SerialPortLib.h File Reference

Functions
RETURN_STATUS EFIAPI	SerialPortInitialize (VOID)
UINTN EFIAPI	SerialPortWrite (IN UINT8 *Buffer, IN UINTN NumberOfBytes)
UINTN EFIAPI	SerialPortRead (OUT UINT8 *Buffer, IN UINTN NumberOfBytes)
BOOLEAN EFIAPI	SerialPortPoll (VOID)
RETURN_STATUS EFIAPI	SerialPortSetControl (IN UINT32 Control)
RETURN_STATUS EFIAPI	SerialPortGetControl (OUT UINT32 *Control)
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)

Detailed Description

This library class provides common serial I/O port functions.

Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
Copyright (c) 2012 - 2014, ARM Ltd. All rights reserved. SPDX-License-Identifier: BSD-2-Clause-Patent

Function Documentation

RETURN_STATUS EFIAPI SerialPortGetControl

(

OUT UINT32 *

Control

)

Retrieve the status of the control bits on a serial device.

Parameters

Control

A pointer to return the current control signals from the serial device.

Return values

RETURN_SUCCESS	The control bits were read from the serial device.
RETURN_UNSUPPORTED	The serial device does not support this operation.
RETURN_DEVICE_ERROR	The serial device is not functioning correctly.

RETURN_STATUS EFIAPI SerialPortInitialize

(

VOID

)

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.

Return values

RETURN_SUCCESS	The serial device was initialized.
RETURN_DEVICE_ERROR	The serial device could not be initialized.

BOOLEAN EFIAPI SerialPortPoll

(

VOID

)

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.

Return values

TRUE	Data is waiting to be read from the serial device.
FALSE	There is no data waiting to be read from the serial device.

UINTN EFIAPI SerialPortRead	(	OUT UINT8 *	Buffer,
		IN UINTN	NumberOfBytes
	)

Read data from serial device and save the datas in buffer.

Reads NumberOfBytes data bytes from a serial device into the buffer specified by Buffer. The number of bytes actually read is returned. If the return value is less than NumberOfBytes, then the rest operation failed. If Buffer is NULL, then ASSERT(). If NumberOfBytes is zero, then return 0.

Parameters

Buffer	Pointer to the data buffer to store the data read from the serial device.
NumberOfBytes	Number of bytes which will be read.

Return values

0	Read data failed, no data is to be read.
>0	Actual number of bytes read from serial device.

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
	)

Sets the baud rate, receive FIFO depth, transmit/receice time out, parity, data bits, and stop bits on a serial device.

Parameters

BaudRate	The requested baud rate. A BaudRate value of 0 will use the device's default interface speed. On output, the value actually set.
ReveiveFifoDepth	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.
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.
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.
DataBits	The number of data bits to use on the serial device. A DataBits vaule of 0 will use the device's default data bit setting. On output, the value actually set.
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.

Return values

RETURN_SUCCESS	The new attributes were set on the serial device.
RETURN_UNSUPPORTED	The serial device does not support this operation.
RETURN_INVALID_PARAMETER	One or more of the attributes has an unsupported value.
RETURN_DEVICE_ERROR	The serial device is not functioning correctly.

RETURN_STATUS EFIAPI SerialPortSetControl

(

IN UINT32

Control

)

Sets the control bits on a serial device.

Parameters

Control

Sets the bits of Control that are settable.

Return values

RETURN_SUCCESS	The new control bits were set on the serial device.
RETURN_UNSUPPORTED	The serial device does not support this operation.
RETURN_DEVICE_ERROR	The serial device is not functioning correctly.

UINTN EFIAPI SerialPortWrite	(	IN UINT8 *	Buffer,
		IN UINTN	NumberOfBytes
	)

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.

Parameters

Buffer	Pointer to the data buffer to be written.
NumberOfBytes	Number of bytes to written to the serial device.

Return values

0	NumberOfBytes is 0.
>0	The number of bytes written to the serial device. If this value is less than NumberOfBytes, then the write operation failed.