diff options
Diffstat (limited to 'drivers/watchdog/ib700wdt.c')
-rw-r--r-- | drivers/watchdog/ib700wdt.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/watchdog/ib700wdt.c b/drivers/watchdog/ib700wdt.c new file mode 100644 index 000000000000..c3a60f52ccb9 --- /dev/null +++ b/drivers/watchdog/ib700wdt.c | |||
@@ -0,0 +1,408 @@ | |||
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/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/fs.h> | ||
40 | #include <linux/init.h> | ||
41 | #include <linux/spinlock.h> | ||
42 | #include <linux/moduleparam.h> | ||
43 | #include <linux/platform_device.h> | ||
44 | |||
45 | #include <asm/io.h> | ||
46 | #include <asm/uaccess.h> | ||
47 | #include <asm/system.h> | ||
48 | |||
49 | static struct platform_device *ibwdt_platform_device; | ||
50 | static unsigned long ibwdt_is_open; | ||
51 | static spinlock_t ibwdt_lock; | ||
52 | static char expect_close; | ||
53 | |||
54 | /* Module information */ | ||
55 | #define DRV_NAME "ib700wdt" | ||
56 | #define PFX DRV_NAME ": " | ||
57 | |||
58 | /* | ||
59 | * | ||
60 | * Watchdog Timer Configuration | ||
61 | * | ||
62 | * The function of the watchdog timer is to reset the system | ||
63 | * automatically and is defined at I/O port 0443H. To enable the | ||
64 | * watchdog timer and allow the system to reset, write I/O port 0443H. | ||
65 | * To disable the timer, write I/O port 0441H for the system to stop the | ||
66 | * watchdog function. The timer has a tolerance of 20% for its | ||
67 | * intervals. | ||
68 | * | ||
69 | * The following describes how the timer should be programmed. | ||
70 | * | ||
71 | * Enabling Watchdog: | ||
72 | * MOV AX,000FH (Choose the values from 0 to F) | ||
73 | * MOV DX,0443H | ||
74 | * OUT DX,AX | ||
75 | * | ||
76 | * Disabling Watchdog: | ||
77 | * MOV AX,000FH (Any value is fine.) | ||
78 | * MOV DX,0441H | ||
79 | * OUT DX,AX | ||
80 | * | ||
81 | * Watchdog timer control table: | ||
82 | * Level Value Time/sec | Level Value Time/sec | ||
83 | * 1 F 0 | 9 7 16 | ||
84 | * 2 E 2 | 10 6 18 | ||
85 | * 3 D 4 | 11 5 20 | ||
86 | * 4 C 6 | 12 4 22 | ||
87 | * 5 B 8 | 13 3 24 | ||
88 | * 6 A 10 | 14 2 26 | ||
89 | * 7 9 12 | 15 1 28 | ||
90 | * 8 8 14 | 16 0 30 | ||
91 | * | ||
92 | */ | ||
93 | |||
94 | static int wd_times[] = { | ||
95 | 30, /* 0x0 */ | ||
96 | 28, /* 0x1 */ | ||
97 | 26, /* 0x2 */ | ||
98 | 24, /* 0x3 */ | ||
99 | 22, /* 0x4 */ | ||
100 | 20, /* 0x5 */ | ||
101 | 18, /* 0x6 */ | ||
102 | 16, /* 0x7 */ | ||
103 | 14, /* 0x8 */ | ||
104 | 12, /* 0x9 */ | ||
105 | 10, /* 0xA */ | ||
106 | 8, /* 0xB */ | ||
107 | 6, /* 0xC */ | ||
108 | 4, /* 0xD */ | ||
109 | 2, /* 0xE */ | ||
110 | 0, /* 0xF */ | ||
111 | }; | ||
112 | |||
113 | #define WDT_STOP 0x441 | ||
114 | #define WDT_START 0x443 | ||
115 | |||
116 | /* Default timeout */ | ||
117 | #define WD_TIMO 0 /* 30 seconds +/- 20%, from table */ | ||
118 | |||
119 | static int wd_margin = WD_TIMO; | ||
120 | |||
121 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
122 | module_param(nowayout, int, 0); | ||
123 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
124 | |||
125 | |||
126 | /* | ||
127 | * Watchdog Operations | ||
128 | */ | ||
129 | |||
130 | static void | ||
131 | ibwdt_ping(void) | ||
132 | { | ||
133 | spin_lock(&ibwdt_lock); | ||
134 | |||
135 | /* Write a watchdog value */ | ||
136 | outb_p(wd_margin, WDT_START); | ||
137 | |||
138 | spin_unlock(&ibwdt_lock); | ||
139 | } | ||
140 | |||
141 | static void | ||
142 | ibwdt_disable(void) | ||
143 | { | ||
144 | spin_lock(&ibwdt_lock); | ||
145 | outb_p(0, WDT_STOP); | ||
146 | spin_unlock(&ibwdt_lock); | ||
147 | } | ||
