reactos/lib/drivers/sound/mmebuddy/kernel.c

   1 /*
   2  * PROJECT:     ReactOS Sound System "MME Buddy" Library
   3  * LICENSE:     GPL - See COPYING in the top level directory
   4  * FILE:        lib/drivers/sound/mmebuddy/kernel.c
   5  *
   6  * PURPOSE:     Routines assisting with device I/O between user-mode and
   7  *              kernel-mode.
   8  *
   9  * PROGRAMMERS: Andrew Greenwood (silverblade@reactos.org)
  10 */
  11
  12 #include <windows.h>
  13 #include <mmsystem.h>
  14 #include <mmddk.h>
  15 #include <ntddsnd.h>
  16 #include <mmebuddy.h>
  17
  18 /*
  19     Wraps around CreateFile in order to provide a simpler interface tailored
  20     towards sound driver support code. This simply takes a device path and
  21     opens the device in either read-only mode, or read/write mode (depending on
  22     the ReadOnly parameter).
  23
  24     If the device is opened in read/write mode, it is opened for overlapped I/O.
  25 */
  26 MMRESULT
  27 OpenKernelSoundDeviceByName(
  28     IN  PWSTR DevicePath,
  29     IN  BOOLEAN ReadOnly,
  30     OUT PHANDLE Handle)
  31 {
  32     DWORD AccessRights;
  33
  34     VALIDATE_MMSYS_PARAMETER( DevicePath );
  35     VALIDATE_MMSYS_PARAMETER( Handle );
  36
  37     AccessRights = ReadOnly ? GENERIC_READ : GENERIC_READ | GENERIC_WRITE;
  38
  39     SND_TRACE(L"OpenKernelSoundDeviceByName: %wS\n", DevicePath);
  40     *Handle = CreateFile(DevicePath,
  41                          AccessRights,
  42                          FILE_SHARE_WRITE,  /* FIXME? Should be read also? */
  43                          NULL,
  44                          OPEN_EXISTING,
  45                          ReadOnly ? 0 : FILE_FLAG_OVERLAPPED,
  46                          NULL);
  47
  48     if ( *Handle == INVALID_HANDLE_VALUE )
  49     {
  50         SND_ERR(L"CreateFile filed - winerror %d\n", GetLastError());
  51         return Win32ErrorToMmResult(GetLastError());
  52     }
  53
  54     return MMSYSERR_NOERROR;
  55 }
  56
  57
  58 /*
  59     Just a wrapped around CloseHandle.
  60 */
  61 MMRESULT
  62 CloseKernelSoundDevice(
  63     IN  HANDLE Handle)
  64 {
  65     VALIDATE_MMSYS_PARAMETER( Handle );
  66
  67     CloseHandle(Handle);
  68
  69     return MMSYSERR_NOERROR;
  70 }
  71
  72 /*
  73     This is a wrapper around DeviceIoControl which provides control over
  74     instantiated sound devices. It waits for I/O to complete (since an
  75     instantiated sound device is opened in overlapped mode, this is necessary).
  76 */
  77 MMRESULT
  78 SyncOverlappedDeviceIoControl(
  79     IN  HANDLE Handle,
  80     IN  DWORD IoControlCode,
  81     IN  LPVOID InBuffer,
  82     IN  DWORD InBufferSize,
  83     OUT LPVOID OutBuffer,
  84     IN  DWORD OutBufferSize,
  85     OUT LPDWORD BytesTransferred OPTIONAL)
  86 {
  87     OVERLAPPED Overlapped;
  88     BOOLEAN IoResult;
  89     DWORD Transferred;
  90
  91     /* Overlapped I/O is done here - this is used for waiting for completion */
  92     ZeroMemory(&Overlapped, sizeof(OVERLAPPED));
  93     Overlapped.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
  94
  95     if ( ! Overlapped.hEvent )
  96         return Win32ErrorToMmResult(GetLastError());
  97
  98     /* Talk to the device */
  99     IoResult = DeviceIoControl(Handle,
 100                                IoControlCode,
 101                                InBuffer,
 102                                InBufferSize,
 103                                OutBuffer,
 104                                OutBufferSize,
 105                                NULL,
 106                                &Overlapped);
 107
 108     /* If failure occurs, make sure it's not just due to the overlapped I/O */
 109     if ( ! IoResult )
 110     {
 111         if ( GetLastError() != ERROR_IO_PENDING )
 112         {
 113             CloseHandle(Overlapped.hEvent);
 114             return Win32ErrorToMmResult(GetLastError());
 115         }
 116     }
 117
 118     /* Wait for the I/O to complete */
 119     IoResult = GetOverlappedResult(Handle,
 120                                    &Overlapped,
 121                                    &Transferred,
 122                                    TRUE);
 123
 124     /* Don't need this any more */
 125     CloseHandle(Overlapped.hEvent);
 126
 127     if ( ! IoResult )
 128         return Win32ErrorToMmResult(GetLastError());
 129
 130     if ( BytesTransferred )
 131         *BytesTransferred = Transferred;
 132
 133     return MMSYSERR_NOERROR;
 134 }