[LPC176x] Endstop Interrupts Feature (#11202)

Enable the endstop interrupts feature for LPC176x boards. Although Smoothieboard chose to use non-interrupt capable pins for their endstops, and this has been copied by clones, so they can't use it.

Marlin/src/HAL/HAL_LPC1768/WInterrupts.cpp

@@ -19,29 +19,20 @@
 #ifdef TARGET_LPC1768
 
 #include "../../inc/MarlinConfig.h"
-#include <Arduino.h>
-#include <pinmapping.h>
-//#include "HAL_timers.h"
-#include "fastio.h"
 
 #define GNUM 31
 
 typedef void (*interruptCB)(void);
 
-static interruptCB callbacksP0[GNUM];
+static interruptCB callbacksP0[GNUM] = {};
-static interruptCB callbacksP2[GNUM];
+static interruptCB callbacksP2[GNUM] = {};
 
 extern "C" void GpioEnableInt(const uint32_t port, const uint32_t pin, const uint32_t mode);
 extern "C" void GpioDisableInt(const uint32_t port, const uint32_t pin);
 
-//void deadloop(void) {}
 
-/* Configure PIO interrupt sources */
 static void __initialize() {
-  for (uint8_t i = 0; i < GNUM; i++) {
+  NVIC_SetPriority(EINT3_IRQn, NVIC_EncodePriority(0, 1, 0));
-    callbacksP0[i] = 0;
-    callbacksP2[i] = 0;
-  }
   NVIC_EnableIRQ(EINT3_IRQn);
 }
 
@@ -54,6 +45,7 @@ void attachInterrupt(const pin_t pin, void (*callback)(void), uint32_t mode) {
     __initialize();
     ++enabled;
   }
+
   uint8_t myport = LPC1768_PIN_PORT(pin),
           mypin = LPC1768_PIN_PIN(pin);
 
@@ -130,60 +122,41 @@ extern "C" void GpioDisableInt(const uint32_t port, const uint32_t pin) {
   }
 }
 
-constexpr bool isPowerOf2(const uint16_t n) {
+extern "C" void EINT3_IRQHandler(void) {
-  return IS_POWER_OF_2(n);
-}
-
-#if 0
-  extern "C" void EINT3_IRQHandler () {
-    LPC_GPIOINT->IO0IntClr = LPC_GPIOINT->IO2IntClr = 0xFFFFFFFF;
-    TOGGLE(13);
-    //NVIC_ClearPendingIRQ(EINT3_IRQn);
-  }
-#else
-
-  extern "C" void EINT3_IRQHandler(void) {
   // Read in all current interrupt registers. We do this once as the
   // GPIO interrupt registers are on the APB bus, and this is slow.
   uint32_t rise0 = LPC_GPIOINT->IO0IntStatR,
            fall0 = LPC_GPIOINT->IO0IntStatF,
            rise2 = LPC_GPIOINT->IO2IntStatR,
            fall2 = LPC_GPIOINT->IO2IntStatF;
+
   // Clear the interrupts ASAP
   LPC_GPIOINT->IO0IntClr = LPC_GPIOINT->IO2IntClr = 0xFFFFFFFF;
   NVIC_ClearPendingIRQ(EINT3_IRQn);
 
-    /* multiple pins changes happened.*/
+  while (rise0 > 0) {                                       // If multiple pins changes happened continue as long as there are interrupts pending
-    if (rise0) while (rise0 > 0) {      // Continue as long as there are interrupts pending
+    const uint8_t bitloc = 31 - __CLZ(rise0);               // CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
-      const uint8_t bitloc = 31 - __CLZ(rise0); //CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
     if (callbacksP0[bitloc] != NULL) callbacksP0[bitloc]();
     rise0 -= _BV(bitloc);
   }
 
-    if (fall0) while (fall0 > 0) {
+  while (fall0 > 0) {
     const uint8_t bitloc = 31 - __CLZ(fall0);
     if (callbacksP0[bitloc] != NULL) callbacksP0[bitloc]();
     fall0 -= _BV(bitloc);
   }
 
