Commit | Line | Data |
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d0173278 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
1da177e4 | 2 | /* |
0f112a86 | 3 | * Eurotech CPU-1220/1410/1420 on board WDT driver |
1da177e4 LT |
4 | * |
5 | * (c) Copyright 2001 Ascensit <support@ascensit.com> | |
6 | * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com> | |
7 | * (c) Copyright 2002 Rob Radez <rob@osinvestor.com> | |
8 | * | |
9 | * Based on wdt.c. | |
10 | * Original copyright messages: | |
11 | * | |
143a2e54 | 12 | * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>, |
29fa0586 | 13 | * All Rights Reserved. |
1da177e4 | 14 | * |
143a2e54 WVS |
15 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide |
16 | * warranty for any of this software. This material is provided | |
17 | * "AS-IS" and at no charge. | |
1da177e4 | 18 | * |
143a2e54 | 19 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>* |
1da177e4 LT |
20 | */ |
21 | ||
22 | /* Changelog: | |
0f112a86 WVS |
23 | * |
24 | * 2001 - Rodolfo Giometti | |
25 | * Initial release | |
1da177e4 LT |
26 | * |
27 | * 2002/04/25 - Rob Radez | |
28 | * clean up #includes | |
29 | * clean up locking | |
30 | * make __setup param unique | |
31 | * proper options in watchdog_info | |
32 | * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls | |
33 | * add expect_close support | |
34 | * | |
1da177e4 | 35 | * 2002.05.30 - Joel Becker <joel.becker@oracle.com> |
143a2e54 | 36 | * Added Matt Domsch's nowayout module option. |
1da177e4 LT |
37 | */ |
38 | ||
0f112a86 WVS |
39 | /* |
40 | * The eurotech CPU-1220/1410/1420's watchdog is a part | |
41 | * of the on-board SUPER I/O device SMSC FDC 37B782. | |
42 | */ | |
43 | ||
27c766aa JP |
44 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
45 | ||
1da177e4 LT |
46 | #include <linux/interrupt.h> |
47 | #include <linux/module.h> | |
48 | #include <linux/moduleparam.h> | |
49 | #include <linux/types.h> | |
50 | #include <linux/miscdevice.h> | |
51 | #include <linux/watchdog.h> | |
52 | #include <linux/fs.h> | |
53 | #include <linux/ioport.h> | |
54 | #include <linux/notifier.h> | |
55 | #include <linux/reboot.h> | |
56 | #include <linux/init.h> | |
89ea2429 AC |
57 | #include <linux/io.h> |
58 | #include <linux/uaccess.h> | |
1da177e4 | 59 | |
1da177e4 LT |
60 | |
61 | static unsigned long eurwdt_is_open; | |
62 | static int eurwdt_timeout; | |
63 | static char eur_expect_close; | |
1334f329 | 64 | static DEFINE_SPINLOCK(eurwdt_lock); |
1da177e4 LT |
65 | |
66 | /* | |
67 | * You must set these - there is no sane way to probe for this board. | |
1da177e4 LT |
68 | */ |
69 | ||
70 | static int io = 0x3f0; | |
71 | static int irq = 10; | |
72 | static char *ev = "int"; | |
73 | ||
74 | #define WDT_TIMEOUT 60 /* 1 minute */ | |
75 | ||
86a1e189 WVS |
76 | static bool nowayout = WATCHDOG_NOWAYOUT; |
77 | module_param(nowayout, bool, 0); | |
89ea2429 AC |
78 | MODULE_PARM_DESC(nowayout, |
79 | "Watchdog cannot be stopped once started (default=" | |
80 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
81 | |
82 | /* | |
83 | * Some symbolic names | |
84 | */ | |
85 | ||
86 | #define WDT_CTRL_REG 0x30 | |
87 | #define WDT_OUTPIN_CFG 0xe2 | |
