blob: db0da7ea4fd8d8c12514f1f8552b1f425c84d9bc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * ICP Wafer 5823 Single Board Computer WDT driver
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +00003 * http://www.icpamerica.com/wafer_5823.php
4 * May also work on other similar models
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
7 *
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +00008 * Release 0.02
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
10 * Based on advantechwdt.c which is based on wdt.c.
11 * Original copyright messages:
12 *
Alan Cox29fa0582008-10-27 15:17:56 +000013 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
14 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
20 *
21 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
22 * warranty for any of this software. This material is provided
23 * "AS-IS" and at no charge.
24 *
25 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
26 *
27 */
28
Joe Perches27c766a2012-02-15 15:06:19 -080029#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/miscdevice.h>
34#include <linux/watchdog.h>
35#include <linux/fs.h>
36#include <linux/ioport.h>
37#include <linux/notifier.h>
38#include <linux/reboot.h>
39#include <linux/init.h>
40#include <linux/spinlock.h>
Alan Cox694b16b2008-05-19 14:09:40 +010041#include <linux/io.h>
42#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44#define WATCHDOG_NAME "Wafer 5823 WDT"
45#define PFX WATCHDOG_NAME ": "
46#define WD_TIMO 60 /* 60 sec default timeout */
47
48static unsigned long wafwdt_is_open;
49static char expect_close;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070050static DEFINE_SPINLOCK(wafwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52/*
53 * You must set these - there is no sane way to probe for this board.
54 *
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000055 * To enable, write the timeout value in seconds (1 to 255) to I/O
56 * port WDT_START, then read the port to start the watchdog. To pat
57 * the dog, read port WDT_STOP to stop the timer, then read WDT_START
58 * to restart it again.
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 */
60
61static int wdt_stop = 0x843;
62static int wdt_start = 0x443;
63
64static int timeout = WD_TIMO; /* in seconds */
65module_param(timeout, int, 0);
Alan Cox694b16b2008-05-19 14:09:40 +010066MODULE_PARM_DESC(timeout,
67 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
68 __MODULE_STRING(WD_TIMO) ".");
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010070static bool nowayout = WATCHDOG_NOWAYOUT;
71module_param(nowayout, bool, 0);
Alan Cox694b16b2008-05-19 14:09:40 +010072MODULE_PARM_DESC(nowayout,
73 "Watchdog cannot be stopped once started (default="
74 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76static void wafwdt_ping(void)
77{
78 /* pat watchdog */
79 spin_lock(&wafwdt_lock);
80 inb_p(wdt_stop);
81 inb_p(wdt_start);
82 spin_unlock(&wafwdt_lock);
83}
84
85static void wafwdt_start(void)
86{
87 /* start up watchdog */
88 outb_p(timeout, wdt_start);
89 inb_p(wdt_start);
90}
91
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000092static void wafwdt_stop(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
94 /* stop watchdog */
95 inb_p(wdt_stop);
96}
97
Alan Cox694b16b2008-05-19 14:09:40 +010098static ssize_t wafwdt_write(struct file *file, const char __user *buf,
99 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
101 /* See if we got the magic character 'V' and reload the timer */
102 if (count) {
103 if (!nowayout) {
104 size_t i;
105
106 /* In case it was set long ago */
107 expect_close = 0;
108
Alan Cox694b16b2008-05-19 14:09:40 +0100109 /* scan to see whether or not we got the magic
110 character */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 for (i = 0; i != count; i++) {
112 char c;
113 if (get_user(c, buf + i))
114 return -EFAULT;
115 if (c == 'V')
116 expect_close = 42;
117 }
118 }
Alan Cox694b16b2008-05-19 14:09:40 +0100119 /* Well, anyhow someone wrote to us, we should
120 return that favour */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 wafwdt_ping();
122 }
123 return count;
124}
125
Alan Cox694b16b2008-05-19 14:09:40 +0100126static long wafwdt_ioctl(struct file *file, unsigned int cmd,
127 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
129 int new_timeout;
130 void __user *argp = (void __user *)arg;
131 int __user *p = argp;
Alan Cox694b16b2008-05-19 14:09:40 +0100132 static const struct watchdog_info ident = {
133 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
134 WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 .firmware_version = 1,
136 .identity = "Wafer 5823 WDT",
137 };
138
139 switch (cmd) {
140 case WDIOC_GETSUPPORT:
Alan Cox694b16b2008-05-19 14:09:40 +0100141 if (copy_to_user(argp, &ident, sizeof(ident)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 return -EFAULT;
143 break;
144
145 case WDIOC_GETSTATUS:
146 case WDIOC_GETBOOTSTATUS:
147 return put_user(0, p);
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 case WDIOC_SETOPTIONS:
150 {
151 int options, retval = -EINVAL;
152
153 if (get_user(options, p))
154 return -EFAULT;
155
156 if (options & WDIOS_DISABLECARD) {
