Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * ICP Wafer 5823 Single Board Computer WDT driver | |
7944d3a5 WVS |
3 | * http://www.icpamerica.com/wafer_5823.php |
4 | * May also work on other similar models | |
1da177e4 LT |
5 | * |
6 | * (c) Copyright 2002 Justin Cormack <justin@street-vision.com> | |
7 | * | |
7944d3a5 | 8 | * Release 0.02 |
1da177e4 LT |
9 | * |
10 | * Based on advantechwdt.c which is based on wdt.c. | |
11 | * Original copyright messages: | |
12 | * | |
29fa0586 AC |
13 | * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>, |
14 | * All Rights Reserved. | |
1da177e4 LT |
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 | * | |
7944d3a5 WVS |
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. | |
1da177e4 LT |
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 | ||
7944d3a5 | 90 | static void wafwdt_stop(void) |
1da177e4 LT |
91 | { |
92 | /* stop watchdog */ | |
93 | inb_p(wdt_stop); | |
94 | } | |
95 | ||
694b16b2 AC |
96 | static ssize_t wafwdt_write(struct file *file, const char __user *buf, |
97 | size_t count, loff_t *ppos) | |
1da177e4 LT |
98 | { |
99 | /* See if we got the magic character 'V' and reload the timer */ | |
100 | if (count) { | |
101 | if (!nowayout) { | |
102 | size_t i; | |
103 | ||
104 | /* In case it was set long ago */ | |
105 | expect_close = 0; | |
106 | ||
694b16b2 AC |
107 | /* scan to see whether or not we got the magic |
108 | character */ | |
1da177e4 LT |
109 | for (i = 0; i != count; i++) { |
110 | char c; | |
111 | if (get_user(c, buf + i)) | |
112 | return -EFAULT; | |
113 | if (c == 'V') | |
114 | expect_close = 42; | |
115 | } | |
116 | } | |
694b16b2 AC |
117 | /* Well, anyhow someone wrote to us, we should |
118 | return that favour */ | |
1da177e4 LT |
119 | wafwdt_ping(); |
120 | } | |
121 | return count; | |
122 | } | |
123 | ||
694b16b2 AC |
124 | static long wafwdt_ioctl(struct file *file, unsigned int cmd, |
125 | unsigned long arg) | |
1da177e4 LT |
126 | { |
127 | int new_timeout; | |
128 | void __user *argp = (void __user *)arg; | |
129 | int __user *p = argp; | |
694b16b2 AC |
130 | static const struct watchdog_info ident = { |
131 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | | |
132 | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
133 | .firmware_version = 1, |
134 | .identity = "Wafer 5823 WDT", | |
135 | }; | |
136 | ||
137 | switch (cmd) { | |
138 | case WDIOC_GETSUPPORT: | |
694b16b2 | 139 | if (copy_to_user(argp, &ident, sizeof(ident))) |
1da177e4 LT |
140 | return -EFAULT; |
141 | break; | |
142 | ||
143 | case WDIOC_GETSTATUS: | |
144 | case WDIOC_GETBOOTSTATUS: | |
145 | return put_user(0, p); | |
146 | ||
1da177e4 LT |
147 | case WDIOC_SETOPTIONS: |
148 | { | |
149 | int options, retval = -EINVAL; | |
150 | ||
151 | if (get_user(options, p)) | |
152 | return -EFAULT; | |
153 | ||
154 | if (options & WDIOS_DISABLECARD) { | |
155 | wafwdt_start(); | |
156 | retval = 0; | |
157 | } | |
158 | ||
159 | if (options & WDIOS_ENABLECARD) { | |
160 | wafwdt_stop(); | |
161 | retval = 0; | |
162 | } | |
163 | ||
164 | return retval; | |
165 | } | |
166 | ||
0c06090c WVS |
167 | case WDIOC_KEEPALIVE: |
168 | wafwdt_ping(); | |
169 | break; | |
170 | ||
171 | case WDIOC_SETTIMEOUT: | |
172 | if (get_user(new_timeout, p)) | |
173 | return -EFAULT; | |
174 | if ((new_timeout < 1) || (new_timeout > 255)) | |
175 | return -EINVAL; | |
176 | timeout = new_timeout; | |
177 | wafwdt_stop(); | |
178 | wafwdt_start(); | |
179 | /* Fall */ | |
180 | case WDIOC_GETTIMEOUT: | |
181 | return put_user(timeout, p); | |
182 | ||
1da177e4 | 183 | default: |
795b89d2 | 184 | return -ENOTTY; |
1da177e4 LT |
185 | } |
186 | return 0; | |
187 | } | |
188 | ||
189 | static int wafwdt_open(struct inode *inode, struct file *file) | |
190 | { | |
191 | if (test_and_set_bit(0, &wafwdt_is_open)) | |
192 | return -EBUSY; | |
193 | ||
194 | /* | |
195 | * Activate | |
196 | */ | |
197 | wafwdt_start(); | |
198 | return nonseekable_open(inode, file); | |
199 | } | |
200 | ||
7944d3a5 | 201 | static int wafwdt_close(struct inode *inode, struct file *file) |
1da177e4 | 202 | { |
