[go: nahoru, domu]
1/*
2 *	Wdt977	0.04:	A Watchdog Device for Netwinder W83977AF chip
3 *
4 *	(c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
5 *
6 *			-----------------------
7 *
8 *	This program is free software; you can redistribute it and/or
9 *	modify it under the terms of the GNU General Public License
10 *	as published by the Free Software Foundation; either version
11 *	2 of the License, or (at your option) any later version.
12 *
13 *			-----------------------
14 *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
15 *           Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
16 *	19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
17 *	06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
18 *				    from minutes to seconds.
19 *      07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
20 *                                    nwwatchdog_init.
21 *      25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
22 *				    remove limitiation to be used on
23 *				    Netwinders only
24 */
25
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/types.h>
31#include <linux/kernel.h>
32#include <linux/fs.h>
33#include <linux/miscdevice.h>
34#include <linux/init.h>
35#include <linux/ioport.h>
36#include <linux/watchdog.h>
37#include <linux/notifier.h>
38#include <linux/reboot.h>
39#include <linux/io.h>
40#include <linux/uaccess.h>
41
42#include <asm/mach-types.h>
43
44#define WATCHDOG_VERSION  "0.04"
45#define WATCHDOG_NAME     "Wdt977"
46
47#define IO_INDEX_PORT	0x370		/* on some systems it can be 0x3F0 */
48#define IO_DATA_PORT	(IO_INDEX_PORT + 1)
49
50#define UNLOCK_DATA	0x87
51#define LOCK_DATA	0xAA
52#define DEVICE_REGISTER	0x07
53
54
55#define	DEFAULT_TIMEOUT	60			/* default timeout in seconds */
56
57static	int timeout = DEFAULT_TIMEOUT;
58static	int timeoutM;				/* timeout in minutes */
59static	unsigned long timer_alive;
60static	int testmode;
61static	char expect_close;
62static	DEFINE_SPINLOCK(spinlock);
63
64module_param(timeout, int, 0);
65MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
66				__MODULE_STRING(DEFAULT_TIMEOUT) ")");
67module_param(testmode, int, 0);
68MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
69
70static bool nowayout = WATCHDOG_NOWAYOUT;
71module_param(nowayout, bool, 0);
72MODULE_PARM_DESC(nowayout,
73		"Watchdog cannot be stopped once started (default="
74				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
75
76/*
77 * Start the watchdog
78 */
79
80static int wdt977_start(void)
81{
82	unsigned long flags;
83
84	spin_lock_irqsave(&spinlock, flags);
85
86	/* unlock the SuperIO chip */
87	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
88	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
89
90	/* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
91	 * F2 has the timeout in minutes
92	 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
93	 *   at timeout, and to reset timer on kbd/mouse activity (not impl.)
94	 * F4 is used to just clear the TIMEOUT'ed state (bit 0)
95	 */
96	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
97	outb_p(0x08, IO_DATA_PORT);
98	outb_p(0xF2, IO_INDEX_PORT);
99	outb_p(timeoutM, IO_DATA_PORT);
100	outb_p(0xF3, IO_INDEX_PORT);
101	outb_p(0x00, IO_DATA_PORT);	/* another setting is 0E for
102					   kbd/mouse/LED */
103	outb_p(0xF4, IO_INDEX_PORT);
104	outb_p(0x00, IO_DATA_PORT);
105
106	/* At last select device Aux1 (dev=7) and set GP16 as a
107	 * watchdog output. In test mode watch the bit 1 on F4 to
108	 * indicate "triggered"
109	 */
110	if (!testmode) {
111		outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
112		outb_p(0x07, IO_DATA_PORT);
113		outb_p(0xE6, IO_INDEX_PORT);
114		outb_p(0x08, IO_DATA_PORT);
115	}
116
117	/* lock the SuperIO chip */
118	outb_p(LOCK_DATA, IO_INDEX_PORT);
119
120	spin_unlock_irqrestore(&spinlock, flags);
121	pr_info("activated\n");
122
123	return 0;
124}
125
126/*
127 * Stop the watchdog
128 */
129
130static int wdt977_stop(void)
131{
