/*
  serial.c - Low level functions for sending and recieving bytes via the serial port
  Part of Grbl

  Copyright (c) 2009-2011 Simen Svale Skogsrud
  Copyright (c) 2011-2012 Sungeun K. Jeon

  Grbl is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  Grbl is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
*/

/* This code was initially inspired by the wiring_serial module by David A. Mellis which
   used to be a part of the Arduino project. */ 

#ifndef serial_h
#define serial_h

#include "nuts_bolts.h"

#if defined(USART_RX_vect) // For atmega328p (Arduino Uno) etc.
#define Serial_RX_vect USART_RX_vect
#define Serial_UDRE_vect USART_UDRE_vect
#elif defined(USART0_RX_vect) // For atmega644p, atmega1280 and atmega2560 (ArduinoMEGA) etc.
#define Serial_RX_vect USART0_RX_vect
#define Serial_UDRE_vect USART0_UDRE_vect
#elif defined(USART_RXC_vect) // For some odd chips
#define Serial_RX_vect USART_RXC_vect
#define Serial_UDRE_vect USART_UDRE_vect
#elif defined(USART1_RX_vect)// Some AVRs have 1 USB and a single USART (USART1), though the USB is often preffered for serial comms (like Arduino Leonardo etc.)
#define Serial1_RX_vect USART1_RX_vect
#define Serial1_UDRE_vect USART1_UDRE_vect
#endif

#ifndef RX_BUFFER_SIZE
  #define RX_BUFFER_SIZE 128
#endif
#ifndef TX_BUFFER_SIZE
  #define TX_BUFFER_SIZE 64
#endif

#define SERIAL_NO_DATA 0xff

#ifdef ENABLE_XONXOFF
  #define RX_BUFFER_FULL 96 // XOFF high watermark
  #define RX_BUFFER_LOW 64 // XON low watermark
  #define SEND_XOFF 1
  #define SEND_XON 2
  #define XOFF_SENT 3
  #define XON_SENT 4
  #define XOFF_CHAR 0x13
  #define XON_CHAR 0x11
#endif

void serial_init();

void serial_write(uint8_t data);

uint8_t serial_read();

// Reset and empty data in read buffer. Used by e-stop and reset.
void serial_reset_read_buffer();

#endif