refactor hardware pwm

Author: hathach

cores/nRF5/HardwarePWM.cpp

@@ -107,6 +107,38 @@ HardwarePWM::HardwarePWM(NRF_PWM_Type* pwm) :
   _pwm->PSEL.OUT[1] = 0xFFFFFFFFUL;
 }
 
+void HardwarePWM::begin(void)
+{
+  // Initialize Registers
+  _pwm->MODE            = PWM_MODE_UPDOWN_Up;
+  _pwm->COUNTERTOP      = _max_value; // default is 255 (8 bit), can be configured before begin()
+  _pwm->PRESCALER       = _clock_div;
+  _pwm->DECODER         = PWM_DECODER_LOAD_Individual;
+  _pwm->LOOP            = 0;
+
+  _pwm->SEQ[0].PTR      = (uint32_t) _seq0;
+  _pwm->SEQ[0].CNT      = MAX_CHANNELS; // default mode is Individual --> count must be 4
+  _pwm->SEQ[0].REFRESH  = 0;
+  _pwm->SEQ[0].ENDDELAY = 0;
+
+  _pwm->SEQ[1].PTR      = 0;
+  _pwm->SEQ[1].CNT      = 0;
+  _pwm->SEQ[1].REFRESH  = 0;
+  _pwm->SEQ[1].ENDDELAY = 0;
+
+  _pwm->ENABLE = 1;
+}
+
+void HardwarePWM::stop(void)
+{
+  _pwm->ENABLE = 0;
+}
+
+bool HardwarePWM::enabled (void)
+{
+  return _pwm->ENABLE;
+}
+
 void HardwarePWM::setResolution(uint8_t bitnum)
 {
   setMaxValue( bit(min8(bitnum, 15)) -1 );
@@ -124,6 +156,25 @@ void HardwarePWM::setClockDiv(uint8_t div)
   _pwm->PRESCALER = _clock_div;
 }
 
+void HardwarePWM::_set_psel(int ch, uint32_t value)
+{
+  // Must disable before changing PSEL
+  if ( enabled() )
+  {
+    _pwm->ENABLE = 0;
+    _pwm->PSEL.OUT[ch] = value;
+    _seq0[ch] = 0;
+    _pwm->ENABLE = 1;
+
+    // re-start sequence
+    if ( usedChannelCount() ) _pwm->TASKS_SEQSTART[0] = 1;
+  }else
+  {
+    _pwm->PSEL.OUT[ch] = value;
+    _seq0[ch] = 0;
+  }
+}
+
 /**
  * Add pin to this group.
  * @param pin Pin to add
@@ -150,17 +201,7 @@ bool HardwarePWM::addPin(uint8_t pin)
   pinMode(pin, OUTPUT);
   digitalWrite(pin, LOW);
 
-  // Must disable before changing PSEL
-  if ( enabled() )
-  {
-    _pwm->ENABLE = 0;
-    _pwm->PSEL.OUT[ch] = g_ADigitalPinMap[pin];
-    _pwm->ENABLE = 1;
-    _start();
-  }else
-  {
-    _pwm->PSEL.OUT[ch] = g_ADigitalPinMap[pin];
-  }
+  _set_psel(ch, g_ADigitalPinMap[pin]);
 
   return true;
 }
@@ -170,70 +211,21 @@ bool HardwarePWM::removePin(uint8_t pin)
   int ch = pin2channel(pin);
   VERIFY( ch >= 0 );
 
-  bool const en = enabled();
-
-  // Must disable before changing PSEL
-  if ( en ) _pwm->ENABLE = 0;
-
-  _pwm->PSEL.OUT[ch] = 0xFFFFFFFFUL;
-  _seq0[ch] = 0;
-
-  if ( en ) _pwm->ENABLE = 1;
-
+  _set_psel(ch, 0xFFFFFFFFUL);
   return true;
 }
 
-bool HardwarePWM::enabled (void)
-{
-  return _pwm->ENABLE;
-}
-
-void HardwarePWM::begin(void)
-{
-  // Initialize Registers
-  _pwm->MODE            = PWM_MODE_UPDOWN_Up;
-  _pwm->COUNTERTOP      = _max_value; // default is 255 (8 bit), can be configured before begin()
-  _pwm->PRESCALER       = _clock_div;
-  _pwm->DECODER         = PWM_DECODER_LOAD_Individual;
-  _pwm->LOOP            = 0;
-
-  _pwm->SEQ[0].PTR      = (uint32_t) _seq0;
-  _pwm->SEQ[0].CNT      = MAX_CHANNELS; // default mode is Individual --> count must be 4
-  _pwm->SEQ[0].REFRESH  = 0;
-  _pwm->SEQ[0].ENDDELAY = 0;
-
-  _pwm->SEQ[1].PTR      = 0;
-  _pwm->SEQ[1].CNT      = 0;
-  _pwm->SEQ[1].REFRESH  = 0;
-  _pwm->SEQ[1].ENDDELAY = 0;
-
-  _pwm->ENABLE = 1;
-}
-
-void HardwarePWM::_start(void)
-{
-  // update sequence count (depending on mode)
-  //  _pwm->SEQ[0].CNT = MAX_CHANNELS;
-
-  // start sequence
-  _pwm->TASKS_SEQSTART[0] = 1;
-}
-
-void HardwarePWM::stop(void)
-{
-  _pwm->ENABLE = 0;
-}
-
 bool HardwarePWM::writeChannel(uint8_t ch, uint16_t value, bool inverted)
 {
   VERIFY( ch < MAX_CHANNELS );
 
   _seq0[ch] = value | (inverted ? 0 : bit(15));
 
-  // Start PWM if not already
+  // Initialize PWM if not already
   if ( !enabled() ) begin();
 
-  _start();
+  // start sequence
+  _pwm->TASKS_SEQSTART[0] = 1;
 
   return true;
 }

cores/nRF5/HardwarePWM.h

@@ -57,8 +57,6 @@ class HardwarePWM
     uint16_t  _max_value;
     uint8_t  _clock_div;
 
-    void _start(void);
-
   public:
     HardwarePWM(NRF_PWM_Type* pwm);
 
@@ -82,9 +80,13 @@ class HardwarePWM
       return this->_owner_token == token;
     }
 
+    // Add a pin to PWM module
     bool addPin     (uint8_t pin);
+
+    // Remove a pin from PWM module
     bool removePin  (uint8_t pin);
 
+    // Get the mapped channel of a pin
     int  pin2channel(uint8_t pin) const
     {
       pin = g_ADigitalPinMap[pin];
@@ -95,6 +97,7 @@ class HardwarePWM
       return (-1);
     }
 
+    // Check if pin is controlled by PWM
     bool checkPin(uint8_t pin) const
     {
       return pin2channel(pin) >= 0;
@@ -117,6 +120,9 @@ class HardwarePWM
     uint8_t freeChannelCount(void) const;
 
     static void DebugOutput(Stream& logger);
+
+  private:
+    void _set_psel(int ch, uint32_t value);
 };
 
 extern HardwarePWM HwPWM0;

cores/nRF5/wiring_analog.cpp

@@ -95,8 +95,8 @@ void analogWrite( uint32_t pin, uint32_t value )
     if ( HwPWMx[i]->isOwner(_analogToken) && HwPWMx[i]->addPin(pin) )
     {
       // successfully added the pin, so write the value also
-      LOG_LV2("Analog", "Added pin %" PRIu32 " to already-owned PWM %d", pin, i);
       HwPWMx[i]->writePin(pin, value);
+      LOG_LV2("Analog", "Added pin %" PRIu32 " to already-owned PWM %d", pin, i);
       return;
     }
   }