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 | 49 | |
745ac1ea | 50 | static struct platform_device *ibwdt_platform_device; |
1da177e4 | 51 | static unsigned long ibwdt_is_open; |
c7dfd0cc | 52 | static DEFINE_SPINLOCK(ibwdt_lock); |
1da177e4 LT |
53 | static char expect_close; |
54 | ||
745ac1ea WVS |
55 | /* Module information */ |
56 | #define DRV_NAME "ib700wdt" | |
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 | ||
1da177e4 LT |
94 | #define WDT_STOP 0x441 |
95 | #define WDT_START 0x443 | |
96 | ||
97 | /* Default timeout */ | |
794db26f WVS |
98 | #define WATCHDOG_TIMEOUT 30 /* 30 seconds +/- 20% */ |
99 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ | |
100 | module_param(timeout, int, 0); | |
101 | MODULE_PARM_DESC(timeout, | |
102 | "Watchdog timeout in seconds. 0<= timeout <=30, default=" | |
103 | __MODULE_STRING(WATCHDOG_TIMEOUT) "."); | |
1da177e4 | 104 | |
86a1e189 WVS |
105 | static bool nowayout = WATCHDOG_NOWAYOUT; |
106 | module_param(nowayout, bool, 0); | |
2e43ba73 AC |
107 | MODULE_PARM_DESC(nowayout, |
108 | "Watchdog cannot be stopped once started (default=" | |
109 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
110 | |
111 | ||
112 | /* | |
35d55c94 | 113 | * Watchdog Operations |
1da177e4 LT |
114 | */ |
115 | ||
7944d3a5 | 116 | static void ibwdt_ping(void) |
1da177e4 | 117 | { |
794db26f WVS |
118 | int wd_margin = 15 - ((timeout + 1) / 2); |
119 | ||
e42162a4 WVS |
120 | spin_lock(&ibwdt_lock); |
121 | ||
1da177e4 LT |
122 | /* Write a watchdog value */ |
123 | outb_p(wd_margin, WDT_START); | |
e42162a4 WVS |
124 | |
125 | spin_unlock(&ibwdt_lock); | |
1da177e4 LT |
126 | } |
127 | ||
7944d3a5 | 128 | static void ibwdt_disable(void) |
35d55c94 | 129 | { |
e42162a4 | 130 | spin_lock(&ibwdt_lock); |
35d55c94 | 131 | outb_p(0, WDT_STOP); |
e42162a4 | 132 | spin_unlock(&ibwdt_lock); |
35d55c94 WVS |
133 | } |
134 | ||
7944d3a5 | 135 | static int ibwdt_set_heartbeat(int t) |
35d55c94 | 136 | { |
794db26f | 137 | if (t < 0 || t > 30) |
35d55c94 WVS |
138 | return -EINVAL; |
139 | ||
794db26f | 140 | timeout = t; |
35d55c94 WVS |
141 | return 0; |
142 | } | |
143 | ||
144 | /* | |
145 | * /dev/watchdog handling | |
146 | */ | |
147 | ||
2e43ba73 AC |
148 | static ssize_t ibwdt_write(struct file *file, const char __user *buf, |
149 | size_t count, loff_t *ppos) | |
1da177e4 LT |
150 | { |
151 | if (count) { | |
152 | if (!nowayout) { | |
153 | size_t i; | |
154 | ||
155 | /* In case it was set long ago */ | |
156 | expect_close = 0; | |
157 | ||
158 | for (i = 0; i != count; i++) { | |
159 | char c; | |
160 | if (get_user(c, buf + i)) | |
161 | return -EFAULT; | |
162 | if (c == 'V') | |
163 | expect_close = 42; | |
164 | } | |
165 | } | |
166 | ibwdt_ping(); | |
167 | } | |
168 | return count; | |
169 | } | |
170 | ||
2e43ba73 | 171 | static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 172 | { |
35d55c94 | 173 | int new_margin; |
1da177e4 LT |
174 | void __user *argp = (void __user *)arg; |
175 | int __user *p = argp; | |
176 | ||
42747d71 | 177 | static const struct watchdog_info ident = { |
2e43ba73 AC |
178 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
179 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
180 | .firmware_version = 1, |
181 | .identity = "IB700 WDT", | |
182 | }; | |
