*
  spindle_control.c - spindle control methods
  Part of Grbl
 
  PEN_SERVO update by Bart Dring 8/2017
  Copyright (c) 2012-2017 Sungeun K. Jeon for Gnea Research LLC
  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"
 
/*
Pen Servo: 
 
For a pen bot I want to use the spindle PWM to control a servo
When the spindle is on, the servo moves the pen down
When it is off the pen moves up
 
The spindle output is using a PWM, but we need to adjust that 
 
We only need a rough 
 
Use 1024 prescaler to get. ... 16,000,000 Mhz  / 1024 = 15625 Hz
It is an 8 bit timer so 15625 / 256 = 61 Hz. This is pretty close the the 50Hz recommended for servos
Each tick = 0.000064sec 
One end of servo is 0.001 sec (0.001 / 0.000064 = 15.6 ticks)
The other end is 0.002 sec (0.002 / 0.000064 = 31 ticks)
 
 
*/
 
#define PEN_SERVO
// these are full travel values. If you want to move less than full travel adjust these values
// If your servo is going the wrong way, swap them.
#define PEN_SERVO_DOWN     16      
#define PEN_SERVO_UP       31        
 
#ifdef VARIABLE_SPINDLE
  static float pwm_gradient; // Precalulated value to speed up rpm to PWM conversions.
#endif
 
 
void spindle_init()
{
  #ifdef VARIABLE_SPINDLE
 
    SPINDLE_PWM_DDR |= (1<<SPINDLE_PWM_BIT); // Configure as PWM output pin.
     
    #ifndef PEN_SERVO 
   
        // Configure variable spindle PWM and enable pin, if required. On the Uno, PWM and enable are
        // combined unless configured otherwise.
         
        SPINDLE_TCCRA_REGISTER = SPINDLE_TCCRA_INIT_MASK; // Configure PWM output compare timer
        SPINDLE_TCCRB_REGISTER = SPINDLE_TCCRB_INIT_MASK;
     
    #else
        #ifdef CPU_MAP_ATMEGA2560
         
        // not supported yet
         
      #else
         
        SPINDLE_TCCRA_REGISTER = (1<<COM2A1) | ((1<<WGM20) | (1<<WGM21));
        TCCR2B = (1<<CS22) | (1 <<CS21) | (1<<CS20);
         
      #endif
    #endif
     
     
     
    #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
 
    pwm_gradient = SPINDLE_PWM_RANGE/(settings.rpm_max-settings.rpm_min);
 
  #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();
}
 
 
uint8_t spindle_get_state()
{
    #ifdef VARIABLE_SPINDLE
    #ifdef USE_SPINDLE_DIR_AS_ENABLE_PIN
          // No spindle direction output pin. 
            #ifdef INVERT_SPINDLE_ENABLE_PIN
              if (bit_isfalse(SPINDLE_ENABLE_PORT,(1<<SPINDLE_ENABLE_BIT))) { return(SPINDLE_STATE_CW); }
        #else
                if (bit_istrue(SPINDLE_ENABLE_PORT,(1<<SPINDLE_ENABLE_BIT))) { return(SPINDLE_STATE_CW); }
        #endif
    #else
      if (SPINDLE_TCCRA_REGISTER & (1<<SPINDLE_COMB_BIT)) { // Check if PWM is enabled.
        if (SPINDLE_DIRECTION_PORT & (1<<SPINDLE_DIRECTION_BIT)) { return(SPINDLE_STATE_CCW); }
        else { return(SPINDLE_STATE_CW); }
      }
    #endif
    #else
        #ifdef INVERT_SPINDLE_ENABLE_PIN
          if (bit_isfalse(SPINDLE_ENABLE_PORT,(1<<SPINDLE_ENABLE_BIT))) {
        #else
          if (bit_istrue(SPINDLE_ENABLE_PORT,(1<<SPINDLE_ENABLE_BIT))) {
        #endif
      if (SPINDLE_DIRECTION_PORT & (1<<SPINDLE_DIRECTION_BIT)) { return(SPINDLE_STATE_CCW); }
      else { return(SPINDLE_STATE_CW); }
    }
    #endif
    return(SPINDLE_STATE_DISABLE);
}
 
