1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * pps-ktimer.c -- kernel timer test client
4  *
5  * Copyright (C) 2005-2006   Rodolfo Giometti <giometti@linux.it>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/time.h>
14 #include <linux/timer.h>
15 #include <linux/pps_kernel.h>
16 
17 /*
18  * Global variables
19  */
20 
21 static struct pps_device *pps;
22 static struct timer_list ktimer;
23 
24 /*
25  * The kernel timer
26  */
27 
pps_ktimer_event(struct timer_list * unused)28 static void pps_ktimer_event(struct timer_list *unused)
29 {
30 	struct pps_event_time ts;
31 
32 	/* First of all we get the time stamp... */
33 	pps_get_ts(&ts);
34 
35 	pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);
36 
37 	mod_timer(&ktimer, jiffies + HZ);
38 }
39 
40 /*
41  * The PPS info struct
42  */
43 
44 static struct pps_source_info pps_ktimer_info = {
45 	.name		= "ktimer",
46 	.path		= "",
47 	.mode		= PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
48 			  PPS_ECHOASSERT |
49 			  PPS_CANWAIT | PPS_TSFMT_TSPEC,
50 	.owner		= THIS_MODULE,
51 };
52 
53 /*
54  * Module staff
55  */
56 
pps_ktimer_exit(void)57 static void __exit pps_ktimer_exit(void)
58 {
59 	dev_info(pps->dev, "ktimer PPS source unregistered\n");
60 
61 	del_timer_sync(&ktimer);
62 	pps_unregister_source(pps);
63 }
64 
pps_ktimer_init(void)65 static int __init pps_ktimer_init(void)
66 {
67 	pps = pps_register_source(&pps_ktimer_info,
68 				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
69 	if (IS_ERR(pps)) {
70 		pr_err("cannot register PPS source\n");
71 		return PTR_ERR(pps);
72 	}
73 
74 	timer_setup(&ktimer, pps_ktimer_event, 0);
75 	mod_timer(&ktimer, jiffies + HZ);
76 
77 	dev_info(pps->dev, "ktimer PPS source registered\n");
78 
79 	return 0;
80 }
81 
82 module_init(pps_ktimer_init);
83 module_exit(pps_ktimer_exit);
84 
85 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
86 MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
87 MODULE_LICENSE("GPL");
88