audk/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c

138 lines
3.5 KiB
C

/** @file
Serial I/O Port library functions with no library constructor/destructor
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
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 <Include/Uefi.h>
#include <Library/IoLib.h>
#include <Drivers/PL011Uart.h>
/*
Programmed hardware of Serial port.
@return Always return EFI_UNSUPPORTED.
**/
RETURN_STATUS
EFIAPI
PL011UartInitialize (
IN UINTN UartBase,
IN UINTN BaudRate,
IN UINTN LineControl
)
{
if (BaudRate == 115200) {
// Initialize baud rate generator
MmioWrite32 (UartBase + UARTIBRD, UART_115200_IDIV);
MmioWrite32 (UartBase + UARTFBRD, UART_115200_FDIV);
} else if (BaudRate == 38400) {
// Initialize baud rate generator
MmioWrite32 (UartBase + UARTIBRD, UART_38400_IDIV);
MmioWrite32 (UartBase + UARTFBRD, UART_38400_FDIV);
} else if (BaudRate == 19200) {
// Initialize baud rate generator
MmioWrite32 (UartBase + UARTIBRD, UART_19200_IDIV);
MmioWrite32 (UartBase + UARTFBRD, UART_19200_FDIV);
} else {
return EFI_INVALID_PARAMETER;
}
// No parity, 1 stop, no fifo, 8 data bits
MmioWrite32 (UartBase + UARTLCR_H, LineControl);
// Clear any pending errors
MmioWrite32 (UartBase + UARTECR, 0);
// Enable tx, rx, and uart overall
MmioWrite32 (UartBase + UARTCR, PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN);
return EFI_SUCCESS;
}
/**
Write data to serial device.
@param Buffer Point of data buffer which need to be written.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Write data failed.
@retval !0 Actual number of bytes written to serial device.
**/
UINTN
EFIAPI
PL011UartWrite (
IN UINTN UartBase,
IN UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Count;
for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
while ((MmioRead32 (UartBase + UARTFR) & UART_TX_EMPTY_FLAG_MASK) == 0);
MmioWrite8 (UartBase + UARTDR, *Buffer);
}
return NumberOfBytes;
}
/**
Read data from serial device and save the data in buffer.
@param Buffer Point of data buffer which need to be written.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Read data failed.
@retval !0 Actual number of bytes read from serial device.
**/
UINTN
EFIAPI
PL011UartRead (
IN UINTN UartBase,
OUT UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Count;
for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
while ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) != 0);
*Buffer = MmioRead8 (UartBase + UARTDR);
}
return NumberOfBytes;
}
/**
Check to see if any data is available to be read from the debug device.
@retval EFI_SUCCESS At least one byte of data is available to be read
@retval EFI_NOT_READY No data is available to be read
@retval EFI_DEVICE_ERROR The serial device is not functioning properly
**/
BOOLEAN
EFIAPI
PL011UartPoll (
IN UINTN UartBase
)
{
return ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) == 0);
}