-    if (rise2) while(rise2 > 0) {
+  while(rise2 > 0) {
     const uint8_t bitloc = 31 - __CLZ(rise2);
     if (callbacksP2[bitloc] != NULL) callbacksP2[bitloc]();
-      //LPC_GPIOINT->IO2IntClr = 1 << bitloc;
     rise2 -= _BV(bitloc);
   }
 
-    if (fall2) while (fall2 > 0) {
+  while (fall2 > 0) {
     const uint8_t bitloc = 31 - __CLZ(fall2);
     if (callbacksP2[bitloc] != NULL) callbacksP2[bitloc]();
-      //LPC_GPIOINT->IO2IntClr = 1 << bitloc;
     fall2 -= _BV(bitloc);
   }
-    //NVIC_ClearPendingIRQ(EINT3_IRQn);
+}
-    //LPC_GPIOINT->IO0IntClr = LPC_GPIOINT->IO2IntClr = 0xFFFFFFFF;
-    //NVIC_ClearPendingIRQ(EINT3_IRQn);
-  }
-
-#endif
 
 #endif // TARGET_LPC1768

Marlin/src/HAL/HAL_LPC1768/endstop_interrupts.h

@@ -37,9 +37,6 @@
 #ifndef _ENDSTOP_INTERRUPTS_H_
 #define _ENDSTOP_INTERRUPTS_H_
 
-//Currently this is untested and broken
-#error "Please disable Endstop Interrupts LPC176x is currently an unsupported platform"
-
 #include "../../module/endstops.h"
 
 // One ISR for all EXT-Interrupts
@@ -47,30 +44,57 @@ void endstop_ISR(void) { endstops.update(); }
 
 void setup_endstop_interrupts(void) {
   #if HAS_X_MAX
-    attachInterrupt(digitalPinToInterrupt(X_MAX_PIN), endstop_ISR, CHANGE); // assign it
+    #if !LPC1768_PIN_INTERRUPT_M(X_MAX_PIN)
+      #error "X_MAX_PIN is not an INTERRUPT capable pin."
+    #endif
+    attachInterrupt(digitalPinToInterrupt(X_MAX_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_X_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(X_MIN_PIN)
+      #error "X_MIN_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(X_MIN_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Y_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(Y_MAX_PIN)
+      #error "Y_MAX_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Y_MAX_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Y_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(Y_MIN_PIN)
+      #error "Y_MIN_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Y_MIN_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Z_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(Z_MAX_PIN)
+      #error "Z_MAX_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Z_MAX_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Z_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(Z_MIN_PIN)
+      #error "Z_MIN_PIN is not an INTERRUPT capable pin."
+    #endif
      attachInterrupt(digitalPinToInterrupt(Z_MIN_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Z2_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(Z2_MAX_PIN)
+      #error "Z2_MAX_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Z2_MAX_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Z2_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(Z2_MIN_PIN)
+      #error "Z2_MIN_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Z2_MIN_PIN), endstop_ISR, CHANGE);
   #endif
   #if HAS_Z_MIN_PROBE_PIN
+    #if !LPC1768_PIN_INTERRUPT_M(Z_MIN_PROBE_PIN)
+      #error "Z_MIN_PROBE_PIN is not an INTERRUPT capable pin."
+    #endif
     attachInterrupt(digitalPinToInterrupt(Z_MIN_PROBE_PIN), endstop_ISR, CHANGE);
   #endif
 }

Marlin/src/HAL/HAL_LPC1768/include/pinmapping.h

@@ -267,7 +267,7 @@ constexpr pin_t adc_pin_table[] = {
 
 // Get the digital pin for an analog index
 pin_t analogInputToDigitalPin(const int8_t p);
-
+#define digitalPinToInterrupt(pin) (pin)
 // Return the index of a pin number
 // The pin number given here is in the form ppp:nnnnn
 int16_t GET_PIN_MAP_INDEX(const pin_t pin);
@@ -283,6 +283,7 @@ bool PWM_PIN(const pin_t p);
 
 // Test whether the pin is interruptable
 bool INTERRUPT_PIN(const pin_t p);
+#define LPC1768_PIN_INTERRUPT_M(pin) (((pin >> 8) & 0b1) != 0)
 
 // Get the pin number at the given index
 pin_t GET_PIN_MAP_PIN(const int16_t ind);