nes-proj/cpu/arm/at91sam7s/sys-interrupt.c

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2009-07-11 14:22:45 +00:00
#include <sys-interrupt.h>
#include <interrupt-utils.h>
#include <AT91SAM7S64.h>
#define ATTR
#ifndef NULL
#define NULL 0
#endif
static SystemInterruptHandler *handlers = NULL;
static void
system_int_safe (void) __attribute__((noinline));
static void
system_int_safe (void)
{
SystemInterruptHandler *h;
h = handlers;
while (h) {
if (h->handler()) break;
h = h->next;
}
}
static void NACKEDFUNC ATTR
system_int (void) /* System Interrupt Handler */
{
ISR_ENTRY();
system_int_safe();
*AT91C_AIC_EOICR = 0; /* End of Interrupt */
ISR_EXIT();
}
static unsigned int enabled = 0; /* Number of times the system
interrupt has been enabled */
#define DIS_INT *AT91C_AIC_IDCR = (1 << AT91C_ID_SYS)
#define EN_INT if (enabled > 0) *AT91C_AIC_IECR = (1 << AT91C_ID_SYS)
void
sys_interrupt_enable()
{
if (enabled++ == 0) {
/* Level trigged at priority 5 */
AT91C_AIC_SMR[AT91C_ID_SYS] = AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 5;
/* Interrupt vector */
AT91C_AIC_SVR[AT91C_ID_SYS] = (unsigned long) system_int;
/* Enable */
EN_INT;
}
}
void
sys_interrupt_disable()
{
if (--enabled == 0) {
DIS_INT;
}
}
void
sys_interrupt_append_handler(SystemInterruptHandler *handler)
{
SystemInterruptHandler **h = &handlers;
while(*h) {
h = &(*h)->next;
}
DIS_INT;
*h = handler;
handler->next = NULL;
EN_INT;
}
void
sys_interrupt_prepend_handler(SystemInterruptHandler *handler)
{
DIS_INT;
handler->next = handlers;
handlers = handler;
EN_INT;
}
void
sys_interrupt_remove_handler(SystemInterruptHandler *handler)
{
SystemInterruptHandler **h = &handlers;
while(*h) {
if (*h == handler) {
DIS_INT;
*h = handler->next;
EN_INT;
break;
}
h = &(*h)->next;
}
}