InterruptIn.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "drivers/InterruptIn.h"
00017 
00018 #if DEVICE_INTERRUPTIN
00019 
00020 namespace mbed {
00021 
00022 static void donothing() {}
00023 
00024 InterruptIn::InterruptIn(PinName pin) : gpio(),
00025                                         gpio_irq(),
00026                                         _rise(),
00027                                         _fall() {
00028     // No lock needed in the constructor
00029 
00030     _rise.attach(donothing);
00031     _fall.attach(donothing);
00032 
00033     gpio_irq_init(&gpio_irq, pin, (&InterruptIn::_irq_handler), (uint32_t)this);
00034     gpio_init_in(&gpio, pin);
00035 }
00036 
00037 InterruptIn::~InterruptIn() {
00038     // No lock needed in the destructor
00039     gpio_irq_free(&gpio_irq);
00040 }
00041 
00042 int InterruptIn::read() {
00043     // Read only
00044     return gpio_read(&gpio);
00045 }
00046 
00047 void InterruptIn::mode(PinMode pull) {
00048     core_util_critical_section_enter();
00049     gpio_mode(&gpio, pull);
00050     core_util_critical_section_exit();
00051 }
00052 
00053 void InterruptIn::rise(Callback<void()> func) {
00054     core_util_critical_section_enter();
00055     if (func) {
00056         _rise.attach(func);
00057         gpio_irq_set(&gpio_irq, IRQ_RISE, 1);
00058     } else {
00059         _rise.attach(donothing);
00060         gpio_irq_set(&gpio_irq, IRQ_RISE, 0);
00061     }
00062     core_util_critical_section_exit();
00063 }
00064 
00065 void InterruptIn::fall(Callback<void()> func) {
00066     core_util_critical_section_enter();
00067     if (func) {
00068         _fall.attach(func);
00069         gpio_irq_set(&gpio_irq, IRQ_FALL, 1);
00070     } else {
00071         _fall.attach(donothing);
00072         gpio_irq_set(&gpio_irq, IRQ_FALL, 0);
00073     }
00074     core_util_critical_section_exit();
00075 }
00076 
00077 void InterruptIn::_irq_handler(uint32_t id, gpio_irq_event event) {
00078     InterruptIn *handler = (InterruptIn*)id;
00079     switch (event) {
00080         case IRQ_RISE: handler->_rise.call(); break;
00081         case IRQ_FALL: handler->_fall.call(); break;
00082         case IRQ_NONE: break;
00083     }
00084 }
00085 
00086 void InterruptIn::enable_irq() {
00087     core_util_critical_section_enter();
00088     gpio_irq_enable(&gpio_irq);
00089     core_util_critical_section_exit();
00090 }
00091 
00092 void InterruptIn::disable_irq() {
00093     core_util_critical_section_enter();
00094     gpio_irq_disable(&gpio_irq);
00095     core_util_critical_section_exit();
00096 }
00097 
00098 InterruptIn::operator int() {
00099     // Underlying call is atomic
00100     return read();
00101 }
00102 
00103 } // namespace mbed
00104 
00105 #endif