]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IB700 Single Board Computer WDT driver | |
3 | * | |
4 | * (c) Copyright 2001 Charles Howes <chowes@vsol.net> | |
5 | * | |
6 | * Based on advantechwdt.c which is based on acquirewdt.c which | |
7 | * is based on wdt.c. | |
8 | * | |
9 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> | |
10 | * | |
11 | * Based on acquirewdt.c which is based on wdt.c. | |
12 | * Original copyright messages: | |
13 | * | |
14 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
15 | * http://www.redhat.com | |
16 | * | |
17 | * This program is free software; you can redistribute it and/or | |
18 | * modify it under the terms of the GNU General Public License | |
19 | * as published by the Free Software Foundation; either version | |
20 | * 2 of the License, or (at your option) any later version. | |
21 | * | |
22 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | |
23 | * warranty for any of this software. This material is provided | |
24 | * "AS-IS" and at no charge. | |
25 | * | |
26 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> | |
27 | * | |
28 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | |
29 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | |
30 | * Added timeout module option to override default | |
31 | * | |
32 | */ | |
33 | ||
1da177e4 LT |
34 | #include <linux/module.h> |
35 | #include <linux/types.h> | |
36 | #include <linux/miscdevice.h> | |
37 | #include <linux/watchdog.h> | |
38 | #include <linux/ioport.h> | |
39 | #include <linux/notifier.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/reboot.h> | |
42 | #include <linux/init.h> | |
43 | #include <linux/spinlock.h> | |
44 | #include <linux/moduleparam.h> | |
45 | ||
46 | #include <asm/io.h> | |
47 | #include <asm/uaccess.h> | |
48 | #include <asm/system.h> | |
49 | ||
50 | static unsigned long ibwdt_is_open; | |
51 | static spinlock_t ibwdt_lock; | |
52 | static char expect_close; | |
53 | ||
54 | #define PFX "ib700wdt: " | |
55 | ||
56 | /* | |
57 | * | |
58 | * Watchdog Timer Configuration | |
59 | * | |
60 | * The function of the watchdog timer is to reset the system | |
61 | * automatically and is defined at I/O port 0443H. To enable the | |
62 | * watchdog timer and allow the system to reset, write I/O port 0443H. | |
63 | * To disable the timer, write I/O port 0441H for the system to stop the | |
64 | * watchdog function. The timer has a tolerance of 20% for its | |
65 | * intervals. | |
66 | * | |
67 | * The following describes how the timer should be programmed. | |
68 | * | |
69 | * Enabling Watchdog: | |
70 | * MOV AX,000FH (Choose the values from 0 to F) | |
71 | * MOV DX,0443H | |
72 | * OUT DX,AX | |
73 | * | |
74 | * Disabling Watchdog: | |
75 | * MOV AX,000FH (Any value is fine.) | |
76 | * MOV DX,0441H | |
77 | * OUT DX,AX | |
78 | * | |
79 | * Watchdog timer control table: | |
80 | * Level Value Time/sec | Level Value Time/sec | |
81 | * 1 F 0 | 9 7 16 | |
82 | * 2 E 2 | 10 6 18 | |
83 | * 3 D 4 | 11 5 20 | |
84 | * 4 C 6 | 12 4 22 | |
85 | * 5 B 8 | 13 3 24 | |
86 | * 6 A 10 | 14 2 26 | |
87 | * 7 9 12 | 15 1 28 | |
88 | * 8 8 14 | 16 0 30 | |
89 | * | |
90 | */ | |
91 | ||
92 | static int wd_times[] = { | |
93 | 30, /* 0x0 */ | |
94 | 28, /* 0x1 */ | |
95 | 26, /* 0x2 */ | |
96 | 24, /* 0x3 */ | |
97 | 22, /* 0x4 */ | |
98 | 20, /* 0x5 */ | |
99 | 18, /* 0x6 */ | |
100 | 16, /* 0x7 */ | |
101 | 14, /* 0x8 */ | |
