/****************************************************************************
* examples/timer/timer_main.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <nuttx/timers/timer.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DEVNAME_SIZE 16
#ifndef CONFIG_EXAMPLES_TIMER_DEVNAME
# define CONFIG_EXAMPLES_TIMER_DEVNAME "/dev/timer0"
#endif
#ifndef CONFIG_EXAMPLES_TIMER_INTERVAL
# define CONFIG_EXAMPLES_TIMER_INTERVAL 1000000
#endif
#ifndef CONFIG_EXAMPLES_TIMER_DELAY
# define CONFIG_EXAMPLES_TIMER_DELAY 100000
#endif
#ifndef CONFIG_EXAMPLES_TIMER_NSAMPLES
# define CONFIG_EXAMPLES_TIMER_NSAMPLES 20
#endif
#ifndef CONFIG_EXAMPLES_TIMER_SIGNO
# define CONFIG_EXAMPLES_TIMER_SIGNO 17
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
static volatile unsigned long g_nsignals;
/****************************************************************************
* timer_sighandler
****************************************************************************/
static void timer_sighandler(int signo, FAR siginfo_t *siginfo,
FAR void *context)
{
/* Does nothing in this example except for increment a count of signals
* received.
*
* NOTE: The use of signal handler is not recommended if you are concerned
* about the signal latency. Instead, a dedicated, high-priority thread
* that waits on sigwaitinfo() is recommended. High priority is required
* if you want a deterministic wake-up time when the signal occurs.
*/
g_nsignals++;
}
/****************************************************************************
* timer_status
****************************************************************************/
static void timer_status(int fd)
{
struct timer_status_s status;
int ret;
/* Get timer status */
ret = ioctl(fd, TCIOC_GETSTATUS, (unsigned long)((uintptr_t)&status));
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to get timer status: %d\n", errno);
close(fd);
exit(EXIT_FAILURE);
}
/* Print the timer status */
printf(" flags: %08lx timeout: %lu timeleft: %lu nsignals: %lu\n",
(unsigned long)status.flags, (unsigned long)status.timeout,
(unsigned long)status.timeleft, g_nsignals);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* timer_main
****************************************************************************/
int main(int argc, FAR char *argv[])
{
struct timer_notify_s notify;
struct sigaction act;
int ret;
int fd;
int i;
int opt;
char devname[DEVNAME_SIZE];
strcpy(devname, CONFIG_EXAMPLES_TIMER_DEVNAME);
while ((opt = getopt(argc, argv, ":d:")) != -1)
{
switch (opt)
{
case 'd':
strcpy(devname, optarg);
break;
case ':':
fprintf(stderr, "ERROR: Option needs a value\n");
exit(EXIT_FAILURE);
default: /* '?' */
fprintf(stderr, "Usage: %s [-d /dev/timerx]\n",
argv[0]);
exit(EXIT_FAILURE);
}
}
/* Open the timer device */
printf("Open %s\n", devname);
fd = open(devname, O_RDONLY);
if (fd < 0)
{
fprintf(stderr, "ERROR: Failed to open %s: %d\n",
devname, errno);
return EXIT_FAILURE;
}
/* Show the timer status before setting the timer interval */
timer_status(fd);
/* Set the timer interval */
printf("Set timer interval to %lu\n",
(unsigned long)CONFIG_EXAMPLES_TIMER_INTERVAL);
ret = ioctl(fd, TCIOC_SETTIMEOUT, CONFIG_EXAMPLES_TIMER_INTERVAL);
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to set the timer interval: %d\n",
errno);
close(fd);
return EXIT_FAILURE;
}
/* Show the timer status before attaching the timer handler */
timer_status(fd);
/* Attach a signal handler to catch the notifications. NOTE that using
* signal handler is very slow. A much more efficient thing to do is to
* create a separate pthread that waits on sigwaitinfo() for timer events.
* Much less overhead in that case.
*/
g_nsignals = 0;
act.sa_sigaction = timer_sighandler;
act.sa_flags = SA_SIGINFO;
sigfillset(&act.sa_mask);
sigdelset(&act.sa_mask, CONFIG_EXAMPLES_TIMER_SIGNO);
ret = sigaction(CONFIG_EXAMPLES_TIMER_SIGNO, &act, NULL);
if (ret != OK)
{
fprintf(stderr, "ERROR: Fsigaction failed: %d\n", errno);
close(fd);
return EXIT_FAILURE;
}
/* Register a callback for notifications using the configured signal.
*
* NOTE: If no callback is attached, the timer stop at the first interrupt.
*/
printf("Attach timer handler\n");
notify.pid = getpid();
notify.event.sigev_notify = SIGEV_SIGNAL;
notify.event.sigev_signo = CONFIG_EXAMPLES_TIMER_SIGNO;
notify.event.sigev_value.sival_ptr = NULL;
ret = ioctl(fd, TCIOC_NOTIFICATION, (unsigned long)((uintptr_t)¬ify));
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to set the timer handler: %d\n", errno);
close(fd);
return EXIT_FAILURE;
}
/* Show the timer status before starting */
timer_status(fd);
/* Start the timer */
printf("Start the timer\n");
ret = ioctl(fd, TCIOC_START, 0);
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to start the timer: %d\n", errno);
close(fd);
return EXIT_FAILURE;
}
/* Wait a bit showing timer status */
for (i = 0; i < CONFIG_EXAMPLES_TIMER_NSAMPLES; i++)
{
usleep(CONFIG_EXAMPLES_TIMER_DELAY);
timer_status(fd);
}
/* Stop the timer */
printf("Stop the timer\n");
ret = ioctl(fd, TCIOC_STOP, 0);
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to stop the timer: %d\n", errno);
close(fd);
return EXIT_FAILURE;
}
/* Detach the signal handler */
act.sa_handler = SIG_DFL;
sigaction(CONFIG_EXAMPLES_TIMER_SIGNO, &act, NULL);
/* Show the timer status before starting */
timer_status(fd);
/* Close the timer driver */
printf("Finished\n");
close(fd);
return EXIT_SUCCESS;
}