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-rw-r--r--lib/exti.c191
1 files changed, 100 insertions, 91 deletions
diff --git a/lib/exti.c b/lib/exti.c
index ccef676..df7f4cb 100644
--- a/lib/exti.c
+++ b/lib/exti.c
@@ -22,110 +22,119 @@
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;
- }
+ 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;
+ /* 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;
-}
+ /* Disable interrupts. */
+ EXTI_IMR &= ~extis;
+
+ /* Disable events. */
+ EXTI_EMR &= ~extis;
+}
/*
-Reset the interrupt request by writing a 1 to the corresponding
-pending bit register
-*/
+ * Reset the interrupt request by writing a 1 to the corresponding
+ * pending bit register.
+ */
void exti_reset_request(u32 extis)
{
- EXTI_PR |= 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 */
+/*
+ * 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
+ 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);
+}