 
// Disables the spindle and sets PWM output to zero when PWM variable spindle speed is enabled.
// Called by various main program and ISR routines. Keep routine small, fast, and efficient.
// Called by spindle_init(), spindle_set_speed(), spindle_set_state(), and mc_reset().
void spindle_stop()
{
     
  #ifndef PEN_SERVO 
     
      #ifdef VARIABLE_SPINDLE
        SPINDLE_TCCRA_REGISTER &= ~(1<<SPINDLE_COMB_BIT); // Disable PWM. Output voltage is zero.
        #ifdef 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
   
  #else   
    SPINDLE_OCR_REGISTER = PEN_SERVO_UP;    
  #endif
   
}
 
 
#ifdef VARIABLE_SPINDLE

  // Sets spindle speed PWM output and enable pin, if configured. Called by spindle_set_state()
  // and stepper ISR. Keep routine small and efficient.
  void spindle_set_speed(uint8_t pwm_value) 
  {
     
    #ifdef PEN_SERVO
        if (pwm_value == SPINDLE_PWM_OFF_VALUE) 
            spindle_stop();
        else // not off
            SPINDLE_OCR_REGISTER = PEN_SERVO_DOWN;
    #else
       
       
        SPINDLE_OCR_REGISTER = pwm_value; // Set PWM output level.
        #ifdef SPINDLE_ENABLE_OFF_WITH_ZERO_SPEED
          if (pwm_value == SPINDLE_PWM_OFF_VALUE) {
				spindle_stop();
			} else {
				SPINDLE_TCCRA_REGISTER |= (1<<SPINDLE_COMB_BIT); // Ensure PWM output is enabled.
				
				#ifdef INVERT_SPINDLE_ENABLE_PIN
					SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
				#else
					SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
				#endif
			}
		#else
			if (pwm_value == SPINDLE_PWM_OFF_VALUE) {
				SPINDLE_TCCRA_REGISTER &= ~(1<<SPINDLE_COMB_BIT); // Disable PWM. Output voltage is zero.
			} else {
				SPINDLE_TCCRA_REGISTER |= (1<<SPINDLE_COMB_BIT); // Ensure PWM output is enabled. 
			} 
		#endif 
	#endif 
	} 

	#ifdef ENABLE_PIECEWISE_LINEAR_SPINDLE // Called by spindle_set_state() and step segment generator. Keep routine small and efficient.
	
		uint8_t spindle_compute_pwm_value(float rpm) // 328p PWM register is 8-bit. 
		{ 
			uint8_t pwm_value; 
			rpm *= (0.010*sys.spindle_speed_ovr); // Scale by spindle speed override value. 

			// Calculate PWM register value based on rpm max/min settings and programmed rpm. 
			if ((settings.rpm_min >= settings.rpm_max) || (rpm >= RPM_MAX)) {
				rpm = RPM_MAX;
				pwm_value = SPINDLE_PWM_MAX_VALUE;
			} else if (rpm <= RPM_MIN){ 
				if (rpm == 0.0)	{ // S0 disables spindle 
					pwm_value = SPINDLE_PWM_OFF_VALUE; 
				} else { 
					rpm = RPM_MIN; 
					pwm_value = SPINDLE_PWM_MIN_VALUE; 
					} 
			} else { 
				
				// Compute intermediate PWM value with linear spindle speed model via piecewise linear fit model. 
				#if (N_PIECES > 3)
					if (rpm > RPM_POINT34) {
						pwm_value = floor(RPM_LINE_A4*rpm - RPM_LINE_B4);
					} else
				#endif
						
				#if (N_PIECES > 2)
					if (rpm > RPM_POINT23) {
						pwm_value = floor(RPM_LINE_A3*rpm - RPM_LINE_B3);
					} else
				#endif
						
