make usePWM per track (trackPWM) 2nd half

GITHUB_SHA.h

@@ -1 +1 @@
-#define GITHUB_SHA "TM-PORTX-20220605"
+#define GITHUB_SHA "TM-PORTX-20220607-1"

MotorDriver.cpp

@@ -41,16 +41,20 @@ MotorDriver::MotorDriver(VPIN power_pin, byte signal_pin, byte signal_pin2, int8
   getFastPin(F("SIG"),signalPin,fastSignalPin);
   pinMode(signalPin, OUTPUT);
 
+  fastSignalPin.shadowinout = NULL;
   if (HAVE_PORTA(fastSignalPin.inout == &PORTA)) {
     DIAG(F("Found PORTA pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &fakePORTA;
   }
   if (HAVE_PORTB(fastSignalPin.inout == &PORTB)) {
     DIAG(F("Found PORTB pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &fakePORTB;
   }
   if (HAVE_PORTC(fastSignalPin.inout == &PORTC)) {
     DIAG(F("Found PORTC pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &fakePORTC;
   }
 
@@ -162,15 +166,45 @@ int MotorDriver::getCurrentRaw() {
 void MotorDriver::setDCSignal(byte speedcode) {
   if (brakePin == UNUSED_PIN)
     return;
-  // spedcoode is a dcc speed /direction
+  // spedcoode is a dcc speed & direction
-  byte tSpeed=speedcode & 0x7F;
+  byte tSpeed=speedcode & 0x7F; // DCC Speed with 0,1 stop and speed steps 2 to 127
-    // DCC Speed with 0,1 stop and speed steps 2 to 127
+  byte tDir=speedcode & 0x80;
   byte brake;
   if (tSpeed <= 1) brake = 255;
   else if (tSpeed >= 127) brake = 0;
   else  brake = 2 * (128-tSpeed);
+  DIAG(F("setDCSignal: speedcode=%d BrakePin=%d brake=%d dir=%d"),speedcode, brakePin, brake, tDir);
   analogWrite(brakePin,brake);
-  setSignal(speedcode & 0x80);  
+  // 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 during
+  // that time as otherwise setDCCSignal() which is called from interrupt
+  // contect can undo whatever we do here.
+  if (fastSignalPin.shadowinout != NULL) {
+    if (HAVE_PORTA(fastSignalPin.shadowinout == &PORTA)) {
+      DIAG(F("setDCSignal: HAVEPORTA"));
+      noInterrupts();
+      HAVE_PORTA(fakePORTA=PORTA);
+      setSignal(tDir);
+      HAVE_PORTA(PORTA=fakePORTA);
+      interrupts();
+    } else if (HAVE_PORTB(fastSignalPin.shadowinout == &PORTB)) {
+      DIAG(F("setDCSignal: HAVEPORTB"));
+      noInterrupts();
+      HAVE_PORTB(fakePORTB=PORTB);
+      setSignal(tDir);
+      HAVE_PORTB(PORTB=fakePORTB);
+      interrupts();
+    } else if (HAVE_PORTC(fastSignalPin.shadowinout == &PORTC)) {
+      DIAG(F("setDCSignal: HAVEPORTC"));
+      noInterrupts();
+      HAVE_PORTC(fakePORTC=PORTC);
+      setSignal(tDir);
+      HAVE_PORTC(PORTC=fakePORTC);
+      interrupts();
+    }
+  } else {
+    setSignal(tDir);
+  }
 }
 
 int MotorDriver::getCurrentRawInInterrupt() {

MotorDriver.h

@@ -2,6 +2,7 @@
  *  © 2021 Mike S
  *  © 2021 Fred Decker
  *  © 2020 Chris Harlow
+ *  © 2022 Harald Barth
  *  All rights reserved.
  *  
  *  This file is part of Asbelos DCC API
@@ -65,13 +66,15 @@
 struct FASTPIN {
   volatile uint32_t *inout;
   uint32_t maskHIGH;  
-  uint32_t maskLOW;  
+  uint32_t maskLOW;
+  volatile uint32_t *shadowinout;
 };
 #else
 struct FASTPIN {
   volatile uint8_t *inout;
   uint8_t maskHIGH;  
-  uint8_t maskLOW;  
+  uint8_t maskLOW;
+  volatile uint8_t *shadowinout;
 };
 #endif
 
@@ -85,7 +88,7 @@ class MotorDriver {
     virtual void setPower( POWERMODE mode);
     virtual POWERMODE getPower() { return powerMode;}
     __attribute__((always_inline)) inline void setSignal( bool high) {
-      if (usePWM) {
+      if (trackPWM) {
 	DCCTimer::setPWM(signalPin,high);
       }
       else {
@@ -119,7 +122,8 @@ class MotorDriver {
     }
     bool isPWMCapable();
     bool canMeasureCurrent();
-    static bool usePWM;
+    bool trackPWM;
+    static bool usePWM; // TODO: Remove
     static bool commonFaultPin; // This is a stupid motor shield which has only a common fault pin for both outputs
     inline byte getFaultPin() {
 	return faultPin;

TrackManager.cpp

@@ -87,11 +87,15 @@ void TrackManager::addTrack(byte t, MotorDriver* driver) {
      } 
 }
 
