/* 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 "cmsis.h" #include "gpio_irq_api.h" #include "error.h" #include "gpio_api.h" // The chip is capable of 4 external interrupts. #define CHANNEL_NUM 4 static uint32_t channel_ids[CHANNEL_NUM] = {0}; static gpio_irq_handler irq_handler; static PinName pin_names[CHANNEL_NUM] = {}; static uint8_t trigger_events[CHANNEL_NUM] = {}; static inline void handle_interrupt_in(uint32_t channel) { // Find out whether the interrupt has been triggered by a high or low value... // As the LPC1114 doesn't have a specific register for this, we'll just have to read // the level of the pin as if it were just a normal input... // Get the number of the pin being used and the port typedef LPC_GPIO_TypeDef *port_reg = ((LPC_GPIO_TypeDef *) (LPC_GPIO0_BASE + (((pin_names[channel] & 0xF000) >> PORT_SHIFT) * 0x10000))); uint8_t pin_num = (pin_names[channel] & (0x0f << PIN_SHIFT)) >> PIN_SHIFT; uint8_t trigger_event = trigger_events[channel]; if (trigger_event == 1) irq_handler(channel_ids[channel], IRQ_RISE); else if (trigger_event == 2) irq_handler(channel_ids[channel], IRQ_FALL); else { // In order to get an idea of which kind of event it is, // We need to read the logic level of the pin... uint8_t logic = (port_reg->DATA & (1 << pin_num)) >> pin_num; if (logic == 1) irq_handler(channel_ids[channel], IRQ_RISE); else irq_handler(channel_ids[channel], IRQ_FALL); } // Clear the interrupt... port_reg->IC |= 1 << pin_num; } void gpio_irq0(void) {handle_interrupt_in(0);} void gpio_irq1(void) {handle_interrupt_in(1);} void gpio_irq2(void) {handle_interrupt_in(2);} void gpio_irq3(void) {handle_interrupt_in(3);} int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32_t id) { if (pin == NC) return -1; // Firstly, we'll put some data in *obj so we can keep track of stuff. obj->pin = pin; // Set the handler to be the pointer at the top... irq_handler = handler; // Which port are we using? int channel; uint32_t port_reg = (LPC_GPIO0_BASE + (((pin & 0xF000) >> PORT_SHIFT) * 0x10000)); switch (port_reg) { case LPC_GPIO0_BASE: NVIC_SetVector(EINT0_IRQn, (uint32_t)gpio_irq0); NVIC_EnableIRQ(EINT0_IRQn); channel = 0; break; case LPC_GPIO1_BASE: NVIC_SetVector(EINT1_IRQn, (uint32_t)gpio_irq1); NVIC_EnableIRQ(EINT1_IRQn); channel = 1; break; case LPC_GPIO2_BASE: NVIC_SetVector(EINT2_IRQn, (uint32_t)gpio_irq2); NVIC_EnableIRQ(EINT2_IRQn); channel = 2; break; case LPC_GPIO3_BASE: NVIC_SetVector(EINT3_IRQn, (uint32_t)gpio_irq3); NVIC_EnableIRQ(EINT3_IRQn); channel = 3; break; default: channel = -1; error("Invalid interrupt choice."); break; } channel_ids[channel] = id; pin_names[channel] = pin; obj->ch = channel; 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) { // Firstly, check if there is an existing event stored... LPC_GPIO_TypeDef *port_reg = ((LPC_GPIO_TypeDef *) (LPC_GPIO0_BASE + (((obj->pin & 0xF000) >> PORT_SHIFT) * 0x10000))); // Need to get the pin number of the pin, not the value of the enum uint8_t pin_num = (obj->pin & (0x0f << PIN_SHIFT)) >> PIN_SHIFT; if (trigger_events[obj->ch] != 0) { // We have an event. // Enable both edge interrupts. if (enable) { trigger_events[obj->ch] = 3; port_reg->IBE |= 1 << pin_num; port_reg->IE |= 1 << pin_num; } else { // These all need to be opposite, to reenable the other one. trigger_events[obj->ch] = event == IRQ_RISE ? 2 : 1; port_reg->IBE &= ~(1 << pin_num); if (event == IRQ_RISE) port_reg->IEV &= ~(1 << pin_num); else port_reg->IEV |= 1 << pin_num; port_reg->IE |= 1 << pin_num; } } else { if (enable) { trigger_events[obj->ch] = event == IRQ_RISE ? 1 : 2; port_reg->IE |= 1 << pin_num; } // One edge port_reg->IBE &= ~(1 << pin_num); // Rising/falling? if (event == IRQ_RISE) port_reg->IEV |= 1 << pin_num; else port_reg->IEV &= ~(1 << pin_num); } // Clear port_reg->IC |= 1 << pin_num; // Make it edge sensitive. port_reg->IS &= ~(1 << pin_num); }