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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/time.h>
  28 #include <linux/timer.h>
  29 #include <linux/pps_kernel.h>
  30
  31 /*
  32  * Global variables
  33  */
  34
  35 static struct pps_device *pps;
  36 static struct timer_list ktimer;
  37
  38 /*
  39  * The kernel timer
  40  */
  41
  42 static void pps_ktimer_event(struct timer_list *unused)
  43 {
  44         struct pps_event_time ts;
  45
  46         /* First of all we get the time stamp... */
  47         pps_get_ts(&ts);
  48
  49         pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);
  50
  51         mod_timer(&ktimer, jiffies + HZ);
  52 }
  53
  54 /*
  55  * The PPS info struct
  56  */
  57
  58 static struct pps_source_info pps_ktimer_info = {
  59         .name           = "ktimer",
  60         .path           = "",
  61         .mode           = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
  62                           PPS_ECHOASSERT |
  63                           PPS_CANWAIT | PPS_TSFMT_TSPEC,
  64         .owner          = THIS_MODULE,
  65 };
  66
  67 /*
  68  * Module staff
  69  */
  70
  71 static void __exit pps_ktimer_exit(void)
  72 {
  73         dev_info(pps->dev, "ktimer PPS source unregistered\n");
  74
  75         del_timer_sync(&ktimer);
  76         pps_unregister_source(pps);
  77 }
  78
  79 static int __init pps_ktimer_init(void)
  80 {
  81         pps = pps_register_source(&pps_ktimer_info,
  82                                 PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
  83         if (pps == NULL) {
  84                 pr_err("cannot register PPS source\n");
  85                 return -ENOMEM;
  86         }
  87
  88         timer_setup(&ktimer, pps_ktimer_event, 0);
  89         mod_timer(&ktimer, jiffies + HZ);
  90
  91         dev_info(pps->dev, "ktimer PPS source registered\n");
  92
  93         return 0;
  94 }
  95
  96 module_init(pps_ktimer_init);
  97 module_exit(pps_ktimer_exit);
  98
  99 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 100 MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
 101 MODULE_LICENSE("GPL");