Axel Lin8a062ac2012-01-18 19:26:43 +0800157 wafwdt_stop();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 retval = 0;
159 }
160
161 if (options & WDIOS_ENABLECARD) {
Axel Lin8a062ac2012-01-18 19:26:43 +0800162 wafwdt_start();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 retval = 0;
164 }
165
166 return retval;
167 }
168
Wim Van Sebroeck0c06090c2008-07-18 11:41:17 +0000169 case WDIOC_KEEPALIVE:
170 wafwdt_ping();
171 break;
172
173 case WDIOC_SETTIMEOUT:
174 if (get_user(new_timeout, p))
175 return -EFAULT;
176 if ((new_timeout < 1) || (new_timeout > 255))
177 return -EINVAL;
178 timeout = new_timeout;
179 wafwdt_stop();
180 wafwdt_start();
181 /* Fall */
182 case WDIOC_GETTIMEOUT:
183 return put_user(timeout, p);
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200186 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 }
188 return 0;
189}
190
191static int wafwdt_open(struct inode *inode, struct file *file)
192{
193 if (test_and_set_bit(0, &wafwdt_is_open))
194 return -EBUSY;
195
196 /*
197 * Activate
198 */
199 wafwdt_start();
200 return nonseekable_open(inode, file);
201}
202
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000203static int wafwdt_close(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204{
Alan Cox694b16b2008-05-19 14:09:40 +0100205 if (expect_close == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 wafwdt_stop();
Alan Cox694b16b2008-05-19 14:09:40 +0100207 else {
Joe Perches27c766a2012-02-15 15:06:19 -0800208 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 wafwdt_ping();
210 }
211 clear_bit(0, &wafwdt_is_open);
212 expect_close = 0;
213 return 0;
214}
215
216/*
217 * Notifier for system down
218 */
219
Alan Cox694b16b2008-05-19 14:09:40 +0100220static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
221 void *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222{
Alan Cox694b16b2008-05-19 14:09:40 +0100223 if (code == SYS_DOWN || code == SYS_HALT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 wafwdt_stop();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 return NOTIFY_DONE;
226}
227
228/*
229 * Kernel Interfaces
230 */
231
Arjan van de Ven62322d22006-07-03 00:24:21 -0700232static const struct file_operations wafwdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 .owner = THIS_MODULE,
234 .llseek = no_llseek,
235 .write = wafwdt_write,
Alan Cox694b16b2008-05-19 14:09:40 +0100236 .unlocked_ioctl = wafwdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 .open = wafwdt_open,
238 .release = wafwdt_close,
239};
240
241static struct miscdevice wafwdt_miscdev = {
242 .minor = WATCHDOG_MINOR,
243 .name = "watchdog",
244 .fops = &wafwdt_fops,
245};
246
247/*
248 * The WDT needs to learn about soft shutdowns in order to
249 * turn the timebomb registers off.
250 */
251
252static struct notifier_block wafwdt_notifier = {
253 .notifier_call = wafwdt_notify_sys,
254};
255
256static int __init wafwdt_init(void)
257{
258 int ret;
259
Joe Perches27c766a2012-02-15 15:06:19 -0800260 pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 if (timeout < 1 || timeout > 255) {
263 timeout = WD_TIMO;
Joe Perches27c766a2012-02-15 15:06:19 -0800264 pr_info("timeout value must be 1 <= x <= 255, using %d\n",
265 timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 }
267
268 if (wdt_stop != wdt_start) {
Alan Cox694b16b2008-05-19 14:09:40 +0100269 if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800270 pr_err("I/O address 0x%04x already in use\n", wdt_stop);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 ret = -EIO;
272 goto error;
273 }
274 }
275
Alan Cox694b16b2008-05-19 14:09:40 +0100276 if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800277 pr_err("I/O address 0x%04x already in use\n", wdt_start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 ret = -EIO;
279 goto error2;
280 }
281
282 ret = register_reboot_notifier(&wafwdt_notifier);
283 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800284 pr_err("cannot register reboot notifier (err=%d)\n", ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 goto error3;
286 }
287
288 ret = misc_register(&wafwdt_miscdev);
289 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800290 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
291 WATCHDOG_MINOR, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 goto error4;
293 }
294
Joe Perches27c766a2012-02-15 15:06:19 -0800295 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 timeout, nowayout);
297
298 return ret;
299error4:
300 unregister_reboot_notifier(&wafwdt_notifier);
301error3:
302 release_region(wdt_start, 1);
303error2:
304 if (wdt_stop != wdt_start)
305 release_region(wdt_stop, 1);
306error:
307 return ret;
308}
309
310static void __exit wafwdt_exit(void)
311{
312 misc_deregister(&wafwdt_miscdev);
313 unregister_reboot_notifier(&wafwdt_notifier);
Alan Cox694b16b2008-05-19 14:09:40 +0100314 if (wdt_stop != wdt_start)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 release_region(wdt_stop, 1);
316 release_region(wdt_start, 1);
317}
318
319module_init(wafwdt_init);
320module_exit(wafwdt_exit);
321
322MODULE_AUTHOR("Justin Cormack");
323MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
324MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
326/* end of wafer5823wdt.c */