marlin/Marlin/endstop_interrupts.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/>.
 *
 */

/**
 *  Endstop interrupts
 *  Without endstop interrups the stepper-ISR must always test all endstops when interested in their states (endstops.update()).
 *  Most time the test will result in finding out nothing has changed.
 *  With endstop interrupts endstops.update() is called only when we know that at least one endstop has changed its state.
 *
 *  This can work only if all __used__ endstop pins can provide ether an 'external interrupt' or a 'pin change interrupt'.
 *  You can find out about pins issuing interrupts by running 'pin_interrupt_test.ino' (Marlin\buildroot\share\pin_interrupt_test\pin_interrupt_test.ino)
 */

 #ifndef _ENDSTOP_INTERRUPTS_H_
   #define _ENDSTOP_INTERRUPTS_H_

  /**
   * Patch for pins_arduino.h (...\Arduino\hardware\arduino\avr\variants\mega\pins_arduino.h)  
   *
   * These macros for the Arduino MEGA do not include the two connected pins on Port J (D13, D14).
   * So we extend them here because this are the normal pins for Y_MIN and Y_MAX on RAMPS.
   * There are more PCI enabled processor pins on Port J, but they are not connected to Arduino MEGA.
   */
  #if defined(ARDUINO_AVR_MEGA2560) || defined(ARDUINO_AVR_MEGA)
    #undef  digitalPinToPCICR
    #define digitalPinToPCICR(p)    ( (((p) >= 10) && ((p) <= 15)) || \
                                    (((p) >= 50) && ((p) <= 53)) || \
                                    (((p) >= 62) && ((p) <= 69)) ? (&PCICR) : ((uint8_t *)0) )
    #undef  digitalPinToPCICRbit
    #define digitalPinToPCICRbit(p) ( (((p) >= 10) && ((p) <= 13)) || (((p) >= 50) && ((p) <= 53)) ? 0 : \
                                    ( (((p) >= 14) && ((p) <= 15)) ? 1 : \
                                    ( (((p) >= 62) && ((p) <= 69)) ? 2 : \
                                    0 ) ) )
    #undef  digitalPinToPCMSK
    #define digitalPinToPCMSK(p)    ( (((p) >= 10) && ((p) <= 13)) || (((p) >= 50) && ((p) <= 53)) ? (&PCMSK0) : \
                                    ( (((p) >= 14) && ((p) <= 15)) ? (&PCMSK1) : \
                                    ( (((p) >= 62) && ((p) <= 69)) ? (&PCMSK2) : \
                                    ((uint8_t *)0) ) ) )
    #undef  digitalPinToPCMSKbit
    #define digitalPinToPCMSKbit(p) ( (((p) >= 10) && ((p) <= 13)) ? ((p) - 6) : \
                                    ( ((p) == 14) ? 2 : \
                                    ( ((p) == 15) ? 1 : \
                                    ( ((p) == 50) ? 3 : \
                                    ( ((p) == 51) ? 2 : \
                                    ( ((p) == 52) ? 1 : \
                                    ( ((p) == 53) ? 0 : \
                                    ( (((p) >= 62) && ((p) <= 69)) ? ((p) - 62) : \
                                    0 ) ) ) ) ) ) ) )
  #endif

  volatile uint8_t e_hit = 0; // Different from 0 when the endstops shall be tested in detail. 
                              // Must be reset to 0 by the test function when the tests are finished.

  // Install Pin change interrupt for a pin, can be called multiple times
  void pciSetup(byte pin) {
    *digitalPinToPCMSK(pin) |= bit (digitalPinToPCMSKbit(pin));  // enable pin
    PCIFR  |= bit (digitalPinToPCICRbit(pin)); // clear any outstanding interrupt
    PCICR  |= bit (digitalPinToPCICRbit(pin)); // enable interrupt for the group
  }

  // This is what is really done inside the interrupts.
  FORCE_INLINE void endstop_ISR_worker( void ) {
    e_hit = 2; // Because the detection of a e-stop hit has a 1 step debouncer it has to be called at least twice.
  }

  // Use one Routine to handle each group
  // One ISR for all EXT-Interrupts
  void endstop_ISR(void) {
    endstop_ISR_worker();
  }

  #ifdef PCINT0_vect
    ISR(PCINT0_vect) { // handle pin change interrupt
      endstop_ISR_worker();
    }
  #endif

  #ifdef PCINT1_vect
    ISR(PCINT1_vect) { // handle pin change interrupt
      endstop_ISR_worker();
    }
  #endif

  #ifdef PCINT2_vect
    ISR(PCINT2_vect) { // handle pin change interrupt
      endstop_ISR_worker();
    }
  #endif

  #ifdef PCINT3_vect
    ISR(PCINT3_vect) { // handle pin change interrupt
      endstop_ISR_worker();
    }
  #endif

  void setup_enstop_interrupts( void ) {

    #if HAS_X_MAX
      #if (digitalPinToInterrupt(X_MAX_PIN) != NOT_AN_INTERRUPT) // if pin has an external interrupt
        attachInterrupt(digitalPinToInterrupt(X_MAX_PIN), endstop_ISR, CHANGE); // assign it
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(X_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR"); // if pin has no pin change interrupt - error
        pciSetup(X_MAX_PIN);                                                            // assign it
      #endif
    #endif

    #if HAS_X_MIN
      #if (digitalPinToInterrupt(X_MIN_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(X_MIN_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(X_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(X_MIN_PIN);
      #endif
    #endif

    #if HAS_Y_MAX
      #if (digitalPinToInterrupt(Y_MAX_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Y_MAX_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Y_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Y_MAX_PIN);
      #endif
    #endif

    #if HAS_Y_MIN
      #if (digitalPinToInterrupt(Y_MIN_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Y_MIN_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Y_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Y_MIN_PIN);
      #endif
    #endif

    #if HAS_Z_MAX
      #if (digitalPinToInterrupt(Z_MAX_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Z_MAX_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Z_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Z_MAX_PIN);
      #endif
    #endif

    #if HAS_Z_MIN
      #if (digitalPinToInterrupt(Z_MIN_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Z_MIN_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Z_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Z_MIN_PIN);
      #endif
    #endif

    #if HAS_Z2_MAX
      #if (digitalPinToInterrupt(Z2_MAX_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Z2_MAX_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Z2_MAX_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Z2_MAX_PIN);
      #endif
    #endif

    #if HAS_Z2_MIN
      #if (digitalPinToInterrupt(Z2_MIN_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Z2_MIN_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Z2_MIN_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Z2_MIN_PIN);
      #endif
    #endif

    #if HAS_Z_MIN_PROBE_PIN
      #if (digitalPinToInterrupt(Z_MIN_PROBE_PIN) != NOT_AN_INTERRUPT)
        attachInterrupt(digitalPinToInterrupt(Z_MIN_PROBE_PIN), endstop_ISR, CHANGE);
      #else
        // Not all used endstop/probe -pins can raise interrupts. Please deactivate ENDSTOP_INTERRUPTS or change the pin configuration!
        static_assert(digitalPinToPCICR(Z_MIN_PROBE_PIN) != NULL, "ENDSTOP_INTERRUPT_ERROR");
        pciSetup(Z_MIN_PROBE_PIN);
      #endif
    #endif

    // When we arive here without error each pin has ether a EXT-interrupt or a PCI.
  }


#endif //_ENDSTOP_INTERRUPTS_H_