fixed some bugs about interrupt

When I used the pin's interrupt, I always get a FALSE state.
So I read the drv_gpio.c and has found that function gpio_exti_source_select has not  truly set yet and the GPIO input mode and the EXTI_(bitno) should be correct.

bsp/gd32vf103v-eval/drivers/drv_gpio.c

@@ -350,8 +350,6 @@ static rt_err_t gd32vf_pin_irq_enable(struct rt_device *device, rt_base_t pin,
         return RT_ENOSYS;
     }
 
-        /* configure pin as input */
-    gpio_init(index->gpio_periph, GPIO_MODE_IN_FLOATING, GPIO_OSPEED_50MHZ, index->pin);
     if (enabled == PIN_IRQ_ENABLE)
     {
         irqindex = bit2bitno(index->pin);
@@ -372,24 +370,31 @@ static rt_err_t gd32vf_pin_irq_enable(struct rt_device *device, rt_base_t pin,
 
         /* enable and set EXTI interrupt to the lowest priority */
         eclic_irq_enable(irqmap->irqno, 1, 1);
-        gpio_exti_source_select(GPIO_PORT_SOURCE_GPIOA, GPIO_PIN_SOURCE_0);
+        /* select SOURCE_PORT_x and SOURCE_PIN_x */
+        gpio_exti_source_select(index->index >> 4, irqindex);
         /* Configure GPIO_InitStructure */
         switch (pin_irq_hdr_tab[irqindex].mode)
         {
         case PIN_IRQ_MODE_RISING:
+            gpio_init( index->gpio_periph, GPIO_MODE_IPD, GPIO_OSPEED_50MHZ,
+                     index->pin );
             exti_init(EXTI_(irqindex), EXTI_INTERRUPT, EXTI_TRIG_RISING);
             break;
         case PIN_IRQ_MODE_FALLING:
+            gpio_init( index->gpio_periph, GPIO_MODE_IPU, GPIO_OSPEED_50MHZ,
+                     index->pin );
             exti_init(EXTI_(irqindex), EXTI_INTERRUPT, EXTI_TRIG_FALLING);
             break;
         case PIN_IRQ_MODE_RISING_FALLING:
+            gpio_init(index->gpio_periph, GPIO_MODE_IN_FLOATING, GPIO_OSPEED_50MHZ,
+                     index->pin);
             exti_init(EXTI_(irqindex), EXTI_INTERRUPT, EXTI_TRIG_BOTH);
             break;
         }
 
         pin_irq_enable_mask |= irqmap->pinbit;
-
-        exti_interrupt_flag_clear(EXTI_(index->pin));
+        /* irqindex should be bitno and then EXTI_(x) can be the bit */
+        exti_interrupt_flag_clear(EXTI_(irqindex));
 
         rt_hw_interrupt_enable(level);
     }
@@ -408,7 +413,7 @@ static rt_err_t gd32vf_pin_irq_enable(struct rt_device *device, rt_base_t pin,
         pin_irq_enable_mask &= ~irqmap->pinbit;
 
         eclic_irq_disable(irqmap->irqno);
-        exti_interrupt_flag_clear(EXTI_(index->pin));
+        exti_interrupt_flag_clear(EXTI_(irqindex));
 
         rt_hw_interrupt_enable(level);
     }