88 | #define WDT_EVENT_INT 0x00 | |
89 | #define WDT_EVENT_REBOOT 0x08 | |
90 | #define WDT_UNIT_SEL 0xf1 | |
91 | #define WDT_UNIT_SECS 0x80 | |
92 | #define WDT_TIMEOUT_VAL 0xf2 | |
93 | #define WDT_TIMER_CFG 0xf3 | |
94 | ||
95 | ||
5d1c93ce | 96 | module_param_hw(io, int, ioport, 0); |
1da177e4 | 97 | MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); |
5d1c93ce | 98 | module_param_hw(irq, int, irq, 0); |
1da177e4 LT |
99 | MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); |
100 | module_param(ev, charp, 0); | |
101 | MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); | |
102 | ||
103 | ||
104 | /* | |
105 | * Programming support | |
106 | */ | |
107 | ||
108 | static inline void eurwdt_write_reg(u8 index, u8 data) | |
109 | { | |
110 | outb(index, io); | |
111 | outb(data, io+1); | |
112 | } | |
113 | ||
114 | static inline void eurwdt_lock_chip(void) | |
115 | { | |
116 | outb(0xaa, io); | |
117 | } | |
118 | ||
119 | static inline void eurwdt_unlock_chip(void) | |
120 | { | |
121 | outb(0x55, io); | |
122 | eurwdt_write_reg(0x07, 0x08); /* set the logical device */ | |
123 | } | |
124 | ||
125 | static inline void eurwdt_set_timeout(int timeout) | |
126 | { | |
127 | eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); | |
128 | } | |
129 | ||
130 | static inline void eurwdt_disable_timer(void) | |
131 | { | |
132 | eurwdt_set_timeout(0); | |
133 | } | |
134 | ||
135 | static void eurwdt_activate_timer(void) | |
136 | { | |
137 | eurwdt_disable_timer(); | |
138 | eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ | |
89ea2429 AC |
139 | eurwdt_write_reg(WDT_OUTPIN_CFG, |
140 | !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); | |
1da177e4 LT |
141 | |
142 | /* Setting interrupt line */ | |
143 | if (irq == 2 || irq > 15 || irq < 0) { | |
27c766aa | 144 | pr_err("invalid irq number\n"); |
1da177e4 LT |
145 | irq = 0; /* if invalid we disable interrupt */ |
146 | } | |
147 | if (irq == 0) | |
27c766aa | 148 | pr_info("interrupt disabled\n"); |
1da177e4 | 149 | |
143a2e54 | 150 | eurwdt_write_reg(WDT_TIMER_CFG, irq << 4); |
1da177e4 LT |
151 | |
152 | eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ | |
153 | eurwdt_set_timeout(0); /* the default timeout */ | |
154 | } | |
155 | ||
156 | ||
157 | /* | |
158 | * Kernel methods. | |
159 | */ | |
160 | ||
7d12e780 | 161 | static irqreturn_t eurwdt_interrupt(int irq, void *dev_id) |
1da177e4 | 162 | { |
27c766aa | 163 | pr_crit("timeout WDT timeout\n"); |
1da177e4 LT |
164 | |
165 | #ifdef ONLY_TESTING | |
27c766aa | 166 | pr_crit("Would Reboot\n"); |
1da177e4 | 167 | #else |
27c766aa | 168 | pr_crit("Initiating system reboot\n"); |
cc1d3a9a | 169 | emergency_restart(); |
1da177e4 LT |
170 | #endif |
171 | return IRQ_HANDLED; | |
172 | } | |
173 | ||
174 | ||
175 | /** | |
176 | * eurwdt_ping: | |
177 | * | |
178 | * Reload counter one with the watchdog timeout. | |
179 | */ | |
180 | ||
181 | static void eurwdt_ping(void) | |
182 | { | |
183 | /* Write the watchdog default value */ | |
184 | eurwdt_set_timeout(eurwdt_timeout); | |
185 | } | |
186 | ||
187 | /** | |
188 | * eurwdt_write: | |
189 | * @file: file handle to the watchdog | |
