audk/DuetPkg/Library/DuetSerialIoLib/SerialPortLib.c

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/** @file
Serial I/O Port library functions with no library constructor/destructor
Copyright (c) 2006, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#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
UINT16 gComBase = 0x3f8;
UINTN gBps = 115200;
UINT8 gData = 8;
UINT8 gStop = 1;
UINT8 gParity = 0;
UINT8 gBreakSet = 0;
/*
Programmed hardware of Serial port.
@return Always return EFI_UNSUPPORTED.
**/
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 (gComBase + LCR_OFFSET, OutputData);
//
// Configure baud rate
//
IoWrite8 (gComBase + BAUD_HIGH_OFFSET, (UINT8)(Divisor >> 8));
IoWrite8 (gComBase + BAUD_LOW_OFFSET, (UINT8)(Divisor & 0xff));
//
// Switch back to bank 0
//
OutputData = (UINT8)((~DLAB<<7)|((gBreakSet<<6)|((gParity<<3)|((gStop<<2)| Data))));
IoWrite8 (gComBase + LCR_OFFSET, OutputData);
return RETURN_SUCCESS;
}
/**
Write data to serial device.
@param Buffer Point of data buffer which need to be writed.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Write data failed.
@retval !0 Actual number of bytes writed to serial device.
**/
UINTN
EFIAPI
SerialPortWrite (
IN UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Result;
UINT8 Data;
if (NULL == Buffer) {
return 0;
}
Result = NumberOfBytes;
while (NumberOfBytes--) {
//
// Wait for the serail port to be ready.
//
do {
Data = IoRead8 (gComBase + LSR_OFFSET);
} while ((Data & LSR_TXRDY) == 0);
IoWrite8 (gComBase, *Buffer++);
}
return Result;
}
/**
Read data from serial device and save the datas in buffer.
@param Buffer Point of data buffer which need to be writed.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Read data failed.
@retval !0 Aactual number of bytes read from serial device.
**/
UINTN
EFIAPI
SerialPortRead (
OUT UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
return 0;
}