Merge pull request #4676 from LMESTM/issue_2959

Correctly enable / disable InterruptIn Edges detection

Author: theotherjimmy

targets/TARGET_STM/gpio_irq_api.c

@@ -90,18 +90,21 @@ static void handle_interrupt_in(uint32_t irq_index, uint32_t max_num_pin_line)
             if (__HAL_GPIO_EXTI_GET_FLAG(pin) != RESET) {
                 __HAL_GPIO_EXTI_CLEAR_FLAG(pin);
 
-                if (gpio_channel->channel_ids[gpio_idx] == 0)
+                if (gpio_channel->channel_ids[gpio_idx] == 0) {
                     continue;
+                }
 
                 // Check which edge has generated the irq
                 if ((gpio->IDR & pin) == 0) {
                     irq_handler(gpio_channel->channel_ids[gpio_idx], IRQ_FALL);
                 } else {
                     irq_handler(gpio_channel->channel_ids[gpio_idx], IRQ_RISE);
                 }
+                return;
             }
         }
     }
+    error("Unexpected Spurious interrupt, index %d\r\n", irq_index);
 }
 
 
@@ -254,18 +257,23 @@ void gpio_irq_free(gpio_irq_t *obj)
 
 void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
 {
+    /*  Enable / Disable Edge triggered interrupt and store event */
     if (event == IRQ_RISE) {
         if (enable) {
             LL_EXTI_EnableRisingTrig_0_31(1 << STM_PIN(obj->pin));
+            obj->event |= IRQ_RISE;
         } else {
             LL_EXTI_DisableRisingTrig_0_31(1 << STM_PIN(obj->pin));
+            obj->event &= ~IRQ_RISE;
         }
     }
     if (event == IRQ_FALL) {
         if (enable) {
             LL_EXTI_EnableFallingTrig_0_31(1 << STM_PIN(obj->pin));
+            obj->event |= IRQ_FALL;
         } else {
             LL_EXTI_DisableFallingTrig_0_31(1 << STM_PIN(obj->pin));
+            obj->event &= ~IRQ_FALL;
         }
     }
 }
@@ -284,14 +292,23 @@ void gpio_irq_enable(gpio_irq_t *obj)
 
     LL_EXTI_EnableIT_0_31(1 << pin_index);
 
+    /* Restore previous edge interrupt configuration if applicable */
+    if (obj->event & IRQ_RISE) {
+        LL_EXTI_EnableRisingTrig_0_31(1 << STM_PIN(obj->pin));
+    }
+    if (obj->event & IRQ_FALL) {
+        LL_EXTI_EnableFallingTrig_0_31(1 << STM_PIN(obj->pin));
+    }
+
     NVIC_EnableIRQ(obj->irq_n);
 }
 
 void gpio_irq_disable(gpio_irq_t *obj)
 {
     /* Clear EXTI line configuration */
+    LL_EXTI_DisableRisingTrig_0_31(1 << STM_PIN(obj->pin));
+    LL_EXTI_DisableFallingTrig_0_31(1 << STM_PIN(obj->pin));
     LL_EXTI_DisableIT_0_31(1 << STM_PIN(obj->pin));
     NVIC_DisableIRQ(obj->irq_n);
     NVIC_ClearPendingIRQ(obj->irq_n);
-    obj->event = EDGE_NONE;
 }