132	unsigned long flags;
133	spin_lock_irqsave(&spinlock, flags);
134
135	/* unlock the SuperIO chip */
136	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
137	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
138
139	/* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
140	* F3 is reset to its default state
141	* F4 can clear the TIMEOUT'ed state (bit 0) - back to default
142	* We can not use GP17 as a PowerLed, as we use its usage as a RedLed
143	*/
144	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
145	outb_p(0x08, IO_DATA_PORT);
146	outb_p(0xF2, IO_INDEX_PORT);
147	outb_p(0xFF, IO_DATA_PORT);
148	outb_p(0xF3, IO_INDEX_PORT);
149	outb_p(0x00, IO_DATA_PORT);
150	outb_p(0xF4, IO_INDEX_PORT);
151	outb_p(0x00, IO_DATA_PORT);
152	outb_p(0xF2, IO_INDEX_PORT);
153	outb_p(0x00, IO_DATA_PORT);
154
155	/* at last select device Aux1 (dev=7) and set
156	   GP16 as a watchdog output */
157	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
158	outb_p(0x07, IO_DATA_PORT);
159	outb_p(0xE6, IO_INDEX_PORT);
160	outb_p(0x08, IO_DATA_PORT);
161
162	/* lock the SuperIO chip */
163	outb_p(LOCK_DATA, IO_INDEX_PORT);
164
165	spin_unlock_irqrestore(&spinlock, flags);
166	pr_info("shutdown\n");
167
168	return 0;
169}
170
171/*
172 * Send a keepalive ping to the watchdog
173 * This is done by simply re-writing the timeout to reg. 0xF2
174 */
175
176static int wdt977_keepalive(void)
177{
178	unsigned long flags;
179	spin_lock_irqsave(&spinlock, flags);
180
181	/* unlock the SuperIO chip */
182	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
183	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
184
185	/* select device Aux2 (device=8) and kicks watchdog reg F2 */
186	/* F2 has the timeout in minutes */
187	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
188	outb_p(0x08, IO_DATA_PORT);
189	outb_p(0xF2, IO_INDEX_PORT);
190	outb_p(timeoutM, IO_DATA_PORT);
191
192	/* lock the SuperIO chip */
193	outb_p(LOCK_DATA, IO_INDEX_PORT);
194	spin_unlock_irqrestore(&spinlock, flags);
195
196	return 0;
197}
198
199/*
200 * Set the watchdog timeout value
201 */
202
203static int wdt977_set_timeout(int t)
204{
205	int tmrval;
206
207	/* convert seconds to minutes, rounding up */
208	tmrval = (t + 59) / 60;
209
210	if (machine_is_netwinder()) {
211		/* we have a hw bug somewhere, so each 977 minute is actually
212		 * only 30sec. This limits the max timeout to half of device
213		 * max of 255 minutes...
214		 */
215		tmrval += tmrval;
216	}
217
218	if (tmrval < 1 || tmrval > 255)
219		return -EINVAL;
220
221	/* timeout is the timeout in seconds, timeoutM is
222	   the timeout in minutes) */
223	timeout = t;
224	timeoutM = tmrval;
225	return 0;
226}
227
228/*
229 * Get the watchdog status
230 */
231
232static int wdt977_get_status(int *status)
233{
234	int new_status;
235	unsigned long flags;
236
237	spin_lock_irqsave(&spinlock, flags);
238
239	/* unlock the SuperIO chip */
240	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
241	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
242
243	/* select device Aux2 (device=8) and read watchdog reg F4 */
244	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
245	outb_p(0x08, IO_DATA_PORT);
246	outb_p(0xF4, IO_INDEX_PORT);
247	new_status = inb_p(IO_DATA_PORT);
248
249	/* lock the SuperIO chip */
250	outb_p(LOCK_DATA, IO_INDEX_PORT);
251
252	spin_unlock_irqrestore(&spinlock, flags);
253
254	*status = 0;
255	if (new_status & 1)
256		*status |= WDIOF_CARDRESET;
257
258	return 0;
259}
260
261
262/*
263 *	/dev/watchdog handling
264 */
265
266static int wdt977_open(struct inode *inode, struct file *file)
267{
268	/* If the watchdog is alive we don't need to start it again */
269	if (test_and_set_bit(0, &timer_alive))
270		return -EBUSY;
271
272	if (nowayout)
273		__module_get(THIS_MODULE);
274
275	wdt977_start();
276	return nonseekable_open(inode, file);
277}
278
279static int wdt977_release(struct inode *inode, struct file *file)
280{
281	/*
282	 *	Shut off the timer.
