diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/ib700wdt.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/ib700wdt.c')
-rw-r--r-- | drivers/char/watchdog/ib700wdt.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/char/watchdog/ib700wdt.c b/drivers/char/watchdog/ib700wdt.c new file mode 100644 index 000000000000..d974f16e84d2 --- /dev/null +++ b/drivers/char/watchdog/ib700wdt.c | |||
@@ -0,0 +1,352 @@ | |||
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 | |||
34 | #include <linux/config.h> | ||
35 | #include <linux/module.h> | ||
36 | #include <linux/types.h> | ||
37 | #include <linux/miscdevice.h> | ||
38 | #include <linux/watchdog.h> | ||
39 | #include <linux/ioport.h> | ||
40 | #include <linux/notifier.h> | ||
41 | #include <linux/fs.h> | ||
42 | #include <linux/reboot.h> | ||
43 | #include <linux/init.h> | ||
44 | #include <linux/spinlock.h> | ||
45 | #include <linux/moduleparam.h> | ||
46 | |||
47 | #include <asm/io.h> | ||
48 | #include <asm/uaccess.h> | ||
49 | #include <asm/system.h> | ||
50 | |||
51 | static unsigned long ibwdt_is_open; | ||
52 | static spinlock_t ibwdt_lock; | ||
53 | static char expect_close; | ||
54 | |||
55 | #define PFX "ib700wdt: " | ||
56 | |||
57 | /* | ||
58 | * | ||
59 | * Watchdog Timer Configuration | ||
60 | * | ||
61 | * The function of the watchdog timer is to reset the system | ||
62 | * automatically and is defined at I/O port 0443H. To enable the | ||
63 | * watchdog timer and allow the system to reset, write I/O port 0443H. | ||
64 | * To disable the timer, write I/O port 0441H for the system to stop the | ||
65 | * watchdog function. The timer has a tolerance of 20% for its | ||
66 | * intervals. | ||
67 | * | ||
68 | * The following describes how the timer should be programmed. | ||
69 | * | ||
70 | * Enabling Watchdog: | ||
71 | * MOV AX,000FH (Choose the values from 0 to F) | ||
72 | * MOV DX,0443H | ||
73 | * OUT DX,AX | ||
74 | * | ||
75 | * Disabling Watchdog: | ||
76 | * MOV AX,000FH (Any value is fine.) | ||
77 | * MOV DX,0441H | ||
78 | * OUT DX,AX | ||
79 | * | ||
80 | * Watchdog timer control table: | ||
81 | * Level Value Time/sec | Level Value Time/sec | ||
82 | * 1 F 0 | 9 7 16 | ||
83 | * 2 E 2 | 10 6 18 | ||
84 | * 3 D 4 | 11 5 20 | ||
85 | * 4 C 6 | 12 4 22 | ||
86 | * 5 B 8 | 13 3 24 | ||
87 | * 6 A 10 | 14 2 26 | ||
88 | * 7 9 12 | 15 1 28 | ||
89 | * 8 8 14 | 16 0 30 | ||
90 | * | ||
91 | */ | ||
92 | |||
93 | static int wd_times[] = { | ||
94 | 30, /* 0x0 */ | ||
95 | 28, /* 0x1 */ | ||
96 | 26, /* 0x2 */ | ||
97 | 24, /* 0x3 */ | ||
98 | 22, /* 0x4 */ | ||
99 | 20, /* 0x5 */ | ||
100 | 18, /* 0x6 */ | ||
101 | 16, /* 0x7 */ | ||
102 | 14, /* 0x8 */ | ||
103 | 12, /* 0x9 */ | ||
104 | 10, /* 0xA */ | ||
105 | 8, /* 0xB */ | ||
106 | 6, /* 0xC */ | ||
107 | 4, /* 0xD */ | ||
108 | 2, /* 0xE */ | ||
109 | 0, /* 0xF */ | ||
110 | }; | ||
111 | |||
112 | #define WDT_STOP 0x441 | ||
113 | #define WDT_START 0x443 | ||
114 | |||
115 | /* Default timeout */ | ||
116 | #define WD_TIMO 0 /* 30 seconds +/- 20%, from table */ | ||
117 | |||
118 | static int wd_margin = WD_TIMO; | ||
119 | |||
120 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
121 | static int nowayout = 1; | ||
122 | #else | ||
123 | static int nowayout = 0; | ||
124 | #endif | ||
