelInit_fnRelease(
+    IDmaChannelInit* iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
     InterlockedDecrement(&This->ref);
 
-    DPRINT("IDmaChannelSlave_Release: This %p new ref %u\n", This, This->ref);
+    DPRINT("IDmaChannelInit_Release: This %p new ref %u\n", This, This->ref);
 
     if (This->ref == 0)
     {
@@ -104,91 +101,94 @@ IDmaChannelSlave_fnRelease(
 // IDmaChannel methods
 //
 
-
 NTSTATUS
 NTAPI
-IDmaChannelSlave_fnAllocateBuffer(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnAllocateBuffer(
+    IN IDmaChannelInit * iface,
     IN ULONG BufferSize,
     IN PPHYSICAL_ADDRESS  PhysicalAddressConstraint OPTIONAL)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
+
+    ASSERT_IRQL_EQUAL(PASSIVE_LEVEL);
 
     /* Did the caller already allocate a buffer ?*/
     if (This->Buffer)
     {
-        DPRINT1("IDmaChannelSlave_AllocateBuffer free common buffer first \n");
+        DPRINT1("IDmaChannelInit_AllocateBuffer free common buffer first \n");
         return STATUS_UNSUCCESSFUL;
     }
 
     This->Buffer = This->pAdapter->DmaOperations->AllocateCommonBuffer(This->pAdapter, BufferSize, &This->Address, FALSE);
     if (!This->Buffer)
     {
-        DPRINT1("IDmaChannelSlave_AllocateBuffer fAllocateCommonBuffer failed \n");
+        DPRINT1("IDmaChannelInit_AllocateBuffer fAllocateCommonBuffer failed \n");
         return STATUS_UNSUCCESSFUL;
     }
 
     This->BufferSize = BufferSize;
     This->AllocatedBufferSize = BufferSize;
-    DPRINT1("IDmaChannelSlave_fnAllocateBuffer Success Buffer %p BufferSize %u Address %x\n", This->Buffer, BufferSize, This->Address);
+    DPRINT1("IDmaChannelInit_fnAllocateBuffer Success Buffer %p BufferSize %u Address %x\n", This->Buffer, BufferSize, This->Address);
 
     return STATUS_SUCCESS;
 }
 
 ULONG
 NTAPI
-IDmaChannelSlave_fnAllocatedBufferSize(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnAllocatedBufferSize(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_AllocatedBufferSize: This %p BufferSize %u\n", This, This->BufferSize);
+    DPRINT("IDmaChannelInit_AllocatedBufferSize: This %p BufferSize %u\n", This, This->BufferSize);
     return This->AllocatedBufferSize;
 }
 
 VOID
 NTAPI
-IDmaChannelSlave_fnCopyFrom(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnCopyFrom(
+    IN IDmaChannelInit * iface,
     IN PVOID  Destination,
     IN PVOID  Source,
     IN ULONG  ByteCount
     )
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_CopyFrom: This %p Destination %p Source %p ByteCount %u\n", This, Destination, Source, ByteCount);
+    DPRINT("IDmaChannelInit_CopyFrom: This %p Destination %p Source %p ByteCount %u\n", This, Destination, Source, ByteCount);
 
     iface->lpVtbl->CopyTo(iface, Destination, Source, ByteCount);
 }
 
 VOID
 NTAPI
-IDmaChannelSlave_fnCopyTo(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnCopyTo(
+    IN IDmaChannelInit * iface,
     IN PVOID  Destination,
     IN PVOID  Source,
     IN ULONG  ByteCount
     )
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_CopyTo: This %p Destination %p Source %p ByteCount %u\n", This, Destination, Source, ByteCount);
+    DPRINT("IDmaChannelInit_CopyTo: This %p Destination %p Source %p ByteCount %u\n", This, Destination, Source, ByteCount);
     RtlCopyMemory(Destination, Source, ByteCount);
 }
   