694b16b2 | 203 | if (expect_close == 42) |
1da177e4 | 204 | wafwdt_stop(); |
694b16b2 AC |
205 | else { |
206 | printk(KERN_CRIT PFX | |
207 | "WDT device closed unexpectedly. WDT will not stop!\n"); | |
1da177e4 LT |
208 | wafwdt_ping(); |
209 | } | |
210 | clear_bit(0, &wafwdt_is_open); | |
211 | expect_close = 0; | |
212 | return 0; | |
213 | } | |
214 | ||
215 | /* | |
216 | * Notifier for system down | |
217 | */ | |
218 | ||
694b16b2 AC |
219 | static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, |
220 | void *unused) | |
1da177e4 | 221 | { |
694b16b2 | 222 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 | 223 | wafwdt_stop(); |
1da177e4 LT |
224 | return NOTIFY_DONE; |
225 | } | |
226 | ||
227 | /* | |
228 | * Kernel Interfaces | |
229 | */ | |
230 | ||
62322d25 | 231 | static const struct file_operations wafwdt_fops = { |
1da177e4 LT |
232 | .owner = THIS_MODULE, |
233 | .llseek = no_llseek, | |
234 | .write = wafwdt_write, | |
694b16b2 | 235 | .unlocked_ioctl = wafwdt_ioctl, |
1da177e4 LT |
236 | .open = wafwdt_open, |
237 | .release = wafwdt_close, | |
238 | }; | |
239 | ||
240 | static struct miscdevice wafwdt_miscdev = { | |
241 | .minor = WATCHDOG_MINOR, | |
242 | .name = "watchdog", | |
243 | .fops = &wafwdt_fops, | |
244 | }; | |
245 | ||
246 | /* | |
247 | * The WDT needs to learn about soft shutdowns in order to | |
248 | * turn the timebomb registers off. | |
249 | */ | |
250 | ||
251 | static struct notifier_block wafwdt_notifier = { | |
252 | .notifier_call = wafwdt_notify_sys, | |
253 | }; | |
254 | ||
255 | static int __init wafwdt_init(void) | |
256 | { | |
257 | int ret; | |
258 | ||
694b16b2 AC |
259 | printk(KERN_INFO |
260 | "WDT driver for Wafer 5823 single board computer initialising.\n"); | |
1da177e4 | 261 | |
1da177e4 LT |
262 | if (timeout < 1 || timeout > 255) { |
263 | timeout = WD_TIMO; | |
694b16b2 AC |
264 | printk(KERN_INFO PFX |
265 | "timeout value must be 1 <= x <= 255, using %d\n", | |
266 | timeout); | |
1da177e4 LT |
267 | } |
268 | ||
269 | if (wdt_stop != wdt_start) { | |
694b16b2 AC |
270 | if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { |
271 | printk(KERN_ERR PFX | |
272 | "I/O address 0x%04x already in use\n", | |
273 | wdt_stop); | |
1da177e4 LT |
274 | ret = -EIO; |
275 | goto error; | |
276 | } | |
277 | } | |
278 | ||
694b16b2 AC |
279 | if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) { |
280 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
1da177e4 LT |
281 | wdt_start); |
282 | ret = -EIO; | |
283 | goto error2; | |
284 | } | |
285 | ||
286 | ret = register_reboot_notifier(&wafwdt_notifier); | |
287 | if (ret != 0) { | |
694b16b2 AC |
288 | printk(KERN_ERR PFX |
289 | "cannot register reboot notifier (err=%d)\n", ret); | |
1da177e4 LT |
290 | goto error3; |
291 | } | |
292 | ||
293 | ret = misc_register(&wafwdt_miscdev); | |
294 | if (ret != 0) { | |
694b16b2 AC |
295 | printk(KERN_ERR PFX |
296 | "cannot register miscdev on minor=%d (err=%d)\n", | |
297 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
298 | goto error4; |
299 | } | |
300 | ||
694b16b2 | 301 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
302 | timeout, nowayout); |
303 | ||
304 | return ret; | |
305 | error4: | |
306 | unregister_reboot_notifier(&wafwdt_notifier); | |
307 | error3: | |
308 | release_region(wdt_start, 1); | |
309 | error2: | |
310 | if (wdt_stop != wdt_start) | |
311 | release_region(wdt_stop, 1); | |
312 | error: | |
313 | return ret; | |
314 | } | |
315 | ||
316 | static void __exit wafwdt_exit(void) | |
317 | { | |
318 | misc_deregister(&wafwdt_miscdev); | |
319 | unregister_reboot_notifier(&wafwdt_notifier); | |
694b16b2 | 320 | if (wdt_stop != wdt_start) |
1da177e4 LT |
321 | release_region(wdt_stop, 1); |
322 | release_region(wdt_start, 1); | |
323 | } | |
324 | ||
325 | module_init(wafwdt_init); | |
326 | module_exit(wafwdt_exit); | |
327 | ||
328 | MODULE_AUTHOR("Justin Cormack"); | |
329 | MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); | |
330 | MODULE_LICENSE("GPL"); | |
331 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
332 | ||
333 | /* end of wafer5823wdt.c */ |