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1da177e4 LT |
1 | /* |
2 | * Advantech Single Board Computer WDT driver | |
3 | * | |
4 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> | |
5 | * | |
6 | * Based on acquirewdt.c which is based on wdt.c. | |
7 | * Original copyright messages: | |
8 | * | |
9 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
10 | * http://www.redhat.com | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | |
18 | * warranty for any of this software. This material is provided | |
19 | * "AS-IS" and at no charge. | |
20 | * | |
21 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> | |
22 | * | |
23 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | |
24 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | |
25 | * | |
26 | * 16-Oct-2002 Rob Radez <rob@osinvestor.com> | |
27 | * Clean up ioctls, clean up init + exit, add expect close support, | |
28 | * add wdt_start and wdt_stop as parameters. | |
29 | */ | |
30 | ||
31 | #include <linux/module.h> | |
32 | #include <linux/moduleparam.h> | |
33 | #include <linux/types.h> | |
34 | #include <linux/miscdevice.h> | |
35 | #include <linux/watchdog.h> | |
36 | #include <linux/fs.h> | |
37 | #include <linux/ioport.h> | |
38 | #include <linux/notifier.h> | |
39 | #include <linux/reboot.h> | |
40 | #include <linux/init.h> | |
41 | ||
42 | #include <asm/io.h> | |
43 | #include <asm/uaccess.h> | |
44 | #include <asm/system.h> | |
45 | ||
46 | #define WATCHDOG_NAME "Advantech WDT" | |
47 | #define PFX WATCHDOG_NAME ": " | |
48 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ | |
49 | ||
50 | static unsigned long advwdt_is_open; | |
51 | static char adv_expect_close; | |
52 | ||
53 | /* | |
54 | * You must set these - there is no sane way to probe for this board. | |
55 | * | |
56 | * To enable or restart, write the timeout value in seconds (1 to 63) | |
57 | * to I/O port wdt_start. To disable, read I/O port wdt_stop. | |
58 | * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but | |
59 | * check your manual (at least the PCA-6159 seems to be different - | |
60 | * the manual says wdt_stop is 0x43, not 0x443). | |
61 | * (0x43 is also a write-only control register for the 8254 timer!) | |
62 | */ | |
63 | ||
64 | static int wdt_stop = 0x443; | |
65 | module_param(wdt_stop, int, 0); | |
66 | MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); | |
67 | ||
68 | static int wdt_start = 0x443; | |
69 | module_param(wdt_start, int, 0); | |
70 | MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); | |
71 | ||
72 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ | |
73 | module_param(timeout, int, 0); | |
74 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); | |
75 | ||
4bfdf378 | 76 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
77 | module_param(nowayout, int, 0); |
78 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
79 | ||
80 | /* | |
81 | * Kernel methods. | |
82 | */ | |
83 | ||
84 | static void | |
85 | advwdt_ping(void) | |
86 | { | |
87 | /* Write a watchdog value */ | |
88 | outb_p(timeout, wdt_start); | |
89 | } | |
90 | ||
91 | static void | |
92 | advwdt_disable(void) | |
93 | { | |
94 | inb_p(wdt_stop); | |
95 | } | |
96 | ||
97 | static ssize_t | |
98 | advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
99 | { | |
100 | if (count) { | |
101 | if (!nowayout) { | |
102 | size_t i; | |
103 | ||
104 | adv_expect_close = 0; | |
105 | ||
106 | for (i = 0; i != count; i++) { | |
107 | char c; | |
108 | if (get_user(c, buf+i)) | |
109 | return -EFAULT; | |
110 | if (c == 'V') | |
111 | adv_expect_close = 42; | |
112 | } | |
113 | } | |
114 | advwdt_ping(); | |
115 | } | |
116 | return count; | |
117 | } | |
118 | ||
119 | static int | |
120 | advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
121 | unsigned long arg) | |
122 | { | |
123 | int new_timeout; | |
124 | void __user *argp = (void __user *)arg; | |
125 | int __user *p = argp; | |
126 | static struct watchdog_info ident = { | |
127 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
128 | .firmware_version = 1, | |
129 | .identity = "Advantech WDT", | |
130 | }; | |
131 | ||
132 | switch (cmd) { | |
133 | case WDIOC_GETSUPPORT: | |
134 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
135 | return -EFAULT; | |
136 | break; | |
137 | ||
138 | case WDIOC_GETSTATUS: | |
139 | case WDIOC_GETBOOTSTATUS: | |
140 | return put_user(0, p); | |
141 | ||
142 | case WDIOC_KEEPALIVE: | |
143 | advwdt_ping(); | |
144 | break; | |
145 | ||
146 | case WDIOC_SETTIMEOUT: | |
147 | if (get_user(new_timeout, p)) | |
148 | return -EFAULT; | |
149 | if ((new_timeout < 1) || (new_timeout > 63)) | |
150 | return -EINVAL; | |
151 | timeout = new_timeout; | |
152 | advwdt_ping(); | |
153 | /* Fall */ | |
154 | ||
155 | case WDIOC_GETTIMEOUT: | |