 VOID
 NTAPI
-IDmaChannelSlave_fnFreeBuffer(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnFreeBuffer(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_FreeBuffer: This %p\n", This);
+    DPRINT("IDmaChannelInit_FreeBuffer: This %p\n", This);
+
+    ASSERT_IRQL_EQUAL(PASSIVE_LEVEL);
 
     if (!This->Buffer)
     {
-        DPRINT1("IDmaChannelSlave_FreeBuffer allocate common buffer first \n");
+        DPRINT1("IDmaChannelInit_FreeBuffer allocate common buffer first \n");
         return;
     }
 
@@ -206,59 +206,60 @@ IDmaChannelSlave_fnFreeBuffer(
 
 PADAPTER_OBJECT
 NTAPI
-IDmaChannelSlave_fnGetAdapterObject(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnGetAdapterObject(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_GetAdapterObject: This %p\n", This);
+    DPRINT("IDmaChannelInit_GetAdapterObject: This %p\n", This);
     return (PADAPTER_OBJECT)This->pAdapter;
 }
 
 ULONG
 NTAPI
-IDmaChannelSlave_fnMaximumBufferSize(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnMaximumBufferSize(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_MaximumBufferSize: This %p\n", This);
+    DPRINT("IDmaChannelInit_MaximumBufferSize: This %p\n", This);
     return This->MaximumBufferSize;
 }
 
 PHYSICAL_ADDRESS
 NTAPI
-IDmaChannelSlave_fnPhysicalAdress(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnPhysicalAdress(
+    IN IDmaChannelInit * iface,
+    PPHYSICAL_ADDRESS Address)
 {
-    PHYSICAL_ADDRESS Address;
+    PHYSICAL_ADDRESS Result;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
+    DPRINT("IDmaChannelInit_PhysicalAdress: This %p Virtuell %p Physical High %x Low %x%\n", This, This->Buffer, This->Address.HighPart, This->Address.LowPart);
 
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
-    DPRINT("IDmaChannelSlave_PhysicalAdress: This %p Virtuell %p Physical High %x Low %x%\n", This, This->Buffer, This->Address.HighPart, This->Address.LowPart);
-
-    Address = This->Address;
-    return Address;
+    Address->QuadPart = This->Address.QuadPart;
+    Result.QuadPart = (PtrToUlong(Address));
+    return Result;
 }
 
 VOID
 NTAPI
-IDmaChannelSlave_fnSetBufferSize(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnSetBufferSize(
+    IN IDmaChannelInit * iface,
     IN ULONG BufferSize)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_SetBufferSize: This %p\n", This);
+    DPRINT("IDmaChannelInit_SetBufferSize: This %p\n", This);
     This->BufferSize = BufferSize;
 
 }
 
 ULONG
 NTAPI
-IDmaChannelSlave_fnBufferSize(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnBufferSize(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
     return This->BufferSize;
 }
@@ -266,33 +267,35 @@ IDmaChannelSlave_fnBufferSize(
 
 PVOID
 NTAPI
-IDmaChannelSlave_fnSystemAddress(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnSystemAddress(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_SystemAddress: This %p\n", This);
+    DPRINT("IDmaChannelInit_SystemAddress: This %p\n", This);
     return This->Buffer;
 }
 
 ULONG
 NTAPI
-IDmaChannelSlave_fnTransferCount(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnTransferCount(
+    IN IDmaChannelInit * iface)
 {
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_TransferCount: This %p\n", This);
+    DPRINT("IDmaChannelInit_TransferCount: This %p\n", This);
     return This->LastTransferCount;
 }
 
 ULONG
 NTAPI
-IDmaChannelSlave_fnReadCounter(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnReadCounter(
+    IN IDmaChannelInit * iface)
 {
     ULONG Counter;
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
+
+    ASSERT_IRQL(DISPATCH_LEVEL);
 
     Counter = This->pAdapter->DmaOperations->ReadDmaCounter(This->pAdapter);
 
@@ -311,7 +314,7 @@ AdapterControl(
     IN PVOID  Context)
 {
     ULONG Length;
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)Context;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)Context;
 
     Length = This->MapSize;
     This->MapRegisterBase = MapRegisterBase;
@@ -333,17 +336,19 @@ AdapterControl(
 
