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 | * | |
29fa0586 AC |
14 | * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, |
15 | * All Rights Reserved. | |
1da177e4 LT |
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 | * | |
29fa0586 | 26 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 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 | ||
27c766aa JP |
34 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
35 | ||
1da177e4 LT |
36 | #include <linux/module.h> |
37 | #include <linux/types.h> | |
38 | #include <linux/miscdevice.h> | |
39 | #include <linux/watchdog.h> | |
40 | #include <linux/ioport.h> | |
1da177e4 | 41 | #include <linux/fs.h> |
1da177e4 LT |
42 | #include <linux/init.h> |
43 | #include <linux/spinlock.h> | |
44 | #include <linux/moduleparam.h> | |
745ac1ea | 45 | #include <linux/platform_device.h> |
2e43ba73 AC |
46 | #include <linux/io.h> |
47 | #include <linux/uaccess.h> | |
089ab079 | 48 | |
1da177e4 LT |
49 | #include <asm/system.h> |
50 | ||
745ac1ea | 51 | static struct platform_device *ibwdt_platform_device; |
1da177e4 | 52 | static unsigned long ibwdt_is_open; |
c7dfd0cc | 53 | static DEFINE_SPINLOCK(ibwdt_lock); |
1da177e4 LT |
54 | static char expect_close; |
55 | ||
745ac1ea WVS |
56 | /* Module information */ |
57 | #define DRV_NAME "ib700wdt" | |
1da177e4 LT |
58 | |
59 | /* | |
60 | * | |
61 | * Watchdog Timer Configuration | |
62 | * | |
63 | * The function of the watchdog timer is to reset the system | |
64 | * automatically and is defined at I/O port 0443H. To enable the | |
65 | * watchdog timer and allow the system to reset, write I/O port 0443H. | |
66 | * To disable the timer, write I/O port 0441H for the system to stop the | |
67 | * watchdog function. The timer has a tolerance of 20% for its | |
68 | * intervals. | |
69 | * | |
70 | * The following describes how the timer should be programmed. | |
71 | * | |
72 | * Enabling Watchdog: | |
73 | * MOV AX,000FH (Choose the values from 0 to F) | |
74 | * MOV DX,0443H | |
75 | * OUT DX,AX | |
76 | * | |
77 | * Disabling Watchdog: | |
78 | * MOV AX,000FH (Any value is fine.) | |
79 | * MOV DX,0441H | |
80 | * OUT DX,AX | |
81 | * | |
82 | * Watchdog timer control table: | |
83 | * Level Value Time/sec | Level Value Time/sec | |
84 | * 1 F 0 | 9 7 16 | |
85 | * 2 E 2 | 10 6 18 | |
86 | * 3 D 4 | 11 5 20 | |
87 | * 4 C 6 | 12 4 22 | |
88 | * 5 B 8 | 13 3 24 | |
89 | * 6 A 10 | 14 2 26 | |
90 | * 7 9 12 | 15 1 28 | |
91 | * 8 8 14 | 16 0 30 | |
92 | * | |
93 | */ | |
94 | ||
1da177e4 LT |
95 | #define WDT_STOP 0x441 |
96 | #define WDT_START 0x443 | |
97 | ||
98 | /* Default timeout */ | |
794db26f WVS |
99 | #define WATCHDOG_TIMEOUT 30 /* 30 seconds +/- 20% */ |
100 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ | |
101 | module_param(timeout, int, 0); | |
102 | MODULE_PARM_DESC(timeout, | |
103 | "Watchdog timeout in seconds. 0<= timeout <=30, default=" | |
104 | __MODULE_STRING(WATCHDOG_TIMEOUT) "."); | |
1da177e4 | 105 | |
