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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Perry Hung.
* Copyright (c) 2011, 2012 LeafLabs, LLC.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file libmaple/exti.c
* @brief External interrupt control routines
*/
#include <libmaple/exti.h>
#include <libmaple/libmaple.h>
#include <libmaple/nvic.h>
#include <libmaple/bitband.h>
static inline void dispatch_single_exti(uint32 exti_num);
static inline void dispatch_extis(uint32 start, uint32 stop);
/*
* Internal state
*/
typedef struct exti_channel {
void (*handler)(void *);
void *arg;
} exti_channel;
static exti_channel exti_channels[] = {
{ .handler = NULL, .arg = NULL }, // EXTI0
{ .handler = NULL, .arg = NULL }, // EXTI1
{ .handler = NULL, .arg = NULL }, // EXTI2
{ .handler = NULL, .arg = NULL }, // EXTI3
{ .handler = NULL, .arg = NULL }, // EXTI4
{ .handler = NULL, .arg = NULL }, // EXTI5
{ .handler = NULL, .arg = NULL }, // EXTI6
{ .handler = NULL, .arg = NULL }, // EXTI7
{ .handler = NULL, .arg = NULL }, // EXTI8
{ .handler = NULL, .arg = NULL }, // EXTI9
{ .handler = NULL, .arg = NULL }, // EXTI10
{ .handler = NULL, .arg = NULL }, // EXTI11
{ .handler = NULL, .arg = NULL }, // EXTI12
{ .handler = NULL, .arg = NULL }, // EXTI13
{ .handler = NULL, .arg = NULL }, // EXTI14
{ .handler = NULL, .arg = NULL }, // EXTI15
};
/*
* Portable routines
*/
/**
* @brief Register a handler to run upon external interrupt.
*
* This function assumes that the interrupt request corresponding to
* the given external interrupt is masked.
*
* @param num External interrupt line number.
* @param port Port to use as source input for external interrupt.
* @param handler Function handler to execute when interrupt is triggered.
* @param mode Type of transition to trigger on, one of:
* EXTI_RISING, EXTI_FALLING, EXTI_RISING_FALLING.
* @see exti_num
* @see exti_cfg
* @see voidFuncPtr
* @see exti_trigger_mode
*/
void exti_attach_interrupt(exti_num num,
exti_cfg port,
voidFuncPtr handler,
exti_trigger_mode mode) {
// Call callback version with arg being null
exti_attach_callback(num, port, (voidArgumentFuncPtr)handler, NULL, mode);
}
/**
* @brief Register a handler with an argument to run upon external interrupt.
*
* This function assumes that the interrupt request corresponding to
* the given external interrupt is masked.
*
* @param num External interrupt line number.
* @param port Port to use as source input for external interrupt.
* @param handler Function handler to execute when interrupt is triggered.
* @param arg Argument to pass to the interrupt handler.
* @param mode Type of transition to trigger on, one of:
* EXTI_RISING, EXTI_FALLING, EXTI_RISING_FALLING.
* @see exti_num
* @see exti_cfg
* @see voidFuncPtr
* @see exti_trigger_mode
*/
void exti_attach_callback(exti_num num,
exti_cfg port,
voidArgumentFuncPtr handler,
void *arg,
exti_trigger_mode mode) {
ASSERT(handler);
/* Register the handler */
exti_channels[num].handler = handler;
exti_channels[num].arg = arg;
/* Set trigger mode */
switch (mode) {
case EXTI_RISING:
bb_peri_set_bit(&EXTI_BASE->RTSR, num, 1);
break;
case EXTI_FALLING:
bb_peri_set_bit(&EXTI_BASE->FTSR, num, 1);
break;
case EXTI_RISING_FALLING:
bb_peri_set_bit(&EXTI_BASE->RTSR, num, 1);
bb_peri_set_bit(&EXTI_BASE->FTSR, num, 1);
break;
}
/* Use the chip-specific exti_select() to map num to port */
exti_select(num, port);
/* Unmask external interrupt request */
bb_peri_set_bit(&EXTI_BASE->IMR, num, 1);
/* Enable the interrupt line */
switch(num)
{
case EXTI0:
nvic_irq_enable(NVIC_EXTI0);
break;
case EXTI1:
nvic_irq_enable(NVIC_EXTI1);
break;
case EXTI2:
nvic_irq_enable(NVIC_EXTI2);
break;
case EXTI3:
nvic_irq_enable(NVIC_EXTI3);
break;
case EXTI4:
nvic_irq_enable(NVIC_EXTI4);
break;
case EXTI5:
case EXTI6:
case EXTI7:
case EXTI8:
case EXTI9:
nvic_irq_enable(NVIC_EXTI_9_5);
break;
case EXTI10:
case EXTI11:
case EXTI12:
case EXTI13:
case EXTI14:
case EXTI15:
nvic_irq_enable(NVIC_EXTI_15_10);
break;
}
}
/**
* @brief Unregister an external interrupt handler
* @param num External interrupt line to disable.
