Added pin C6 to hardware PWM backlight

quantum/quantum.c

@@ -898,14 +898,29 @@ static const uint8_t backlight_pin = BACKLIGHT_PIN;
 
 // depending on the pin, we use a different output compare unit
 #if BACKLIGHT_PIN == B7
-#  define COM1x1 COM1C1
-#  define OCR1x  OCR1C
+#  define TCCRxA TCCR1A
+#  define TCCRxB TCCR1B
+#  define COMxx1 COM1C1
+#  define OCRxx  OCR1C
+#  define ICRx   ICR1
 #elif BACKLIGHT_PIN == B6
-#  define COM1x1 COM1B1
-#  define OCR1x  OCR1B
+#  define TCCRxA TCCR1A
+#  define TCCRxB TCCR1B
+#  define COMxx1 COM1B1
+#  define OCRxx  OCR1B
+#  define ICRx   ICR1
 #elif BACKLIGHT_PIN == B5
-#  define COM1x1 COM1A1
-#  define OCR1x  OCR1A
+#  define TCCRxA TCCR1A
+#  define TCCRxB TCCR1B
+#  define COMxx1 COM1A1
+#  define OCRxx  OCR1A
+#  define ICRx   ICR1
+#elif BACKLIGHT_PIN == C6
+#  define TCCRxA TCCR3A
+#  define TCCRxB TCCR3B
+#  define COMxx1 COM1A1
+#  define OCRxx  OCR3A
+#  define ICRx   ICR3
 #else
 #  define NO_HARDWARE_PWM
 #endif
@@ -987,7 +1002,7 @@ static uint16_t cie_lightness(uint16_t v) {
 
 // range for val is [0..TIMER_TOP]. PWM pin is high while the timer count is below val.
 static inline void set_pwm(uint16_t val) {
-  OCR1x = val;
+	OCRxx = val;
 }
 
 #ifndef BACKLIGHT_CUSTOM_DRIVER
@@ -998,10 +1013,10 @@ void backlight_set(uint8_t level) {
 
   if (level == 0) {
     // Turn off PWM control on backlight pin
-    TCCR1A &= ~(_BV(COM1x1));
+    TCCRxA &= ~(_BV(COMxx1));
   } else {
     // Turn on PWM control of backlight pin
-    TCCR1A |= _BV(COM1x1);
+    TCCRxA |= _BV(COMxx1);
   }
   // Set the brightness
   set_pwm(cie_lightness(TIMER_TOP * (uint32_t)level / BACKLIGHT_LEVELS));
@@ -1149,11 +1164,10 @@ void backlight_init_ports(void)
   "In fast PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM [..]."
   "In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGMn3:0 = 5, 6, or 7), the value in ICRn (WGMn3:0 = 14), or the value in OCRnA (WGMn3:0 = 15)."
   */
-
-  TCCR1A = _BV(COM1x1) | _BV(WGM11); // = 0b00001010;
-  TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001;
+  TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010;
+  TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001;
   // Use full 16-bit resolution. Counter counts to ICR1 before reset to 0.
-  ICR1 = TIMER_TOP;
+  ICRx = TIMER_TOP;
 
   backlight_init();
   #ifdef BACKLIGHT_BREATHING