Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IB700 Single Board Computer WDT driver | |
3 | * | |
4 | * (c) Copyright 2001 Charles Howes <chowes@vsol.net> | |
5 | * | |
c9d7710e WVS |
6 | * Based on advantechwdt.c which is based on acquirewdt.c which |
7 | * is based on wdt.c. | |
1da177e4 LT |
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 | * | |
c9d7710e WVS |
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 | |
1da177e4 LT |
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> | |
1da177e4 | 39 | #include <linux/fs.h> |
1da177e4 LT |
40 | #include <linux/init.h> |
41 | #include <linux/spinlock.h> | |
42 | #include <linux/moduleparam.h> | |
745ac1ea | 43 | #include <linux/platform_device.h> |
1da177e4 LT |
44 | |
45 | #include <asm/io.h> | |
46 | #include <asm/uaccess.h> | |
47 | #include <asm/system.h> | |
48 | ||
745ac1ea | 49 | static struct platform_device *ibwdt_platform_device; |
1da177e4 | 50 | static unsigned long ibwdt_is_open; |
c7dfd0cc | 51 | static DEFINE_SPINLOCK(ibwdt_lock); |
1da177e4 LT |
52 | static char expect_close; |
53 | ||
745ac1ea WVS |
54 | /* Module information */ |
55 | #define DRV_NAME "ib700wdt" | |
56 | #define PFX DRV_NAME ": " | |
1da177e4 LT |
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 | ||
4bfdf378 | 121 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 122 | module_param(nowayout, int, 0); |
bffda5c8 | 123 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4 LT |
124 | |
125 | ||
126 | /* | |
35d55c94 | 127 | * Watchdog Operations |
1da177e4 LT |
128 | */ |
129 | ||
130 | static void | |
131 | ibwdt_ping(void) | |
132 | { | |
e42162a4 WVS |
133 | spin_lock(&ibwdt_lock); |
134 | ||
1da177e4 LT |
135 | /* Write a watchdog value */ |
136 | outb_p(wd_margin, WDT_START); | |
e42162a4 WVS |
137 | |
138 | spin_unlock(&ibwdt_lock); | |
1da177e4 LT |
139 | } |
140 | ||
35d55c94 WVS |
141 | static void |
142 | ibwdt_disable(void) | |
143 | { | |
e42162a4 | 144 | spin_lock(&ibwdt_lock); |
35d55c94 | 145 | outb_p(0, WDT_STOP); |
e42162a4 | 146 | spin_unlock(&ibwdt_lock); |
35d55c94 WVS |
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 | ||
1da177e4 LT |
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 | { | |
35d55c94 | 195 | int new_margin; |
1da177e4 LT |
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: | |
c9d7710e | 212 | case WDIOC_GETBOOTSTATUS: |
1da177e4 LT |
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; | |
35d55c94 | 222 | if (ibwdt_set_heartbeat(new_margin)) |
1da177e4 | 223 | return -EINVAL; |
1da177e4 LT |
224 | ibwdt_ping(); |
225 | /* Fall */ | |
226 | ||
227 | case WDIOC_GETTIMEOUT: | |
228 | return put_user(wd_times[wd_margin], p); | |
e42162a4 WVS |
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 | } | |
1da177e4 LT |
249 | |
250 | default: | |
795b89d2 | 251 | return -ENOTTY; |
1da177e4 LT |
252 | } |
253 | return 0; | |
254 | } | |
255 | ||
256 | static int | |
257 | ibwdt_open(struct inode *inode, struct file *file) | |
258 | { | |
1da177e4 | 259 | if (test_and_set_bit(0, &ibwdt_is_open)) { |
1da177e4 LT |
260 | return -EBUSY; |
261 | } | |
262 | if (nowayout) | |
263 | __module_get(THIS_MODULE); | |
264 | ||
265 | /* Activate */ | |
266 | ibwdt_ping(); | |
1da177e4 LT |
267 | return nonseekable_open(inode, file); |
268 | } | |
269 | ||
270 | static int | |
271 | ibwdt_close(struct inode *inode, struct file *file) | |
272 | { | |
c9d7710e | 273 | if (expect_close == 42) { |
35d55c94 | 274 | ibwdt_disable(); |
c9d7710e | 275 | } else { |
1da177e4 | 276 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); |
c9d7710e WVS |
277 | ibwdt_ping(); |
278 | } | |
1da177e4 LT |
