Diff: targets/hal/TARGET_NXP/TARGET_LPC408X/gpio_irq_api.c

Revision:

29:6ac4027eff2b

Parent:

15:4892fe388435

Child:

35:371630885ad6

--- a/targets/hal/TARGET_NXP/TARGET_LPC408X/gpio_irq_api.c	Fri Sep 20 10:00:04 2013 +0100
+++ b/targets/hal/TARGET_NXP/TARGET_LPC408X/gpio_irq_api.c	Mon Sep 23 11:30:07 2013 +0100
@@ -30,44 +30,66 @@
     uint32_t fall0 = LPC_GPIOINT->IO0IntStatF;
     uint32_t rise2 = LPC_GPIOINT->IO2IntStatR;
     uint32_t fall2 = LPC_GPIOINT->IO2IntStatF;
-    uint32_t mask0 = 0;
-    uint32_t mask2 = 0;
-    int i;
-    
-    // P0.0-0.31
-    for (i = 0; i < 32; i++) {
-        uint32_t pmask = (1 << i);
-        if (rise0 & pmask) {
-            mask0 |= pmask;
-            if (channel_ids[i] != 0)
-                irq_handler(channel_ids[i], IRQ_RISE);
-        }
-        if (fall0 & pmask) {
-            mask0 |= pmask;
-            if (channel_ids[i] != 0)
-                irq_handler(channel_ids[i], IRQ_FALL);
-        }
+
+    uint8_t bitloc;
+
+    // Continue as long as there are interrupts pending
+    while(rise0 > 0) {
+        // CLZ returns number of leading zeros, 31 minus that is location of
+        // first pending interrupt
+        bitloc = 31 - __CLZ(rise0);
+        if (channel_ids[bitloc] != 0)
+            irq_handler(channel_ids[bitloc], IRQ_RISE); //Run that interrupt
+
+        // Both clear the interrupt with clear register, and remove it from
+        // our local copy of the interrupt pending register
+        LPC_GPIOINT->IO0IntClr = 1 << bitloc;
+        rise0 -= 1<<bitloc;
+    }
+
+    // Continue as long as there are interrupts pending
+    while(fall0 > 0) {
+        // CLZ returns number of leading zeros, 31 minus that is location of
+        // first pending interrupt
+        bitloc = 31 - __CLZ(fall0);
+        if (channel_ids[bitloc] != 0)
+            irq_handler(channel_ids[bitloc], IRQ_FALL); //Run that interrupt
+
+        // Both clear the interrupt with clear register, and remove it from
+        // our local copy of the interrupt pending register
+        LPC_GPIOINT->IO0IntClr = 1 << bitloc;
+        fall0 -= 1<<bitloc;
     }
-    
-    // P2.0-2.31
-    for (i = 0; i < 32; i++) {
-        uint32_t pmask = (1 << i);
-        int channel_index = i + 32;
-        if (rise2 & pmask) {
-            mask2 |= pmask;
-            if (channel_ids[channel_index] != 0)
-                irq_handler(channel_ids[channel_index], IRQ_RISE);
-        }
-        if (fall2 & pmask) {
-            mask2 |= pmask;
-            if (channel_ids[channel_index] != 0)
-                irq_handler(channel_ids[channel_index], IRQ_FALL);
-        }
+
+    // Same for port 2
+
+    // Continue as long as there are interrupts pending
+    while(rise2 > 0) {
+        // CLZ returns number of leading zeros, 31 minus that is location of
+        // first pending interrupt
+        bitloc = 31 - __CLZ(rise2);
+        if (channel_ids[bitloc+32] != 0)
+            irq_handler(channel_ids[bitloc+32], IRQ_RISE); //Run that interrupt
+
+        // Both clear the interrupt with clear register, and remove it from
+        // our local copy of the interrupt pending register
+        LPC_GPIOINT->IO2IntClr = 1 << bitloc;
+        rise2 -= 1<<bitloc;
     }
-    
-    // Clear the interrupts we just handled
-    LPC_GPIOINT->IO0IntClr = mask0;
-    LPC_GPIOINT->IO2IntClr = mask2;
+
+    // Continue as long as there are interrupts pending
+    while(fall2 > 0) {
+        // CLZ returns number of leading zeros, 31 minus that is location of
+        // first pending interrupt
+        bitloc = 31 - __CLZ(fall2);
+        if (channel_ids[bitloc+32] != 0)
+            irq_handler(channel_ids[bitloc+32], IRQ_FALL); //Run that interrupt
+
+        // Both clear the interrupt with clear register, and remove it from
+        // our local copy of the interrupt pending register
+        LPC_GPIOINT->IO2IntClr = 1 << bitloc;
+        fall2 -= 1<<bitloc;
+    }
 }
 
 int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32_t id) {