Diff: targets/hal/TARGET_NXP/TARGET_LPC176X/gpio_irq_api.c

Revision:

13:0645d8841f51

Parent:

10:3bc89ef62ce7

Child:

21:67d3158c7b56

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_NXP/TARGET_LPC176X/gpio_irq_api.c	Mon Aug 05 14:12:34 2013 +0300
@@ -0,0 +1,144 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stddef.h>
+
+#include "gpio_irq_api.h"
+#include "error.h"
+#include "cmsis.h"
+
+#define CHANNEL_NUM     48
+
+static uint32_t channel_ids[CHANNEL_NUM] = {0};
+static gpio_irq_handler irq_handler;
+
+static void handle_interrupt_in(void) {
+    // Read in all current interrupt registers. We do this once as the
+    // GPIO interrupt registers are on the APB bus, and this is slow.
+    uint32_t rise0 = LPC_GPIOINT->IO0IntStatR;
+    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);
+        }
+    }
+    
+    // P2.0-2.15
+    for (i = 0; i < 16; 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);
+        }
+    }
+
+    // Clear the interrupts we just handled
+    LPC_GPIOINT->IO0IntClr = mask0;
+    LPC_GPIOINT->IO2IntClr = mask2;
+}
+
+int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32_t id) {
+    if (pin == NC) return -1;
+    
+    irq_handler = handler;
+    
+    obj->port = (int)pin & ~0x1F;
+    obj->pin = (int)pin & 0x1F;
+    
+    // Interrupts available only on GPIO0 and GPIO2
+    if (obj->port != LPC_GPIO0_BASE && obj->port != LPC_GPIO2_BASE) {
+        error("pins on this port cannot generate interrupts\n");
+    }
+    
+    // put us in the interrupt table
+    int index = (obj->port == LPC_GPIO0_BASE) ? obj->pin : obj->pin + 32;
+    channel_ids[index] = id;
+    obj->ch = index;
+    
+    NVIC_SetVector(EINT3_IRQn, (uint32_t)handle_interrupt_in);
+    NVIC_EnableIRQ(EINT3_IRQn);
+    return 0;
+}
+
+void gpio_irq_free(gpio_irq_t *obj) {
+    channel_ids[obj->ch] = 0;
+}
+
+void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable) {
+    // ensure nothing is pending
+    switch (obj->port) {
+         case LPC_GPIO0_BASE: LPC_GPIOINT->IO0IntClr = 1 << obj->pin; break;
+         case LPC_GPIO2_BASE: LPC_GPIOINT->IO2IntClr = 1 << obj->pin; break;
+    }
+
+    // enable the pin interrupt
+    if (event == IRQ_RISE) {
+        switch (obj->port) {
+            case LPC_GPIO0_BASE:
+                if (enable) {
+                    LPC_GPIOINT->IO0IntEnR |= 1 << obj->pin;
+                } else {
+                    LPC_GPIOINT->IO0IntEnR &= ~(1 << obj->pin);
+                }
+                break;
+            case LPC_GPIO2_BASE:
+                if (enable) {
+                    LPC_GPIOINT->IO2IntEnR |= 1 << obj->pin;
+                } else {
+                    LPC_GPIOINT->IO2IntEnR &= ~(1 << obj->pin);
+                }
+                break;
+        }
+    } else {
+        switch (obj->port) {
+            case LPC_GPIO0_BASE:
+                if (enable) {
+                    LPC_GPIOINT->IO0IntEnF |= 1 << obj->pin;
+                } else {
+                    LPC_GPIOINT->IO0IntEnF &= ~(1 << obj->pin);
+                }
+                break;
+            case LPC_GPIO2_BASE:
+                if (enable) {
+                    LPC_GPIOINT->IO2IntEnF |= 1 << obj->pin;
+                } else {
+                    LPC_GPIOINT->IO2IntEnF &= ~(1 << obj->pin);
+                }
+                break;
+        }
+    }
+}