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#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <error.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include "linux/input.h"
int main(void) {
int event_dev_fd;
const char *path = "/dev/input/by-path/platform-soc:base-fpga-region:keys-event";
struct input_event the_event;
int result;
unsigned char keys[9];
// open the event device node
event_dev_fd = open(path, O_RDONLY | O_SYNC);
if(event_dev_fd < 0)
error(1, errno, "could not open file '%s'", path);
while(1) {
// read the next event
result = read(event_dev_fd, &the_event,
sizeof(struct input_event));
if(result < 0)
error(1, errno, "reading %d from '%s'",
sizeof(struct input_event), path);
if(result != sizeof(struct input_event))
error(1, 0, "did not read %d bytes from '%s'",
sizeof(struct input_event), path);
// if the event is EV_KEY, then process it, otherwise ignore it
if(the_event.type == EV_KEY) {
// look for the codes that we expect
switch(the_event.code) {
case(KEY_F6) :
printf("SW0");
break;
case(KEY_F7) :
printf("SW1");
break;
case(KEY_F8) :
printf("SW2");
break;
case(KEY_F9) :
printf("SW3");
break;
default :
printf("unknown");
break;
}
// output the value of the event
printf(" moved to value '%d'\n", the_event.value);
// read the current state of the keys
result = ioctl (event_dev_fd, EVIOCGKEY(sizeof keys),
&keys);
if(result < 0)
error(1, errno, "ioctl from '%s'", path);
printf("SW0(%d) SW1(%d) SW2(%d) SW3(%d)\n",
(keys[8] & 0x01) ? (1) : (0),
(keys[8] & 0x02) ? (1) : (0),
(keys[8] & 0x04) ? (1) : (0),
(keys[8] & 0x08) ? (1) : (0)
);
}
}
}
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