183 | ||
184 | switch (cmd) { | |
185 | case WDIOC_GETSUPPORT: | |
2e43ba73 AC |
186 | if (copy_to_user(argp, &ident, sizeof(ident))) |
187 | return -EFAULT; | |
188 | break; | |
1da177e4 LT |
189 | |
190 | case WDIOC_GETSTATUS: | |
c9d7710e | 191 | case WDIOC_GETBOOTSTATUS: |
2e43ba73 | 192 | return put_user(0, p); |
1da177e4 | 193 | |
e42162a4 WVS |
194 | case WDIOC_SETOPTIONS: |
195 | { | |
2e43ba73 | 196 | int options, retval = -EINVAL; |
e42162a4 | 197 | |
2e43ba73 AC |
198 | if (get_user(options, p)) |
199 | return -EFAULT; | |
e42162a4 | 200 | |
2e43ba73 AC |
201 | if (options & WDIOS_DISABLECARD) { |
202 | ibwdt_disable(); | |
203 | retval = 0; | |
204 | } | |
205 | if (options & WDIOS_ENABLECARD) { | |
206 | ibwdt_ping(); | |
207 | retval = 0; | |
208 | } | |
209 | return retval; | |
e42162a4 | 210 | } |
0c06090c WVS |
211 | case WDIOC_KEEPALIVE: |
212 | ibwdt_ping(); | |
213 | break; | |
214 | ||
215 | case WDIOC_SETTIMEOUT: | |
216 | if (get_user(new_margin, p)) | |
217 | return -EFAULT; | |
218 | if (ibwdt_set_heartbeat(new_margin)) | |
219 | return -EINVAL; | |
220 | ibwdt_ping(); | |
221 | /* Fall */ | |
222 | ||
223 | case WDIOC_GETTIMEOUT: | |
794db26f | 224 | return put_user(timeout, p); |
0c06090c | 225 | |
1da177e4 | 226 | default: |
2e43ba73 | 227 | return -ENOTTY; |
1da177e4 LT |
228 | } |
229 | return 0; | |
230 | } | |
231 | ||
2e43ba73 | 232 | static int ibwdt_open(struct inode *inode, struct file *file) |
1da177e4 | 233 | { |
2e43ba73 | 234 | if (test_and_set_bit(0, &ibwdt_is_open)) |
1da177e4 | 235 | return -EBUSY; |
1da177e4 LT |
236 | if (nowayout) |
237 | __module_get(THIS_MODULE); | |
238 | ||
239 | /* Activate */ | |
240 | ibwdt_ping(); | |
1da177e4 LT |
241 | return nonseekable_open(inode, file); |
242 | } | |
243 | ||
7944d3a5 | 244 | static int ibwdt_close(struct inode *inode, struct file *file) |
1da177e4 | 245 | { |
c9d7710e | 246 | if (expect_close == 42) { |
35d55c94 | 247 | ibwdt_disable(); |
c9d7710e | 248 | } else { |
27c766aa | 249 | pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); |
c9d7710e WVS |
250 | ibwdt_ping(); |
251 | } | |
1da177e4 LT |
252 | clear_bit(0, &ibwdt_is_open); |
253 | expect_close = 0; | |
1da177e4 LT |
254 | return 0; |
255 | } | |
256 | ||
1da177e4 LT |
257 | /* |
258 | * Kernel Interfaces | |
259 | */ | |
260 | ||
62322d25 | 261 | static const struct file_operations ibwdt_fops = { |
1da177e4 LT |
262 | .owner = THIS_MODULE, |
263 | .llseek = no_llseek, | |
264 | .write = ibwdt_write, | |
2e43ba73 | 265 | .unlocked_ioctl = ibwdt_ioctl, |
1da177e4 LT |
266 | .open = ibwdt_open, |
267 | .release = ibwdt_close, | |
268 | }; | |
269 | ||
270 | static struct miscdevice ibwdt_miscdev = { | |
271 | .minor = WATCHDOG_MINOR, | |
272 | .name = "watchdog", | |
273 | .fops = &ibwdt_fops, | |
274 | }; | |
275 | ||
f6e48039 WVS |
276 | /* |
277 | * Init & exit routines | |
278 | */ | |
279 | ||
2d991a16 | 280 | static int ibwdt_probe(struct platform_device *dev) |
1da177e4 LT |
281 | { |
282 | int res; | |
283 | ||
1da177e4 LT |
284 | #if WDT_START != WDT_STOP |
285 | if (!request_region(WDT_STOP, 1, "IB700 WDT")) { | |
27c766aa | 286 | pr_err("STOP method I/O %X is not available\n", WDT_STOP); |
1da177e4 LT |
287 | res = -EIO; |
288 | goto out_nostopreg; | |
289 | } | |
290 | #endif | |
291 | ||
