MarlinSerial.cpp

/**
 * 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/>.
 *
 */

/**
 * MarlinSerial.cpp - Hardware serial library for Wiring
 * Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
 *
 * Modified 23 November 2006 by David A. Mellis
 * Modified 28 September 2010 by Mark Sproul
 * Modified 14 February 2016 by Andreas Hardtung (added tx buffer)
 */
#include "MarlinSerial.h"

#include "stepper.h"
#include "Marlin.h"

#ifndef USBCON
// this next line disables the entire HardwareSerial.cpp,
// this is so I can support Attiny series and any other chip without a UART
#if defined(UBRRH) || defined(UBRR0H) || defined(UBRR1H) || defined(UBRR2H) || defined(UBRR3H)

#if UART_PRESENT(SERIAL_PORT)
  ring_buffer_r rx_buffer  =  { { 0 }, 0, 0 };
  #if TX_BUFFER_SIZE > 0
    ring_buffer_t tx_buffer  =  { { 0 }, 0, 0 };
    static bool _written;
  #endif
#endif


FORCE_INLINE void store_char(unsigned char c) {
  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;

  #if ENABLED(EMERGENCY_PARSER)
    emergency_parser(c);
  #endif
}

#if TX_BUFFER_SIZE > 0

  FORCE_INLINE void _tx_udr_empty_irq(void) {
    // If interrupts are enabled, there must be more data in the output
    // buffer. Send the next byte
    uint8_t t = tx_buffer.tail;
    uint8_t c = tx_buffer.buffer[t];
    tx_buffer.tail = (t + 1) & (TX_BUFFER_SIZE - 1);

    M_UDRx = c;

    // clear the TXC bit -- "can be cleared by writing a one to its bit
    // location". This makes sure flush() won't return until the bytes
    // actually got written
    SBI(M_UCSRxA, M_TXCx);

    if (tx_buffer.head == tx_buffer.tail) {
      // Buffer empty, so disable interrupts
      CBI(M_UCSRxB, M_UDRIEx);
    }
  }

  #if defined(M_USARTx_UDRE_vect)
    ISR(M_USARTx_UDRE_vect) {
      _tx_udr_empty_irq();
    }
  #endif

#endif // TX_BUFFER_SIZE

#if defined(M_USARTx_RX_vect)
  ISR(M_USARTx_RX_vect) {
    unsigned char c  =  M_UDRx;
    store_char(c);
  }
#endif

// Constructors ////////////////////////////////////////////////////////////////

MarlinSerial::MarlinSerial() { }

// Public Methods //////////////////////////////////////////////////////////////

void MarlinSerial::begin(long baud) {
  uint16_t baud_setting;
  bool useU2X = true;

  #if F_CPU == 16000000UL && SERIAL_PORT == 0
    // hard-coded exception for compatibility with the bootloader shipped
    // with the Duemilanove and previous boards and the firmware on the 8U2
    // on the Uno and Mega 2560.
    if (baud == 57600) {
      useU2X = false;
    }
  #endif

  if (useU2X) {
    M_UCSRxA = _BV(M_U2Xx);
    baud_setting = (F_CPU / 4 / baud - 1) / 2;
  }
  else {
    M_UCSRxA = 0;
    baud_setting = (F_CPU / 8 / baud - 1) / 2;
  }

  // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
  M_UBRRxH = baud_setting >> 8;
  M_UBRRxL = baud_setting;

  SBI(M_UCSRxB, M_RXENx);
  SBI(M_UCSRxB, M_TXENx);
  SBI(M_UCSRxB, M_RXCIEx);
  #if TX_BUFFER_SIZE > 0
    CBI(M_UCSRxB, M_UDRIEx);
    _written = false;
  #endif
}

void MarlinSerial::end() {
  CBI(M_UCSRxB, M_RXENx);
  CBI(M_UCSRxB, M_TXENx);
  CBI(M_UCSRxB, M_RXCIEx);
  CBI(M_UCSRxB, M_UDRIEx);
}

void MarlinSerial::checkRx(void) {
  if (TEST(M_UCSRxA, M_RXCx)) {
    uint8_t c  =  M_UDRx;
    store_char(c);
  }
}

int MarlinSerial::peek(void) {
  CRITICAL_SECTION_START;
    int v = rx_buffer.head == rx_buffer.tail ? -1 : rx_buffer.buffer[rx_buffer.tail];
  CRITICAL_SECTION_END;
  return v;
}

int MarlinSerial::read(void) {
  int v;
  CRITICAL_SECTION_START;
    uint8_t t = rx_buffer.tail;
    if (rx_buffer.head == t) {
      v = -1;
    }
    else {
      v = rx_buffer.buffer[t];
      rx_buffer.tail = (uint8_t)(t + 1) & (RX_BUFFER_SIZE - 1);
    }
  CRITICAL_SECTION_END;
  return v;
}

