xref: /openbmc/linux/drivers/pps/clients/pps-ktimer.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * pps-ktimer.c -- kernel timer test client
3  *
4  *
5  * Copyright (C) 2005-2006   Rodolfo Giometti <giometti@linux.it>
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/time.h>
27 #include <linux/timer.h>
28 #include <linux/pps_kernel.h>
29 
30 /*
31  * Global variables
32  */
33 
34 static int source;
35 static struct timer_list ktimer;
36 
37 /*
38  * The kernel timer
39  */
40 
41 static void pps_ktimer_event(unsigned long ptr)
42 {
43 	struct timespec __ts;
44 	struct pps_ktime ts;
45 
46 	/* First of all we get the time stamp... */
47 	getnstimeofday(&__ts);
48 
49 	pr_info("PPS event at %lu\n", jiffies);
50 
51 	/* ... and translate it to PPS time data struct */
52 	ts.sec = __ts.tv_sec;
53 	ts.nsec = __ts.tv_nsec;
54 
55 	pps_event(source, &ts, PPS_CAPTUREASSERT, NULL);
56 
57 	mod_timer(&ktimer, jiffies + HZ);
58 }
59 
60 /*
61  * The echo function
62  */
63 
64 static void pps_ktimer_echo(int source, int event, void *data)
65 {
66 	pr_info("echo %s %s for source %d\n",
67 		event & PPS_CAPTUREASSERT ? "assert" : "",
68 		event & PPS_CAPTURECLEAR ? "clear" : "",
69 		source);
70 }
71 
72 /*
73  * The PPS info struct
74  */
75 
76 static struct pps_source_info pps_ktimer_info = {
77 	.name		= "ktimer",
78 	.path		= "",
79 	.mode		= PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
80 			  PPS_ECHOASSERT |
81 			  PPS_CANWAIT | PPS_TSFMT_TSPEC,
82 	.echo		= pps_ktimer_echo,
83 	.owner		= THIS_MODULE,
84 };
85 
86 /*
87  * Module staff
88  */
89 
90 static void __exit pps_ktimer_exit(void)
91 {
92 	del_timer_sync(&ktimer);
93 	pps_unregister_source(source);
94 
95 	pr_info("ktimer PPS source unregistered\n");
96 }
97 
98 static int __init pps_ktimer_init(void)
99 {
100 	int ret;
101 
102 	ret = pps_register_source(&pps_ktimer_info,
103 				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
104 	if (ret < 0) {
105 		printk(KERN_ERR "cannot register ktimer source\n");
106 		return ret;
107 	}
108 	source = ret;
109 
110 	setup_timer(&ktimer, pps_ktimer_event, 0);
111 	mod_timer(&ktimer, jiffies + HZ);
112 
113 	pr_info("ktimer PPS source registered at %d\n", source);
114 
115 	return  0;
116 }
117 
118 module_init(pps_ktimer_init);
119 module_exit(pps_ktimer_exit);
120 
121 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
122 MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
123 MODULE_LICENSE("GPL");
124