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-rw-r--r--lib/exti.c131
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diff --git a/lib/exti.c b/lib/exti.c
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+/*
+ * 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
+} \ No newline at end of file