148 | |||
149 | static int | ||
150 | ibwdt_set_heartbeat(int t) | ||
151 | { | ||
152 | int i; | ||
153 | |||
154 | if ((t < 0) || (t > 30)) | ||
155 | return -EINVAL; | ||
156 | |||
157 | for (i = 0x0F; i > -1; i--) | ||
158 | if (wd_times[i] > t) | ||
159 | break; | ||
160 | wd_margin = i; | ||
161 | return 0; | ||
162 | } | ||
163 | |||
164 | /* | ||
165 | * /dev/watchdog handling | ||
166 | */ | ||
167 | |||
168 | static ssize_t | ||
169 | ibwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | ||
170 | { | ||
171 | if (count) { | ||
172 | if (!nowayout) { | ||
173 | size_t i; | ||
174 | |||
175 | /* In case it was set long ago */ | ||
176 | expect_close = 0; | ||
177 | |||
178 | for (i = 0; i != count; i++) { | ||
179 | char c; | ||
180 | if (get_user(c, buf + i)) | ||
181 | return -EFAULT; | ||
182 | if (c == 'V') | ||
183 | expect_close = 42; | ||
184 | } | ||
185 | } | ||
186 | ibwdt_ping(); | ||
187 | } | ||
188 | return count; | ||
189 | } | ||
190 | |||
191 | static int | ||
192 | ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
193 | unsigned long arg) | ||
194 | { | ||
195 | int new_margin; | ||
196 | void __user *argp = (void __user *)arg; | ||
197 | int __user *p = argp; | ||
198 | |||
199 | static struct watchdog_info ident = { | ||
200 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | ||
201 | .firmware_version = 1, | ||
202 | .identity = "IB700 WDT", | ||
203 | }; | ||
204 | |||
205 | switch (cmd) { | ||
206 | case WDIOC_GETSUPPORT: | ||
207 | if (copy_to_user(argp, &ident, sizeof(ident))) | ||
208 | return -EFAULT; | ||
209 | break; | ||
210 | |||
211 | case WDIOC_GETSTATUS: | ||
212 | case WDIOC_GETBOOTSTATUS: | ||
213 | return put_user(0, p); | ||
214 | |||
215 | case WDIOC_KEEPALIVE: | ||
216 | ibwdt_ping(); | ||
217 | break; | ||
218 | |||
219 | case WDIOC_SETTIMEOUT: | ||
220 | if (get_user(new_margin, p)) | ||
221 | return -EFAULT; | ||
222 | if (ibwdt_set_heartbeat(new_margin)) | ||
223 | return -EINVAL; | ||
224 | ibwdt_ping(); | ||
225 | /* Fall */ | ||
226 | |||
227 | case WDIOC_GETTIMEOUT: | ||
228 | return put_user(wd_times[wd_margin], p); | ||
229 | |||
230 | case WDIOC_SETOPTIONS: | ||
231 | { | ||
232 | int options, retval = -EINVAL; | ||
233 | |||
234 | if (get_user(options, p)) | ||
235 | return -EFAULT; | ||
236 | |||
237 | if (options & WDIOS_DISABLECARD) { | ||
238 | ibwdt_disable(); | ||
239 | retval = 0; | ||
240 | } | ||
241 | |||
242 | if (options & WDIOS_ENABLECARD) { | ||
243 | ibwdt_ping(); | ||
244 | retval = 0; | ||
245 | } | ||
246 | |||
247 | return retval; | ||
248 | } | ||
249 | |||
250 | default: | ||
251 | return -ENOTTY; | ||
252 | } | ||
253 | return 0; | ||
254 | } | ||
255 | |||
256 | static int | ||
257 | ibwdt_open(struct inode *inode, struct file *file) | ||
258 | { | ||
259 | if (test_and_set_bit(0, &ibwdt_is_open)) { | ||
260 | return -EBUSY; | ||
261 | } | ||
262 | if (nowayout) | ||
263 | __module_get(THIS_MODULE); | ||
264 | |||
265 | /* Activate */ | ||
266 | ibwdt_ping(); | ||
267 | return nonseekable_open(inode, file); | ||
268 | } | ||
269 | |||
270 | static int | ||
271 | ibwdt_close(struct inode *inode, struct file *file) | ||
272 | { | ||
273 | if (expect_close == 42) { | ||
274 | ibwdt_disable(); | ||
275 | } else { | ||
276 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); | ||
277 | ibwdt_ping(); | ||
278 | } | ||
279 | clear_bit(0, &ibwdt_is_open); | ||
280 | expect_close = 0; | ||
281 | return 0; | ||
282 | } | ||
283 | |||
284 | /* | ||
285 | * Kernel Interfaces | ||
286 | */ | ||
287 | |||
288 | static const struct file_operations ibwdt_fops = { | ||
289 | .owner = THIS_MODULE, | ||
