// For PurgeComm. The PDD only handle The clean up the hardware.
BOOL CSerialPDD::PurgeComm( DWORD fdwAction)
{
if (fdwAction & PURGE_RXCLEAR ) {
CancelReceive();
}
if (fdwAction & PURGE_TXCLEAR ) {
CancelXmit();
}
return TRUE;
}
BOOL CommonCmdHandler (
IN void *pvCmdBuf, // Address of buffer contaiing command packet
IN size_t tCmdSize, // Size of command packet
OUT void *pvRspBuf, // Address of buffer for response packet
IN size_t tRspSize // Expected size of response packet
)
{
BOOL bSucceeded = FALSE; // Success indicator
DWORD dwCount; // Count returned by WriteFile()/ReadFile()
DWORD dwStatus; // Buffer for status codes
int iRetries; // Retry counter
// Obtain (thread) exclusive access to resources
switch( WaitForSingleObject( hMutex, INFINITE ) )
{
case WAIT_ABANDONED:
case WAIT_OBJECT_0:
break;
default:
return( FALSE );
}
// Attach to HECI driver if we aren't already
if( !bAttached && !AttachDriver() )
{
// Couldn't attach the driver...
dwStatus = GetLastError();
}
else
{
// Attached; now have info to verify max command/response size...
if( (tCmdSize > stProperties.minRxBufferSize) || (tRspSize > stProperties.minRxBufferSize) )
dwStatus = ERROR_BAD_LENGTH;
// Length ok, attempt communication...
else
{
// Support retries during communication...
for( iRetries = 0; iRetries < RETRY_COUNT; iRetries++ )
{
bReceivePosted = FALSE;
// Post Receive Buffer if a response expected
if( (tRspSize == 0) || PostReceive( pvBuffer, stProperties.minRxBufferSize ) )
{
// Send Command Packet
if( DoSend( pvCmdBuf, tCmdSize ) )
{
// If no response is desired, we're done!
if( tRspSize == 0 )
{
bSucceeded = TRUE;
break;
}
// Receive and process Response Packet
dwCount = CompleteReceive( TRUE );
if( dwCount )
{
// Have a response; verify it
if( (dwCount != tRspSize) && (CheckRspSuccess(pvBuffer)) )
{
// Data received is larger/smaller than expected
dwStatus = ERROR_BAD_LENGTH;
}
else
{
// Data received is right length (or QST rejected command)
// Place info available into caller's buffer
memcpy( pvRspBuf, pvBuffer, __min(dwCount, tRspSize) );
bSucceeded = TRUE;
}
// We're done!
break;
}
}
// Remember ccode from first failed operation...
if( iRetries == 0 )
dwStatus = GetLastError();
// Won't need the buffer we posted...
if( tRspSize != 0 )
CancelReceive();
}
// A retry is necessary; recreate attachment to driver in case lost due to PM transition, etc.
DetachDriver();
if( !AttachDriver() )
break; // Can't reattach, time to give up
if( !AsyncDelay( RETRY_DELAY ) ) // Delay retry to give driver a break
break;
}
}
}
ReleaseMutex( hMutex );
if( !bSucceeded )
SetLastError( dwStatus ); // Indicate why we're failing
return (bSucceeded);
}