Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * ICP Wafer 5823 Single Board Computer WDT driver | |
3 | * http://www.icpamerica.com/wafer_5823.php | |
4 | * May also work on other similar models | |
5 | * | |
6 | * (c) Copyright 2002 Justin Cormack <justin@street-vision.com> | |
7 | * | |
8 | * Release 0.02 | |
9 | * | |
10 | * Based on advantechwdt.c which is based on wdt.c. | |
11 | * Original copyright messages: | |
12 | * | |
13 | * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
14 | * http://www.redhat.com | |
15 | * | |
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 | ||
29 | #include <linux/module.h> | |
30 | #include <linux/moduleparam.h> | |
31 | #include <linux/miscdevice.h> | |
32 | #include <linux/watchdog.h> | |
33 | #include <linux/fs.h> | |
34 | #include <linux/ioport.h> | |
35 | #include <linux/notifier.h> | |
36 | #include <linux/reboot.h> | |
37 | #include <linux/init.h> | |
38 | #include <linux/spinlock.h> | |
694b16b2 AC |
39 | #include <linux/io.h> |
40 | #include <linux/uaccess.h> | |
1da177e4 LT |
41 | |
42 | #define WATCHDOG_NAME "Wafer 5823 WDT" | |
43 | #define PFX WATCHDOG_NAME ": " | |
44 | #define WD_TIMO 60 /* 60 sec default timeout */ | |
45 | ||
46 | static unsigned long wafwdt_is_open; | |
47 | static char expect_close; | |
c7dfd0cc | 48 | static DEFINE_SPINLOCK(wafwdt_lock); |
1da177e4 LT |
49 | |
50 | /* | |
51 | * You must set these - there is no sane way to probe for this board. | |
52 | * | |
53 | * To enable, write the timeout value in seconds (1 to 255) to I/O | |
54 | * port WDT_START, then read the port to start the watchdog. To pat | |
55 | * the dog, read port WDT_STOP to stop the timer, then read WDT_START | |
56 | * to restart it again. | |
57 | */ | |
58 | ||
59 | static int wdt_stop = 0x843; | |
60 | static int wdt_start = 0x443; | |
61 | ||
62 | static int timeout = WD_TIMO; /* in seconds */ | |
63 | module_param(timeout, int, 0); | |
694b16b2 AC |
64 | MODULE_PARM_DESC(timeout, |
65 | "Watchdog timeout in seconds. 1 <= timeout <= 255, default=" | |
66 | __MODULE_STRING(WD_TIMO) "."); | |
1da177e4 | 67 | |
4bfdf378 | 68 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 69 | module_param(nowayout, int, 0); |
694b16b2 AC |
70 | MODULE_PARM_DESC(nowayout, |
71 | "Watchdog cannot be stopped once started (default=" | |
72 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
73 | |
74 | static void wafwdt_ping(void) | |
75 | { | |
76 | /* pat watchdog */ | |
77 | spin_lock(&wafwdt_lock); | |
78 | inb_p(wdt_stop); | |
79 | inb_p(wdt_start); | |
80 | spin_unlock(&wafwdt_lock); | |
81 | } | |
82 | ||
83 | static void wafwdt_start(void) | |
84 | { | |
85 | /* start up watchdog */ | |
86 | outb_p(timeout, wdt_start); | |
87 | inb_p(wdt_start); | |
88 | } | |
89 | ||
90 | static void | |
91 | wafwdt_stop(void) | |
92 | { | |
93 | /* stop watchdog */ | |
94 | inb_p(wdt_stop); | |
95 | } | |
96 | ||
694b16b2 AC |
97 | static ssize_t wafwdt_write(struct file *file, const char __user *buf, |
98 | size_t count, loff_t *ppos) | |
1da177e4 LT |
99 | { |
100 | /* See if we got the magic character 'V' and reload the timer */ | |
101 | if (count) { | |
102 | if (!nowayout) { | |
103 | size_t i; | |
104 | ||
105 | /* In case it was set long ago */ | |
106 | expect_close = 0; | |
107 | ||
694b16b2 AC |
108 | /* scan to see whether or not we got the magic |
109 | character */ | |