+// The port registers that are shadowing
+// the real port registers. These are
 // defined in Motordriver.cpp
 extern byte fakePORTA;
 extern byte fakePORTB;
 extern byte fakePORTC;
 
+// setDCCSignal(), called from interrupt context
+// does assume ports are shadowed if they can be
 void TrackManager::setDCCSignal( bool on) {
   HAVE_PORTA(fakePORTA=PORTA);
   HAVE_PORTB(fakePORTB=PORTB);
@@ -108,6 +112,8 @@ void TrackManager::setCutout( bool on) {
     // TODO      APPLY_BY_MODE(TRACK_MODE_MAIN,setCutout(on));
 }
 
+// setPROGSignal(), called from interrupt context
+// does assume ports are shadowed if they can be
 void TrackManager::setPROGSignal( bool on) {
   HAVE_PORTA(fakePORTA=PORTA);
   HAVE_PORTB(fakePORTB=PORTB);
@@ -118,25 +124,22 @@ void TrackManager::setPROGSignal( bool on) {
   HAVE_PORTC(PORTC=fakePORTC);
 }
 
+// setDCSignal(), called from normal context
+// MotorDriver::setDCSignal handles shadowed IO port changes.
+// with interrupts turned off around the critical section
 void TrackManager::setDCSignal(int16_t cab, byte speedbyte) {
-  HAVE_PORTA(fakePORTA=PORTA);
-  HAVE_PORTB(fakePORTB=PORTB);
-  HAVE_PORTC(fakePORTC=PORTC);
   FOR_EACH_TRACK(t) {
     if (trackDCAddr[t]!=cab) continue;
     if (trackMode[t]==TRACK_MODE_DC) track[t]->setDCSignal(speedbyte);
     else if (trackMode[t]==TRACK_MODE_DCX) track[t]->setDCSignal(speedbyte ^ 128);
   }
-  HAVE_PORTA(PORTA=fakePORTA);
-  HAVE_PORTB(PORTB=fakePORTB);
-  HAVE_PORTC(PORTC=fakePORTC);
 }    
 
 
 bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr) {
     if (trackToSet>lastTrack || track[trackToSet]==NULL) return false;
 
-    //DIAG(F("Track=%c"),trackToSet+'A');
+    DIAG(F("Track=%c"),trackToSet+'A');
     // DC tracks require a motorDriver that can set brake!
     if ((mode==TRACK_MODE_DC || mode==TRACK_MODE_DCX)
          && !track[trackToSet]->brakeCanPWM()) {
@@ -187,16 +190,30 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
       // capable tracks is now DC or DCX.
       if (trackMode[t]==TRACK_MODE_DC || trackMode[t]==TRACK_MODE_DCX) {
 	if (track[t]->isPWMCapable()) {
-	  canDo=false;
+	  canDo=false;    // this track is capable but can not run PWM
-	  break;
+	  break;          // in this mode, so abort and prevent globally below
+	} else {
+	  track[t]->trackPWM=false; // this track sure can not run with PWM
+	  DIAG(F("Track %c trackPWM 0 (not capable)"), t+'A');
 	}
-      } else if (trackMode[t]==TRACK_MODE_MAIN || trackMode[t]==TRACK_MODE_PROG)
+      } else if (trackMode[t]==TRACK_MODE_MAIN || trackMode[t]==TRACK_MODE_PROG) {
-	canDo &= track[t]->isPWMCapable();
+	track[t]->trackPWM = track[t]->isPWMCapable(); // trackPWM is still a guess here
+	DIAG(F("Track %c trackPWM %d"), t+'A', track[t]->trackPWM);
+	canDo &= track[t]->trackPWM;
+      }
     }
-    //DIAG(F("HAMode=%d"),canDo);
+
     if (!canDo) {
-      DCCTimer::clearPWM();
+      // if we discover that HA mode was globally impossible
+      // we must adjust the trackPWM capabilities
+      FOR_EACH_TRACK(t) {
+	track[t]->trackPWM=false;
+	DIAG(F("Track %c trackPWM 0 (global override)"), t+'A');
+      }
+      DCCTimer::clearPWM(); // has to be AFTER trackPWM changes because if trackPWM==true this is undone for  that track
     }
+    if (MotorDriver::usePWM != canDo)
+      DIAG(F("HA mode changed from %d to %d"), MotorDriver::usePWM, canDo);
     MotorDriver::usePWM=canDo;
 
     
@@ -204,14 +221,14 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
     track[trackToSet]->setPower(
         (mode==TRACK_MODE_MAIN || mode==TRACK_MODE_DC || mode==TRACK_MODE_DCX || mode==TRACK_MODE_EXT) ?
         mainPowerGuess : POWERMODE::OFF);
-    //DIAG(F("TrackMode=%d"),mode);
+    DIAG(F("TrackMode=%d"),mode);
     return true; 
 }
 
 void TrackManager::applyDCSpeed(byte t) {
   uint8_t speedByte=DCC::getThrottleSpeedByte(trackDCAddr[t]);
   if (trackMode[t]==TRACK_MODE_DCX)
-    speedByte = (speedByte & 0xF7) | ~(speedByte & 0x80); // Reverse highest bit
+    speedByte = speedByte ^ 128; // reverse direction bit
   track[t]->setDCSignal(speedByte);
 }