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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> | |
39 | #include <asm/io.h> | |
40 | #include <asm/uaccess.h> | |
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); | |
64 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WD_TIMO) "."); | |
65 | ||
4bfdf378 | 66 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 67 | module_param(nowayout, int, 0); |
bffda5c8 | 68 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4 LT |
69 | |
70 | static void wafwdt_ping(void) | |
71 | { | |
72 | /* pat watchdog */ | |
73 | spin_lock(&wafwdt_lock); | |
74 | inb_p(wdt_stop); | |
75 | inb_p(wdt_start); | |
76 | spin_unlock(&wafwdt_lock); | |
77 | } | |
78 | ||
79 | static void wafwdt_start(void) | |
80 | { | |
81 | /* start up watchdog */ | |
82 | outb_p(timeout, wdt_start); | |
83 | inb_p(wdt_start); | |
84 | } | |
85 | ||
86 | static void | |
87 | wafwdt_stop(void) | |
88 | { | |
89 | /* stop watchdog */ | |
90 | inb_p(wdt_stop); | |
91 | } | |
92 | ||
93 | static ssize_t wafwdt_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) | |
94 | { | |
95 | /* See if we got the magic character 'V' and reload the timer */ | |
96 | if (count) { | |
97 | if (!nowayout) { | |
98 | size_t i; | |
99 | ||
100 | /* In case it was set long ago */ | |
101 | expect_close = 0; | |
102 | ||
103 | /* scan to see whether or not we got the magic character */ | |
104 | for (i = 0; i != count; i++) { | |
105 | char c; | |
106 | if (get_user(c, buf + i)) | |
107 | return -EFAULT; | |
108 | if (c == 'V') | |
109 | expect_close = 42; | |
110 | } | |
111 | } | |
112 | /* Well, anyhow someone wrote to us, we should return that favour */ | |
113 | wafwdt_ping(); | |
114 | } | |
115 | return count; | |
116 | } | |
117 | ||
118 | static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
119 | unsigned long arg) | |
120 | { | |
121 | int new_timeout; | |
122 | void __user *argp = (void __user *)arg; | |
123 | int __user *p = argp; | |
124 | static struct watchdog_info ident = { | |
125 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
126 | .firmware_version = 1, | |
127 | .identity = "Wafer 5823 WDT", | |
128 | }; | |
129 | ||
130 | switch (cmd) { | |
131 | case WDIOC_GETSUPPORT: | |
132 | if (copy_to_user(argp, &ident, sizeof (ident))) | |
133 | return -EFAULT; | |
134 | break; | |
135 | ||
136 | case WDIOC_GETSTATUS: | |
137 | case WDIOC_GETBOOTSTATUS: | |
138 | return put_user(0, p); | |
139 | ||
140 | case WDIOC_KEEPALIVE: | |
141 | wafwdt_ping(); | |
142 | break; | |
143 | ||
144 | case WDIOC_SETTIMEOUT: | |
145 | if (get_user(new_timeout, p)) | |
146 | return -EFAULT; | |
147 | if ((new_timeout < 1) || (new_timeout > 255)) | |
148 | return -EINVAL; | |
149 | timeout = new_timeout; | |
150 | wafwdt_stop(); | |
151 | wafwdt_start(); | |
152 | /* Fall */ | |
153 | case WDIOC_GETTIMEOUT: | |
154 | return put_user(timeout, p); | |
155 | ||
156 | case WDIOC_SETOPTIONS: | |
157 | { | |
158 | int options, retval = -EINVAL; | |
159 | ||
160 | if (get_user(options, p)) | |
161 | return -EFAULT; | |
162 | ||
163 | if (options & WDIOS_DISABLECARD) { | |
164 | wafwdt_start(); | |
165 | retval = 0; | |
166 | } | |
167 | ||
168 | if (options & WDIOS_ENABLECARD) { | |
169 | wafwdt_stop(); | |
170 | retval = 0; | |
171 | } | |
172 | ||
173 | return retval; | |
174 | } | |
175 | ||
176 | default: | |
795b89d2 | 177 | return -ENOTTY; |
1da177e4 LT |
178 | } |
179 | return 0; | |
180 | } | |
181 | ||
182 | static int wafwdt_open(struct inode *inode, struct file *file) | |
183 | { | |
184 | if (test_and_set_bit(0, &wafwdt_is_open)) | |
185 | return -EBUSY; | |
186 | ||
187 | /* | |
188 | * Activate | |
189 | */ | |
190 | wafwdt_start(); | |
191 | return nonseekable_open(inode, file); | |
192 | } | |
193 | ||
194 | static int | |