 NTSTATUS
 NTAPI
-IDmaChannelSlave_fnStart(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnStart(
+    IN IDmaChannelInit * iface,
     ULONG  MapSize,
     BOOLEAN WriteToDevice)
 {
     NTSTATUS Status;
     ULONG MapRegisters;
     KIRQL OldIrql;
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_Start: This %p\n", This);
+    DPRINT("IDmaChannelInit_Start: This %p\n", This);
+
+    ASSERT_IRQL_EQUAL(PASSIVE_LEVEL);
 
     if (This->DmaStarted)
         return STATUS_UNSUCCESSFUL;
@@ -379,13 +384,14 @@ IDmaChannelSlave_fnStart(
 
 NTSTATUS
 NTAPI
-IDmaChannelSlave_fnStop(
-    IN IDmaChannelSlave * iface)
+IDmaChannelInit_fnStop(
+    IN IDmaChannelInit * iface)
 {
     KIRQL OldIrql;
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
 
-    DPRINT("IDmaChannelSlave_fnStop: This %p\n", This);
+    DPRINT("IDmaChannelInit_fnStop: This %p\n", This);
+    ASSERT_IRQL(DISPATCH_LEVEL);
 
     if (!This->DmaStarted)
         return STATUS_SUCCESS;
@@ -413,15 +419,17 @@ IDmaChannelSlave_fnStop(
 
 NTSTATUS
 NTAPI
-IDmaChannelSlave_fnWaitForTC(
-    IN IDmaChannelSlave * iface,
+IDmaChannelInit_fnWaitForTC(
+    IN IDmaChannelInit * iface,
     ULONG  Timeout)
 {
     ULONG RetryCount;
     ULONG BytesRemaining;
     ULONG PrevBytesRemaining;
 
-    IDmaChannelSlaveImpl * This = (IDmaChannelSlaveImpl*)iface;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
+
+    ASSERT_IRQL_EQUAL(PASSIVE_LEVEL);
 
     BytesRemaining = This->pAdapter->DmaOperations->ReadDmaCounter(This->pAdapter);
     if (!BytesRemaining)
@@ -454,30 +462,73 @@ IDmaChannelSlave_fnWaitForTC(
 