125 | |||
126 | module_param(nowayout, int, 0); | ||
127 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | ||
128 | |||
129 | |||
130 | /* | ||
131 | * Kernel methods. | ||
132 | */ | ||
133 | |||
134 | static void | ||
135 | ibwdt_ping(void) | ||
136 | { | ||
137 | /* Write a watchdog value */ | ||
138 | outb_p(wd_margin, WDT_START); | ||
139 | } | ||
140 | |||
141 | static ssize_t | ||
142 | ibwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | ||
143 | { | ||
144 | if (count) { | ||
145 | if (!nowayout) { | ||
146 | size_t i; | ||
147 | |||
148 | /* In case it was set long ago */ | ||
149 | expect_close = 0; | ||
150 | |||
151 | for (i = 0; i != count; i++) { | ||
152 | char c; | ||
153 | if (get_user(c, buf + i)) | ||
154 | return -EFAULT; | ||
155 | if (c == 'V') | ||
156 | expect_close = 42; | ||
157 | } | ||
158 | } | ||
159 | ibwdt_ping(); | ||
160 | } | ||
161 | return count; | ||
162 | } | ||
163 | |||
164 | static int | ||
165 | ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
166 | unsigned long arg) | ||
167 | { | ||
168 | int i, new_margin; | ||
169 | void __user *argp = (void __user *)arg; | ||
170 | int __user *p = argp; | ||
171 | |||
172 | static struct watchdog_info ident = { | ||
173 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | ||
174 | .firmware_version = 1, | ||
175 | .identity = "IB700 WDT", | ||
176 | }; | ||
177 | |||
178 | switch (cmd) { | ||
179 | case WDIOC_GETSUPPORT: | ||
180 | if (copy_to_user(argp, &ident, sizeof(ident))) | ||
181 | return -EFAULT; | ||
182 | break; | ||
183 | |||
184 | case WDIOC_GETSTATUS: | ||
185 | return put_user(0, p); | ||
186 | |||
187 | case WDIOC_KEEPALIVE: | ||
188 | ibwdt_ping(); | ||
189 | break; | ||
190 | |||
191 | case WDIOC_SETTIMEOUT: | ||
192 | if (get_user(new_margin, p)) | ||
193 | return -EFAULT; | ||
194 | if ((new_margin < 0) || (new_margin > 30)) | ||
195 | return -EINVAL; | ||
196 | for (i = 0x0F; i > -1; i--) | ||
197 | if (wd_times[i] > new_margin) | ||
198 | break; | ||
199 | wd_margin = i; | ||
200 | ibwdt_ping(); | ||
201 | /* Fall */ | ||
202 | |||
203 | case WDIOC_GETTIMEOUT: | ||
204 | return put_user(wd_times[wd_margin], p); | ||
205 | break; | ||
206 | |||
207 | default: | ||
208 | return -ENOIOCTLCMD; | ||
209 | } | ||
210 | return 0; | ||
211 | } | ||
212 | |||
213 | static int | ||
214 | ibwdt_open(struct inode *inode, struct file *file) | ||
215 | { | ||
216 | spin_lock(&ibwdt_lock); | ||
217 | if (test_and_set_bit(0, &ibwdt_is_open)) { | ||
218 | spin_unlock(&ibwdt_lock); | ||
219 | return -EBUSY; | ||
220 | } | ||
221 | if (nowayout) | ||
222 | __module_get(THIS_MODULE); | ||
223 | |||
224 | /* Activate */ | ||
225 | ibwdt_ping(); | ||
226 | spin_unlock(&ibwdt_lock); | ||
227 | return nonseekable_open(inode, file); | ||
228 | } | ||
229 | |||
230 | static int | ||
231 | ibwdt_close(struct inode *inode, struct file *file) | ||
232 | { | ||
233 | spin_lock(&ibwdt_lock); | ||
234 | if (expect_close == 42) | ||
235 | outb_p(0, WDT_STOP); | ||
236 | else | ||
237 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); | ||
238 | |||
239 | clear_bit(0, &ibwdt_is_open); | ||
240 | expect_close = 0; | ||
241 | spin_unlock(&ibwdt_lock); | ||
242 | return 0; | ||
243 | } | ||
244 | |||
245 | /* | ||
