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

  Copyright (c) 2012-2015 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 "grbl.h"


void spindle_init()
{    
  #ifdef VARIABLE_SPINDLE

    // Configure variable spindle PWM and enable pin, if requried. On the Uno, PWM and enable are
    // combined unless configured otherwise.
    SPINDLE_PWM_DDR |= (1<<SPINDLE_PWM_BIT); // Configure as PWM output pin.
    TCCRA_REGISTER = TCCRA_INIT_MASK; // Configure PWM output compare timer
    TCCRB_REGISTER = TCCRB_INIT_MASK;
    #ifdef CPU_MAP_ATMEGA2560
      OCRA_REGISTER = OCRA_TOP_VALUE; // Set the top value for 16-bit fast PWM mode
      SPINDLE_ENABLE_DDR |= (1<<SPINDLE_ENABLE_BIT); // Configure as output pin.
      SPINDLE_DIRECTION_DDR |= (1<<SPINDLE_DIRECTION_BIT); // Configure as output pin.
    #else // Otherwise 328p
      #ifdef USE_SPINDLE_DIR_AS_ENABLE_PIN
        SPINDLE_ENABLE_DDR |= (1<<SPINDLE_ENABLE_BIT); // Configure as output pin.
      #else 
        SPINDLE_DIRECTION_DDR |= (1<<SPINDLE_DIRECTION_BIT); // Configure as output pin.
      #endif
    #endif     
  
  #else  

    // Configure no variable spindle and only enable pin.
    SPINDLE_ENABLE_DDR |= (1<<SPINDLE_ENABLE_BIT); // Configure as output pin.
    SPINDLE_DIRECTION_DDR |= (1<<SPINDLE_DIRECTION_BIT); // Configure as output pin.
  
  #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.
    #if defined(CPU_MAP_ATMEGA2560) || defined(USE_SPINDLE_DIR_AS_ENABLE_PIN)
      #ifdef INVERT_SPINDLE_ENABLE_PIN
        SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
      #else
        SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
      #endif
    #endif
  #else
    #ifdef INVERT_SPINDLE_ENABLE_PIN
      SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
    #else
      SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
    #endif
  #endif  
}


void spindle_set_state(uint8_t state, float rpm)
{
  if (sys.abort) { return; } // Block during abort.
  
  // Halt or set spindle direction and rpm. 
  if (state == SPINDLE_DISABLE) {

    spindle_stop();

  } else {

    #ifndef USE_SPINDLE_DIR_AS_ENABLE_PIN
      if (state == SPINDLE_ENABLE_CW) {
        SPINDLE_DIRECTION_PORT &= ~(1<<SPINDLE_DIRECTION_BIT);
      } else {
        SPINDLE_DIRECTION_PORT |= (1<<SPINDLE_DIRECTION_BIT);
      }
    #endif

    #ifdef VARIABLE_SPINDLE

      // TODO: Install the optional capability for frequency-based output for servos.
      #ifdef CPU_MAP_ATMEGA2560
        uint16_t current_pwm; // 2560 PWM register is 16-bit.
      #else
        uint8_t current_pwm;  // 328p PWM register is 8-bit.
      #endif

      // Calculate PWM register value based on rpm max/min settings and programmed rpm.
      if (settings.rpm_max <= settings.rpm_min) {
        // No PWM range possible. Set simple on/off spindle control pin state.
        current_pwm = PWM_MAX_VALUE;
      } else {
        if (rpm > settings.rpm_max) { rpm = settings.rpm_max; }
        if (rpm < settings.rpm_min) { rpm = settings.rpm_min; }
        #ifdef SPINDLE_MINIMUM_PWM
          float pwm_gradient = (PWM_MAX_VALUE-SPINDLE_MINIMUM_PWM)/(settings.rpm_max-settings.rpm_min);
          current_pwm = floor( (rpm-settings.rpm_min)*pwm_gradient + (SPINDLE_MINIMUM_PWM+0.5));
        #else
          float pwm_gradient = (PWM_MAX_VALUE)/(settings.rpm_max-settings.rpm_min);
          current_pwm = floor( (rpm-settings.rpm_min)*pwm_gradient + 0.5);
        #endif
      }
      
      OCR_REGISTER = current_pwm; // Set PWM output level.
      TCCRA_REGISTER |= (1<<COMB_BIT); // Ensure PWM output is enabled.
    
      // On the Uno, spindle enable and PWM are shared, unless otherwise specified.
      #if defined(CPU_MAP_ATMEGA2560) || defined(USE_SPINDLE_DIR_AS_ENABLE_PIN) 
        #ifdef INVERT_SPINDLE_ENABLE_PIN
          SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
        #else
          SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
        #endif
      #endif
      
    #else
       
      #ifdef INVERT_SPINDLE_ENABLE_PIN
        SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
      #else
        SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
      #endif
    
    #endif

  }
}


void spindle_run(uint8_t state, float rpm)
{
  if (sys.state == STATE_CHECK_MODE) { return; }
  protocol_buffer_synchronize(); // Empty planner buffer to ensure spindle is set when programmed.  
  spindle_set_state(state, rpm);
}