 }
 
-IDmaChannelSlaveVtbl vt_IDmaChannelSlaveVtbl =
+NTSTATUS
+NTAPI
+IDmaChannelInit_fnInit(
+    IN IDmaChannelInit * iface,
+    IN PDEVICE_DESCRIPTION DeviceDescription,
+    IN PDEVICE_OBJECT DeviceObject)
+{
+    INTERFACE_TYPE BusType;
+    NTSTATUS Status;
+    PDMA_ADAPTER Adapter;
+    PPCLASS_DEVICE_EXTENSION DeviceExt;
+    ULONG MapRegisters;
+    ULONG ResultLength;
+    IDmaChannelInitImpl * This = (IDmaChannelInitImpl*)iface;
+
+    /* Get bus type */
+    Status = IoGetDeviceProperty(DeviceObject, DevicePropertyLegacyBusType, sizeof(BusType), (PVOID)&BusType, &ResultLength);
+    if (NT_SUCCESS(Status))
+    {
+        DeviceDescription->InterfaceType = BusType;
+    }
+    /* Fetch device extension */
+    DeviceExt = (PPCLASS_DEVICE_EXTENSION) DeviceObject->DeviceExtension;
+    /* Acquire dma adapter */
+    Adapter = IoGetDmaAdapter(DeviceExt->PhysicalDeviceObject, DeviceDescription, &MapRegisters);
+    if (!Adapter)
+    {
+        FreeItem(This, TAG_PORTCLASS);
+        return STATUS_DEVICE_CONFIGURATION_ERROR;
+    }
+
+    /* initialize object */
+    This->ref = 1;
+    This->pAdapter = Adapter;
+    This->pDeviceObject = DeviceObject;
+    This->MaximumBufferSize = DeviceDescription->MaximumLength;
+    This->MaxMapRegisters = MapRegisters;
+
+    return STATUS_SUCCESS;
+}
+
+
+IDmaChannelInitVtbl vt_IDmaChannelInitVtbl =
 {
     /* IUnknown methods */
-    IDmaChannelSlave_fnQueryInterface,
-    IDmaChannelSlave_fnAddRef,
-    IDmaChannelSlave_fnRelease,
+    IDmaChannelInit_fnQueryInterface,
+    IDmaChannelInit_fnAddRef,
+    IDmaChannelInit_fnRelease,
     /* IDmaChannel methods */
-    IDmaChannelSlave_fnAllocateBuffer,
-    IDmaChannelSlave_fnFreeBuffer,
-    IDmaChannelSlave_fnTransferCount,
-    IDmaChannelSlave_fnMaximumBufferSize,
-    IDmaChannelSlave_fnAllocatedBufferSize,
-    IDmaChannelSlave_fnBufferSize,
-    IDmaChannelSlave_fnSetBufferSize,
-    IDmaChannelSlave_fnSystemAddress,
-    IDmaChannelSlave_fnPhysicalAdress,
-    IDmaChannelSlave_fnGetAdapterObject,
-    IDmaChannelSlave_fnCopyTo,
-    IDmaChannelSlave_fnCopyFrom,
-    /* IDmaChannelSlave methods */
-    IDmaChannelSlave_fnStart,
-    IDmaChannelSlave_fnStop,
-    IDmaChannelSlave_fnReadCounter,
-    IDmaChannelSlave_fnWaitForTC
+    IDmaChannelInit_fnAllocateBuffer,
+    IDmaChannelInit_fnFreeBuffer,
+    IDmaChannelInit_fnTransferCount,
+    IDmaChannelInit_fnMaximumBufferSize,
+    IDmaChannelInit_fnAllocatedBufferSize,
+    IDmaChannelInit_fnBufferSize,
+    IDmaChannelInit_fnSetBufferSize,
+    IDmaChannelInit_fnSystemAddress,
+    IDmaChannelInit_fnPhysicalAdress,
+    IDmaChannelInit_fnGetAdapterObject,
+    IDmaChannelInit_fnCopyTo,
+    IDmaChannelInit_fnCopyFrom,
+    /* IDmaChannelInit methods */
+    IDmaChannelInit_fnStart,
+    IDmaChannelInit_fnStop,
+    IDmaChannelInit_fnReadCounter,
+    IDmaChannelInit_fnWaitForTC,
+    IDmaChannelInit_fnInit
 };
 
 
@@ -493,48 +544,26 @@ PcNewDmaChannel(
     IN  PDEVICE_OBJECT DeviceObject)
 {
     NTSTATUS Status;
-    PDMA_ADAPTER Adapter;
-    ULONG MapRegisters;
-    INTERFACE_TYPE BusType;
-    ULONG ResultLength;
-    PPCLASS_DEVICE_EXTENSION DeviceExt;
-
-    IDmaChannelSlaveImpl * This;
+    IDmaChannelInitImpl * This;
 
     DPRINT("OutDmaChannel %p OuterUnknown %p PoolType %p DeviceDescription %p DeviceObject %p\n",
             OutDmaChannel, OuterUnknown, PoolType, DeviceDescription, DeviceObject);
 
-    This = AllocateItem(PoolType, sizeof(IDmaChannelSlaveImpl), TAG_PORTCLASS);
+    This = AllocateItem(PoolType, sizeof(IDmaChannelInitImpl), TAG_PORTCLASS);
     if (!This)
     {
         return STATUS_INSUFFICIENT_RESOURCES;
     }
 
-    DeviceExt = (PPCLASS_DEVICE_EXTENSION) DeviceObject->DeviceExtension;
-
-    Status = IoGetDeviceProperty(DeviceObject, DevicePropertyLegacyBusType, sizeof(BusType), (PVOID)&BusType, &ResultLength);
+    /* initialize object */
+    Status = IDmaChannelInit_fnInit((IDmaChannelInit*)This, DeviceDescription, DeviceObject);
     if (NT_SUCCESS(Status))
     {
-        DeviceDescription->InterfaceType = BusType;
+        /* store result */
+        This->lpVtbl = &vt_IDmaChannelInitVtbl;
+        *OutDmaChannel = (PVOID)(&This->lpVtbl);
     }
 