4bfdf378 | 106 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 107 | module_param(nowayout, int, 0); |
2e43ba73 AC |
108 | MODULE_PARM_DESC(nowayout, |
109 | "Watchdog cannot be stopped once started (default=" | |
110 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
111 | |
112 | ||
113 | /* | |
35d55c94 | 114 | * Watchdog Operations |
1da177e4 LT |
115 | */ |
116 | ||
7944d3a5 | 117 | static void ibwdt_ping(void) |
1da177e4 | 118 | { |
794db26f WVS |
119 | int wd_margin = 15 - ((timeout + 1) / 2); |
120 | ||
e42162a4 WVS |
121 | spin_lock(&ibwdt_lock); |
122 | ||
1da177e4 LT |
123 | /* Write a watchdog value */ |
124 | outb_p(wd_margin, WDT_START); | |
e42162a4 WVS |
125 | |
126 | spin_unlock(&ibwdt_lock); | |
1da177e4 LT |
127 | } |
128 | ||
7944d3a5 | 129 | static void ibwdt_disable(void) |
35d55c94 | 130 | { |
e42162a4 | 131 | spin_lock(&ibwdt_lock); |
35d55c94 | 132 | outb_p(0, WDT_STOP); |
e42162a4 | 133 | spin_unlock(&ibwdt_lock); |
35d55c94 WVS |
134 | } |
135 | ||
7944d3a5 | 136 | static int ibwdt_set_heartbeat(int t) |
35d55c94 | 137 | { |
794db26f | 138 | if (t < 0 || t > 30) |
35d55c94 WVS |
139 | return -EINVAL; |
140 | ||
794db26f | 141 | timeout = t; |
35d55c94 WVS |
142 | return 0; |
143 | } | |
144 | ||
145 | /* | |
146 | * /dev/watchdog handling | |
147 | */ | |
148 | ||
2e43ba73 AC |
149 | static ssize_t ibwdt_write(struct file *file, const char __user *buf, |
150 | size_t count, loff_t *ppos) | |
1da177e4 LT |
151 | { |
152 | if (count) { | |
153 | if (!nowayout) { | |
154 | size_t i; | |
155 | ||
156 | /* In case it was set long ago */ | |
157 | expect_close = 0; | |
158 | ||
159 | for (i = 0; i != count; i++) { | |
160 | char c; | |
161 | if (get_user(c, buf + i)) | |
162 | return -EFAULT; | |
163 | if (c == 'V') | |
164 | expect_close = 42; | |
165 | } | |
166 | } | |
167 | ibwdt_ping(); | |
168 | } | |
169 | return count; | |
170 | } | |
171 | ||
2e43ba73 | 172 | static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 173 | { |
35d55c94 | 174 | int new_margin; |
1da177e4 LT |
175 | void __user *argp = (void __user *)arg; |
176 | int __user *p = argp; | |
177 | ||
42747d71 | 178 | static const struct watchdog_info ident = { |
2e43ba73 AC |
179 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
180 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
181 | .firmware_version = 1, |
182 | .identity = "IB700 WDT", | |
183 | }; | |
184 | ||
185 | switch (cmd) { | |
186 | case WDIOC_GETSUPPORT: | |
2e43ba73 AC |
187 | if (copy_to_user(argp, &ident, sizeof(ident))) |
188 | return -EFAULT; | |
189 | break; | |
1da177e4 LT |
190 | |
191 | case WDIOC_GETSTATUS: | |
c9d7710e | 192 | case WDIOC_GETBOOTSTATUS: |
2e43ba73 | 193 | return put_user(0, p); |
1da177e4 | 194 | |
e42162a4 WVS |
195 | case WDIOC_SETOPTIONS: |
196 | { | |
2e43ba73 | 197 | int options, retval = -EINVAL; |
e42162a4 | 198 | |
2e43ba73 AC |
199 | if (get_user(options, p)) |
200 | return -EFAULT; | |
e42162a4 | 201 | |
2e43ba73 AC |
202 | if (options & WDIOS_DISABLECARD) { |
