pps/clients/pps-ktimer.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * pps-ktimer.c -- kernel timer test client
0004  *
0005  * Copyright (C) 2005-2006   Rodolfo Giometti <giometti@linux.it>
0006  */
0007
0008 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0009
0010 #include <linux/kernel.h>
0011 #include <linux/module.h>
0012 #include <linux/init.h>
0013 #include <linux/time.h>
0014 #include <linux/timer.h>
0015 #include <linux/pps_kernel.h>
0016
0017 /*
0018  * Global variables
0019  */
0020
0021 static struct pps_device *pps;
0022 static struct timer_list ktimer;
0023
0024 /*
0025  * The kernel timer
0026  */
0027
0028 static void pps_ktimer_event(struct timer_list *unused)
0029 {
0030     struct pps_event_time ts;
0031
0032     /* First of all we get the time stamp... */
0033     pps_get_ts(&ts);
0034
0035     pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);
0036
0037     mod_timer(&ktimer, jiffies + HZ);
0038 }
0039
0040 /*
0041  * The PPS info struct
0042  */
0043
0044 static struct pps_source_info pps_ktimer_info = {
0045     .name       = "ktimer",
0046     .path       = "",
0047     .mode       = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
0048               PPS_ECHOASSERT |
0049               PPS_CANWAIT | PPS_TSFMT_TSPEC,
0050     .owner      = THIS_MODULE,
0051 };
0052
0053 /*
0054  * Module staff
0055  */
0056
0057 static void __exit pps_ktimer_exit(void)
0058 {
0059     dev_info(pps->dev, "ktimer PPS source unregistered\n");
0060
0061     del_timer_sync(&ktimer);
0062     pps_unregister_source(pps);
0063 }
0064
0065 static int __init pps_ktimer_init(void)
0066 {
0067     pps = pps_register_source(&pps_ktimer_info,
0068                 PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
0069     if (IS_ERR(pps)) {
0070         pr_err("cannot register PPS source\n");
0071         return PTR_ERR(pps);
0072     }
0073
0074     timer_setup(&ktimer, pps_ktimer_event, 0);
0075     mod_timer(&ktimer, jiffies + HZ);
0076
0077     dev_info(pps->dev, "ktimer PPS source registered\n");
0078
0079     return 0;
0080 }
0081
0082 module_init(pps_ktimer_init);
0083 module_exit(pps_ktimer_exit);
0084
0085 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
0086 MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
0087 MODULE_LICENSE("GPL");