102 | 12, /* 0x9 */ | |
103 | 10, /* 0xA */ | |
104 | 8, /* 0xB */ | |
105 | 6, /* 0xC */ | |
106 | 4, /* 0xD */ | |
107 | 2, /* 0xE */ | |
108 | 0, /* 0xF */ | |
109 | }; | |
110 | ||
111 | #define WDT_STOP 0x441 | |
112 | #define WDT_START 0x443 | |
113 | ||
114 | /* Default timeout */ | |
115 | #define WD_TIMO 0 /* 30 seconds +/- 20%, from table */ | |
116 | ||
117 | static int wd_margin = WD_TIMO; | |
118 | ||
4bfdf378 | 119 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
120 | module_param(nowayout, int, 0); |
121 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
122 | ||
123 | ||
124 | /* | |
125 | * Kernel methods. | |
126 | */ | |
127 | ||
128 | static void | |
129 | ibwdt_ping(void) | |
130 | { | |
131 | /* Write a watchdog value */ | |
132 | outb_p(wd_margin, WDT_START); | |
133 | } | |
134 | ||
135 | static ssize_t | |
136 | ibwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
137 | { | |
138 | if (count) { | |
139 | if (!nowayout) { | |
140 | size_t i; | |
141 | ||
142 | /* In case it was set long ago */ | |
143 | expect_close = 0; | |
144 | ||
145 | for (i = 0; i != count; i++) { | |
146 | char c; | |
147 | if (get_user(c, buf + i)) | |
148 | return -EFAULT; | |
149 | if (c == 'V') | |
150 | expect_close = 42; | |
151 | } | |
152 | } | |
153 | ibwdt_ping(); | |
154 | } | |
155 | return count; | |
156 | } | |
157 | ||
158 | static int | |
159 | ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
160 | unsigned long arg) | |
161 | { | |
162 | int i, new_margin; | |
163 | void __user *argp = (void __user *)arg; | |
164 | int __user *p = argp; | |
165 | ||
166 | static struct watchdog_info ident = { | |
167 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
168 | .firmware_version = 1, | |
169 | .identity = "IB700 WDT", | |
170 | }; | |
171 | ||
172 | switch (cmd) { | |
173 | case WDIOC_GETSUPPORT: | |
174 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
175 | return -EFAULT; | |
176 | break; | |
177 | ||
178 | case WDIOC_GETSTATUS: | |
179 | return put_user(0, p); | |
180 | ||
181 | case WDIOC_KEEPALIVE: | |
182 | ibwdt_ping(); | |
183 | break; | |
184 | ||
185 | case WDIOC_SETTIMEOUT: | |
186 | if (get_user(new_margin, p)) | |
187 | return -EFAULT; | |
188 | if ((new_margin < 0) || (new_margin > 30)) | |
189 | return -EINVAL; | |
190 | for (i = 0x0F; i > -1; i--) | |
191 | if (wd_times[i] > new_margin) | |
192 | break; | |
193 | wd_margin = i; | |
194 | ibwdt_ping(); | |
195 | /* Fall */ | |
196 | ||
197 | case WDIOC_GETTIMEOUT: | |
198 | return put_user(wd_times[wd_margin], p); | |
199 | break; | |
200 | ||
201 | default: | |
795b89d2 | 202 | return -ENOTTY; |
1da177e4 LT |
203 | } |
204 | return 0; | |
205 | } | |
206 | ||
207 | static int | |
208 | ibwdt_open(struct inode *inode, struct file *file) | |
209 | { | |
210 | spin_lock(&ibwdt_lock); | |
211 | if (test_and_set_bit(0, &ibwdt_is_open)) { | |
212 | spin_unlock(&ibwdt_lock); | |
213 | return -EBUSY; | |
214 | } | |
215 | if (nowayout) | |
216 | __module_get(THIS_MODULE); | |
217 | ||
218 | /* Activate */ | |
219 | ibwdt_ping(); | |
220 | spin_unlock(&ibwdt_lock); | |
221 | return nonseekable_open(inode, file); | |
222 | } | |
223 | ||
224 | static int | |
225 | ibwdt_close(struct inode *inode, struct file *file) | |
226 | { | |
227 | spin_lock(&ibwdt_lock); | |
228 | if (expect_close == 42) | |
229 | outb_p(0, WDT_STOP); | |
230 | else | |