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

void MarlinSerial::flush(void) {
  // RX
  // don't reverse this or there may be problems if the RX interrupt
  // occurs after reading the value of rx_buffer_head but before writing
  // the value to rx_buffer_tail; the previous value of rx_buffer_head
  // may be written to rx_buffer_tail, making it appear as if the buffer
  // were full, not empty.
  CRITICAL_SECTION_START;
    rx_buffer.head = rx_buffer.tail;
  CRITICAL_SECTION_END;
}

#if TX_BUFFER_SIZE > 0
  uint8_t MarlinSerial::availableForWrite(void) {
    CRITICAL_SECTION_START;
      uint8_t h = tx_buffer.head;
      uint8_t t = tx_buffer.tail;
    CRITICAL_SECTION_END;
    return (uint8_t)(TX_BUFFER_SIZE + h - t) & (TX_BUFFER_SIZE - 1);
  }

  void MarlinSerial::write(uint8_t c) {
    _written = true;
    CRITICAL_SECTION_START;
      bool emty = (tx_buffer.head == tx_buffer.tail);
    CRITICAL_SECTION_END;
    // If the buffer and the data register is empty, just write the byte
    // to the data register and be done. This shortcut helps
    // significantly improve the effective datarate at high (>
    // 500kbit/s) bitrates, where interrupt overhead becomes a slowdown.
    if (emty && TEST(M_UCSRxA, M_UDREx)) {
      CRITICAL_SECTION_START;
        M_UDRx = c;
        SBI(M_UCSRxA, M_TXCx);
      CRITICAL_SECTION_END;
      return;
    }
    uint8_t i = (tx_buffer.head + 1) & (TX_BUFFER_SIZE - 1);

    // If the output buffer is full, there's nothing for it other than to
    // wait for the interrupt handler to empty it a bit
    while (i == tx_buffer.tail) {
      if (!TEST(SREG, SREG_I)) {
        // Interrupts are disabled, so we'll have to poll the data
        // register empty flag ourselves. If it is set, pretend an
        // interrupt has happened and call the handler to free up
        // space for us.
        if (TEST(M_UCSRxA, M_UDREx))
          _tx_udr_empty_irq();
      } else {
        // nop, the interrupt handler will free up space for us
      }
    }

    tx_buffer.buffer[tx_buffer.head] = c;
    { CRITICAL_SECTION_START;
        tx_buffer.head = i;
        SBI(M_UCSRxB, M_UDRIEx);
      CRITICAL_SECTION_END;
    }
    return;
  }

  void MarlinSerial::flushTX(void) {
    // TX
    // If we have never written a byte, no need to flush. This special
    // case is needed since there is no way to force the TXC (transmit
    // complete) bit to 1 during initialization
    if (!_written)
      return;

    while (TEST(M_UCSRxB, M_UDRIEx) || !TEST(M_UCSRxA, M_TXCx)) {
      if (!TEST(SREG, SREG_I) && TEST(M_UCSRxB, M_UDRIEx))
        // Interrupts are globally disabled, but the DR empty
        // interrupt should be enabled, so poll the DR empty flag to
        // prevent deadlock
        if (TEST(M_UCSRxA, M_UDREx))
          _tx_udr_empty_irq();
    }
    // If we get here, nothing is queued anymore (DRIE is disabled) and
    // the hardware finished tranmission (TXC is set).
}

#else
  void MarlinSerial::write(uint8_t c) {
    while (!TEST(M_UCSRxA, M_UDREx))
      ;
    M_UDRx = c;
  }
#endif

// end NEW

/// imports from print.h


void MarlinSerial::print(char c, int base) {
  print((long) c, base);
}

void MarlinSerial::print(unsigned char b, int base) {
  print((unsigned long) b, base);
}

void MarlinSerial::print(int n, int base) {
  print((long) n, base);
}

void MarlinSerial::print(unsigned int n, int base) {
  print((unsigned long) n, base);
}

void MarlinSerial::print(long n, int base) {
  if (base == 0) {
    write(n);
  }
  else if (base == 10) {
    if (n < 0) {
      print('-');
      n = -n;
    }
    printNumber(n, 10);
  }
  else {
    printNumber(n, base);
  }
}

void MarlinSerial::print(unsigned long n, int base) {
  if (base == 0) write(n);
  else printNumber(n, base);
}

