Merge pull request #649 from Makuna/interrupts

Interrupt cleanup

Author: igrr

cores/esp8266/Arduino.h

@@ -137,17 +137,29 @@ void timer0_detachInterrupt(void);
 void ets_intr_lock();
 void ets_intr_unlock();
 
-// level (0-15),
-// level 15 will disable ALL interrupts,
-// level 0 will disable most software interrupts
+#ifndef __STRINGIFY
+#define __STRINGIFY(a) #a
+#endif
+
+// these low level routines provide a replacement for SREG interrupt save that AVR uses
+// but are esp8266 specific. A normal use pattern is like
 //
-#define xt_disable_interrupts(state, level) __asm__ __volatile__("rsil %0," __STRINGIFY(level) : "=a" (state))
-#define xt_enable_interrupts(state)  __asm__ __volatile__("wsr %0,ps; isync" :: "a" (state) : "memory")
+//{
+//    uint32_t savedPS = xt_rsil(1); // this routine will allow level 2 and above
+//    // do work here
+//    xt_wsr_ps(savedPS); // restore the state
+//}
+//
+// level (0-15), interrupts of the given level and above will be active
+// level 15 will disable ALL interrupts,
+// level 0 will enable ALL interrupts,
+// 
+#define xt_rsil(level) (__extension__({uint32_t state; __asm__ __volatile__("rsil %0," __STRINGIFY(level) : "=a" (state)); state;}))
+#define xt_wsr_ps(state)  __asm__ __volatile__("wsr %0,ps; isync" :: "a" (state) : "memory")
 
-extern uint32_t interruptsState;
+#define interrupts() xt_rsil(0)
+#define noInterrupts() xt_rsil(15)
 
-#define interrupts() xt_enable_interrupts(interruptsState)
-#define noInterrupts() __asm__ __volatile__("rsil %0,15" : "=a" (interruptsState))
 
 #define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
 #define clockCyclesToMicroseconds(a) ( (a) / clockCyclesPerMicrosecond() )

cores/esp8266/core_esp8266_timer.c

@@ -32,7 +32,13 @@ static volatile timercallback timer1_user_cb = NULL;
 void timer1_isr_handler(void *para){
     if ((T1C & ((1 << TCAR) | (1 << TCIT))) == 0) TEIE &= ~TEIE1;//edge int disable
     T1I = 0;
-    if (timer1_user_cb) timer1_user_cb();
+    if (timer1_user_cb) {
+        // to make ISR compatible to Arduino AVR model where interrupts are disabled
+        // we disable them before we call the client ISR
+        uint32_t savedPS = xt_rsil(15); // stop other interrupts 
+        timer1_user_cb();
+        xt_wsr_ps(savedPS);
+    }
 }
 
 void timer1_isr_init(){
@@ -72,7 +78,11 @@ static volatile timercallback timer0_user_cb = NULL;
 
 void timer0_isr_handler(void* para){
     if (timer0_user_cb) {
+        // to make ISR compatible to Arduino AVR model where interrupts are disabled
+        // we disable them before we call the client ISR
+        uint32_t savedPS = xt_rsil(15); // stop other interrupts
         timer0_user_cb();
+        xt_wsr_ps(savedPS);
     }
 }
 

cores/esp8266/core_esp8266_wiring_digital.c

@@ -123,7 +123,11 @@ void interrupt_handler(void *arg) {
     if (handler->fn && 
         (handler->mode == CHANGE || 
          (handler->mode & 1) == digitalRead(i))) {
+      // to make ISR compatible to Arduino AVR model where interrupts are disabled
+      // we disable them before we call the client ISR
+      uint32_t savedPS = xt_rsil(15); // stop other interrupts 
       handler->fn();
+      xt_wsr_ps(savedPS);
     }
   }
   ETS_GPIO_INTR_ENABLE();
@@ -152,9 +156,6 @@ extern void __detachInterrupt(uint8_t pin) {
   }
 }
 
-// stored state for the noInterrupts/interrupts methods
-uint32_t interruptsState = 0;
-
 void initPins() {
   //Disable UART interrupts
   system_set_os_print(0);

cores/esp8266/interrupts.h

@@ -8,23 +8,51 @@ extern "C" {
 #include "ets_sys.h"
 }
 
-
-#define xt_disable_interrupts(state, level) __asm__ __volatile__("rsil %0," __STRINGIFY(level) : "=a" (state))
-#define xt_enable_interrupts(state)  __asm__ __volatile__("wsr %0,ps; isync" :: "a" (state) : "memory")
+// these auto classes wrap up xt_rsil so your code can be simplier, but can only be
+// used in an ino or cpp files. 
+
+// InterruptLock is used when you want to completely disable locks
+//{
+//    {
+//      InterruptLock lock; 
+//      // do work within interrupt lock here
+//    }
+//    do work outside of interrupt lock here outside its scope
+//}
+//
 
 class InterruptLock {
 public:
     InterruptLock() {
-        xt_disable_interrupts(_state, 15);
+        _state = xt_rsil(15);
     }
 
     ~InterruptLock() {
-        xt_enable_interrupts(_state);
+        xt_wsr_ps(_state);
     }
 
 protected:
     uint32_t _state;
 };
 
+// AutoInterruptLock is when you need to set a specific level, A normal use pattern is like
+//
+//{
+//    {
+//      AutoInterruptLock(1); // this routine will allow level 2 and above
+//      // do work within interrupt lock here
+//    }
+//    do work outside of interrupt lock here outside its scope
+//}
+//
+#define AutoInterruptLock(intrLevel) \
+class _AutoDisableIntr { \
+public: \
+    _AutoDisableIntr() { _savedPS = xt_rsil(intrLevel);  } \
+    ~_AutoDisableIntr() { xt_wsr_ps(_savedPS); } \
+private: \
+    uint32_t _savedPS; \
+    }; \
+_AutoDisableIntr _autoDisableIntr 
 
 #endif //INTERRUPTS_H

libraries/Servo/src/esp8266/Servo.cpp

@@ -59,8 +59,6 @@ static uint8_t s_servoCount = 0;            // the total number of attached s_se
 //------------------------------------------------------------------------------
 template <class T> void Servo_Handler(T* timer)
 {
-    noInterrupts();
-    
     uint8_t servoIndex;
 
     // clear interrupt
@@ -101,8 +99,6 @@ template <class T> void Servo_Handler(T* timer)
 
         timer->setEndOfCycle();
     }
-    
-    interrupts();
 }
 
 static void initISR(ServoTimerSequence timerId)

tools/sdk/include/ets_sys.h

@@ -65,8 +65,8 @@ inline bool ETS_INTR_WITHINISR()
 {
     uint32_t ps;
     __asm__ __volatile__("rsr %0,ps":"=a" (ps));
-    // PS.EXCM bit check
-    return ((ps & (1 << 4)) != 0);
+    // PS.INTLEVEL check
+    return ((ps & 0x0f) != 0);
 }
 
 inline uint32_t ETS_INTR_ENABLED(void)