BOOLEAN
SerialTurnOnBreak(
IN PVOID Context
)
/*++
Routine Description:
This routine will turn on break in the hardware and
record the fact the break is on, in the extension variable
that holds reasons that transmission is stopped.
Arguments:
Context - Really a pointer to the device extension.
Return Value:
This routine always returns FALSE.
--*/
{
PSERIAL_DEVICE_EXTENSION Extension = Context;
UCHAR OldLineControl;
if ((Extension->HandFlow.FlowReplace & SERIAL_RTS_MASK) ==
SERIAL_TRANSMIT_TOGGLE) {
SerialSetRTS(Extension);
}
OldLineControl = READ_LINE_CONTROL(Extension->Controller);
OldLineControl |= SERIAL_LCR_BREAK;
WRITE_LINE_CONTROL(
Extension->Controller,
OldLineControl
);
Extension->TXHolding |= SERIAL_TX_BREAK;
return FALSE;
}
VOID
SerialSaveDeviceState(IN PSERIAL_DEVICE_EXTENSION PDevExt)
/*++
Routine Description:
This routine saves the device state of the UART
Arguments:
PDevExt - Pointer to the device extension for the devobj to save the state
for.
Return Value:
VOID
--*/
{
PSERIAL_DEVICE_STATE pDevState = &PDevExt->DeviceState;
PAGED_CODE();
SerialDbgPrintEx(TRACE_LEVEL_INFORMATION, DBG_POWER, "Entering SerialSaveDeviceState\n");
//
// Read necessary registers direct
//
pDevState->IER = READ_INTERRUPT_ENABLE(PDevExt, PDevExt->Controller);
pDevState->MCR = READ_MODEM_CONTROL(PDevExt, PDevExt->Controller);
pDevState->LCR = READ_LINE_CONTROL(PDevExt, PDevExt->Controller);
SerialDbgPrintEx(TRACE_LEVEL_INFORMATION, DBG_POWER, "Leaving SerialSaveDeviceState\n");
}
BOOLEAN
SerialTurnOffBreak(
IN PVOID Context
)
/*++
Routine Description:
This routine will turn off break in the hardware and
record the fact the break is off, in the extension variable
that holds reasons that transmission is stopped.
Arguments:
Context - Really a pointer to the device extension.
Return Value:
This routine always returns FALSE.
--*/
{
PSERIAL_DEVICE_EXTENSION Extension = Context;
UCHAR OldLineControl;
if (Extension->TXHolding & SERIAL_TX_BREAK) {
//
// We actually have a good reason for testing if transmission
// is holding instead of blindly clearing the bit.
//
// If transmission actually was holding and the result of
// clearing the bit is that we should restart transmission
// then we will poke the interrupt enable bit, which will
// cause an actual interrupt and transmission will then
// restart on its own.
//
// If transmission wasn't holding and we poked the bit
// then we would interrupt before a character actually made
// it out and we could end up over writing a character in
// the transmission hardware.
OldLineControl = READ_LINE_CONTROL(Extension->Controller);
OldLineControl &= ~SERIAL_LCR_BREAK;
WRITE_LINE_CONTROL(
Extension->Controller,
OldLineControl
);
Extension->TXHolding &= ~SERIAL_TX_BREAK;
if (!Extension->TXHolding &&
(Extension->TransmitImmediate ||
Extension->WriteLength) &&
Extension->HoldingEmpty) {
DISABLE_ALL_INTERRUPTS(Extension->Controller);
ENABLE_ALL_INTERRUPTS(Extension->Controller);
} else {
//
// The following routine will lower the rts if we
// are doing transmit toggleing and there is no
// reason to keep it up.
