/** @file
  Serial IO protocol as defined in the UEFI 2.0 specification.

  Abstraction of a basic serial device. Targeted at 16550 UART, but
  could be much more generic.

  Copyright (c) 2006 - 2008, Intel Corporation. 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.             

**/

#ifndef __SERIAL_IO_PROTOCOL_H__
#define __SERIAL_IO_PROTOCOL_H__

#define EFI_SERIAL_IO_PROTOCOL_GUID \
  { \
    0xBB25CF6F, 0xF1D4, 0x11D2, {0x9A, 0x0C, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0xFD } \
  }

///
/// Protocol GUID defined in EFI1.1.
/// 
#define SERIAL_IO_PROTOCOL  EFI_SERIAL_IO_PROTOCOL_GUID

typedef struct _EFI_SERIAL_IO_PROTOCOL EFI_SERIAL_IO_PROTOCOL;


///
/// Backward-compatible with EFI1.1.
/// 
typedef EFI_SERIAL_IO_PROTOCOL  SERIAL_IO_INTERFACE;

///
/// 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.
///
typedef enum {
  DefaultParity,
  NoParity,
  EvenParity,
  OddParity,
  MarkParity,
  SpaceParity
} EFI_PARITY_TYPE;

///
/// Stop bits type
///
typedef enum {
  DefaultStopBits,
  OneStopBit,
  OneFiveStopBits,
  TwoStopBits
} EFI_STOP_BITS_TYPE;

//
// define for Control bits, grouped by read only, write only, and read write
//
//
// Read Only
//
#define EFI_SERIAL_CLEAR_TO_SEND        0x00000010
#define EFI_SERIAL_DATA_SET_READY       0x00000020
#define EFI_SERIAL_RING_INDICATE        0x00000040
#define EFI_SERIAL_CARRIER_DETECT       0x00000080
#define EFI_SERIAL_INPUT_BUFFER_EMPTY   0x00000100
#define EFI_SERIAL_OUTPUT_BUFFER_EMPTY  0x00000200

//
// Write Only
//
#define EFI_SERIAL_REQUEST_TO_SEND      0x00000002
#define EFI_SERIAL_DATA_TERMINAL_READY  0x00000001

//
// Read Write
//
#define EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE     0x00001000
#define EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE     0x00002000
#define EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE 0x00004000

//
// Serial IO Member Functions
//
/**
  Reset the serial device.

  @param  This              Protocol instance pointer.
                            
  @retval EFI_SUCCESS       The device was reset.
  @retval EFI_DEVICE_ERROR  The serial device could not be reset.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_RESET)(
  IN EFI_SERIAL_IO_PROTOCOL *This
  );

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

  @param  This             Protocol instance pointer.
  @param  BaudRate         The requested baud rate. A BaudRate value of 0 will use the
                           device's default interface speed.
  @param  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.
  @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.
  @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.
  @param  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.
  @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.

  @retval EFI_SUCCESS      The device was reset.
  @retval EFI_DEVICE_ERROR The serial device could not be reset.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_SET_ATTRIBUTES)(
  IN EFI_SERIAL_IO_PROTOCOL         *This,
  IN UINT64                         BaudRate,
  IN UINT32                         ReceiveFifoDepth,
  IN UINT32                         Timeout,
  IN EFI_PARITY_TYPE                Parity,
  IN UINT8                          DataBits,
  IN EFI_STOP_BITS_TYPE             StopBits
  );

/**
  Set the control bits on a serial device

  @param  This             Protocol instance pointer.
  @param  Control          Set the bits of Control that are settable.

  @retval EFI_SUCCESS      The new control bits were set on the serial device.
  @retval EFI_UNSUPPORTED  The serial device does not support this operation.
  @retval EFI_DEVICE_ERROR The serial device is not functioning correctly.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_SET_CONTROL_BITS)(
  IN EFI_SERIAL_IO_PROTOCOL         *This,
  IN UINT32                         Control
  );

/**
  Retrieves the status of thecontrol bits on a serial device

  @param  This              Protocol instance pointer.
  @param  Control           A pointer to return the current Control signals from the serial device.
                            
