blackmagic/lib/exti.c
Thomas Otto 388f940475 Initial EXTI support.
Thanks to Mark Butler <mbutler@physics.otago.ac.nz>.
2010-05-12 18:12:31 +02:00

131 lines
2.8 KiB
C

/*
* This file is part of the libopenstm32 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 <libopenstm32/exti.h>
#include <libopenstm32/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 less lines of code */
void exti_select_source(u32 exti, u32 gpioport)
{
u8 shift =0;
u8 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;
}
if(exti < EXTI4) AFIO_EXTICR1 &=~ ( bits << shift );
else if (exti < EXTI8) AFIO_EXTICR2 &=~ ( bits << shift );
else if (exti < EXTI12) AFIO_EXTICR3 &=~ ( bits << shift );
else if (exti < EXTI16) AFIO_EXTICR4 &=~ ( bits << shift ); //ensure that only valid EXTI lines are used
}