TS-4700 Interrupts example code
From embeddedTS Manuals
This example below will work with any of our products that support userspace IRQs. It opens the IRQ number specified in the first argument, and prints when it detects an IRQ.
#include <stdio.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <unistd.h>
int main(int argc, char **argv)
{
char proc_irq[32];
int ret, irqfd = 0;
int buf; // Holds irq junk data
fd_set fds;
if(argc < 2) {
printf("Usage: %s <irq number>\n", argv[0]);
return 1;
}
snprintf(proc_irq, sizeof(proc_irq), "/proc/irq/%d/irq", atoi(argv[1]));
irqfd = open(proc_irq, O_RDONLY| O_NONBLOCK, S_IREAD);
if(irqfd == -1) {
printf("Could not open IRQ %s\n", argv[1]);
return 1;
}
while(1) {
FD_SET(irqfd, &fds); //add the fd to the set
// See if the IRQ has any data available to read
ret = select(irqfd + 1, &fds, NULL, NULL, NULL);
if(FD_ISSET(irqfd, &fds))
{
FD_CLR(irqfd, &fds); //Remove the filedes from set
printf("IRQ detected\n");
// Clear the junk data in the IRQ file
read(irqfd, &buf, sizeof(buf));
}
//Sleep, or do any other processing here
usleep(10000);
}
return 0;
}