aboutsummaryrefslogtreecommitdiff
path: root/lib/stm32/exti.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/stm32/exti.c')
-rw-r--r--lib/stm32/exti.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/lib/stm32/exti.c b/lib/stm32/exti.c
new file mode 100644
index 0000000..df7f4cb
--- /dev/null
+++ b/lib/stm32/exti.c
@@ -0,0 +1,140 @@
+/*
+ * 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, 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)
+ 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);
+}