190 | * @buf: buffer to write (unused as data does not matter here | |
191 | * @count: count of bytes | |
192 | * @ppos: pointer to the position to write. No seeks allowed | |
193 | * | |
194 | * A write to a watchdog device is defined as a keepalive signal. Any | |
195 | * write of data will do, as we we don't define content meaning. | |
196 | */ | |
197 | ||
198 | static ssize_t eurwdt_write(struct file *file, const char __user *buf, | |
199 | size_t count, loff_t *ppos) | |
200 | { | |
5f3b2756 | 201 | if (count) { |
1da177e4 LT |
202 | if (!nowayout) { |
203 | size_t i; | |
204 | ||
205 | eur_expect_close = 0; | |
206 | ||
207 | for (i = 0; i != count; i++) { | |
208 | char c; | |
7944d3a5 | 209 | if (get_user(c, buf + i)) |
1da177e4 LT |
210 | return -EFAULT; |
211 | if (c == 'V') | |
212 | eur_expect_close = 42; | |
213 | } | |
214 | } | |
89ea2429 | 215 | spin_lock(&eurwdt_lock); |
1da177e4 | 216 | eurwdt_ping(); /* the default timeout */ |
89ea2429 | 217 | spin_unlock(&eurwdt_lock); |
1da177e4 | 218 | } |
1da177e4 LT |
219 | return count; |
220 | } | |
221 | ||
222 | /** | |
223 | * eurwdt_ioctl: | |
1da177e4 LT |
224 | * @file: file handle to the device |
225 | * @cmd: watchdog command | |
226 | * @arg: argument pointer | |
227 | * | |
228 | * The watchdog API defines a common set of functions for all watchdogs | |
229 | * according to their available features. | |
230 | */ | |
231 | ||
89ea2429 AC |
232 | static long eurwdt_ioctl(struct file *file, |
233 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
234 | { |
235 | void __user *argp = (void __user *)arg; | |
236 | int __user *p = argp; | |
42747d71 | 237 | static const struct watchdog_info ident = { |
89ea2429 AC |
238 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
239 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
240 | .firmware_version = 1, |
241 | .identity = "WDT Eurotech CPU-1220/1410", | |
242 | }; | |
243 | ||
244 | int time; | |
245 | int options, retval = -EINVAL; | |
246 | ||
89ea2429 | 247 | switch (cmd) { |
1da177e4 LT |
248 | case WDIOC_GETSUPPORT: |
249 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
250 | ||
251 | case WDIOC_GETSTATUS: | |
252 | case WDIOC_GETBOOTSTATUS: | |
253 | return put_user(0, p); | |
254 | ||
0c06090c WVS |
255 | case WDIOC_SETOPTIONS: |
256 | if (get_user(options, p)) | |
257 | return -EFAULT; | |
258 | spin_lock(&eurwdt_lock); | |
259 | if (options & WDIOS_DISABLECARD) { | |
260 | eurwdt_disable_timer(); | |
261 | retval = 0; | |
262 | } | |
263 | if (options & WDIOS_ENABLECARD) { | |
264 | eurwdt_activate_timer(); | |
265 | eurwdt_ping(); | |
266 | retval = 0; | |
267 | } | |
268 | spin_unlock(&eurwdt_lock); | |
269 | return retval; | |
270 | ||
1da177e4 | 271 | case WDIOC_KEEPALIVE: |
89ea2429 | 272 | spin_lock(&eurwdt_lock); |
1da177e4 | 273 | eurwdt_ping(); |
89ea2429 | 274 | spin_unlock(&eurwdt_lock); |
1da177e4 LT |
275 | return 0; |
276 | ||
277 | case WDIOC_SETTIMEOUT: | |
278 | if (copy_from_user(&time, p, sizeof(int))) | |
279 | return -EFAULT; | |
280 | ||
281 | /* Sanity check */ | |
282 | if (time < 0 || time > 255) | |
283 | return -EINVAL; | |
284 | ||
89ea2429 | 285 | spin_lock(&eurwdt_lock); |
