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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2010 Mark Butler <mbutler@physics.otago.ac.nz>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/exti.h>
#include <libopencm3/stm32/f2/syscfg.h>
#include <libopencm3/stm32/f2/gpio.h>
void exti_set_trigger(u32 extis, exti_trigger_type trig)
{
switch (trig) {
case EXTI_TRIGGER_RISING:
EXTI_RTSR |= extis;
EXTI_FTSR &= ~extis;
break;
case EXTI_TRIGGER_FALLING:
EXTI_RTSR &= ~extis;
EXTI_FTSR |= extis;
break;
case EXTI_TRIGGER_BOTH:
EXTI_RTSR |= extis;
EXTI_FTSR |= extis;
break;
}
}
void exti_enable_request(u32 extis)
{
/* Enable interrupts. */
EXTI_IMR |= extis;
/* Enable events. */
EXTI_EMR |= extis;
}
void exti_disable_request(u32 extis)
{
/* Disable interrupts. */
EXTI_IMR &= ~extis;
/* Disable events. */
EXTI_EMR &= ~extis;
}
/*
* Reset the interrupt request by writing a 1 to the corresponding
* pending bit register.
*/
void exti_reset_request(u32 extis)
{
EXTI_PR = extis;
}
/*
* Remap an external interrupt line to the corresponding pin on the
* specified GPIO port.
*
* TODO: This could be rewritten in fewer lines of code.
*/
void exti_select_source(u32 exti, u32 gpioport)
{
u8 shift, bits;
shift = bits = 0;
switch (exti) {
case EXTI0:
case EXTI4:
case EXTI8:
case EXTI12:
shift = 0;
break;
case EXTI1:
case EXTI5:
case EXTI9:
case EXTI13:
shift = 4;
break;
case EXTI2:
case EXTI6:
case EXTI10:
case EXTI14:
shift = 8;
break;
case EXTI3:
case EXTI7:
case EXTI11:
case EXTI15:
shift = 12;
break;
}
switch (gpioport) {
case GPIOA:
bits = 0xf;
break;
case GPIOB:
bits = 0xe;
break;
case GPIOC:
bits = 0xd;
break;
case GPIOD:
bits = 0xc;
break;
case GPIOE:
bits = 0xb;
break;
case GPIOF:
bits = 0xa;
break;
case GPIOG:
bits = 0x9;
break;
}
/* Ensure that only valid EXTI lines are used. */
if (exti < EXTI4) {
SYSCFG_EXTICR1 &= ~(0x000F << shift);
SYSCFG_EXTICR1 |= (~bits << shift);
} else if (exti < EXTI8) {
SYSCFG_EXTICR2 &= ~(0x000F << shift);
SYSCFG_EXTICR2 |= (~bits << shift);
} else if (exti < EXTI12) {
SYSCFG_EXTICR3 &= ~(0x000F << shift);
SYSCFG_EXTICR3 |= (~bits << shift);
} else if (exti < EXTI16) {
SYSCFG_EXTICR4 &= ~(0x000F << shift);
SYSCFG_EXTICR4 |= (~bits << shift);
}
}