drivers/pps/clients/pps-ktimer.c

   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");