203 | ibwdt_disable(); | |
204 | retval = 0; | |
205 | } | |
206 | if (options & WDIOS_ENABLECARD) { | |
207 | ibwdt_ping(); | |
208 | retval = 0; | |
209 | } | |
210 | return retval; | |
e42162a4 | 211 | } |
0c06090c WVS |
212 | case WDIOC_KEEPALIVE: |
213 | ibwdt_ping(); | |
214 | break; | |
215 | ||
216 | case WDIOC_SETTIMEOUT: | |
217 | if (get_user(new_margin, p)) | |
218 | return -EFAULT; | |
219 | if (ibwdt_set_heartbeat(new_margin)) | |
220 | return -EINVAL; | |
221 | ibwdt_ping(); | |
222 | /* Fall */ | |
223 | ||
224 | case WDIOC_GETTIMEOUT: | |
794db26f | 225 | return put_user(timeout, p); |
0c06090c | 226 | |
1da177e4 | 227 | default: |
2e43ba73 | 228 | return -ENOTTY; |
1da177e4 LT |
229 | } |
230 | return 0; | |
231 | } | |
232 | ||
2e43ba73 | 233 | static int ibwdt_open(struct inode *inode, struct file *file) |
1da177e4 | 234 | { |
2e43ba73 | 235 | if (test_and_set_bit(0, &ibwdt_is_open)) |
1da177e4 | 236 | return -EBUSY; |
1da177e4 LT |
237 | if (nowayout) |
238 | __module_get(THIS_MODULE); | |
239 | ||
240 | /* Activate */ | |
241 | ibwdt_ping(); | |
1da177e4 LT |
242 | return nonseekable_open(inode, file); |
243 | } | |
244 | ||
7944d3a5 | 245 | static int ibwdt_close(struct inode *inode, struct file *file) |
1da177e4 | 246 | { |
c9d7710e | 247 | if (expect_close == 42) { |
35d55c94 | 248 | ibwdt_disable(); |
c9d7710e | 249 | } else { |
27c766aa | 250 | pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); |
c9d7710e WVS |
251 | ibwdt_ping(); |
252 | } | |
1da177e4 LT |
253 | clear_bit(0, &ibwdt_is_open); |
254 | expect_close = 0; | |
1da177e4 LT |
255 | return 0; |
256 | } | |
257 | ||
1da177e4 LT |
258 | /* |
259 | * Kernel Interfaces | |
260 | */ | |
261 | ||
62322d25 | 262 | static const struct file_operations ibwdt_fops = { |
1da177e4 LT |
263 | .owner = THIS_MODULE, |
264 | .llseek = no_llseek, | |
265 | .write = ibwdt_write, | |
2e43ba73 | 266 | .unlocked_ioctl = ibwdt_ioctl, |
1da177e4 LT |
267 | .open = ibwdt_open, |
268 | .release = ibwdt_close, | |
269 | }; | |
270 | ||
271 | static struct miscdevice ibwdt_miscdev = { | |
272 | .minor = WATCHDOG_MINOR, | |
273 | .name = "watchdog", | |
274 | .fops = &ibwdt_fops, | |
275 | }; | |
276 | ||
f6e48039 WVS |
277 | /* |
278 | * Init & exit routines | |
279 | */ | |
280 | ||
745ac1ea | 281 | static int __devinit ibwdt_probe(struct platform_device *dev) |
1da177e4 LT |
282 | { |
283 | int res; | |
284 | ||
1da177e4 LT |
285 | #if WDT_START != WDT_STOP |
286 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | |
27c766aa | 287 | pr_err("STOP method I/O %X is not available\n", WDT_STOP); |
1da177e4 LT |
288 | res = -EIO; |
289 | goto out_nostopreg; | |
290 | } | |
291 | #endif | |
292 | ||
293 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | |
27c766aa | 294 | pr_err("START method I/O %X is not available\n", WDT_START); |
1da177e4 LT |
295 | res = -EIO; |
296 | goto out_nostartreg; | |
297 | } | |
f6e48039 | 298 | |
794db26f WVS |
299 | /* Check that the heartbeat value is within it's range ; |
