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