156 | return put_user(timeout, p); | |
157 | ||
158 | case WDIOC_SETOPTIONS: | |
159 | { | |
160 | int options, retval = -EINVAL; | |
161 | ||
162 | if (get_user(options, p)) | |
163 | return -EFAULT; | |
164 | ||
165 | if (options & WDIOS_DISABLECARD) { | |
166 | advwdt_disable(); | |
167 | retval = 0; | |
168 | } | |
169 | ||
170 | if (options & WDIOS_ENABLECARD) { | |
171 | advwdt_ping(); | |
172 | retval = 0; | |
173 | } | |
174 | ||
175 | return retval; | |
176 | } | |
177 | ||
178 | default: | |
795b89d2 | 179 | return -ENOTTY; |
1da177e4 LT |
180 | } |
181 | return 0; | |
182 | } | |
183 | ||
184 | static int | |
185 | advwdt_open(struct inode *inode, struct file *file) | |
186 | { | |
187 | if (test_and_set_bit(0, &advwdt_is_open)) | |
188 | return -EBUSY; | |
189 | /* | |
190 | * Activate | |
191 | */ | |
192 | ||
193 | advwdt_ping(); | |
194 | return nonseekable_open(inode, file); | |
195 | } | |
196 | ||
197 | static int | |
198 | advwdt_close(struct inode *inode, struct file *file) | |
199 | { | |
200 | if (adv_expect_close == 42) { | |
201 | advwdt_disable(); | |
202 | } else { | |
203 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | |
204 | advwdt_ping(); | |
205 | } | |
206 | clear_bit(0, &advwdt_is_open); | |
207 | adv_expect_close = 0; | |
208 | return 0; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Notifier for system down | |
213 | */ | |
214 | ||
215 | static int | |
216 | advwdt_notify_sys(struct notifier_block *this, unsigned long code, | |
217 | void *unused) | |
218 | { | |
219 | if (code == SYS_DOWN || code == SYS_HALT) { | |
220 | /* Turn the WDT off */ | |
221 | advwdt_disable(); | |
222 | } | |
223 | return NOTIFY_DONE; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Kernel Interfaces | |
228 | */ | |
229 | ||
62322d25 | 230 | static const struct file_operations advwdt_fops = { |
1da177e4 LT |
231 | .owner = THIS_MODULE, |
232 | .llseek = no_llseek, | |
233 | .write = advwdt_write, | |
234 | .ioctl = advwdt_ioctl, | |
235 | .open = advwdt_open, | |
236 | .release = advwdt_close, | |
237 | }; | |
238 | ||
239 | static struct miscdevice advwdt_miscdev = { | |
240 | .minor = WATCHDOG_MINOR, | |
241 | .name = "watchdog", | |
242 | .fops = &advwdt_fops, | |
243 | }; | |
244 | ||
245 | /* | |
246 | * The WDT needs to learn about soft shutdowns in order to | |
247 | * turn the timebomb registers off. | |
248 | */ | |
249 | ||
250 | static struct notifier_block advwdt_notifier = { | |
251 | .notifier_call = advwdt_notify_sys, | |
252 | }; | |
253 | ||
254 | static int __init | |
255 | advwdt_init(void) | |
256 | { | |
257 | int ret; | |
258 | ||
259 | printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); | |
260 | ||
261 | if (timeout < 1 || timeout > 63) { | |
262 | timeout = WATCHDOG_TIMEOUT; | |
263 | printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n", | |
264 | timeout); | |
265 | } | |
266 | ||
267 | if (wdt_stop != wdt_start) { | |
268 | if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { | |
269 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
270 | wdt_stop); | |
271 | ret = -EIO; | |
272 | goto out; | |
273 | } | |
274 | } | |
275 | ||
276 | if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { | |
277 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
278 | wdt_start); | |
279 | ret = -EIO; | |
280 | goto unreg_stop; | |
281 | } | |
282 | ||
283 | ret = register_reboot_notifier(&advwdt_notifier); | |
284 | if (ret != 0) { | |
285 | printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
286 | ret); | |
287 | goto unreg_regions; | |
288 | } | |
289 | ||
290 | ret = misc_register(&advwdt_miscdev); | |
291 | if (ret != 0) { | |
292 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
293 | WATCHDOG_MINOR, ret); | |
294 | goto unreg_reboot; | |
295 | } | |
296 | ||
297 | printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | |
298 | timeout, nowayout); | |
299 | ||
300 | out: | |
301 | return ret; | |
302 | unreg_reboot: | |
303 | unregister_reboot_notifier(&advwdt_notifier); | |
304 | unreg_regions: | |
305 | release_region(wdt_start, 1); | |
306 | unreg_stop: | |
307 | if (wdt_stop != wdt_start) | |
308 | release_region(wdt_stop, 1); | |
309 | goto out; | |
310 | } | |
311 | ||
312 | static void __exit | |
313 | advwdt_exit(void) | |
314 | { | |
315 | misc_deregister(&advwdt_miscdev); | |
316 | unregister_reboot_notifier(&advwdt_notifier); | |
317 | if(wdt_stop != wdt_start) | |
318 | release_region(wdt_stop,1); | |
319 | release_region(wdt_start,1); | |
320 | } | |
321 | ||
322 | module_init(advwdt_init); | |
323 | module_exit(advwdt_exit); | |
324 | ||
325 | MODULE_LICENSE("GPL"); | |
326 | MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); | |
327 | MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); | |
328 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |