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audk/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c

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/** @file
UART Serial Port library functions
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Library/IoLib.h>
#include <Library/SerialPortLib.h>
//---------------------------------------------
// UART Register Offsets
//---------------------------------------------
#define BAUD_LOW_OFFSET 0x00
#define BAUD_HIGH_OFFSET 0x01
#define IER_OFFSET 0x01
#define LCR_SHADOW_OFFSET 0x01
#define FCR_SHADOW_OFFSET 0x02
#define IR_CONTROL_OFFSET 0x02
#define FCR_OFFSET 0x02
#define EIR_OFFSET 0x02
#define BSR_OFFSET 0x03
#define LCR_OFFSET 0x03
#define MCR_OFFSET 0x04
#define LSR_OFFSET 0x05
#define MSR_OFFSET 0x06
//---------------------------------------------
// UART Register Bit Defines
//---------------------------------------------
#define LSR_TXRDY 0x20
#define LSR_RXDA 0x01
#define DLAB 0x01
#define MCR_DTRC 0x01
#define MCR_RTS 0x02
#define MSR_CTS 0x10
#define MSR_DSR 0x20
#define MSR_RI 0x40
#define MSR_DCD 0x80
//---------------------------------------------
// UART Settings
//---------------------------------------------
UINT16 gUartBase = 0x3F8;
UINTN gBps = 115200;
UINT8 gData = 8;
UINT8 gStop = 1;
UINT8 gParity = 0;
UINT8 gBreakSet = 0;
/**
Initialize the serial device hardware.
If no initialization is required, then return RETURN_SUCCESS.
If the serial device was successfully initialized, then return RETURN_SUCCESS.
If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.
@retval RETURN_SUCCESS The serial device was initialized.
@retval RETURN_DEVICE_ERROR The serail device could not be initialized.
**/
RETURN_STATUS
EFIAPI
SerialPortInitialize (
VOID
)
{
UINTN Divisor;
UINT8 OutputData;
UINT8 Data;
//
// Map 5..8 to 0..3
//
Data = (UINT8) (gData - (UINT8) 5);
//
// Calculate divisor for baud generator
//
Divisor = 115200 / gBps;
//
// Set communications format
//
OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
//
// Configure baud rate
//
IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8));
IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff));
//
// Switch back to bank 0
//
OutputData = (UINT8) ( (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
return RETURN_SUCCESS;
}
/**
Write data from buffer to serial device.
Writes NumberOfBytes data bytes from Buffer to the serial device.
The number of bytes actually written to the serial device is returned.
If the return value is less than NumberOfBytes, then the write operation failed.
If Buffer is NULL, then ASSERT().
If NumberOfBytes is zero, then return 0.
@param Buffer Pointer to the data buffer to be written.
@param NumberOfBytes Number of bytes to written to the serial device.
@retval 0 NumberOfBytes is 0.
@retval >0 The number of bytes written to the serial device.
If this value is less than NumberOfBytes, then the write operation failed.
**/
UINTN
EFIAPI
SerialPortWrite (
IN UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Result;
UINT8 Data;
if (Buffer == NULL) {
return 0;
}
Result = NumberOfBytes;
while ((NumberOfBytes--) != 0) {
//
// Wait for the serail port to be ready.
//
do {
Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
} while ((Data & LSR_TXRDY) == 0);
IoWrite8 ((UINT16) gUartBase, *Buffer++);
}
return Result;
}
/**
Reads data from a serial device into a buffer.
@param Buffer Pointer to the data buffer to store the data read from the serial device.
@param NumberOfBytes Number of bytes to read from the serial device.
@retval 0 NumberOfBytes is 0.
@retval >0 The number of bytes read from the serial device.
If this value is less than NumberOfBytes, then the read operation failed.
**/
UINTN
EFIAPI
SerialPortRead (
OUT UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Result;
UINT8 Data;
if (NULL == Buffer) {
return 0;
}
Result = NumberOfBytes;
while ((NumberOfBytes--) != 0) {
//
// Wait for the serail port to be ready.
//
do {
Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
} while ((Data & LSR_RXDA) == 0);
*Buffer++ = IoRead8 ((UINT16) gUartBase);
}
return Result;
}
/**
Polls a serial device to see if there is any data waiting to be read.
Polls a serial device to see if there is any data waiting to be read.
If there is data waiting to be read from the serial device, then TRUE is returned.
If there is no data waiting to be read from the serial device, then FALSE is returned.
@retval TRUE Data is waiting to be read from the serial device.
@retval FALSE There is no data waiting to be read from the serial device.
**/
BOOLEAN
EFIAPI
SerialPortPoll (
VOID
)
{
UINT8 Data;
//
// Read the serial port status.
//
Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
return (BOOLEAN) ((Data & LSR_RXDA) != 0);
}
/**
Sets the control bits on a serial device.
@param Control Sets the bits of Control that are settable.
@retval RETURN_SUCCESS The new control bits were set on the serial device.
@retval RETURN_UNSUPPORTED The serial device does not support this operation.
@retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
**/
RETURN_STATUS
EFIAPI
SerialPortSetControl (
IN UINT32 Control
)
{
UINT8 Mcr;
//
// First determine the parameter is invalid.
//
if ((Control & (~(EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY))) != 0) {
return RETURN_UNSUPPORTED;
}
//
// Read the Modem Control Register.
//
Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET);
Mcr &= (~(MCR_DTRC | MCR_RTS));
if ((Control & EFI_SERIAL_DATA_TERMINAL_READY) == EFI_SERIAL_DATA_TERMINAL_READY) {
Mcr |= MCR_DTRC;
}
if ((Control & EFI_SERIAL_REQUEST_TO_SEND) == EFI_SERIAL_REQUEST_TO_SEND) {
Mcr |= MCR_RTS;
}
//
// Write the Modem Control Register.
