CommandStation-EX/MotorDriver.h

/*
 *  © 2022 Paul M Antoine
 *  © 2021 Mike S
 *  © 2021 Fred Decker
 *  © 2020 Chris Harlow
 *  © 2022 Harald Barth
 *  All rights reserved.
 *  
 *  This file is part of CommandStation-EX
 *
 *  This 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.
 *
 *  It 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 CommandStation.  If not, see <https://www.gnu.org/licenses/>.
 */
#ifndef MotorDriver_h
#define MotorDriver_h
#include "FSH.h"
#include "IODevice.h"
#include "DCCTimer.h"

#define setHIGH(fastpin)  *fastpin.inout |= fastpin.maskHIGH
#define setLOW(fastpin)   *fastpin.inout &= fastpin.maskLOW
#define isHIGH(fastpin)   (*fastpin.inout & fastpin.maskHIGH)
#define isLOW(fastpin)    (!isHIGH(fastpin))

#define TOKENPASTE(x, y) x ## y
#define TOKENPASTE2(x, y) TOKENPASTE(x, y)

#if defined(ARDUINO_AVR_MEGA) || defined(ARDUINO_AVR_MEGA2560)
#define HAVE_PORTA(X) X
#define HAVE_PORTB(X) X
#define HAVE_PORTC(X) X
#endif
#if defined(ARDUINO_AVR_UNO)
#define HAVE_PORTB(X) X
#endif
#if defined(ARDUINO_ARCH_SAMD)
#define PORTA REG_PORT_OUT0
#define HAVE_PORTA(X) X
#define PORTB REG_PORT_OUT1
#define HAVE_PORTB(X) X
#endif
#if defined(ARDUINO_ARCH_STM32)
#define PORTA GPIOA->ODR
#define HAVE_PORTA(X) X
#define PORTB GPIOB->ODR
#define HAVE_PORTB(X) X
#define PORTC GPIOC->ODR
#define HAVE_PORTC(X) X
#endif

// if macros not defined as pass-through we define
// them here as someting that is valid as a
// statement and evaluates to false.
#ifndef HAVE_PORTA
#define HAVE_PORTA(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
#endif
#ifndef HAVE_PORTB
#define HAVE_PORTB(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
#endif
#ifndef HAVE_PORTC
#define HAVE_PORTC(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
#endif

// Virtualised Motor shield 1-track hardware Interface

#ifndef UNUSED_PIN     // sync define with the one in MotorDrivers.h
#define UNUSED_PIN 255 // inside uint8_t
#endif
#define MAX_PIN 254

class pinpair {
public:
  pinpair(byte p1, byte p2) {
    pin = p1;
    invpin = p2;
  };
  byte pin = UNUSED_PIN;
  byte invpin = UNUSED_PIN;
};

#if defined(__IMXRT1062__) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_SAMD) || defined(ARDUINO_ARCH_STM32)
typedef uint32_t portreg_t;
#else
typedef uint8_t portreg_t;
#endif

struct FASTPIN {
  volatile portreg_t *inout;
  portreg_t maskHIGH;
  portreg_t maskLOW;
  volatile portreg_t *shadowinout;
};
// The port registers that are shadowing
// the real port registers. These are
// defined in Motordriver.cpp
extern volatile portreg_t shadowPORTA;
extern volatile portreg_t shadowPORTB;
extern volatile portreg_t shadowPORTC;

enum class POWERMODE : byte { OFF, ON, OVERLOAD };

class MotorDriver {
  public:
    
    MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, int16_t brake_pin, 
                byte current_pin, float senseFactor, unsigned int tripMilliamps, int16_t fault_pin);
    void setPower( POWERMODE mode);
    POWERMODE getPower() { return powerMode;}
    // as the port registers can be shadowed to get syncronized DCC signals
    // we need to take care of that and we have to turn off interrupts if
    // we setSignal() or setBrake() or setPower() during that time as
    // otherwise the call from interrupt context can undo whatever we do
    // from outside interrupt
    void setBrake( bool on, bool interruptContext=false);
  __attribute__((always_inline)) inline void setSignal( bool high) {
      if (trackPWM) {
	DCCTimer::setPWM(signalPin,high);
      }
      else {
	if (high) {
	  setHIGH(fastSignalPin);
	  if (dualSignal) setLOW(fastSignalPin2);
	}
	else {
	  setLOW(fastSignalPin);
	  if (dualSignal) setHIGH(fastSignalPin2);
	}
      }
    };
    inline void enableSignal(bool on) {
      if (on)
	pinMode(signalPin, OUTPUT);
      else
	pinMode(signalPin, INPUT);
    };
    inline pinpair getSignalPin() { return pinpair(signalPin,signalPin2); };
    void setDCSignal(byte speedByte);
    inline void detachDCSignal() {
#if defined(__arm__)
      pinMode(brakePin, OUTPUT);
#elif defined(ARDUINO_ARCH_ESP32)
      ledcDetachPin(brakePin);
#else
      setDCSignal(128);
#endif
    };
    int  getCurrentRaw(bool fromISR=false);
    unsigned int raw2mA( int raw);
    unsigned int mA2raw( unsigned int mA);
    inline bool brakeCanPWM() {
#if defined(ARDUINO_ARCH_ESP32) || defined(__arm__)
      // TODO: on ARM we can use digitalPinHasPWM, and may wish/need to
      return true;
#else
#ifdef digitalPinToTimer
      return ((brakePin!=UNUSED_PIN) && (digitalPinToTimer(brakePin)));
#else
      return (brakePin<14 && brakePin >1);
#endif //digitalPinToTimer
#endif //ESP32/ARM
    }
    inline int getRawCurrentTripValue() {
	    return rawCurrentTripValue;
    }
    bool isPWMCapable();
    bool canMeasureCurrent();
    bool trackPWM = false; // this track uses PWM timer to generate the DCC waveform
    bool commonFaultPin = false; // This is a stupid motor shield which has only a common fault pin for both outputs
    inline byte setCommonFaultPin() {
      return commonFaultPin = true;
    }
    inline byte getFaultPin() {
	return faultPin;
    }
    inline void makeProgTrack(bool on) {  // let this output know it's a prog track.
      isProgTrack = on;
    }
    void checkPowerOverload(bool useProgLimit, byte trackno);
    inline void setTrackLetter(char c) {
      trackLetter = c;
    };
    // this returns how much time has passed since the last power change. If it
    // was really long ago (approx > 52min) advance counter approx 35 min so that
    // we are at 18 minutes again. Times for 32 bit unsigned long.
    inline unsigned long microsSinceLastPowerChange() {
      unsigned long now = micros();
      unsigned long diff = now - lastPowerChange;
      if (diff > (1UL << (7 *sizeof(unsigned long)))) // 2^(4*7)us = 268.4 seconds
        lastPowerChange = now - 30000000UL;           // 30 seconds ago
      return diff;
    };
    inline void setLastPowerChange() {
      lastPowerChange = micros();
    };
    // as setLastPowerChange but sets the global timestamp as well which
    // is only used to sync power restore in case of common Fault pin.
    inline void setLastPowerChangeOverload() {
      if (commonFaultPin)
	globalOverloadStart = lastPowerChange = micros();
      else
	setLastPowerChange();
    };
#ifdef ANALOG_READ_INTERRUPT
    bool sampleCurrentFromHW();
    void startCurrentFromHW();
#endif
  private:
    char trackLetter = '?';
    bool isProgTrack = false; // tells us if this is a prog track
    void  getFastPin(const FSH* type,int pin, bool input, FASTPIN & result);
    void  getFastPin(const FSH* type,int pin, FASTPIN & result) {
	getFastPin(type, pin, 0, result);
    }
    VPIN powerPin;
    byte signalPin, signalPin2, currentPin, faultPin, brakePin;
    FASTPIN fastSignalPin, fastSignalPin2, fastBrakePin,fastFaultPin;
    bool dualSignal;       // true to use signalPin2
    bool invertBrake;       // brake pin passed as negative means pin is inverted
    bool invertPower;       // power pin passed as negative means pin is inverted
    bool invertFault;       // fault pin passed as negative means pin is inverted
    
    // Raw to milliamp conversion factors avoiding float data types.
    // Milliamps=rawADCreading * sensefactorInternal / senseScale
    //
    // senseScale is chosen as 256 to give enough scale for 2 decimal place 
    // raw->mA conversion with an ultra fast optimised integer multiplication  
    int senseFactorInternal;  // set to senseFactor * senseScale
    static const int senseScale=256;
    int senseOffset;
    unsigned int tripMilliamps;
    int rawCurrentTripValue;
    // current sampling
    POWERMODE powerMode;
    bool overloadNow = false;
    unsigned long lastPowerChange;            // timestamp in microseconds
    // used to sync restore time when common Fault pin detected
    static unsigned long globalOverloadStart; // timestamp in microseconds
    int progTripValue;
    int  lastCurrent;
#ifdef ANALOG_READ_INTERRUPT
    volatile unsigned long sampleCurrentTimestamp;
    volatile uint16_t sampleCurrent;
#endif
    int maxmA;
    int tripmA;

    // Times for overload management. Unit: microseconds.
    // Base for wait time until power is turned on again
    static const unsigned long POWER_SAMPLE_OVERLOAD_WAIT =     10000UL;
    // Time after we consider all faults old and forgotten
    static const unsigned long POWER_SAMPLE_ALL_GOOD =        5000000UL;
    // How long to ignore fault pin if current is under limit
    static const unsigned long POWER_SAMPLE_IGNORE_FAULT_LOW =  50000UL;
    // How long to ignore fault pin if current is higher than limit
    static const unsigned long POWER_SAMPLE_IGNORE_FAULT_HIGH =  5000UL;
    // How long to wait between overcurrent and turning off
    static const unsigned long POWER_SAMPLE_OFF_DELAY =        100000UL;
    // Upper limit for retry period
    static const unsigned long POWER_SAMPLE_RETRY_MAX =      10000000UL;
    
    // Trip current for programming track, 250mA. Change only if you really
    // need to be non-NMRA-compliant because of decoders that are not either.
    static const int TRIP_CURRENT_PROG=250;
    unsigned long power_sample_overload_wait = POWER_SAMPLE_OVERLOAD_WAIT;
    unsigned int power_good_counter = 0;

};
#endif