void dc_dbg_init()
{
#ifdef DBG_COM
u32 divisor;
u8 lcr;
/* set baud rate and data format (8N1) */
/* turn on DTR and RTS */
WRITE_PORT_UCHAR(pv(SER_MCR(COM_BASE)), SR_MCR_DTR | SR_MCR_RTS);
/* set DLAB */
lcr = READ_PORT_UCHAR(pv(SER_LCR(COM_BASE))) | SR_LCR_DLAB;
WRITE_PORT_UCHAR(pv(SER_LCR(COM_BASE)), lcr);
/* set baud rate */
divisor = 115200 / DEFAULT_BAUD_RATE;
WRITE_PORT_UCHAR(pv(SER_DLL(COM_BASE)), divisor & 0xff);
WRITE_PORT_UCHAR(pv(SER_DLM(COM_BASE)), (divisor >> 8) & 0xff);
/* reset DLAB and set 8N1 format */
WRITE_PORT_UCHAR(pv(SER_LCR(COM_BASE)),
SR_LCR_CS8 | SR_LCR_ST1 | SR_LCR_PNO);
/* read junk out of the RBR */
READ_PORT_UCHAR(pv(SER_RBR(COM_BASE)));
#endif /* DBG_COM */
#ifdef DBG_HAL_DISPLAY
InbvAcquireDisplayOwnership();
InbvEnableDisplayString(TRUE);
#endif /* DBG_HAL_DISPLAY */
}
NTSTATUS NTAPI
SerialSetBaudRate(
IN PSERIAL_DEVICE_EXTENSION DeviceExtension,
IN ULONG NewBaudRate)
{
ULONG BaudRate;
USHORT divisor;
PUCHAR ComPortBase = ULongToPtr(DeviceExtension->BaseAddress);
NTSTATUS Status = STATUS_SUCCESS;
if (NewBaudRate == 0)
return STATUS_INVALID_PARAMETER;
divisor = (USHORT)(BAUD_CLOCK / (CLOCKS_PER_BIT * NewBaudRate));
BaudRate = BAUD_CLOCK / (CLOCKS_PER_BIT * divisor);
Status = IoAcquireRemoveLock(&DeviceExtension->RemoveLock, ULongToPtr(DeviceExtension->ComPort));
if (NT_SUCCESS(Status))
{
UCHAR Lcr;
TRACE_(SERIAL, "SerialSetBaudRate(COM%lu, %lu Bauds)\n", DeviceExtension->ComPort, BaudRate);
/* Set Bit 7 of LCR to expose baud registers */
Lcr = READ_PORT_UCHAR(SER_LCR(ComPortBase));
WRITE_PORT_UCHAR(SER_LCR(ComPortBase), Lcr | SR_LCR_DLAB);
/* Write the baud rate */
WRITE_PORT_UCHAR(SER_DLL(ComPortBase), divisor & 0xff);
WRITE_PORT_UCHAR(SER_DLM(ComPortBase), divisor >> 8);
/* Switch back to normal registers */
WRITE_PORT_UCHAR(SER_LCR(ComPortBase), Lcr);
IoReleaseRemoveLock(&DeviceExtension->RemoveLock, ULongToPtr(DeviceExtension->ComPort));
}
if (NT_SUCCESS(Status))
DeviceExtension->BaudRate = BaudRate;
return Status;
}