195 | wafwdt_close(struct inode *inode, struct file *file) | |
196 | { | |
197 | if (expect_close == 42) { | |
198 | wafwdt_stop(); | |
199 | } else { | |
200 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); | |
201 | wafwdt_ping(); | |
202 | } | |
203 | clear_bit(0, &wafwdt_is_open); | |
204 | expect_close = 0; | |
205 | return 0; | |
206 | } | |
207 | ||
208 | /* | |
209 | * Notifier for system down | |
210 | */ | |
211 | ||
212 | static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | |
213 | { | |
214 | if (code == SYS_DOWN || code == SYS_HALT) { | |
215 | /* Turn the WDT off */ | |
216 | wafwdt_stop(); | |
217 | } | |
218 | return NOTIFY_DONE; | |
219 | } | |
220 | ||
221 | /* | |
222 | * Kernel Interfaces | |
223 | */ | |
224 | ||
62322d25 | 225 | static const struct file_operations wafwdt_fops = { |
1da177e4 LT |
226 | .owner = THIS_MODULE, |
227 | .llseek = no_llseek, | |
228 | .write = wafwdt_write, | |
229 | .ioctl = wafwdt_ioctl, | |
230 | .open = wafwdt_open, | |
231 | .release = wafwdt_close, | |
232 | }; | |
233 | ||
234 | static struct miscdevice wafwdt_miscdev = { | |
235 | .minor = WATCHDOG_MINOR, | |
236 | .name = "watchdog", | |
237 | .fops = &wafwdt_fops, | |
238 | }; | |
239 | ||
240 | /* | |
241 | * The WDT needs to learn about soft shutdowns in order to | |
242 | * turn the timebomb registers off. | |
243 | */ | |
244 | ||
245 | static struct notifier_block wafwdt_notifier = { | |
246 | .notifier_call = wafwdt_notify_sys, | |
247 | }; | |
248 | ||
249 | static int __init wafwdt_init(void) | |
250 | { | |
251 | int ret; | |
252 | ||
253 | printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n"); | |
254 | ||
1da177e4 LT |
255 | if (timeout < 1 || timeout > 255) { |
256 | timeout = WD_TIMO; | |
257 | printk (KERN_INFO PFX "timeout value must be 1<=x<=255, using %d\n", | |
258 | timeout); | |
259 | } | |
260 | ||
261 | if (wdt_stop != wdt_start) { | |
262 | if(!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { | |
263 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
264 | wdt_stop); | |
265 | ret = -EIO; | |
266 | goto error; | |
267 | } | |
268 | } | |
269 | ||
270 | if(!request_region(wdt_start, 1, "Wafer 5823 WDT")) { | |
271 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
272 | wdt_start); | |
273 | ret = -EIO; | |
274 | goto error2; | |
275 | } | |
276 | ||
277 | ret = register_reboot_notifier(&wafwdt_notifier); | |
278 | if (ret != 0) { | |
279 | printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
280 | ret); | |
281 | goto error3; | |
282 | } | |
283 | ||
284 | ret = misc_register(&wafwdt_miscdev); | |
285 | if (ret != 0) { | |
286 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
287 | WATCHDOG_MINOR, ret); | |
288 | goto error4; | |
289 | } | |
290 | ||
291 | printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | |
292 | timeout, nowayout); | |
293 | ||
294 | return ret; | |
295 | error4: | |
296 | unregister_reboot_notifier(&wafwdt_notifier); | |
297 | error3: | |
298 | release_region(wdt_start, 1); | |
299 | error2: | |
300 | if (wdt_stop != wdt_start) | |
301 | release_region(wdt_stop, 1); | |
302 | error: | |
303 | return ret; | |
304 | } | |
305 | ||
306 | static void __exit wafwdt_exit(void) | |
307 | { | |
308 | misc_deregister(&wafwdt_miscdev); | |
309 | unregister_reboot_notifier(&wafwdt_notifier); | |
310 | if(wdt_stop != wdt_start) | |
311 | release_region(wdt_stop, 1); | |
312 | release_region(wdt_start, 1); | |
313 | } | |
314 | ||
315 | module_init(wafwdt_init); | |
316 | module_exit(wafwdt_exit); | |
317 | ||
318 | MODULE_AUTHOR("Justin Cormack"); | |
319 | MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); | |
320 | MODULE_LICENSE("GPL"); | |
321 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
322 | ||
323 | /* end of wafer5823wdt.c */ |