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(unsigned long ptr) 43 { 44 struct pps_event_time ts; 45 46 /* First of all we get the time stamp... */ 47 pps_get_ts(&ts); 48 49 dev_info(pps->dev, "PPS event at %lu\n", jiffies); 50 51 pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL); 52 53 mod_timer(&ktimer, jiffies + HZ); 54 } 55 56 /* 57 * The echo function 58 */ 59 60 static void pps_ktimer_echo(struct pps_device *pps, int event, void *data) 61 { 62 dev_info(pps->dev, "echo %s %s\n", 63 event & PPS_CAPTUREASSERT ? "assert" : "", 64 event & PPS_CAPTURECLEAR ? "clear" : ""); 65 } 66 67 /* 68 * The PPS info struct 69 */ 70 71 static struct pps_source_info pps_ktimer_info = { 72 .name = "ktimer", 73 .path = "", 74 .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | 75 PPS_ECHOASSERT | 76 PPS_CANWAIT | PPS_TSFMT_TSPEC, 77 .echo = pps_ktimer_echo, 78 .owner = THIS_MODULE, 79 }; 80 81 /* 82 * Module staff 83 */ 84 85 static void __exit pps_ktimer_exit(void) 86 { 87 dev_info(pps->dev, "ktimer PPS source unregistered\n"); 88 89 del_timer_sync(&ktimer); 90 pps_unregister_source(pps); 91 } 92 93 static int __init pps_ktimer_init(void) 94 { 95 pps = pps_register_source(&pps_ktimer_info, 96 PPS_CAPTUREASSERT | PPS_OFFSETASSERT); 97 if (pps == NULL) { 98 pr_err("cannot register PPS source\n"); 99 return -ENOMEM; 100 } 101 102 setup_timer(&ktimer, pps_ktimer_event, 0); 103 mod_timer(&ktimer, jiffies + HZ); 104 105 dev_info(pps->dev, "ktimer PPS source registered\n"); 106 107 return 0; 108 } 109 110 module_init(pps_ktimer_init); 111 module_exit(pps_ktimer_exit); 112 113 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); 114 MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)"); 115 MODULE_LICENSE("GPL"); 116