void MarlinSerial::print(double n, int digits) {
  printFloat(n, digits);
}

void MarlinSerial::println(void) {
  print('\r');
  print('\n');
}

void MarlinSerial::println(const String& s) {
  print(s);
  println();
}

void MarlinSerial::println(const char c[]) {
  print(c);
  println();
}

void MarlinSerial::println(char c, int base) {
  print(c, base);
  println();
}

void MarlinSerial::println(unsigned char b, int base) {
  print(b, base);
  println();
}

void MarlinSerial::println(int n, int base) {
  print(n, base);
  println();
}

void MarlinSerial::println(unsigned int n, int base) {
  print(n, base);
  println();
}

void MarlinSerial::println(long n, int base) {
  print(n, base);
  println();
}

void MarlinSerial::println(unsigned long n, int base) {
  print(n, base);
  println();
}

void MarlinSerial::println(double n, int digits) {
  print(n, digits);
  println();
}

// Private Methods /////////////////////////////////////////////////////////////

void MarlinSerial::printNumber(unsigned long n, uint8_t base) {
  if (n) {
    unsigned char buf[8 * sizeof(long)]; // Enough space for base 2
    int8_t i = 0;
    while (n) {
      buf[i++] = n % base;
      n /= base;
    }
    while (i--)
      print((char)(buf[i] + (buf[i] < 10 ? '0' : 'A' - 10)));
  }
  else
    print('0');
}

void MarlinSerial::printFloat(double number, uint8_t digits) {
  // Handle negative numbers
  if (number < 0.0) {
    print('-');
    number = -number;
  }

  // Round correctly so that print(1.999, 2) prints as "2.00"
  double rounding = 0.5;
  for (uint8_t i = 0; i < digits; ++i)
    rounding *= 0.1;

  number += rounding;

  // Extract the integer part of the number and print it
  unsigned long int_part = (unsigned long)number;
  double remainder = number - (double)int_part;
  print(int_part);

  // Print the decimal point, but only if there are digits beyond
  if (digits) {
    print('.');
    // Extract digits from the remainder one at a time
    while (digits--) {
      remainder *= 10.0;
      int toPrint = int(remainder);
      print(toPrint);
      remainder -= toPrint;
    }
  }
}
// Preinstantiate Objects //////////////////////////////////////////////////////


MarlinSerial customizedSerial;

#endif // whole file
#endif // !USBCON

// For AT90USB targets use the UART for BT interfacing
#if defined(USBCON) && ENABLED(BLUETOOTH)
  HardwareSerial bluetoothSerial;
#endif

#if ENABLED(EMERGENCY_PARSER)

  // Currently looking for: M108, M112, M410
  // If you alter the parser please don't forget to update the capabilities in Conditionals_post.h

  FORCE_INLINE void emergency_parser(unsigned char c) {

    static e_parser_state state = state_RESET;

    switch (state) {
      case state_RESET:
        switch (c) {
          case ' ': break;
          case 'N': state = state_N;      break;
          case 'M': state = state_M;      break;
          default: state = state_IGNORE;
        }
        break;

      case state_N:
        switch (c) {
          case '0': case '1': case '2':
          case '3': case '4': case '5':
          case '6': case '7': case '8':
          case '9': case '-': case ' ':   break;
          case 'M': state = state_M;      break;
          default:  state = state_IGNORE;
        }
        break;

      case state_M:
        switch (c) {
          case ' ': break;
          case '1': state = state_M1;     break;
          case '4': state = state_M4;     break;
          default: state = state_IGNORE;
        }
        break;

      case state_M1:
        switch (c) {
          case '0': state = state_M10;    break;
          case '1': state = state_M11;    break;
          default: state = state_IGNORE;
        }
        break;

      case state_M10:
        state = (c == '8') ? state_M108 : state_IGNORE;
        break;

      case state_M11:
        state = (c == '2') ? state_M112 : state_IGNORE;
        break;

      case state_M4:
        state = (c == '1') ? state_M41 : state_IGNORE;
        break;

      case state_M41:
        state = (c == '0') ? state_M410 : state_IGNORE;
        break;

      case state_IGNORE:
        if (c == '\n') state = state_RESET;
        break;

      default:
        if (c == '\n') {
          switch (state) {
            case state_M108:
              wait_for_user = wait_for_heatup = false;
              break;
            case state_M112:
              kill(PSTR(MSG_KILLED));
              break;
            case state_M410:
              quickstop_stepper();
              break;
            default:
              break;
          }
          state = state_RESET;
        }
    }
  }

#endif