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