279 | clear_bit(0, &ibwdt_is_open); |
280 | expect_close = 0; | |
1da177e4 LT |
281 | return 0; |
282 | } | |
283 | ||
1da177e4 LT |
284 | /* |
285 | * Kernel Interfaces | |
286 | */ | |
287 | ||
62322d25 | 288 | static const struct file_operations ibwdt_fops = { |
1da177e4 LT |
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 | ||
f6e48039 WVS |
303 | /* |
304 | * Init & exit routines | |
305 | */ | |
306 | ||
745ac1ea | 307 | static int __devinit ibwdt_probe(struct platform_device *dev) |
1da177e4 LT |
308 | { |
309 | int res; | |
310 | ||
1da177e4 LT |
311 | #if WDT_START != WDT_STOP |
312 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | |
313 | printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP); | |
314 | res = -EIO; | |
315 | goto out_nostopreg; | |
316 | } | |
317 | #endif | |
318 | ||
319 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | |
320 | printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START); | |
321 | res = -EIO; | |
322 | goto out_nostartreg; | |
323 | } | |
f6e48039 | 324 | |
f6e48039 WVS |
325 | res = misc_register(&ibwdt_miscdev); |
326 | if (res) { | |
327 | printk (KERN_ERR PFX "failed to register misc device\n"); | |
328 | goto out_nomisc; | |
329 | } | |
1da177e4 LT |
330 | return 0; |
331 | ||
f6e48039 | 332 | out_nomisc: |
1da177e4 LT |
333 | release_region(WDT_START, 1); |
334 | out_nostartreg: | |
335 | #if WDT_START != WDT_STOP | |
336 | release_region(WDT_STOP, 1); | |
337 | #endif | |
338 | out_nostopreg: | |
1da177e4 LT |
339 | return res; |
340 | } | |
341 | ||
745ac1ea | 342 | static int __devexit ibwdt_remove(struct platform_device *dev) |
1da177e4 LT |
343 | { |
344 | misc_deregister(&ibwdt_miscdev); | |
f6e48039 | 345 | release_region(WDT_START,1); |
1da177e4 LT |
346 | #if WDT_START != WDT_STOP |
347 | release_region(WDT_STOP,1); | |
348 | #endif | |
745ac1ea WVS |
349 | return 0; |
350 | } | |
351 | ||
35fcf538 WVS |
352 | static void ibwdt_shutdown(struct platform_device *dev) |
353 | { | |
354 | /* Turn the WDT off if we have a soft shutdown */ | |
355 | ibwdt_disable(); | |
356 | } | |
357 | ||
745ac1ea WVS |
358 | static struct platform_driver ibwdt_driver = { |
359 | .probe = ibwdt_probe, | |
360 | .remove = __devexit_p(ibwdt_remove), | |
35fcf538 | 361 | .shutdown = ibwdt_shutdown, |
745ac1ea WVS |
362 | .driver = { |
363 | .owner = THIS_MODULE, | |
364 | .name = DRV_NAME, | |
365 | }, | |
366 | }; | |
367 | ||
368 | static int __init ibwdt_init(void) | |
369 | { | |
370 | int err; | |
371 | ||
372 | printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n"); | |
373 | ||
374 | err = platform_driver_register(&ibwdt_driver); | |
375 | if (err) | |
376 | return err; | |
377 | ||
378 | ibwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); | |
379 | if (IS_ERR(ibwdt_platform_device)) { | |
380 | err = PTR_ERR(ibwdt_platform_device); | |
381 | goto unreg_platform_driver; | |
382 | } | |
383 | ||
384 | return 0; | |
385 | ||
386 | unreg_platform_driver: | |
387 | platform_driver_unregister(&ibwdt_driver); | |
388 | return err; | |
389 | } | |
390 | ||
391 | static void __exit ibwdt_exit(void) | |
392 | { | |
393 | platform_device_unregister(ibwdt_platform_device); | |
394 | platform_driver_unregister(&ibwdt_driver); | |
395 | printk(KERN_INFO PFX "Watchdog Module Unloaded.\n"); | |
1da177e4 LT |
396 | } |
397 | ||
398 | module_init(ibwdt_init); | |
399 | module_exit(ibwdt_exit); | |
400 | ||
401 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | |
402 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | |
403 | MODULE_LICENSE("GPL"); | |
404 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
405 | ||
406 | /* end of ib700wdt.c */ |