-    Adapter = IoGetDmaAdapter(DeviceExt->PhysicalDeviceObject, DeviceDescription, &MapRegisters);
-    if (!Adapter)
-    {
-        FreeItem(This, TAG_PORTCLASS);
-        return STATUS_DEVICE_CONFIGURATION_ERROR;
-    }
-
-    /* initialize object */
-    This->ref = 1;
-    This->lpVtbl = &vt_IDmaChannelSlaveVtbl;
-    This->pAdapter = Adapter;
-    This->pDeviceObject = DeviceObject;
-    This->MaximumBufferSize = DeviceDescription->MaximumLength;
-    This->MaxMapRegisters = MapRegisters;
-
-    *OutDmaChannel = (PVOID)(&This->lpVtbl);
-    DPRINT("PcNewDmaChannel result %p\n", *OutDmaChannel);
-    return STATUS_SUCCESS;
+    return Status;
 
 }
diff --git a/reactos/drivers/wdm/audio/backpln/portcls/interfaces.h b/reactos/drivers/wdm/audio/backpln/portcls/interfaces.h
index f168a460cd6..ac35f4ccd5d 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/interfaces.h
+++ b/reactos/drivers/wdm/audio/backpln/portcls/interfaces.h
@@ -520,4 +520,60 @@ DECLARE_INTERFACE_(IPortPinWaveCyclic, IIrpTarget)
     STDMETHOD_(PMINIPORT, GetMiniport)(THIS);
 };
 
+/*****************************************************************************
+ * IDmaChannelInit
+ *****************************************************************************
+ */
+
+#undef INTERFACE
+#define INTERFACE IDmaChannelInit
+
+DECLARE_INTERFACE_(IDmaChannelInit, IUnknown)
+{
+    DEFINE_ABSTRACT_UNKNOWN()
+
+    STDMETHOD_(NTSTATUS,AllocateBuffer)(THIS_
+        IN  ULONG BufferSize,
+        IN  PPHYSICAL_ADDRESS PhysicalAddressConstraint OPTIONAL);
+
+    STDMETHOD_(VOID, FreeBuffer)(THIS);
+    STDMETHOD_(ULONG, TransferCount)(THIS);
+    STDMETHOD_(ULONG, MaximumBufferSize)(THIS);
+    STDMETHOD_(ULONG, AllocatedBufferSize)(THIS);
+    STDMETHOD_(ULONG, BufferSize)(THIS);
+
+    STDMETHOD_(VOID, SetBufferSize)(THIS_ 
+        IN  ULONG BufferSize);
+
+    STDMETHOD_(PVOID, SystemAddress)(THIS);
+    STDMETHOD_(PHYSICAL_ADDRESS, PhysicalAddress)(THIS_
+        IN PPHYSICAL_ADDRESS Address);
+
+    STDMETHOD_(PADAPTER_OBJECT, GetAdapterObject)(THIS);
+
+    STDMETHOD_(VOID, CopyTo)(THIS_
+        IN  PVOID Destination,
+        IN  PVOID Source,
+        IN  ULONG ByteCount);
+
+    STDMETHOD_(VOID, CopyFrom)(THIS_
+        IN  PVOID Destination,
+        IN  PVOID Source,
+        IN  ULONG ByteCount);
+
+    STDMETHOD_(NTSTATUS, Start)( THIS_ 
+        IN  ULONG MapSize,
+        IN  BOOLEAN WriteToDevice) PURE;
+
+    STDMETHOD_(NTSTATUS, Stop)( THIS ) PURE;
+    STDMETHOD_(ULONG, ReadCounter)( THIS ) PURE;
+
+    STDMETHOD_(NTSTATUS, WaitForTC)( THIS_
+        ULONG Timeout) PURE;
+
+    STDMETHOD_(NTSTATUS, Init)( THIS_
+        IN PDEVICE_DESCRIPTION DeviceDescription,
+        IN PDEVICE_OBJECT DeviceObject) PURE;
+};
+
 #endif