/**************************************************************************** * examples/timer/timer_main.c * * Copyright (C) 2015 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #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 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; /* Open the timer device */ printf("Open %s\n", CONFIG_EXAMPLES_TIMER_DEVNAME); fd = open(CONFIG_EXAMPLES_TIMER_DEVNAME, O_RDONLY); if (fd < 0) { fprintf(stderr, "ERROR: Failed to open %s: %d\n", CONFIG_EXAMPLES_TIMER_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; }