  @retval EFI_SUCCESS       The control bits were read from the serial device.
  @retval EFI_DEVICE_ERROR  The serial device is not functioning correctly.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_GET_CONTROL_BITS)(
  IN EFI_SERIAL_IO_PROTOCOL         *This,
  OUT UINT32                        *Control
  );

/**
  Writes data to a serial device.

  @param  This              Protocol instance pointer.
  @param  BufferSize        On input, the size of the Buffer. On output, the amount of
                            data actually written.
  @param  Buffer            The buffer of data to write

  @retval EFI_SUCCESS       The data was written.
  @retval EFI_DEVICE_ERROR  The device reported an error.
  @retval EFI_TIMEOUT       The data write was stopped due to a timeout.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_WRITE)(
  IN EFI_SERIAL_IO_PROTOCOL         *This,
  IN OUT UINTN                      *BufferSize,
  IN VOID                           *Buffer
  );

/**
  Writes data to a serial device.

  @param  This              Protocol instance pointer.
  @param  BufferSize        On input, the size of the Buffer. On output, the amount of
                            data returned in Buffer.
  @param  Buffer            The buffer to return the data into.

  @retval EFI_SUCCESS       The data was read.
  @retval EFI_DEVICE_ERROR  The device reported an error.
  @retval EFI_TIMEOUT       The data write was stopped due to a timeout.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_SERIAL_READ)(
  IN EFI_SERIAL_IO_PROTOCOL         *This,
  IN OUT UINTN                      *BufferSize,
  OUT VOID                          *Buffer
  );

/**
  @par Data Structure Description:
  The data values in SERIAL_IO_MODE are read-only and are updated by the code 
  that produces the SERIAL_IO_PROTOCOL member functions.

  @param ControlMask
  A mask for the Control bits that the device supports. The device
  must always support the Input Buffer Empty control bit.
  
  @param TimeOut
  If applicable, the number of microseconds to wait before timing out
  a Read or Write operation.
  
  @param BaudRate
  If applicable, the current baud rate setting of the device; otherwise,
  baud rate has the value of zero to indicate that device runs at the
  device's designed speed.
  
  @param ReceiveFifoDepth
  The number of characters the device will buffer on input
  
  @param DataBits
  The number of characters the device will buffer on input
  
  @param Parity
  If applicable, this is the EFI_PARITY_TYPE that is computed or 
  checked as each character is transmitted or reveived. If the device
  does not support parity the value is the default parity value.
  
  @param 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 values.

**/
typedef struct {
  UINT32  ControlMask;

  //
  // current Attributes
  //
  UINT32  Timeout;
  UINT64  BaudRate;
  UINT32  ReceiveFifoDepth;
  UINT32  DataBits;
  UINT32  Parity;
  UINT32  StopBits;
} EFI_SERIAL_IO_MODE;

#define EFI_SERIAL_IO_PROTOCOL_REVISION    0x00010000
#define SERIAL_IO_INTERFACE_REVISION  EFI_SERIAL_IO_PROTOCOL_REVISION

///
/// The Serial I/O protocol is used to communicate with UART-style serial devices. 
/// These can be standard UART serial ports in PC-AT systems, serial ports attached 
/// to a USB interface, or potentially any character-based I/O device.
///
struct _EFI_SERIAL_IO_PROTOCOL {
  ///
  /// The revision to which the EFI_SERIAL_IO_PROTOCOL adheres. All future revisions 
  /// must be backwards compatible. If a future version is not backwards compatible, 
  /// it is not the same GUID.
  ///
  UINT32                      Revision;
  EFI_SERIAL_RESET            Reset;
  EFI_SERIAL_SET_ATTRIBUTES   SetAttributes;
  EFI_SERIAL_SET_CONTROL_BITS SetControl;
  EFI_SERIAL_GET_CONTROL_BITS GetControl;
  EFI_SERIAL_WRITE            Write;
  EFI_SERIAL_READ             Read;
  ///
  /// Pointer to SERIAL_IO_MODE data.
  ///
  EFI_SERIAL_IO_MODE          *Mode;
};

extern EFI_GUID gEfiSerialIoProtocolGuid;

#endif
