Diff: targets/TARGET_NXP/TARGET_LPC176X/gpio_irq_api.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NXP/TARGET_LPC176X/gpio_irq_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,161 @@
+/* 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 "mbed_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;
+    uint8_t bitloc;
+    
+    while(rise0 > 0) {      //Continue as long as there are interrupts pending
+        bitloc = 31 - __CLZ(rise0); //CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
+        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;
+    }
+    
+    while(fall0 > 0) {      //Continue as long as there are interrupts pending
+        bitloc = 31 - __CLZ(fall0); //CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
+        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;
+    }
+    
+    //Same for port 2, only we need to watch the channel_index
+    while(rise2 > 0) {      //Continue as long as there are interrupts pending
+        bitloc = 31 - __CLZ(rise2); //CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
+        
+        if (bitloc < 16)            //Not sure if this is actually needed
+            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;
+    }
+    
+    while(fall2 > 0) {      //Continue as long as there are interrupts pending
+        bitloc = 31 - __CLZ(fall2); //CLZ returns number of leading zeros, 31 minus that is location of first pending interrupt
+        
+        if (bitloc < 16)            //Not sure if this is actually needed
+            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) {
+    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");
+    }
+    
+    // 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;
+        }
+    }
+}
+
+void gpio_irq_enable(gpio_irq_t *obj) {
+    NVIC_EnableIRQ(EINT3_IRQn);
+}
+
+void gpio_irq_disable(gpio_irq_t *obj) {
+    NVIC_DisableIRQ(EINT3_IRQn);
+}
+