//
Extension->CountOfTryingToLowerRTS++;
SerialPerhapsLowerRTS(Extension);
}
}
return FALSE;
}
//
// Internal Function: UartCtlGetLineControl
//
VOID
UartCtlGetLineControl(
_In_ WDFDEVICE Device,
_In_ WDFREQUEST Request,
_In_ size_t OutputBufferLength,
_In_ size_t InputBufferLength
)
{
NTSTATUS status = STATUS_UNSUCCESSFUL;
PUART_DEVICE_EXTENSION pDevExt = UartGetDeviceExtension(Device);
UCHAR lineControlRegister = 0;
PSERIAL_LINE_CONTROL pLineControl = NULL;
UNREFERENCED_PARAMETER(OutputBufferLength);
UNREFERENCED_PARAMETER(InputBufferLength);
FuncEntry(TRACE_FLAG_CONTROL);
status = WdfRequestRetrieveOutputBuffer(Request,
sizeof(SERIAL_LINE_CONTROL),
(PVOID*)(& pLineControl),
NULL);
if (!NT_SUCCESS(status))
{
TraceMessage(
TRACE_LEVEL_ERROR,
TRACE_FLAG_CONTROL,
"Failed to retrieve output buffer for WDFREQUEST %p - "
"%!STATUS!",
Request,
status);
}
if (NT_SUCCESS(status))
{
// Acquires the interrupt lock and reads the LCR.
WdfInterruptAcquireLock(pDevExt->WdfInterrupt);
lineControlRegister = READ_LINE_CONTROL(pDevExt, pDevExt->Controller);
WdfInterruptReleaseLock(pDevExt->WdfInterrupt);
status = UartRegLCRToStruct(lineControlRegister, pLineControl);
if (!NT_SUCCESS(status))
{
TraceMessage(
TRACE_LEVEL_ERROR,
TRACE_FLAG_CONTROL,
"Failed to calculate SERIAL_LINE_CONTROL from LCR %c - "
"%!STATUS!",
lineControlRegister,
status);
}
}
if (NT_SUCCESS(status))
{
WdfRequestSetInformation(Request, sizeof(SERIAL_LINE_CONTROL));
}
TraceMessage(TRACE_LEVEL_INFORMATION,
TRACE_FLAG_CONTROL,
"WdfRequestComplete( %!HANDLE! => %!STATUS! )",
Request,
status);
WdfRequestComplete(Request, status);
FuncExit(TRACE_FLAG_CONTROL);
}
//
// Internal Function: UartCtlSetLineControl
//
VOID
UartCtlSetLineControl(
_In_ WDFDEVICE Device,
_In_ WDFREQUEST Request,
_In_ size_t OutputBufferLength,
_In_ size_t InputBufferLength
)
{
NTSTATUS status = STATUS_UNSUCCESSFUL;
PUART_DEVICE_EXTENSION pDevExt = UartGetDeviceExtension(Device);
UCHAR lineControlRegister = 0;
PSERIAL_LINE_CONTROL pLineControl = NULL;
UNREFERENCED_PARAMETER(OutputBufferLength);
UNREFERENCED_PARAMETER(InputBufferLength);
FuncEntry(TRACE_FLAG_CONTROL);
status = WdfRequestRetrieveInputBuffer(Request,
sizeof(SERIAL_LINE_CONTROL),
(PVOID*)(& pLineControl),
NULL);
if (!NT_SUCCESS(status))
{
TraceMessage(
TRACE_LEVEL_ERROR,
TRACE_FLAG_CONTROL,
"Failed to retrieve input buffer for WDFREQUEST %p - "
"%!STATUS!",
Request,
status);
}
if (NT_SUCCESS(status))
{
status = UartRegStructToLCR(pLineControl, &lineControlRegister);
if (!NT_SUCCESS(status))
{
TraceMessage(
TRACE_LEVEL_ERROR,
TRACE_FLAG_CONTROL,
"Failed to calculate LCR from SERIAL_LINE_CONTROL %p - "
"%!STATUS!",
pLineControl,
status);
}
}
if (NT_SUCCESS(status))
{
WdfInterruptAcquireLock(pDevExt->WdfInterrupt);
// Set line control, save break setting
lineControlRegister = lineControlRegister |
(READ_LINE_CONTROL(pDevExt, pDevExt->Controller) & SERIAL_LCR_BREAK);
WRITE_LINE_CONTROL(pDevExt, pDevExt->Controller, lineControlRegister);
WdfInterruptReleaseLock(pDevExt->WdfInterrupt);
}
TraceMessage(TRACE_LEVEL_INFORMATION,
TRACE_FLAG_CONTROL,
"WdfRequestComplete( %!HANDLE! => %!STATUS! )",
Request,
status);
WdfRequestComplete(Request, status);
FuncExit(TRACE_FLAG_CONTROL);
}