290 | .llseek = no_llseek, | ||
291 | .write = ibwdt_write, | ||
292 | .ioctl = ibwdt_ioctl, | ||
293 | .open = ibwdt_open, | ||
294 | .release = ibwdt_close, | ||
295 | }; | ||
296 | |||
297 | static struct miscdevice ibwdt_miscdev = { | ||
298 | .minor = WATCHDOG_MINOR, | ||
299 | .name = "watchdog", | ||
300 | .fops = &ibwdt_fops, | ||
301 | }; | ||
302 | |||
303 | /* | ||
304 | * Init & exit routines | ||
305 | */ | ||
306 | |||
307 | static int __devinit ibwdt_probe(struct platform_device *dev) | ||
308 | { | ||
309 | int res; | ||
310 | |||
311 | spin_lock_init(&ibwdt_lock); | ||
312 | |||
313 | #if WDT_START != WDT_STOP | ||
314 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | ||
315 | printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP); | ||
316 | res = -EIO; | ||
317 | goto out_nostopreg; | ||
318 | } | ||
319 | #endif | ||
320 | |||
321 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | ||
322 | printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START); | ||
323 | res = -EIO; | ||
324 | goto out_nostartreg; | ||
325 | } | ||
326 | |||
327 | res = misc_register(&ibwdt_miscdev); | ||
328 | if (res) { | ||
329 | printk (KERN_ERR PFX "failed to register misc device\n"); | ||
330 | goto out_nomisc; | ||
331 | } | ||
332 | return 0; | ||
333 | |||
334 | out_nomisc: | ||
335 | release_region(WDT_START, 1); | ||
336 | out_nostartreg: | ||
337 | #if WDT_START != WDT_STOP | ||
338 | release_region(WDT_STOP, 1); | ||
339 | #endif | ||
340 | out_nostopreg: | ||
341 | return res; | ||
342 | } | ||
343 | |||
344 | static int __devexit ibwdt_remove(struct platform_device *dev) | ||
345 | { | ||
346 | misc_deregister(&ibwdt_miscdev); | ||
347 | release_region(WDT_START,1); | ||
348 | #if WDT_START != WDT_STOP | ||
349 | release_region(WDT_STOP,1); | ||
350 | #endif | ||
351 | return 0; | ||
352 | } | ||
353 | |||
354 | static void ibwdt_shutdown(struct platform_device *dev) | ||
355 | { | ||
356 | /* Turn the WDT off if we have a soft shutdown */ | ||
357 | ibwdt_disable(); | ||
358 | } | ||
359 | |||
360 | static struct platform_driver ibwdt_driver = { | ||
361 | .probe = ibwdt_probe, | ||
362 | .remove = __devexit_p(ibwdt_remove), | ||
363 | .shutdown = ibwdt_shutdown, | ||
364 | .driver = { | ||
365 | .owner = THIS_MODULE, | ||
366 | .name = DRV_NAME, | ||
367 | }, | ||
368 | }; | ||
369 | |||
370 | static int __init ibwdt_init(void) | ||
371 | { | ||
372 | int err; | ||
373 | |||
374 | printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n"); | ||
375 | |||
376 | err = platform_driver_register(&ibwdt_driver); | ||
377 | if (err) | ||
378 | return err; | ||
379 | |||
380 | ibwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); | ||
381 | if (IS_ERR(ibwdt_platform_device)) { | ||
382 | err = PTR_ERR(ibwdt_platform_device); | ||
383 | goto unreg_platform_driver; | ||
384 | } | ||
385 | |||
386 | return 0; | ||
387 | |||
388 | unreg_platform_driver: | ||
389 | platform_driver_unregister(&ibwdt_driver); | ||
390 | return err; | ||
391 | } | ||
392 | |||
393 | static void __exit ibwdt_exit(void) | ||
394 | { | ||
395 | platform_device_unregister(ibwdt_platform_device); | ||
396 | platform_driver_unregister(&ibwdt_driver); | ||
397 | printk(KERN_INFO PFX "Watchdog Module Unloaded.\n"); | ||
398 | } | ||
399 | |||
400 | module_init(ibwdt_init); | ||
401 | module_exit(ibwdt_exit); | ||
402 | |||
403 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | ||
404 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | ||
405 | MODULE_LICENSE("GPL"); | ||
406 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
407 | |||
408 | /* end of ib700wdt.c */ | ||