1da177e4 LT |
286 | eurwdt_timeout = time; |
287 | eurwdt_set_timeout(time); | |
89ea2429 | 288 | spin_unlock(&eurwdt_lock); |
bd490f82 | 289 | fallthrough; |
1da177e4 LT |
290 | |
291 | case WDIOC_GETTIMEOUT: | |
292 | return put_user(eurwdt_timeout, p); | |
293 | ||
0c06090c WVS |
294 | default: |
295 | return -ENOTTY; | |
1da177e4 LT |
296 | } |
297 | } | |
298 | ||
299 | /** | |
300 | * eurwdt_open: | |
301 | * @inode: inode of device | |
302 | * @file: file handle to device | |
303 | * | |
304 | * The misc device has been opened. The watchdog device is single | |
305 | * open and on opening we load the counter. | |
306 | */ | |
307 | ||
308 | static int eurwdt_open(struct inode *inode, struct file *file) | |
309 | { | |
310 | if (test_and_set_bit(0, &eurwdt_is_open)) | |
311 | return -EBUSY; | |
312 | eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ | |
313 | /* Activate the WDT */ | |
314 | eurwdt_activate_timer(); | |
c5bf68fe | 315 | return stream_open(inode, file); |
1da177e4 LT |
316 | } |
317 | ||
318 | /** | |
319 | * eurwdt_release: | |
320 | * @inode: inode to board | |
321 | * @file: file handle to board | |
322 | * | |
323 | * The watchdog has a configurable API. There is a religious dispute | |
324 | * between people who want their watchdog to be able to shut down and | |
325 | * those who want to be sure if the watchdog manager dies the machine | |
326 | * reboots. In the former case we disable the counters, in the latter | |
327 | * case you have to open it again very soon. | |
328 | */ | |
329 | ||
330 | static int eurwdt_release(struct inode *inode, struct file *file) | |
331 | { | |
89ea2429 | 332 | if (eur_expect_close == 42) |
1da177e4 | 333 | eurwdt_disable_timer(); |
89ea2429 | 334 | else { |
27c766aa | 335 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
1da177e4 LT |
336 | eurwdt_ping(); |
337 | } | |
338 | clear_bit(0, &eurwdt_is_open); | |
339 | eur_expect_close = 0; | |
340 | return 0; | |
341 | } | |
342 | ||
343 | /** | |
344 | * eurwdt_notify_sys: | |
345 | * @this: our notifier block | |
346 | * @code: the event being reported | |
347 | * @unused: unused | |
348 | * | |
349 | * Our notifier is called on system shutdowns. We want to turn the card | |
350 | * off at reboot otherwise the machine will reboot again during memory | |
351 | * test or worse yet during the following fsck. This would suck, in fact | |
352 | * trust me - if it happens it does suck. | |
353 | */ | |
354 | ||
355 | static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, | |
356 | void *unused) | |
357 | { | |
7944d3a5 WVS |
358 | if (code == SYS_DOWN || code == SYS_HALT) |
359 | eurwdt_disable_timer(); /* Turn the card off */ | |
1da177e4 LT |
360 | |
361 | return NOTIFY_DONE; | |
362 | } | |
363 | ||
364 | /* | |
365 | * Kernel Interfaces | |
366 | */ | |
367 | ||
368 | ||
62322d25 | 369 | static const struct file_operations eurwdt_fops = { |
89ea2429 AC |
370 | .owner = THIS_MODULE, |
371 | .llseek = no_llseek, | |
372 | .write = eurwdt_write, | |
373 | .unlocked_ioctl = eurwdt_ioctl, | |
b6dfb247 | 374 | .compat_ioctl = compat_ptr_ioctl, |
89ea2429 | 375 | .open = eurwdt_open, |
1da177e4 LT |
376 | .release = eurwdt_release, |
