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Enhanced module to handle half handshake flow control.

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git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8816 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
gikidy
2009-07-08 09:29:08 +00:00
parent 5b3ea840c4
commit fa70a2c4cc
5 changed files with 49 additions and 36 deletions
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77
IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c
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@@ -83,7 +83,8 @@ SERIAL_DEV gSerialDevTempate = {
FALSE,
FALSE,
Uart16550A,
NULL
NULL,
FixedPcdGetBool (PcdIsaBusSerialUseHalfHandshake) //UseHalfHandshake
};
/**
@@ -801,6 +802,18 @@ IsaSerialReceiveTransmit (
} while (!IsaSerialFifoEmpty (&SerialDevice->Transmit));
} else {
ReceiveFifoFull = IsaSerialFifoFull (&SerialDevice->Receive);
//
// For full handshake flow control, tell the peer to send data
// if receive buffer is available.
//
if (SerialDevice->HardwareFlowControl &&
!SerialDevice->UseHalfHandshake &&
!ReceiveFifoFull
) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts = 1;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
do {
Lsr.Data = READ_LSR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
@@ -821,23 +834,21 @@ IsaSerialReceiveTransmit (
continue;
}
}
//
// Make sure the receive data will not be missed, Assert DTR
//
if (SerialDevice->HardwareFlowControl) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.DtrC &= 0;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
Data = READ_RBR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
IsaSerialFifoAdd (&SerialDevice->Receive, Data);
//
// Deassert DTR
// For full handshake flow control, if receive buffer full
// tell the peer to stop sending data.
//
if (SerialDevice->HardwareFlowControl) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.DtrC |= 1;
if (SerialDevice->HardwareFlowControl &&
!SerialDevice->UseHalfHandshake &&
IsaSerialFifoFull (&SerialDevice->Receive)
) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts = 0;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
@@ -861,17 +872,19 @@ IsaSerialReceiveTransmit (
//
if (SerialDevice->HardwareFlowControl) {
//
// Send RTS
// For half handshake flow control assert RTS before sending.
//
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts |= 1;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
if (SerialDevice->UseHalfHandshake) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts= 0;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
//
// Wait for CTS
//
TimeOut = 0;
Msr.Data = READ_MSR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
while (Msr.Bits.Cts == 0) {
while (Msr.Bits.Dcd == 1 && (!Msr.Bits.Cts ^ SerialDevice->UseHalfHandshake)) {
gBS->Stall (TIMEOUT_STALL_INTERVAL);
TimeOut++;
if (TimeOut > 5) {
@@ -881,29 +894,23 @@ IsaSerialReceiveTransmit (
Msr.Data = READ_MSR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
}
if (Msr.Bits.Cts == 1) {
if (Msr.Bits.Dcd== 0 || (Msr.Bits.Cts ^ SerialDevice->UseHalfHandshake)) {
IsaSerialFifoRemove (&SerialDevice->Transmit, &Data);
WRITE_THR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Data);
}
}
//
// write the data out
//
if (!SerialDevice->HardwareFlowControl) {
//
// For half handshake flow control, tell DCE we are done.
//
if (SerialDevice->UseHalfHandshake) {
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts = 1;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
} else {
IsaSerialFifoRemove (&SerialDevice->Transmit, &Data);
WRITE_THR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Data);
}
//
// Make sure the transmit data will not be missed
//
if (SerialDevice->HardwareFlowControl) {
//
// Assert RTS
//
Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
Mcr.Bits.Rts &= 0;
WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
}
}
} while (Lsr.Bits.Thre == 1 && !IsaSerialFifoEmpty (&SerialDevice->Transmit));
}