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 | ||
27c766aa JP |
29 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
30 | ||
1da177e4 LT |
31 | #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> | |
694b16b2 AC |
41 | #include <linux/io.h> |
42 | #include <linux/uaccess.h> | |
1da177e4 LT |
43 | |
44 | #define WATCHDOG_NAME "Wafer 5823 WDT" | |
45 | #define PFX WATCHDOG_NAME ": " | |
46 | #define WD_TIMO 60 /* 60 sec default timeout */ | |
47 | ||
48 | static unsigned long wafwdt_is_open; | |
49 | static char expect_close; | |
c7dfd0cc | 50 | static DEFINE_SPINLOCK(wafwdt_lock); |
1da177e4 LT |
51 | |
52 | /* | |
53 | * You must set these - there is no sane way to probe for this board. | |
54 | * | |
7944d3a5 WVS |
55 | * 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. | |
1da177e4 LT |
59 | */ |
60 | ||
61 | static int wdt_stop = 0x843; | |
62 | static int wdt_start = 0x443; | |
63 | ||
64 | static int timeout = WD_TIMO; /* in seconds */ | |
65 | module_param(timeout, int, 0); | |
694b16b2 AC |
66 | MODULE_PARM_DESC(timeout, |
67 | "Watchdog timeout in seconds. 1 <= timeout <= 255, default=" | |
68 | __MODULE_STRING(WD_TIMO) "."); | |
1da177e4 | 69 | |
86a1e189 WVS |
70 | static bool nowayout = WATCHDOG_NOWAYOUT; |
71 | module_param(nowayout, bool, 0); | |
694b16b2 AC |
72 | MODULE_PARM_DESC(nowayout, |
73 | "Watchdog cannot be stopped once started (default=" | |
74 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
75 | |
76 | static 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 | ||
85 | static void wafwdt_start(void) | |
86 | { | |
87 | /* start up watchdog */ | |
88 | outb_p(timeout, wdt_start); | |
89 | inb_p(wdt_start); | |
90 | } | |
91 | ||
7944d3a5 | 92 | static void wafwdt_stop(void) |
1da177e4 LT |
93 | { |
94 | /* stop watchdog */ | |
95 | inb_p(wdt_stop); | |
96 | } | |
97 | ||
694b16b2 AC |
98 | static ssize_t wafwdt_write(struct file *file, const char __user *buf, |
99 | size_t count, loff_t *ppos) | |
1da177e4 LT |
100 | { |
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 | ||
694b16b2 AC |
109 | /* scan to see whether or not we got the magic |
110 | character */ | |
1da177e4 LT |
111 | 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 | } | |
694b16b2 AC |
119 | /* Well, anyhow someone wrote to us, we should |
120 | return that favour */ | |
1da177e4 LT |
121 | wafwdt_ping(); |
122 | } | |
123 | return count; | |
124 | } | |
125 | ||
694b16b2 AC |
126 | static long wafwdt_ioctl(struct file *file, unsigned int cmd, |
127 | unsigned long arg) | |
1da177e4 LT |
128 | { |
129 | int new_timeout; | |
130 | void __user *argp = (void __user *)arg; | |
131 | int __user *p = argp; | |
694b16b2 AC |
132 | static const struct watchdog_info ident = { |
133 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | | |
134 | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
135 | .firmware_version = 1, |
136 | .identity = "Wafer 5823 WDT", | |
137 | }; | |
138 | ||
139 | switch (cmd) { | |
140 | case WDIOC_GETSUPPORT: | |
694b16b2 | 141 | if (copy_to_user(argp, &ident, sizeof(ident))) |
1da177e4 LT |
142 | return -EFAULT; |
143 | break; | |
144 | ||
145 | case WDIOC_GETSTATUS: | |
146 | case WDIOC_GETBOOTSTATUS: | |
147 | return put_user(0, p); | |
148 | ||
1da177e4 LT |
149 | 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) { | |
8a062ac6 | 157 | wafwdt_stop(); |
1da177e4 LT |
158 | retval = 0; |
159 | } | |
160 | ||
161 | if (options & WDIOS_ENABLECARD) { | |
8a062ac6 | 162 | wafwdt_start(); |
1da177e4 LT |
163 | retval = 0; |
164 | } | |
165 | ||
166 | return retval; | |
167 | } | |
168 | ||
0c06090c WVS |
169 | 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 | ||
1da177e4 | 185 | default: |
795b89d2 | 186 | return -ENOTTY; |
1da177e4 LT |
187 | } |
