// 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;}
// 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;
}