1da177e4 LT |
110 | for (i = 0; i != count; i++) { |
111 | char c; | |
112 | if (get_user(c, buf + i)) | |
113 | return -EFAULT; | |
114 | if (c == 'V') | |
115 | expect_close = 42; | |
116 | } | |
117 | } | |
694b16b2 AC |
118 | /* Well, anyhow someone wrote to us, we should |
119 | return that favour */ | |
1da177e4 LT |
120 | wafwdt_ping(); |
121 | } | |
122 | return count; | |
123 | } | |
124 | ||
694b16b2 AC |
125 | static long wafwdt_ioctl(struct file *file, unsigned int cmd, |
126 | unsigned long arg) | |
1da177e4 LT |
127 | { |
128 | int new_timeout; | |
129 | void __user *argp = (void __user *)arg; | |
130 | int __user *p = argp; | |
694b16b2 AC |
131 | static const struct watchdog_info ident = { |
132 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | | |
133 | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
134 | .firmware_version = 1, |
135 | .identity = "Wafer 5823 WDT", | |
136 | }; | |
137 | ||
138 | switch (cmd) { | |
139 | case WDIOC_GETSUPPORT: | |
694b16b2 | 140 | if (copy_to_user(argp, &ident, sizeof(ident))) |
1da177e4 LT |
141 | return -EFAULT; |
142 | break; | |
143 | ||
144 | case WDIOC_GETSTATUS: | |
145 | case WDIOC_GETBOOTSTATUS: | |
146 | return put_user(0, p); | |
147 | ||
148 | case WDIOC_KEEPALIVE: | |
149 | wafwdt_ping(); | |
150 | break; | |
151 | ||
152 | case WDIOC_SETTIMEOUT: | |
153 | if (get_user(new_timeout, p)) | |
154 | return -EFAULT; | |
155 | if ((new_timeout < 1) || (new_timeout > 255)) | |
156 | return -EINVAL; | |
157 | timeout = new_timeout; | |
158 | wafwdt_stop(); | |
159 | wafwdt_start(); | |
160 | /* Fall */ | |
161 | case WDIOC_GETTIMEOUT: | |
162 | return put_user(timeout, p); | |
163 | ||
164 | case WDIOC_SETOPTIONS: | |
165 | { | |
166 | int options, retval = -EINVAL; | |
167 | ||
168 | if (get_user(options, p)) | |
169 | return -EFAULT; | |
170 | ||
171 | if (options & WDIOS_DISABLECARD) { | |
172 | wafwdt_start(); | |
173 | retval = 0; | |
174 | } | |
175 | ||
176 | if (options & WDIOS_ENABLECARD) { | |
177 | wafwdt_stop(); | |
178 | retval = 0; | |
179 | } | |
180 | ||
181 | return retval; | |
182 | } | |
183 | ||
184 | default: | |
795b89d2 | 185 | return -ENOTTY; |
1da177e4 LT |
186 | } |
187 | return 0; | |
188 | } | |
189 | ||
190 | static int wafwdt_open(struct inode *inode, struct file *file) | |
191 | { | |
192 | if (test_and_set_bit(0, &wafwdt_is_open)) | |
193 | return -EBUSY; | |
194 | ||
195 | /* | |
196 | * Activate | |
197 | */ | |
198 | wafwdt_start(); | |
199 | return nonseekable_open(inode, file); | |
200 | } | |
201 | ||
202 | static int | |
203 | wafwdt_close(struct inode *inode, struct file *file) | |
204 | { | |
694b16b2 | 205 | if (expect_close == 42) |
1da177e4 | 206 | wafwdt_stop(); |
694b16b2 AC |
207 | else { |
208 | printk(KERN_CRIT PFX | |
209 | "WDT device closed unexpectedly. WDT will not stop!\n"); | |
1da177e4 LT |
210 | wafwdt_ping(); |
211 | } | |
212 | clear_bit(0, &wafwdt_is_open); | |
213 | expect_close = 0; | |
214 | return 0; | |
215 | } | |
216 | ||
217 | /* | |
218 | * Notifier for system down | |
219 | */ | |
220 | ||
694b16b2 AC |
221 | static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, |
222 | void *unused) | |
1da177e4 | 223 | { |
694b16b2 | 224 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 | 225 | wafwdt_stop(); |
1da177e4 LT |
226 | return NOTIFY_DONE; |
227 | } | |
228 | ||
229 | /* | |
230 | * Kernel Interfaces | |
