ArmPlatformPkg/Include/Library/PL011UartLib.h

/** @file
*
*  Copyright (c) 2011-2016, ARM Limited. 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.
*
**/

#ifndef __PL011_UART_LIB_H__
#define __PL011_UART_LIB_H__

#include <Uefi/UefiBaseType.h>

#include <Protocol/SerialIo.h>

/**

  Initialise the serial port to the specified settings.
  All unspecified settings will be set to the default values.

  @param[in]  UartBase            The base address of the serial device.
  @param[in]  UartClkInHz         The clock in Hz for the serial device.
                                  Ignored if the PCD PL011UartInteger is not 0
  @param[in out] BaudRate         The baud rate of the serial device. If the
                                  baud rate is not supported, the speed will be
                                  reduced to the nearest supported one and the
                                  variable's value will be updated accordingly.
  @param[in out] ReceiveFifoDepth The number of characters the device will
                                  buffer on input.  Value of 0 will use the
                                  device's default FIFO depth.
  @param[in out]  Parity          If applicable, this is the EFI_PARITY_TYPE
                                  that is computed or checked as each character
                                  is transmitted or received. If the device
                                  does not support parity, the value is the
                                  default parity value.
  @param[in out]  DataBits        The number of data bits in each character.
  @param[in out]  StopBits        If applicable, the EFI_STOP_BITS_TYPE number
                                  of stop bits per character.
                                  If the device does not support stop bits, the
                                  value is the default stop bit value.

  @retval RETURN_SUCCESS            All attributes were set correctly on the
                                    serial device.
  @retval RETURN_INVALID_PARAMETER  One or more of the attributes has an
                                    unsupported value.

**/
RETURN_STATUS
EFIAPI
PL011UartInitializePort (
  IN     UINTN               UartBase,
  IN     UINT32              UartClkInHz,
  IN OUT UINT64              *BaudRate,
  IN OUT UINT32              *ReceiveFifoDepth,
  IN OUT EFI_PARITY_TYPE     *Parity,
  IN OUT UINT8               *DataBits,
  IN OUT EFI_STOP_BITS_TYPE  *StopBits
  );

/**

  Assert or deassert the control signals on a serial port.
  The following control signals are set according their bit settings :
  . Request to Send
  . Data Terminal Ready

  @param[in]  UartBase  UART registers base address
  @param[in]  Control   The following bits are taken into account :
                        . EFI_SERIAL_REQUEST_TO_SEND : assert/deassert the
                          "Request To Send" control signal if this bit is
                          equal to one/zero.
                        . EFI_SERIAL_DATA_TERMINAL_READY : assert/deassert
                          the "Data Terminal Ready" control signal if this
                          bit is equal to one/zero.
                        . EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : enable/disable
                          the hardware loopback if this bit is equal to
                          one/zero.
                        . EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : not supported.
                        . EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : enable/
                          disable the hardware flow control based on CTS (Clear
                          To Send) and RTS (Ready To Send) control signals.

  @retval  RETURN_SUCCESS      The new control bits were set on the device.
  @retval  RETURN_UNSUPPORTED  The device does not support this operation.

**/
RETURN_STATUS
EFIAPI
PL011UartSetControl (
  IN UINTN   UartBase,
  IN UINT32  Control
  );

/**

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

  @param[in]   UartBase  UART registers base address
  @param[out]  Control   Status of the control bits on a serial device :

                         . EFI_SERIAL_DATA_CLEAR_TO_SEND,
                           EFI_SERIAL_DATA_SET_READY,
                           EFI_SERIAL_RING_INDICATE,
                           EFI_SERIAL_CARRIER_DETECT,
                           EFI_SERIAL_REQUEST_TO_SEND,
                           EFI_SERIAL_DATA_TERMINAL_READY
                           are all related to the DTE (Data Terminal Equipment)
                           and DCE (Data Communication Equipment) modes of
                           operation of the serial device.
                         . EFI_SERIAL_INPUT_BUFFER_EMPTY : equal to one if the
                           receive buffer is empty, 0 otherwise.
                         . EFI_SERIAL_OUTPUT_BUFFER_EMPTY : equal to one if the
                           transmit buffer is empty, 0 otherwise.
                         . EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : equal to one if
                           the hardware loopback is enabled (the ouput feeds the
                           receive buffer), 0 otherwise.
                         . EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : equal to one if
                           a loopback is accomplished by software, 0 otherwise.
                         . EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : equal to
                           one if the hardware flow control based on CTS (Clear
                           To Send) and RTS (Ready To Send) control signals is
                           enabled, 0 otherwise.

  @retval RETURN_SUCCESS  The control bits were read from the serial device.

**/
RETURN_STATUS
EFIAPI
PL011UartGetControl (
  IN UINTN     UartBase,
  OUT UINT32  *Control
  );

/**
  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
  );

/**
  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
  );

/**
  Check to see if any data is available to be read from the debug device.

  @retval TRUE       At least one byte of data is available to be read
  @retval FALSE      No data is available to be read

**/
BOOLEAN
EFIAPI
PL011UartPoll (
  IN  UINTN       UartBase
  );

#endif