231 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); | |
232 | ||
233 | clear_bit(0, &ibwdt_is_open); | |
234 | expect_close = 0; | |
235 | spin_unlock(&ibwdt_lock); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | /* | |
240 | * Notifier for system down | |
241 | */ | |
242 | ||
243 | static int | |
244 | ibwdt_notify_sys(struct notifier_block *this, unsigned long code, | |
245 | void *unused) | |
246 | { | |
247 | if (code == SYS_DOWN || code == SYS_HALT) { | |
248 | /* Turn the WDT off */ | |
249 | outb_p(0, WDT_STOP); | |
250 | } | |
251 | return NOTIFY_DONE; | |
252 | } | |
253 | ||
254 | /* | |
255 | * Kernel Interfaces | |
256 | */ | |
257 | ||
62322d25 | 258 | static const struct file_operations ibwdt_fops = { |
1da177e4 LT |
259 | .owner = THIS_MODULE, |
260 | .llseek = no_llseek, | |
261 | .write = ibwdt_write, | |
262 | .ioctl = ibwdt_ioctl, | |
263 | .open = ibwdt_open, | |
264 | .release = ibwdt_close, | |
265 | }; | |
266 | ||
267 | static struct miscdevice ibwdt_miscdev = { | |
268 | .minor = WATCHDOG_MINOR, | |
269 | .name = "watchdog", | |
270 | .fops = &ibwdt_fops, | |
271 | }; | |
272 | ||
273 | /* | |
274 | * The WDT needs to learn about soft shutdowns in order to | |
275 | * turn the timebomb registers off. | |
276 | */ | |
277 | ||
278 | static struct notifier_block ibwdt_notifier = { | |
279 | .notifier_call = ibwdt_notify_sys, | |
280 | }; | |
281 | ||
282 | static int __init ibwdt_init(void) | |
283 | { | |
284 | int res; | |
285 | ||
286 | printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n"); | |
287 | ||
288 | spin_lock_init(&ibwdt_lock); | |
289 | res = misc_register(&ibwdt_miscdev); | |
290 | if (res) { | |
291 | printk (KERN_ERR PFX "failed to register misc device\n"); | |
292 | goto out_nomisc; | |
293 | } | |
294 | ||
295 | #if WDT_START != WDT_STOP | |
296 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | |
297 | printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP); | |
298 | res = -EIO; | |
299 | goto out_nostopreg; | |
300 | } | |
301 | #endif | |
302 | ||
303 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | |
304 | printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START); | |
305 | res = -EIO; | |
306 | goto out_nostartreg; | |
307 | } | |
308 | res = register_reboot_notifier(&ibwdt_notifier); | |
309 | if (res) { | |
310 | printk (KERN_ERR PFX "Failed to register reboot notifier.\n"); | |
311 | goto out_noreboot; | |
312 | } | |
313 | return 0; | |
314 | ||
315 | out_noreboot: | |
316 | release_region(WDT_START, 1); | |
317 | out_nostartreg: | |
318 | #if WDT_START != WDT_STOP | |
319 | release_region(WDT_STOP, 1); | |
320 | #endif | |
321 | out_nostopreg: | |
322 | misc_deregister(&ibwdt_miscdev); | |
323 | out_nomisc: | |
324 | return res; | |
325 | } | |
326 | ||
327 | static void __exit | |
328 | ibwdt_exit(void) | |
329 | { | |
330 | misc_deregister(&ibwdt_miscdev); | |
331 | unregister_reboot_notifier(&ibwdt_notifier); | |
332 | #if WDT_START != WDT_STOP | |
333 | release_region(WDT_STOP,1); | |
334 | #endif | |
335 | release_region(WDT_START,1); | |
336 | } | |
337 | ||
338 | module_init(ibwdt_init); | |
339 | module_exit(ibwdt_exit); | |
340 | ||
341 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | |
342 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | |
343 | MODULE_LICENSE("GPL"); | |
344 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
345 | ||
346 | /* end of ib700wdt.c */ |