//
IoWrite8 ((UINT16) gUartBase + MCR_OFFSET, Mcr);
return RETURN_SUCCESS;
}
/**
Retrieve the status of the control bits on a serial device.
@param Control A pointer to return the current control signals from the serial device.
@retval RETURN_SUCCESS The control bits were read from the serial device.
@retval RETURN_UNSUPPORTED The serial device does not support this operation.
@retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
**/
RETURN_STATUS
EFIAPI
SerialPortGetControl (
OUT UINT32 *Control
)
{
UINT8 Msr;
UINT8 Mcr;
UINT8 Lsr;
*Control = 0;
//
// Read the Modem Status Register.
//
Msr = IoRead8 ((UINT16) gUartBase + MSR_OFFSET);
if ((Msr & MSR_CTS) == MSR_CTS) {
*Control |= EFI_SERIAL_CLEAR_TO_SEND;
}
if ((Msr & MSR_DSR) == MSR_DSR) {
*Control |= EFI_SERIAL_DATA_SET_READY;
}
if ((Msr & MSR_RI) == MSR_RI) {
*Control |= EFI_SERIAL_RING_INDICATE;
}
if ((Msr & MSR_DCD) == MSR_DCD) {
*Control |= EFI_SERIAL_CARRIER_DETECT;
}
//
// Read the Modem Control Register.
//
Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET);
if ((Mcr & MCR_DTRC) == MCR_DTRC) {
*Control |= EFI_SERIAL_DATA_TERMINAL_READY;
}
if ((Mcr & MCR_RTS) == MCR_RTS) {
*Control |= EFI_SERIAL_REQUEST_TO_SEND;
}
//
// Read the Line Status Register.
//
Lsr = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
if ((Lsr & LSR_TXRDY) == LSR_TXRDY) {
*Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY;
}
if ((Lsr & LSR_RXDA) == 0) {
*Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
}
return RETURN_SUCCESS;
}
/**
Sets the baud rate, receive FIFO depth, transmit/receive time out, parity,
data bits, and stop bits on a serial device.
@param BaudRate The requested baud rate. A BaudRate value of 0 will use the
device's default interface speed.
On output, the value actually set.
@param ReceiveFifoDepth The requested depth of the FIFO on the receive side of the
serial interface. A ReceiveFifoDepth value of 0 will use
the device's default FIFO depth.
On output, the value actually set.
@param Timeout The requested time out for a single character in microseconds.
This timeout applies to both the transmit and receive side of the
interface. A Timeout value of 0 will use the device's default time
out value.
On output, the value actually set.
@param Parity The type of parity to use on this serial device. A Parity value of
DefaultParity will use the device's default parity value.
On output, the value actually set.
@param DataBits The number of data bits to use on the serial device. A DataBits
value of 0 will use the device's default data bit setting.
On output, the value actually set.
@param StopBits The number of stop bits to use on this serial device. A StopBits
value of DefaultStopBits will use the device's default number of
stop bits.
On output, the value actually set.
@retval RETURN_SUCCESS The new attributes were set on the serial device.
@retval RETURN_UNSUPPORTED The serial device does not support this operation.
@retval RETURN_INVALID_PARAMETER One or more of the attributes has an unsupported value.
@retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
**/
RETURN_STATUS
EFIAPI
SerialPortSetAttributes (
IN OUT UINT64 *BaudRate,
IN OUT UINT32 *ReceiveFifoDepth,
IN OUT UINT32 *Timeout,
IN OUT EFI_PARITY_TYPE *Parity,
IN OUT UINT8 *DataBits,
IN OUT EFI_STOP_BITS_TYPE *StopBits
)
{
UINTN Divisor;
UINT8 OutputData;
UINT8 LcrData;
UINT8 LcrParity;
UINT8 LcrStop;
//
// Check for default settings and fill in actual values.
//
if (*BaudRate == 0) {
*BaudRate = gBps;
}
if (*DataBits == 0) {
*DataBits = gData;
}
if (*Parity == DefaultParity) {
*Parity = NoParity;
}
if (*StopBits == DefaultStopBits) {
*StopBits = OneStopBit;
}
if ((*DataBits < 5) || (*DataBits > 8)) {
return RETURN_INVALID_PARAMETER;
}
//
// Map 5..8 to 0..3
//
LcrData = (UINT8) (*DataBits - (UINT8) 5);
switch (*Parity) {
case NoParity:
LcrParity = 0;
break;
case EvenParity:
LcrParity = 3;
break;
case OddParity:
LcrParity = 1;
break;
case SpaceParity:
LcrParity = 7;
break;
case MarkParity:
LcrParity = 5;
break;
default:
return RETURN_INVALID_PARAMETER;
}
switch (*StopBits) {
case OneStopBit:
LcrStop = 0;
break;
case OneFiveStopBits:
case TwoStopBits:
LcrStop = 1;
break;
default:
return RETURN_INVALID_PARAMETER;
}
//
// Calculate divisor for baud generator
//
Divisor = 115200 / (UINTN) *BaudRate;
//
// Set communications format
//
OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (LcrParity << 3) | (LcrStop << 2) | LcrData);
IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
//
// Configure baud rate
//
IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8));
IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff));
//
// Switch back to bank 0
//
OutputData = (UINT8) ((gBreakSet << 6) | (LcrParity << 3) | (LcrStop << 2) | LcrData);
IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
return RETURN_SUCCESS;
}
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