/*
  spindle_control.c - spindle control methods
  Part of Grbl

  Copyright (c) 2012-2014 Sungeun K. Jeon
  Copyright (c) 2009-2011 Simen Svale Skogsrud

  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/>.
*/

#include "system.h"
#include "spindle_control.h"
#include "planner.h"


void spindle_init()
{  
  SPINDLE_DIRECTION_DDR |= (1<<SPINDLE_DIRECTION_BIT);
  
  // On the Uno, spindle enable and PWM are shared. Other CPUs have seperate enable pin.
  #ifdef VARIABLE_SPINDLE
    SPINDLE_PWM_DDR |= (1<<SPINDLE_PWM_BIT);
    #ifndef CPU_MAP_ATMEGA328P 
      SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
    #endif     
  #else
    SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
  #endif
  
  spindle_stop();
}


void spindle_stop()
{
  // On the Uno, spindle enable and PWM are shared. Other CPUs have seperate enable pin.
  #ifdef VARIABLE_SPINDLE
    TCCRA_REGISTER &= ~(1<<COMB_BIT); // Disable PWM. Output voltage is zero.
    #ifndef CPU_MAP_ATMEGA328P 
      SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
    #endif
  #else
    SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
  #endif  
}


void spindle_run(uint8_t direction, float rpm) 
{
  // Empty planner buffer to ensure spindle is set when programmed.
  plan_synchronize(); 

  // Halt or set spindle direction and rpm. 
  if (direction == SPINDLE_DISABLE) {
  
    spindle_stop();
  
  } else {
  
    if (direction == SPINDLE_ENABLE_CW) {
      SPINDLE_DIRECTION_PORT &= ~(1<<SPINDLE_DIRECTION_BIT);
    } else {
      SPINDLE_DIRECTION_PORT |= (1<<SPINDLE_DIRECTION_BIT);
    }

    #ifdef VARIABLE_SPINDLE
      #define SPINDLE_RPM_RANGE (SPINDLE_MAX_RPM-SPINDLE_MIN_RPM)
      TCCRA_REGISTER = (1<<COMB_BIT) | (1<<WAVE1_REGISTER) | (1<<WAVE0_REGISTER);
      TCCRB_REGISTER = (TCCRB_REGISTER & 0b11111000) | 0x02; // set to 1/8 Prescaler
      rpm -= SPINDLE_MIN_RPM;
      if ( rpm > SPINDLE_RPM_RANGE ) { rpm = SPINDLE_RPM_RANGE; } // Prevent uint8 overflow
      uint8_t current_pwm = floor( rpm*(255.0/SPINDLE_RPM_RANGE) + 0.5);
      OCR_REGISTER = current_pwm;
      
      #ifndef CPU_MAP_ATMEGA328P // On the Uno, spindle enable and PWM are shared.
        SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
      #endif
    #else   
      SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
    #endif

  }
}