Marlin_Firmware/Marlin/MarlinSerial.h

/**
 * Marlin 3D Printer Firmware
 * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
  HardwareSerial.h - Hardware serial library for Wiring
  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.

  Modified 28 September 2010 by Mark Sproul
*/

#ifndef MarlinSerial_h
#define MarlinSerial_h
#include "Marlin.h"

#ifndef CRITICAL_SECTION_START
  #define CRITICAL_SECTION_START  unsigned char _sreg = SREG; cli();
  #define CRITICAL_SECTION_END    SREG = _sreg;
#endif


#ifndef SERIAL_PORT
  #define SERIAL_PORT 0
#endif

// The presence of the UBRRH register is used to detect a UART.
#define UART_PRESENT(port) ((port == 0 && (defined(UBRRH) || defined(UBRR0H))) || \
                            (port == 1 && defined(UBRR1H)) || (port == 2 && defined(UBRR2H)) || \
                            (port == 3 && defined(UBRR3H)))

// These are macros to build serial port register names for the selected SERIAL_PORT (C preprocessor
// requires two levels of indirection to expand macro values properly)
#define SERIAL_REGNAME(registerbase,number,suffix) SERIAL_REGNAME_INTERNAL(registerbase,number,suffix)
#if SERIAL_PORT == 0 && (!defined(UBRR0H) || !defined(UDR0)) // use un-numbered registers if necessary
  #define SERIAL_REGNAME_INTERNAL(registerbase,number,suffix) registerbase##suffix
#else
  #define SERIAL_REGNAME_INTERNAL(registerbase,number,suffix) registerbase##number##suffix
#endif

// Registers used by MarlinSerial class (these are expanded
// depending on selected serial port
#define M_UCSRxA SERIAL_REGNAME(UCSR,SERIAL_PORT,A) // defines M_UCSRxA to be UCSRnA where n is the serial port number
#define M_UCSRxB SERIAL_REGNAME(UCSR,SERIAL_PORT,B)
#define M_RXENx SERIAL_REGNAME(RXEN,SERIAL_PORT,)
#define M_TXENx SERIAL_REGNAME(TXEN,SERIAL_PORT,)
#define M_RXCIEx SERIAL_REGNAME(RXCIE,SERIAL_PORT,)
#define M_UDREx SERIAL_REGNAME(UDRE,SERIAL_PORT,)
#define M_UDRx SERIAL_REGNAME(UDR,SERIAL_PORT,)
#define M_UBRRxH SERIAL_REGNAME(UBRR,SERIAL_PORT,H)
#define M_UBRRxL SERIAL_REGNAME(UBRR,SERIAL_PORT,L)
#define M_RXCx SERIAL_REGNAME(RXC,SERIAL_PORT,)
#define M_USARTx_RX_vect SERIAL_REGNAME(USART,SERIAL_PORT,_RX_vect)
#define M_U2Xx SERIAL_REGNAME(U2X,SERIAL_PORT,)


#define DEC 10
#define HEX 16
#define OCT 8
#define BIN 2
#define BYTE 0


#ifndef USBCON
// Define constants and variables for buffering incoming serial data.  We're
// using a ring buffer (I think), in which rx_buffer_head is the index of the
// location to which to write the next incoming character and rx_buffer_tail
// is the index of the location from which to read.
// 256 is the max limit due to uint8_t head and tail. Use only powers of 2. (...,16,32,64,128,256)
#ifndef RX_BUFFER_SIZE
  #define RX_BUFFER_SIZE 128
#endif
#if !((RX_BUFFER_SIZE == 256) ||(RX_BUFFER_SIZE == 128) ||(RX_BUFFER_SIZE == 64) ||(RX_BUFFER_SIZE == 32) ||(RX_BUFFER_SIZE == 16) ||(RX_BUFFER_SIZE == 8) ||(RX_BUFFER_SIZE == 4) ||(RX_BUFFER_SIZE == 2))
  #error RX_BUFFER_SIZE has to be a power of 2 and >= 2
#endif

struct ring_buffer {
  unsigned char buffer[RX_BUFFER_SIZE];
  volatile uint8_t head;
  volatile uint8_t tail;
};

#if UART_PRESENT(SERIAL_PORT)
  extern ring_buffer rx_buffer;
#endif

class MarlinSerial { //: public Stream

  public:
    MarlinSerial();
    void begin(long);
    void end();
    int peek(void);
    int read(void);
    void flush(void);

    FORCE_INLINE uint8_t available(void) {
      CRITICAL_SECTION_START;
        uint8_t h = rx_buffer.head;
        uint8_t t = rx_buffer.tail;
      CRITICAL_SECTION_END;
      return (uint8_t)(RX_BUFFER_SIZE + h - t) & (RX_BUFFER_SIZE - 1);
    }

    FORCE_INLINE void write(uint8_t c) {
      while (!TEST(M_UCSRxA, M_UDREx))
        ;
      M_UDRx = c;
    }

    FORCE_INLINE void checkRx(void) {
      if (TEST(M_UCSRxA, M_RXCx)) {
        unsigned char c  =  M_UDRx;
        CRITICAL_SECTION_START;
          uint8_t h = rx_buffer.head;
          uint8_t i = (uint8_t)(h + 1) & (RX_BUFFER_SIZE - 1);

          // if we should be storing the received character into the location
          // just before the tail (meaning that the head would advance to the
          // current location of the tail), we're about to overflow the buffer
          // and so we don't write the character or advance the head.
          if (i != rx_buffer.tail) {
            rx_buffer.buffer[h] = c;
            rx_buffer.head = i;
          }
        CRITICAL_SECTION_END;
      }
    }

  private:
    void printNumber(unsigned long, uint8_t);
    void printFloat(double, uint8_t);

  public:
    FORCE_INLINE void write(const char* str) { while (*str) write(*str++); }
    FORCE_INLINE void write(const uint8_t* buffer, size_t size) { while (size--) write(*buffer++); }
    FORCE_INLINE void print(const String& s) { for (int i = 0; i < (int)s.length(); i++) write(s[i]); }
    FORCE_INLINE void print(const char* str) { write(str); }

    void print(char, int = BYTE);
    void print(unsigned char, int = BYTE);
    void print(int, int = DEC);
    void print(unsigned int, int = DEC);
    void print(long, int = DEC);
    void print(unsigned long, int = DEC);
    void print(double, int = 2);

    void println(const String& s);
    void println(const char[]);
    void println(char, int = BYTE);
    void println(unsigned char, int = BYTE);
    void println(int, int = DEC);
    void println(unsigned int, int = DEC);
    void println(long, int = DEC);
    void println(unsigned long, int = DEC);
    void println(double, int = 2);
    void println(void);
};

extern MarlinSerial customizedSerial;
#endif // !USBCON

// Use the UART for Bluetooth in AT90USB configurations
#if defined(USBCON) && ENABLED(BLUETOOTH)
  extern HardwareSerial bluetoothSerial;
#endif

#endif