				#if (N_PIECES > 1)
					if (rpm > RPM_POINT12){
						pwm_value = floor(RPM_LINE_A2*rpm - RPM_LINE_B2);
					} else
				#endif
						
					{
								pwm_value = floor(RPM_LINE_A1*rpm - RPM_LINE_B1);
					}
			}
			sys.spindle_speed = rpm;
			return(pwm_value);
		}
     
  #else 
   
    // Called by spindle_set_state() and step segment generator. Keep routine small and efficient.
    uint8_t spindle_compute_pwm_value(float rpm) // 328p PWM register is 8-bit.
    {
      uint8_t pwm_value;
      rpm *= (0.010*sys.spindle_speed_ovr); // Scale by spindle speed override value.
	  
      // Calculate PWM register value based on rpm max/min settings and programmed rpm.
      if ((settings.rpm_min >= settings.rpm_max) || (rpm >= settings.rpm_max)) {
		  
			// No PWM range possible. Set simple on/off spindle control pin state.
			sys.spindle_speed = settings.rpm_max;
			pwm_value = SPINDLE_PWM_MAX_VALUE;
      } else if (rpm <= settings.rpm_min) {
				if (rpm == 0.0) { // S0 disables spindle
					sys.spindle_speed = 0.0;
					pwm_value = SPINDLE_PWM_OFF_VALUE;
				} else { // Set minimum PWM output
					sys.spindle_speed = settings.rpm_min;
					pwm_value = SPINDLE_PWM_MIN_VALUE;
				}
			} else { 
				// Compute intermediate PWM value with linear spindle speed model.
				// NOTE: A nonlinear model could be installed here, if required, but keep it VERY light-weight.
				sys.spindle_speed = rpm;
				pwm_value = floor((rpm-settings.rpm_min)*pwm_gradient) + SPINDLE_PWM_MIN_VALUE;
			}
			return(pwm_value);
		}
     
		#endif
	#endif
 
 
	// Immediately sets spindle running state with direction and spindle rpm via PWM, if enabled.
	// Called by g-code parser spindle_sync(), parking retract and restore, g-code program end,
	// sleep, and spindle stop override.
	#ifdef VARIABLE_SPINDLE
		void spindle_set_state(uint8_t state, float rpm)
	#else
		void _spindle_set_state(uint8_t state)
	#endif
	{
		if (sys.abort) { return; } // Block during abort.
		if (state == SPINDLE_DISABLE) { // Halt or set spindle direction and rpm.
   
			#ifdef VARIABLE_SPINDLE
				sys.spindle_speed = 0.0;
			#endif
			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
		// NOTE: Assumes all calls to this function is when Grbl is not moving or must remain off.
		if (settings.flags & BITFLAG_LASER_MODE) { 
			if (state == SPINDLE_ENABLE_CCW) { rpm = 0.0; } // TODO: May need to be rpm_min*(100/MAX_SPINDLE_SPEED_OVERRIDE);
		}
		spindle_set_speed(spindle_compute_pwm_value(rpm));
    #endif
	
    #if (defined(USE_SPINDLE_DIR_AS_ENABLE_PIN) && !defined(SPINDLE_ENABLE_OFF_WITH_ZERO_SPEED)) || !defined(VARIABLE_SPINDLE)
		// NOTE: Without variable spindle, the enable bit should just turn on or off, regardless
		// if the spindle speed value is zero, as its ignored anyhow.
		#ifdef INVERT_SPINDLE_ENABLE_PIN
			SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
		#else
			SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
		#endif    
    #endif
   
  }
   
  sys.report_ovr_counter = 0; // Set to report change immediately
}
 
 
// G-code parser entry-point for setting spindle state. Forces a planner buffer sync and bails 
// if an abort or check-mode is active.
#ifdef VARIABLE_SPINDLE
  void spindle_sync(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);
  }
#else
  void _spindle_sync(uint8_t state)
  {
    if (sys.state == STATE_CHECK_MODE) { return; }
    protocol_buffer_synchronize(); // Empty planner buffer to ensure spindle is set when programmed.
    _spindle_set_state(state);
  }
#endif