From 6f793fbb5a9941a59595f74ca2e67ae2d39ae6de Mon Sep 17 00:00:00 2001
From: Chun-Chieh Li <ccli8@nuvoton.com>
Date: Fri, 7 Feb 2020 15:48:57 +0800
Subject: [PATCH] M2351: Fix GPIO rising/falling edge interrupts cannot exist
 simultaneously

---
 .../TARGET_M2351/gpio_irq_api.c               | 41 +++++++++++--------
 targets/TARGET_NUVOTON/TARGET_M2351/objects.h |  1 +
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/gpio_irq_api.c b/targets/TARGET_NUVOTON/TARGET_M2351/gpio_irq_api.c
index a6b2a8be55..5a6e2f8c7a 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/gpio_irq_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/gpio_irq_api.c
@@ -23,6 +23,7 @@
 #include "pinmap.h"
 #include "PeripheralPins.h"
 #include "nu_bitutil.h"
+#include "mbed_assert.h"
 
 #define NU_MAX_PIN_PER_PORT     16
 
@@ -89,6 +90,7 @@ int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32
     }
 
     obj->pin = pin;
+    obj->irq_types = 0;
     obj->irq_handler = (uint32_t) handler;
     obj->irq_id = id;
 
@@ -156,27 +158,32 @@ void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
     uint32_t port_index = NU_PINNAME_TO_PORT(obj->pin);
     GPIO_T *gpio_base = NU_PORT_BASE(port_index);
 
+    /* We assume BSP has such coding so that we can easily add/remove either irq type. */
+    MBED_STATIC_ASSERT(GPIO_INT_BOTH_EDGE == (GPIO_INT_RISING | GPIO_INT_FALLING),
+        "GPIO_INT_BOTH_EDGE must be bitwise OR of GPIO_INT_RISING and GPIO_INT_FALLING");
+    uint32_t irq_type;
     switch (event) {
-    case IRQ_RISE:
-        if (enable) {
-            GPIO_EnableInt(gpio_base, pin_index, GPIO_INT_RISING);
-        } else {
-            gpio_base->INTEN &= ~(GPIO_INT_RISING << pin_index);
-        }
-        break;
+        case IRQ_RISE:
+            irq_type = GPIO_INT_RISING;
+            break;
 
-    case IRQ_FALL:
-        if (enable) {
-            GPIO_EnableInt(gpio_base, pin_index, GPIO_INT_FALLING);
-        } else {
-            gpio_base->INTEN &= ~(GPIO_INT_FALLING << pin_index);
-        }
-        break;
+        case IRQ_FALL:
+            irq_type = GPIO_INT_FALLING;
+            break;
 
-    case IRQ_NONE:
-    default:
-        break;
+        default:
+            irq_type = 0;
     }
+
+    /* We can handle invalid/null irq type. */
+    if (enable) {
+        obj->irq_types |= irq_type;
+    } else {
+        obj->irq_types &= ~irq_type;
+    }
+
+    /* Update irq types */
+    GPIO_EnableInt(gpio_base, pin_index, obj->irq_types);
 }
 
 void gpio_irq_enable(gpio_irq_t *obj)
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/objects.h b/targets/TARGET_NUVOTON/TARGET_M2351/objects.h
index 5bef7dbae2..5755be0f0e 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/objects.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/objects.h
@@ -29,6 +29,7 @@ extern "C" {
 
 struct gpio_irq_s {
     PinName     pin;
+    uint32_t    irq_types;
     uint32_t    irq_handler;
     uint32_t    irq_id;
     struct gpio_irq_s   *next;