188 | return 0; | |
189 | } | |
190 | ||
191 | static 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 | ||
7944d3a5 | 203 | static int wafwdt_close(struct inode *inode, struct file *file) |
1da177e4 | 204 | { |
694b16b2 | 205 | if (expect_close == 42) |
1da177e4 | 206 | wafwdt_stop(); |
694b16b2 | 207 | else { |
27c766aa | 208 | pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); |
1da177e4 LT |
209 | 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 | ||
694b16b2 AC |
220 | static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, |
221 | void *unused) | |
1da177e4 | 222 | { |
694b16b2 | 223 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 | 224 | wafwdt_stop(); |
1da177e4 LT |
225 | return NOTIFY_DONE; |
226 | } | |
227 | ||
228 | /* | |
229 | * Kernel Interfaces | |
230 | */ | |
231 | ||
62322d25 | 232 | static const struct file_operations wafwdt_fops = { |
1da177e4 LT |
233 | .owner = THIS_MODULE, |
234 | .llseek = no_llseek, | |
235 | .write = wafwdt_write, | |
694b16b2 | 236 | .unlocked_ioctl = wafwdt_ioctl, |
1da177e4 LT |
237 | .open = wafwdt_open, |
238 | .release = wafwdt_close, | |
239 | }; | |
240 | ||
241 | static 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 | ||
252 | static struct notifier_block wafwdt_notifier = { | |
253 | .notifier_call = wafwdt_notify_sys, | |
254 | }; | |
255 | ||
256 | static int __init wafwdt_init(void) | |
257 | { | |
258 | int ret; | |
259 | ||
27c766aa | 260 | pr_info("WDT driver for Wafer 5823 single board computer initialising\n"); |
1da177e4 | 261 | |
1da177e4 LT |
262 | if (timeout < 1 || timeout > 255) { |
263 | timeout = WD_TIMO; | |
27c766aa JP |
264 | pr_info("timeout value must be 1 <= x <= 255, using %d\n", |
265 | timeout); | |
1da177e4 LT |
266 | } |
267 | ||
268 | if (wdt_stop != wdt_start) { | |
694b16b2 | 269 | if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { |
27c766aa | 270 | pr_err("I/O address 0x%04x already in use\n", wdt_stop); |
1da177e4 LT |
271 | ret = -EIO; |
272 | goto error; | |
273 | } | |
274 | } | |
275 | ||
694b16b2 | 276 | if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) { |
27c766aa | 277 | pr_err("I/O address 0x%04x already in use\n", wdt_start); |
1da177e4 LT |
278 | ret = -EIO; |
279 | goto error2; | |
280 | } | |
281 | ||
282 | ret = register_reboot_notifier(&wafwdt_notifier); | |
283 | if (ret != 0) { | |
27c766aa | 284 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
285 | goto error3; |
286 | } | |
287 | ||
288 | ret = misc_register(&wafwdt_miscdev); | |
289 | if (ret != 0) { | |
27c766aa JP |
290 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
291 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
292 | goto error4; |
293 | } | |
294 | ||
27c766aa | 295 | pr_info("initialized. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
296 | timeout, nowayout); |
297 | ||
298 | return ret; | |
299 | error4: | |
300 | unregister_reboot_notifier(&wafwdt_notifier); | |
301 | error3: | |
302 | release_region(wdt_start, 1); | |
303 | error2: | |
304 | if (wdt_stop != wdt_start) | |
305 | release_region(wdt_stop, 1); | |
306 | error: | |
307 | return ret; | |
308 | } | |
309 | ||
310 | static void __exit wafwdt_exit(void) | |
311 | { | |
312 | misc_deregister(&wafwdt_miscdev); | |
313 | unregister_reboot_notifier(&wafwdt_notifier); | |
694b16b2 | 314 | if (wdt_stop != wdt_start) |
1da177e4 LT |
315 | release_region(wdt_stop, 1); |
316 | release_region(wdt_start, 1); | |
317 | } | |
318 | ||
319 | module_init(wafwdt_init); | |
320 | module_exit(wafwdt_exit); | |
321 | ||
322 | MODULE_AUTHOR("Justin Cormack"); | |
323 | MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); | |
324 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
325 | |
326 | /* end of wafer5823wdt.c */ |