292 | if (!request_region(WDT_START, 1, "IB700 WDT")) { | |
27c766aa | 293 | pr_err("START method I/O %X is not available\n", WDT_START); |
1da177e4 LT |
294 | res = -EIO; |
295 | goto out_nostartreg; | |
296 | } | |
f6e48039 | 297 | |
794db26f WVS |
298 | /* Check that the heartbeat value is within it's range ; |
299 | * if not reset to the default */ | |
300 | if (ibwdt_set_heartbeat(timeout)) { | |
301 | ibwdt_set_heartbeat(WATCHDOG_TIMEOUT); | |
27c766aa | 302 | pr_info("timeout value must be 0<=x<=30, using %d\n", timeout); |
794db26f WVS |
303 | } |
304 | ||
f6e48039 WVS |
305 | res = misc_register(&ibwdt_miscdev); |
306 | if (res) { | |
27c766aa | 307 | pr_err("failed to register misc device\n"); |
f6e48039 WVS |
308 | goto out_nomisc; |
309 | } | |
1da177e4 LT |
310 | return 0; |
311 | ||
f6e48039 | 312 | out_nomisc: |
1da177e4 LT |
313 | release_region(WDT_START, 1); |
314 | out_nostartreg: | |
315 | #if WDT_START != WDT_STOP | |
316 | release_region(WDT_STOP, 1); | |
317 | #endif | |
318 | out_nostopreg: | |
1da177e4 LT |
319 | return res; |
320 | } | |
321 | ||
4b12b896 | 322 | static int ibwdt_remove(struct platform_device *dev) |
1da177e4 LT |
323 | { |
324 | misc_deregister(&ibwdt_miscdev); | |
2e43ba73 | 325 | release_region(WDT_START, 1); |
1da177e4 | 326 | #if WDT_START != WDT_STOP |
2e43ba73 | 327 | release_region(WDT_STOP, 1); |
1da177e4 | 328 | #endif |
745ac1ea WVS |
329 | return 0; |
330 | } | |
331 | ||
35fcf538 WVS |
332 | static void ibwdt_shutdown(struct platform_device *dev) |
333 | { | |
334 | /* Turn the WDT off if we have a soft shutdown */ | |
335 | ibwdt_disable(); | |
336 | } | |
337 | ||
745ac1ea WVS |
338 | static struct platform_driver ibwdt_driver = { |
339 | .probe = ibwdt_probe, | |
82268714 | 340 | .remove = ibwdt_remove, |
35fcf538 | 341 | .shutdown = ibwdt_shutdown, |
745ac1ea WVS |
342 | .driver = { |
343 | .owner = THIS_MODULE, | |
344 | .name = DRV_NAME, | |
345 | }, | |
346 | }; | |
347 | ||
348 | static int __init ibwdt_init(void) | |
349 | { | |
350 | int err; | |
351 | ||
27c766aa | 352 | pr_info("WDT driver for IB700 single board computer initialising\n"); |
745ac1ea WVS |
353 | |
354 | err = platform_driver_register(&ibwdt_driver); | |
355 | if (err) | |
356 | return err; | |
357 | ||
2e43ba73 AC |
358 | ibwdt_platform_device = platform_device_register_simple(DRV_NAME, |
359 | -1, NULL, 0); | |
745ac1ea WVS |
360 | if (IS_ERR(ibwdt_platform_device)) { |
361 | err = PTR_ERR(ibwdt_platform_device); | |
362 | goto unreg_platform_driver; | |
363 | } | |
364 | ||
365 | return 0; | |
366 | ||
367 | unreg_platform_driver: | |
368 | platform_driver_unregister(&ibwdt_driver); | |
369 | return err; | |
370 | } | |
371 | ||
372 | static void __exit ibwdt_exit(void) | |
373 | { | |
374 | platform_device_unregister(ibwdt_platform_device); | |
375 | platform_driver_unregister(&ibwdt_driver); | |
27c766aa | 376 | pr_info("Watchdog Module Unloaded\n"); |
1da177e4 LT |
377 | } |
378 | ||
379 | module_init(ibwdt_init); | |
380 | module_exit(ibwdt_exit); | |
381 | ||
382 | MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); | |
383 | MODULE_DESCRIPTION("IB700 SBC watchdog driver"); | |
384 | MODULE_LICENSE("GPL"); | |
385 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
386 | ||
387 | /* end of ib700wdt.c */ |