300 | * if not reset to the default */ | |
301 | if (ibwdt_set_heartbeat(timeout)) { | |
302 | ibwdt_set_heartbeat(WATCHDOG_TIMEOUT); | |
27c766aa | 303 | pr_info("timeout value must be 0<=x<=30, using %d\n", timeout); |
794db26f WVS |
304 | } |
305 | ||
f6e48039 WVS |
306 | res = misc_register(&ibwdt_miscdev); |
307 | if (res) { | |
27c766aa | 308 | pr_err("failed to register misc device\n"); |
f6e48039 WVS |
309 | goto out_nomisc; |
310 | } | |
1da177e4 LT |
311 | return 0; |
312 | ||
f6e48039 | 313 | out_nomisc: |
1da177e4 LT |
314 | release_region(WDT_START, 1); |
315 | out_nostartreg: | |
316 | #if WDT_START != WDT_STOP | |
317 | release_region(WDT_STOP, 1); | |
318 | #endif | |
319 | out_nostopreg: | |
1da177e4 LT |
320 | return res; |
321 | } | |
322 | ||
745ac1ea | 323 | static int __devexit ibwdt_remove(struct platform_device *dev) |
1da177e4 LT |
324 | { |
325 | misc_deregister(&ibwdt_miscdev); | |
2e43ba73 | 326 | release_region(WDT_START, 1); |
1da177e4 | 327 | #if WDT_START != WDT_STOP |
2e43ba73 | 328 | release_region(WDT_STOP, 1); |
1da177e4 | 329 | #endif |
745ac1ea WVS |
330 | return 0; |
331 | } | |
332 | ||
35fcf538 WVS |
333 | static void ibwdt_shutdown(struct platform_device *dev) |
334 | { | |
335 | /* Turn the WDT off if we have a soft shutdown */ | |
336 | ibwdt_disable(); | |
337 | } | |
338 | ||
745ac1ea WVS |
339 | static struct platform_driver ibwdt_driver = { |
340 | .probe = ibwdt_probe, | |
341 | .remove = __devexit_p(ibwdt_remove), | |
35fcf538 | 342 | .shutdown = ibwdt_shutdown, |
745ac1ea WVS |
343 | .driver = { |
344 | .owner = THIS_MODULE, | |
345 | .name = DRV_NAME, | |
346 | }, | |
347 | }; | |
348 | ||
349 | static int __init ibwdt_init(void) | |
350 | { | |
351 | int err; | |
352 | ||
27c766aa | 353 | pr_info("WDT driver for IB700 single board computer initialising\n"); |
745ac1ea WVS |
354 | |
355 | err = platform_driver_register(&ibwdt_driver); | |
356 | if (err) | |
357 | return err; | |
358 | ||
2e43ba73 AC |
359 | ibwdt_platform_device = platform_device_register_simple(DRV_NAME, |
360 | -1, NULL, 0); | |
745ac1ea WVS |
361 | if (IS_ERR(ibwdt_platform_device)) { |
362 | err = PTR_ERR(ibwdt_platform_device); | |
363 | goto unreg_platform_driver; | |
364 | } | |
365 | ||
366 | return 0; | |
367 | ||
368 | unreg_platform_driver: | |
369 | platform_driver_unregister(&ibwdt_driver); | |
370 | return err; | |
371 | } | |
372 | ||
373 | static void __exit ibwdt_exit(void) | |
374 | { | |
375 | platform_device_unregister(ibwdt_platform_device); | |
376 | platform_driver_unregister(&ibwdt_driver); | |
27c766aa | 377 | pr_info("Watchdog Module Unloaded\n"); |
1da177e4 LT |
378 | } |
379 | ||
380 | module_init(ibwdt_init); | |
381 | module_exit(ibwdt_exit); | |
382 | ||
383 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | |
384 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | |
385 | MODULE_LICENSE("GPL"); | |
386 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
387 | ||
388 | /* end of ib700wdt.c */ |