/****************************************************************************
* examples/oneshot/oneshot_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 <string.h>
#include <signal.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>
#include <nuttx/timers/oneshot.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_EXAMPLES_ONESHOT_DEVNAME
# define CONFIG_EXAMPLES_ONESHOT_DEVNAME "/dev/oneshot"
#endif
#ifndef CONFIG_EXAMPLES_ONESHOT_DELAY
# define CONFIG_EXAMPLES_ONESHOT_DELAY 100000
#endif
#ifndef CONFIG_EXAMPLES_ONESHOT_SIGNO
# define CONFIG_EXAMPLES_ONESHOT_SIGNO 13
#endif
/* For long delays that have to be broken into segments, some loss of
* precision is expected due to interrupt and context switching overhead.
* This inaccuracy will cause somewhat longer times than the time requested
* due to this overhead. It might be possible to reduce this inaccuracy
* some by (1) making this task very high priority so that it runs in a more
* deterministic way, and (2) by subtracting a "fudge factor" to account for
* time lost due to the overhead.
*/
#define FUDGE_FACTOR 10
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: oneshot_main
****************************************************************************/
static void show_usage(FAR const char *progname)
{
fprintf(stderr, "USAGE: %s [-d <usecs>] [<devname>]\n", progname);
fprintf(stderr, "Where:\n");
fprintf(stderr, "\t-d <usecs>:\n");
fprintf(stderr, "\tSpecifies the oneshot delay in microseconds. Default %ld\n",
(unsigned long)CONFIG_EXAMPLES_ONESHOT_DELAY);
fprintf(stderr, "\t<devname>:\n");
fprintf(stderr, "\tSpecifies the path to the oneshot driver. Default %s\n",
CONFIG_EXAMPLES_ONESHOT_DEVNAME);
exit(EXIT_FAILURE);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: oneshot_main
****************************************************************************/
#ifdef BUILD_MODULE
int main(int argc, FAR char *argv[])
#else
int oneshot_main(int argc, char *argv[])
#endif
{
FAR const char *devname = CONFIG_EXAMPLES_ONESHOT_DEVNAME;
unsigned long usecs = CONFIG_EXAMPLES_ONESHOT_DELAY;
unsigned long secs;
struct oneshot_start_s start;
struct timespec ts;
uint64_t maxus;
sigset_t set;
int ret;
int fd;
/* USAGE: nsh> oneshot [-d <usecs>] [<devname>] */
if (argc > 1)
{
if (argc == 2)
{
/* FORM: nsh> oneshot [<devname>] */
devname = argv[1];
}
else if (argc < 5)
{
/* FORM: nsh> oneshot [-d <usecs>] */
if (strcmp(argv[1], "-d") != 0)
{
fprintf(stderr, "ERROR: Unrecognized option: %s\n", argv[1]);
show_usage(argv[0]);
}
usecs = strtoul(argv[2], NULL, 10);
if (argc == 4)
{
/* FORM: nsh> oneshot [-d <usecs>] [<devname>] */
devname = argv[3];
}
}
else
{
fprintf(stderr, "ERROR: Unsupported number of arguments: %d\n", argc);
show_usage(argv[0]);
}
}
/* Open the oneshot device */
printf("Opening %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;
}
/* Get the maximum delay */
ret = ioctl(fd, OSIOC_MAXDELAY, (unsigned long)((uintptr_t)&ts));
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to get the maximum delayl: %d\n",
errno);
close(fd);
return EXIT_FAILURE;
}
maxus = (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000;
printf("Maximum delay is %llu\n", maxus);
/* Loop waiting until the full delay expires */
while (usecs > 0)
{
/* Start the oneshot timer */
sigemptyset(&set);
sigaddset(&set, CONFIG_EXAMPLES_ONESHOT_SIGNO);
if (usecs < maxus)
{
/* Wait for the remaining time */
printf("Starting oneshot timer with delay %lu microseconds\n",
usecs);
start.pid = 0;
start.signo = CONFIG_EXAMPLES_ONESHOT_SIGNO;
start.arg = NULL;
secs = usecs / 1000000;
usecs -= 1000000 * secs;
start.ts.tv_sec = secs;
start.ts.tv_nsec = usecs * 1000;
/* Zero usecs to terminate the loop */
usecs = 0;
}
else
{
/* Wait for the maximum */
printf("Starting oneshot timer with delay %llu microseconds\n",
maxus);
start.ts.tv_sec = ts.tv_sec;
start.ts.tv_nsec = ts.tv_nsec;
usecs -= maxus;
#if FUDGE_FACTOR > 0
if (usecs > FUDGE_FACTOR)
{
usecs -= FUDGE_FACTOR;
}
else
{
usecs = 0;
}
#endif
}
ret = ioctl(fd, OSIOC_START, (unsigned long)((uintptr_t)&start));
if (ret < 0)
{
fprintf(stderr, "ERROR: Failed to start the oneshot interval: %d\n",
errno);
close(fd);
return EXIT_FAILURE;
}
/* Wait for the oneshot to fire */
printf("Waiting...\n");
ret = sigwaitinfo(&set, NULL);
if (ret < 0)
{
fprintf(stderr, "ERROR: sigwaitinfo failed: %d\n",
errno);
close(fd);
return EXIT_FAILURE;
}
}
/* Close the oneshot driver */
printf("Finished\n");
close(fd);
return EXIT_SUCCESS;
}