2 * MixCom Watchdog: A Simple Hardware Watchdog Device
3 * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
5 * Author: Gergely Madarasz <gorgo@itc.hu>
7 * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
14 * Version 0.1 (99/04/15):
17 * Version 0.2 (99/06/16):
18 * - added kernel timer watchdog ping after close
19 * since the hardware does not support watchdog shutdown
21 * Version 0.3 (99/06/21):
22 * - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
24 * Version 0.3.1 (99/06/22):
25 * - allow module removal while internal timer is active,
26 * print warning about probable reset
28 * Version 0.4 (99/11/15):
29 * - support for one more type board
31 * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
32 * - added nowayout module option to override
33 * CONFIG_WATCHDOG_NOWAYOUT
35 * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
36 * - make mixcomwd_opened unsigned,
37 * removed lock_kernel/unlock_kernel from mixcomwd_release,
38 * modified ioctl a bit to conform to API
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45 #define WATCHDOG_NAME "mixcomwd"
47 #include <linux/module.h>
48 #include <linux/moduleparam.h>
49 #include <linux/types.h>
50 #include <linux/miscdevice.h>
51 #include <linux/ioport.h>
52 #include <linux/watchdog.h>
54 #include <linux/reboot.h>
55 #include <linux/init.h>
56 #include <linux/jiffies.h>
57 #include <linux/timer.h>
58 #include <linux/uaccess.h>
62 * We have two types of cards that can be probed:
63 * 1) The Mixcom cards: these cards can be found at addresses
64 * 0x180, 0x280, 0x380 with an additional offset of 0xc10.
65 * (Or 0xd90, 0xe90, 0xf90).
66 * 2) The FlashCOM cards: these cards can be set up at
67 * 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
68 * (Or 0x304 -> 0x37c in 0x8 jumps).
69 * Each card has it's own ID.
71 #define MIXCOM_ID 0x11
72 #define FLASHCOM_ID 0x18
76 } mixcomwd_io_info[] = {
77 /* The Mixcom cards */
81 /* The FlashCOM cards */
82 {0x0304, FLASHCOM_ID},
83 {0x030c, FLASHCOM_ID},
84 {0x0314, FLASHCOM_ID},
85 {0x031c, FLASHCOM_ID},
86 {0x0324, FLASHCOM_ID},
87 {0x032c, FLASHCOM_ID},
88 {0x0334, FLASHCOM_ID},
89 {0x033c, FLASHCOM_ID},
90 {0x0344, FLASHCOM_ID},
91 {0x034c, FLASHCOM_ID},
92 {0x0354, FLASHCOM_ID},
93 {0x035c, FLASHCOM_ID},
94 {0x0364, FLASHCOM_ID},
95 {0x036c, FLASHCOM_ID},
96 {0x0374, FLASHCOM_ID},
97 {0x037c, FLASHCOM_ID},
98 /* The end of the list */
102 static void mixcomwd_timerfun(unsigned long d);
104 static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
106 static int watchdog_port;
107 static int mixcomwd_timer_alive;
108 static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
109 static char expect_close;
111 static bool nowayout = WATCHDOG_NOWAYOUT;
112 module_param(nowayout, bool, 0);
113 MODULE_PARM_DESC(nowayout,
114 "Watchdog cannot be stopped once started (default="
115 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
117 static void mixcomwd_ping(void)
119 outb_p(55, watchdog_port);
123 static void mixcomwd_timerfun(unsigned long d)
126 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
130 * Allow only one person to hold it open
133 static int mixcomwd_open(struct inode *inode, struct file *file)
135 if (test_and_set_bit(0, &mixcomwd_opened))
142 * fops_get() code via open() has already done
143 * a try_module_get() so it is safe to do the
146 __module_get(THIS_MODULE);
148 if (mixcomwd_timer_alive) {
149 del_timer(&mixcomwd_timer);
150 mixcomwd_timer_alive = 0;
153 return nonseekable_open(inode, file);
156 static int mixcomwd_release(struct inode *inode, struct file *file)
158 if (expect_close == 42) {
159 if (mixcomwd_timer_alive) {
160 pr_err("release called while internal timer alive\n");
163 mixcomwd_timer_alive = 1;
164 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
166 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
168 clear_bit(0, &mixcomwd_opened);
174 static ssize_t mixcomwd_write(struct file *file, const char __user *data,
175 size_t len, loff_t *ppos)
181 /* In case it was set long ago */
184 for (i = 0; i != len; i++) {
186 if (get_user(c, data + i))
197 static long mixcomwd_ioctl(struct file *file,
198 unsigned int cmd, unsigned long arg)
200 void __user *argp = (void __user *)arg;
201 int __user *p = argp;
203 static const struct watchdog_info ident = {
204 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
205 .firmware_version = 1,
206 .identity = "MixCOM watchdog",
210 case WDIOC_GETSUPPORT:
211 if (copy_to_user(argp, &ident, sizeof(ident)))
214 case WDIOC_GETSTATUS:
215 status = mixcomwd_opened;
217 status |= mixcomwd_timer_alive;
218 return put_user(status, p);
219 case WDIOC_GETBOOTSTATUS:
220 return put_user(0, p);
221 case WDIOC_KEEPALIVE:
230 static const struct file_operations mixcomwd_fops = {
231 .owner = THIS_MODULE,
233 .write = mixcomwd_write,
234 .unlocked_ioctl = mixcomwd_ioctl,
235 .open = mixcomwd_open,
236 .release = mixcomwd_release,
239 static struct miscdevice mixcomwd_miscdev = {
240 .minor = WATCHDOG_MINOR,
242 .fops = &mixcomwd_fops,
245 static int __init checkcard(int port, int card_id)
249 if (!request_region(port, 1, "MixCOM watchdog"))
253 if (card_id == MIXCOM_ID)
257 release_region(port, 1);
263 static int __init mixcomwd_init(void)
265 int i, ret, found = 0;
267 for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
268 if (checkcard(mixcomwd_io_info[i].ioport,
269 mixcomwd_io_info[i].id)) {
271 watchdog_port = mixcomwd_io_info[i].ioport;
276 pr_err("No card detected, or port not available\n");
280 ret = misc_register(&mixcomwd_miscdev);
282 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
283 WATCHDOG_MINOR, ret);
284 goto error_misc_register_watchdog;
287 pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
288 VERSION, watchdog_port);
292 error_misc_register_watchdog:
293 release_region(watchdog_port, 1);
294 watchdog_port = 0x0000;
298 static void __exit mixcomwd_exit(void)
301 if (mixcomwd_timer_alive) {
302 pr_warn("I quit now, hardware will probably reboot!\n");
303 del_timer_sync(&mixcomwd_timer);
304 mixcomwd_timer_alive = 0;
307 misc_deregister(&mixcomwd_miscdev);
308 release_region(watchdog_port, 1);
311 module_init(mixcomwd_init);
312 module_exit(mixcomwd_exit);
314 MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
315 MODULE_DESCRIPTION("MixCom Watchdog driver");
316 MODULE_VERSION(VERSION);
317 MODULE_LICENSE("GPL");