diff options
Diffstat (limited to 'IntelFrameworkModulePkg/Bus')
3 files changed, 44 insertions, 35 deletions
diff --git a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/IsaSerialDxe.inf b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/IsaSerialDxe.inf index aa7c315e1d..4c8c08fd53 100644 --- a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/IsaSerialDxe.inf +++ b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/IsaSerialDxe.inf @@ -65,3 +65,4 @@ gEfiMdePkgTokenSpaceGuid.PcdUartDefaultDataBits|8
gEfiMdePkgTokenSpaceGuid.PcdUartDefaultParity|1
gEfiMdePkgTokenSpaceGuid.PcdUartDefaultStopBits|1
+ gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdIsaBusSerialUseHalfHandshake|FALSE
diff --git a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c index f9d08ce3a0..65f072356b 100644 --- a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c +++ b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c @@ -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) {
@@ -881,28 +894,22 @@ 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) {
- 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
+ // For half handshake flow control, tell DCE we are done.
//
- Mcr.Data = READ_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress);
- Mcr.Bits.Rts &= 0;
- WRITE_MCR (SerialDevice->IsaIo, SerialDevice->BaseAddress, Mcr.Data);
+ 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);
}
}
} while (Lsr.Bits.Thre == 1 && !IsaSerialFifoEmpty (&SerialDevice->Transmit));
diff --git a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.h b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.h index c7f2105f62..8d985a408f 100644 --- a/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.h +++ b/IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.h @@ -109,6 +109,7 @@ typedef struct { BOOLEAN HardwareFlowControl;
EFI_UART_TYPE Type;
EFI_UNICODE_STRING_TABLE *ControllerNameTable;
+ BOOLEAN UseHalfHandshake;
} SERIAL_DEV;
#define SERIAL_DEV_FROM_THIS(a) CR (a, SERIAL_DEV, SerialIo, SERIAL_DEV_SIGNATURE)
|