93 lines
2.2 KiB
C
93 lines
2.2 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/* Counter - example userspace application
|
||
|
|
*
|
||
|
|
* The userspace application opens /dev/counter0, configures the
|
||
|
|
* COUNTER_EVENT_INDEX event channel 0 to gather Count 0 count and Count
|
||
|
|
* 1 count, and prints out the data as it becomes available on the
|
||
|
|
* character device node.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2021 William Breathitt Gray
|
||
|
|
*/
|
||
|
|
#include <errno.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <linux/counter.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <sys/ioctl.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
|
||
|
|
static struct counter_watch watches[2] = {
|
||
|
|
{
|
||
|
|
/* Component data: Count 0 count */
|
||
|
|
.component.type = COUNTER_COMPONENT_COUNT,
|
||
|
|
.component.scope = COUNTER_SCOPE_COUNT,
|
||
|
|
.component.parent = 0,
|
||
|
|
/* Event type: Index */
|
||
|
|
.event = COUNTER_EVENT_INDEX,
|
||
|
|
/* Device event channel 0 */
|
||
|
|
.channel = 0,
|
||
|
|
},
|
||
|
|
{
|
||
|
|
/* Component data: Count 1 count */
|
||
|
|
.component.type = COUNTER_COMPONENT_COUNT,
|
||
|
|
.component.scope = COUNTER_SCOPE_COUNT,
|
||
|
|
.component.parent = 1,
|
||
|
|
/* Event type: Index */
|
||
|
|
.event = COUNTER_EVENT_INDEX,
|
||
|
|
/* Device event channel 0 */
|
||
|
|
.channel = 0,
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
int main(void)
|
||
|
|
{
|
||
|
|
int fd;
|
||
|
|
int ret;
|
||
|
|
int i;
|
||
|
|
struct counter_event event_data[2];
|
||
|
|
|
||
|
|
fd = open("/dev/counter0", O_RDWR);
|
||
|
|
if (fd == -1) {
|
||
|
|
perror("Unable to open /dev/counter0");
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (i = 0; i < 2; i++) {
|
||
|
|
ret = ioctl(fd, COUNTER_ADD_WATCH_IOCTL, watches + i);
|
||
|
|
if (ret == -1) {
|
||
|
|
fprintf(stderr, "Error adding watches[%d]: %s\n", i,
|
||
|
|
strerror(errno));
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ret = ioctl(fd, COUNTER_ENABLE_EVENTS_IOCTL);
|
||
|
|
if (ret == -1) {
|
||
|
|
perror("Error enabling events");
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (;;) {
|
||
|
|
ret = read(fd, event_data, sizeof(event_data));
|
||
|
|
if (ret == -1) {
|
||
|
|
perror("Failed to read event data");
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ret != sizeof(event_data)) {
|
||
|
|
fprintf(stderr, "Failed to read event data\n");
|
||
|
|
return -EIO;
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("Timestamp 0: %llu\tCount 0: %llu\n"
|
||
|
|
"Error Message 0: %s\n"
|
||
|
|
"Timestamp 1: %llu\tCount 1: %llu\n"
|
||
|
|
"Error Message 1: %s\n",
|
||
|
|
event_data[0].timestamp, event_data[0].value,
|
||
|
|
strerror(event_data[0].status),
|
||
|
|
event_data[1].timestamp, event_data[1].value,
|
||
|
|
strerror(event_data[1].status));
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|