* @see exti_num
*/
void exti_detach_interrupt(exti_num num) {
/* First, mask the interrupt request */
bb_peri_set_bit(&EXTI_BASE->IMR, num, 0);
/* Then, clear the trigger selection registers */
bb_peri_set_bit(&EXTI_BASE->FTSR, num, 0);
bb_peri_set_bit(&EXTI_BASE->RTSR, num, 0);
/* Finally, unregister the user's handler */
exti_channels[num].handler = NULL;
exti_channels[num].arg = NULL;
}
/*
* Private routines
*/
void exti_do_select(__io uint32 *exti_cr, exti_num num, exti_cfg port) {
uint32 shift = 4 * (num % 4);
uint32 cr = *exti_cr;
cr &= ~(0xF << shift);
cr |= port << shift;
*exti_cr = cr;
}
/*
* Interrupt handlers
*/
void __irq_exti0(void) {
dispatch_single_exti(EXTI0);
}
void __irq_exti1(void) {
dispatch_single_exti(EXTI1);
}
void __irq_exti2(void) {
dispatch_single_exti(EXTI2);
}
void __irq_exti3(void) {
dispatch_single_exti(EXTI3);
}
void __irq_exti4(void) {
dispatch_single_exti(EXTI4);
}
void __irq_exti9_5(void) {
dispatch_extis(5, 9);
}
void __irq_exti15_10(void) {
dispatch_extis(10, 15);
}
/*
* Auxiliary functions
*/
/* Clear the pending bits for EXTIs whose bits are set in exti_msk.
*
* If a pending bit is cleared as the last instruction in an ISR, it
* won't actually be cleared in time and the ISR will fire again. To
* compensate, this function NOPs for 2 cycles after clearing the
* pending bits to ensure it takes effect. */
static __always_inline void clear_pending_msk(uint32 exti_msk) {
EXTI_BASE->PR = exti_msk;
asm volatile("nop");
asm volatile("nop");
}
/* This dispatch routine is for non-multiplexed EXTI lines only; i.e.,
* it doesn't check EXTI_PR. */
static __always_inline void dispatch_single_exti(uint32 exti) {
voidArgumentFuncPtr handler = exti_channels[exti].handler;
if (!handler) {
return;
}
handler(exti_channels[exti].arg);
clear_pending_msk(1U << exti);
}
/* Dispatch routine for EXTIs which share an IRQ. */
static __always_inline void dispatch_extis(uint32 start, uint32 stop) {
uint32 pr = EXTI_BASE->PR;
uint32 handled_msk = 0;
uint32 exti;
/* Dispatch user handlers for pending EXTIs. */
for (exti = start; exti <= stop; exti++) {
uint32 eb = (1U << exti);
if (pr & eb) {
voidArgumentFuncPtr handler = exti_channels[exti].handler;
if (handler) {
handler(exti_channels[exti].arg);
handled_msk |= eb;
}
}
}
/* Clear the pending bits for handled EXTIs. */
clear_pending_msk(handled_msk);
}