231 | */ | |
232 | ||
62322d25 | 233 | static const struct file_operations wafwdt_fops = { |
1da177e4 LT |
234 | .owner = THIS_MODULE, |
235 | .llseek = no_llseek, | |
236 | .write = wafwdt_write, | |
694b16b2 | 237 | .unlocked_ioctl = wafwdt_ioctl, |
1da177e4 LT |
238 | .open = wafwdt_open, |
239 | .release = wafwdt_close, | |
240 | }; | |
241 | ||
242 | static struct miscdevice wafwdt_miscdev = { | |
243 | .minor = WATCHDOG_MINOR, | |
244 | .name = "watchdog", | |
245 | .fops = &wafwdt_fops, | |
246 | }; | |
247 | ||
248 | /* | |
249 | * The WDT needs to learn about soft shutdowns in order to | |
250 | * turn the timebomb registers off. | |
251 | */ | |
252 | ||
253 | static struct notifier_block wafwdt_notifier = { | |
254 | .notifier_call = wafwdt_notify_sys, | |
255 | }; | |
256 | ||
257 | static int __init wafwdt_init(void) | |
258 | { | |
259 | int ret; | |
260 | ||
694b16b2 AC |
261 | printk(KERN_INFO |
262 | "WDT driver for Wafer 5823 single board computer initialising.\n"); | |
1da177e4 | 263 | |
1da177e4 LT |
264 | if (timeout < 1 || timeout > 255) { |
265 | timeout = WD_TIMO; | |
694b16b2 AC |
266 | printk(KERN_INFO PFX |
267 | "timeout value must be 1 <= x <= 255, using %d\n", | |
268 | timeout); | |
1da177e4 LT |
269 | } |
270 | ||
271 | if (wdt_stop != wdt_start) { | |
694b16b2 AC |
272 | if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { |
273 | printk(KERN_ERR PFX | |
274 | "I/O address 0x%04x already in use\n", | |
275 | wdt_stop); | |
1da177e4 LT |
276 | ret = -EIO; |
277 | goto error; | |
278 | } | |
279 | } | |
280 | ||
694b16b2 AC |
281 | if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) { |
282 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
1da177e4 LT |
283 | wdt_start); |
284 | ret = -EIO; | |
285 | goto error2; | |
286 | } | |
287 | ||
288 | ret = register_reboot_notifier(&wafwdt_notifier); | |
289 | if (ret != 0) { | |
694b16b2 AC |
290 | printk(KERN_ERR PFX |
291 | "cannot register reboot notifier (err=%d)\n", ret); | |
1da177e4 LT |
292 | goto error3; |
293 | } | |
294 | ||
295 | ret = misc_register(&wafwdt_miscdev); | |
296 | if (ret != 0) { | |
694b16b2 AC |
297 | printk(KERN_ERR PFX |
298 | "cannot register miscdev on minor=%d (err=%d)\n", | |
299 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
300 | goto error4; |
301 | } | |
302 | ||
694b16b2 | 303 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
304 | timeout, nowayout); |
305 | ||
306 | return ret; | |
307 | error4: | |
308 | unregister_reboot_notifier(&wafwdt_notifier); | |
309 | error3: | |
310 | release_region(wdt_start, 1); | |
311 | error2: | |
312 | if (wdt_stop != wdt_start) | |
313 | release_region(wdt_stop, 1); | |
314 | error: | |
315 | return ret; | |
316 | } | |
317 | ||
318 | static void __exit wafwdt_exit(void) | |
319 | { | |
320 | misc_deregister(&wafwdt_miscdev); | |
321 | unregister_reboot_notifier(&wafwdt_notifier); | |
694b16b2 | 322 | if (wdt_stop != wdt_start) |
1da177e4 LT |
323 | release_region(wdt_stop, 1); |
324 | release_region(wdt_start, 1); | |
325 | } | |
326 | ||
327 | module_init(wafwdt_init); | |
328 | module_exit(wafwdt_exit); | |
329 | ||
330 | MODULE_AUTHOR("Justin Cormack"); | |
331 | MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); | |
332 | MODULE_LICENSE("GPL"); | |
333 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
334 | ||
335 | /* end of wafer5823wdt.c */ |