mbed-os/targets/TARGET_NXP/TARGET_LPC81X/gpio_irq_api.c

136 lines
4.1 KiB
C

/* 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 "mbed_error.h"
#define CHANNEL_NUM 8
#define LPC_GPIO_X LPC_PIN_INT
#define PININT_IRQ PININT0_IRQn
static uint32_t channel_ids[CHANNEL_NUM] = {0};
static gpio_irq_handler irq_handler;
static inline void handle_interrupt_in(uint32_t channel) {
uint32_t ch_bit = (1 << channel);
// Return immediately if:
// * The interrupt was already served
// * There is no user handler
// * It is a level interrupt, not an edge interrupt
if ( ((LPC_GPIO_X->IST & ch_bit) == 0) ||
(channel_ids[channel] == 0 ) ||
(LPC_GPIO_X->ISEL & ch_bit ) ) return;
if ((LPC_GPIO_X->IENR & ch_bit) && (LPC_GPIO_X->RISE & ch_bit)) {
irq_handler(channel_ids[channel], IRQ_RISE);
LPC_GPIO_X->RISE = ch_bit;
}
if ((LPC_GPIO_X->IENF & ch_bit) && (LPC_GPIO_X->FALL & ch_bit)) {
irq_handler(channel_ids[channel], IRQ_FALL);
}
LPC_GPIO_X->IST = ch_bit;
}
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);}
void gpio_irq4(void) {handle_interrupt_in(4);}
void gpio_irq5(void) {handle_interrupt_in(5);}
void gpio_irq6(void) {handle_interrupt_in(6);}
void gpio_irq7(void) {handle_interrupt_in(7);}
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;
int found_free_channel = 0;
int i = 0;
for (i=0; i<CHANNEL_NUM; i++) {
if (channel_ids[i] == 0) {
channel_ids[i] = id;
obj->ch = i;
found_free_channel = 1;
break;
}
}
if (!found_free_channel) return -1;
/* Enable AHB clock to the GPIO domain. */
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<6);
LPC_SYSCON->PINTSEL[obj->ch] = pin;
// Interrupt Wake-Up Enable
LPC_SYSCON->STARTERP0 |= 1 << obj->ch;
void (*channels_irq)(void) = NULL;
switch (obj->ch) {
case 0: channels_irq = &gpio_irq0; break;
case 1: channels_irq = &gpio_irq1; break;
case 2: channels_irq = &gpio_irq2; break;
case 3: channels_irq = &gpio_irq3; break;
case 4: channels_irq = &gpio_irq4; break;
case 5: channels_irq = &gpio_irq5; break;
case 6: channels_irq = &gpio_irq6; break;
case 7: channels_irq = &gpio_irq7; break;
}
NVIC_SetVector((IRQn_Type)(PININT_IRQ + obj->ch), (uint32_t)channels_irq);
NVIC_EnableIRQ((IRQn_Type)(PININT_IRQ + obj->ch));
return 0;
}
void gpio_irq_free(gpio_irq_t *obj) {
channel_ids[obj->ch] = 0;
LPC_SYSCON->STARTERP0 &= ~(1 << obj->ch);
}
void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable) {
unsigned int ch_bit = (1 << obj->ch);
// Clear interrupt
if (!(LPC_GPIO_X->ISEL & ch_bit))
LPC_GPIO_X->IST = ch_bit;
// Edge trigger
LPC_GPIO_X->ISEL &= ~ch_bit;
if (event == IRQ_RISE) {
if (enable) {
LPC_GPIO_X->IENR |= ch_bit;
} else {
LPC_GPIO_X->IENR &= ~ch_bit;
}
} else {
if (enable) {
LPC_GPIO_X->IENF |= ch_bit;
} else {
LPC_GPIO_X->IENF &= ~ch_bit;
}
}
}
void gpio_irq_enable(gpio_irq_t *obj) {
NVIC_EnableIRQ((IRQn_Type)(PININT_IRQ + obj->ch));
}
void gpio_irq_disable(gpio_irq_t *obj) {
NVIC_DisableIRQ((IRQn_Type)(PININT_IRQ + obj->ch));
}