246 | * Notifier for system down | ||
247 | */ | ||
248 | |||
249 | static int | ||
250 | ibwdt_notify_sys(struct notifier_block *this, unsigned long code, | ||
251 | void *unused) | ||
252 | { | ||
253 | if (code == SYS_DOWN || code == SYS_HALT) { | ||
254 | /* Turn the WDT off */ | ||
255 | outb_p(0, WDT_STOP); | ||
256 | } | ||
257 | return NOTIFY_DONE; | ||
258 | } | ||
259 | |||
260 | /* | ||
261 | * Kernel Interfaces | ||
262 | */ | ||
263 | |||
264 | static struct file_operations ibwdt_fops = { | ||
265 | .owner = THIS_MODULE, | ||
266 | .llseek = no_llseek, | ||
267 | .write = ibwdt_write, | ||
268 | .ioctl = ibwdt_ioctl, | ||
269 | .open = ibwdt_open, | ||
270 | .release = ibwdt_close, | ||
271 | }; | ||
272 | |||
273 | static struct miscdevice ibwdt_miscdev = { | ||
274 | .minor = WATCHDOG_MINOR, | ||
275 | .name = "watchdog", | ||
276 | .fops = &ibwdt_fops, | ||
277 | }; | ||
278 | |||
279 | /* | ||
280 | * The WDT needs to learn about soft shutdowns in order to | ||
281 | * turn the timebomb registers off. | ||
282 | */ | ||
283 | |||
284 | static struct notifier_block ibwdt_notifier = { | ||
285 | .notifier_call = ibwdt_notify_sys, | ||
286 | }; | ||
287 | |||
288 | static int __init ibwdt_init(void) | ||
289 | { | ||
290 | int res; | ||
291 | |||
292 | printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n"); | ||
293 | |||
294 | spin_lock_init(&ibwdt_lock); | ||
295 | res = misc_register(&ibwdt_miscdev); | ||
296 | if (res) { | ||
297 | printk (KERN_ERR PFX "failed to register misc device\n"); | ||
298 | goto out_nomisc; | ||
299 | } | ||
300 | |||
301 | #if WDT_START != WDT_STOP | ||
302 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | ||
303 | printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP); | ||
304 | res = -EIO; | ||
305 | goto out_nostopreg; | ||
306 | } | ||
307 | #endif | ||
308 | |||
309 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | ||
310 | printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START); | ||
311 | res = -EIO; | ||
312 | goto out_nostartreg; | ||
313 | } | ||
314 | res = register_reboot_notifier(&ibwdt_notifier); | ||
315 | if (res) { | ||
316 | printk (KERN_ERR PFX "Failed to register reboot notifier.\n"); | ||
317 | goto out_noreboot; | ||
318 | } | ||
319 | return 0; | ||
320 | |||
321 | out_noreboot: | ||
322 | release_region(WDT_START, 1); | ||
323 | out_nostartreg: | ||
324 | #if WDT_START != WDT_STOP | ||
325 | release_region(WDT_STOP, 1); | ||
326 | #endif | ||
327 | out_nostopreg: | ||
328 | misc_deregister(&ibwdt_miscdev); | ||
329 | out_nomisc: | ||
330 | return res; | ||
331 | } | ||
332 | |||
333 | static void __exit | ||
334 | ibwdt_exit(void) | ||
335 | { | ||
336 | misc_deregister(&ibwdt_miscdev); | ||
337 | unregister_reboot_notifier(&ibwdt_notifier); | ||
338 | #if WDT_START != WDT_STOP | ||
339 | release_region(WDT_STOP,1); | ||
340 | #endif | ||
341 | release_region(WDT_START,1); | ||
342 | } | ||
343 | |||
344 | module_init(ibwdt_init); | ||
345 | module_exit(ibwdt_exit); | ||
346 | |||
347 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | ||
348 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | ||
349 | MODULE_LICENSE("GPL"); | ||
350 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
351 | |||
352 | /* end of ib700wdt.c */ | ||