377 | }; | |
378 | ||
379 | static struct miscdevice eurwdt_miscdev = { | |
380 | .minor = WATCHDOG_MINOR, | |
381 | .name = "watchdog", | |
382 | .fops = &eurwdt_fops, | |
383 | }; | |
384 | ||
385 | /* | |
386 | * The WDT card needs to learn about soft shutdowns in order to | |
387 | * turn the timebomb registers off. | |
388 | */ | |
389 | ||
390 | static struct notifier_block eurwdt_notifier = { | |
391 | .notifier_call = eurwdt_notify_sys, | |
392 | }; | |
393 | ||
394 | /** | |
4700df05 | 395 | * eurwdt_exit: |
1da177e4 LT |
396 | * |
397 | * Unload the watchdog. You cannot do this with any file handles open. | |
398 | * If your watchdog is set to continue ticking on close and you unload | |
399 | * it, well it keeps ticking. We won't get the interrupt but the board | |
400 | * will not touch PC memory so all is fine. You just have to load a new | |
401 | * module in 60 seconds or reboot. | |
402 | */ | |
403 | ||
404 | static void __exit eurwdt_exit(void) | |
405 | { | |
406 | eurwdt_lock_chip(); | |
407 | ||
408 | misc_deregister(&eurwdt_miscdev); | |
409 | ||
410 | unregister_reboot_notifier(&eurwdt_notifier); | |
411 | release_region(io, 2); | |
412 | free_irq(irq, NULL); | |
413 | } | |
414 | ||
415 | /** | |
416 | * eurwdt_init: | |
417 | * | |
418 | * Set up the WDT watchdog board. After grabbing the resources | |
419 | * we require we need also to unlock the device. | |
420 | * The open() function will actually kick the board off. | |
421 | */ | |
422 | ||
423 | static int __init eurwdt_init(void) | |
424 | { | |
425 | int ret; | |
426 | ||
86b59128 | 427 | ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL); |
89ea2429 | 428 | if (ret) { |
27c766aa | 429 | pr_err("IRQ %d is not free\n", irq); |
fb8f7ba0 | 430 | goto out; |
1da177e4 LT |
431 | } |
432 | ||
433 | if (!request_region(io, 2, "eurwdt")) { | |
27c766aa | 434 | pr_err("IO %X is not free\n", io); |
1da177e4 LT |
435 | ret = -EBUSY; |
436 | goto outirq; | |
437 | } | |
438 | ||
439 | ret = register_reboot_notifier(&eurwdt_notifier); | |
440 | if (ret) { | |
27c766aa | 441 | pr_err("can't register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
442 | goto outreg; |
443 | } | |
444 | ||
fb8f7ba0 AD |
445 | ret = misc_register(&eurwdt_miscdev); |
446 | if (ret) { | |
27c766aa | 447 | pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR); |
fb8f7ba0 AD |
448 | goto outreboot; |
449 | } | |
450 | ||
1da177e4 LT |
451 | eurwdt_unlock_chip(); |
452 | ||
453 | ret = 0; | |
27c766aa | 454 | pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n", |
1da177e4 LT |
455 | io, irq, (!strcmp("int", ev) ? "int" : "reboot")); |
456 | ||
457 | out: | |
458 | return ret; | |
459 | ||
fb8f7ba0 AD |
460 | outreboot: |
461 | unregister_reboot_notifier(&eurwdt_notifier); | |
462 | ||
1da177e4 LT |
463 | outreg: |
464 | release_region(io, 2); | |
465 | ||
466 | outirq: | |
467 | free_irq(irq, NULL); | |
1da177e4 LT |
468 | goto out; |
469 | } | |
470 | ||
471 | module_init(eurwdt_init); | |
472 | module_exit(eurwdt_exit); | |
473 | ||
474 | MODULE_AUTHOR("Rodolfo Giometti"); | |
475 | MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); | |
476 | MODULE_LICENSE("GPL"); |