283	 *	Lock it in if it's a module and we set nowayout
284	 */
285	if (expect_close == 42) {
286		wdt977_stop();
287		clear_bit(0, &timer_alive);
288	} else {
289		wdt977_keepalive();
290		pr_crit("Unexpected close, not stopping watchdog!\n");
291	}
292	expect_close = 0;
293	return 0;
294}
295
296
297/*
298 *      wdt977_write:
299 *      @file: file handle to the watchdog
300 *      @buf: buffer to write (unused as data does not matter here
301 *      @count: count of bytes
302 *      @ppos: pointer to the position to write. No seeks allowed
303 *
304 *      A write to a watchdog device is defined as a keepalive signal. Any
305 *      write of data will do, as we we don't define content meaning.
306 */
307
308static ssize_t wdt977_write(struct file *file, const char __user *buf,
309			    size_t count, loff_t *ppos)
310{
311	if (count) {
312		if (!nowayout) {
313			size_t i;
314
315			/* In case it was set long ago */
316			expect_close = 0;
317
318			for (i = 0; i != count; i++) {
319				char c;
320				if (get_user(c, buf + i))
321					return -EFAULT;
322				if (c == 'V')
323					expect_close = 42;
324			}
325		}
326
327		/* someone wrote to us, we should restart timer */
328		wdt977_keepalive();
329	}
330	return count;
331}
332
333static const struct watchdog_info ident = {
334	.options =		WDIOF_SETTIMEOUT |
335				WDIOF_MAGICCLOSE |
336				WDIOF_KEEPALIVEPING,
337	.firmware_version =	1,
338	.identity =		WATCHDOG_NAME,
339};
340
341/*
342 *      wdt977_ioctl:
343 *      @inode: inode of the device
344 *      @file: file handle to the device
345 *      @cmd: watchdog command
346 *      @arg: argument pointer
347 *
348 *      The watchdog API defines a common set of functions for all watchdogs
349 *      according to their available features.
350 */
351
352static long wdt977_ioctl(struct file *file, unsigned int cmd,
353							unsigned long arg)
354{
355	int status;
356	int new_options, retval = -EINVAL;
357	int new_timeout;
358	union {
359		struct watchdog_info __user *ident;
360		int __user *i;
361	} uarg;
362
363	uarg.i = (int __user *)arg;
364
365	switch (cmd) {
366	case WDIOC_GETSUPPORT:
367		return copy_to_user(uarg.ident, &ident,
368			sizeof(ident)) ? -EFAULT : 0;
369
370	case WDIOC_GETSTATUS:
371		wdt977_get_status(&status);
372		return put_user(status, uarg.i);
373
374	case WDIOC_GETBOOTSTATUS:
375		return put_user(0, uarg.i);
376
377	case WDIOC_SETOPTIONS:
378		if (get_user(new_options, uarg.i))
379			return -EFAULT;
380
381		if (new_options & WDIOS_DISABLECARD) {
382			wdt977_stop();
383			retval = 0;
384		}
385
386		if (new_options & WDIOS_ENABLECARD) {
387			wdt977_start();
388			retval = 0;
389		}
390
391		return retval;
392
393	case WDIOC_KEEPALIVE:
394		wdt977_keepalive();
395		return 0;
396
397	case WDIOC_SETTIMEOUT:
398		if (get_user(new_timeout, uarg.i))
399			return -EFAULT;
400
401		if (wdt977_set_timeout(new_timeout))
402			return -EINVAL;
403
404		wdt977_keepalive();
405		/* Fall */
406
407	case WDIOC_GETTIMEOUT:
408		return put_user(timeout, uarg.i);
409
410	default:
411		return -ENOTTY;
412
413	}
414}
415
416static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
417	void *unused)
418{
419	if (code == SYS_DOWN || code == SYS_HALT)
420		wdt977_stop();
421	return NOTIFY_DONE;
422}
423
424static const struct file_operations wdt977_fops = {
425	.owner		= THIS_MODULE,
426	.llseek		= no_llseek,
427	.write		= wdt977_write,
428	.unlocked_ioctl	= wdt977_ioctl,
429	.open		= wdt977_open,
430	.release	= wdt977_release,
431};
432
433static struct miscdevice wdt977_miscdev = {
434	.minor		= WATCHDOG_MINOR,
435	.name		= "watchdog",
436	.fops		= &wdt977_fops,
437};
438
439static struct notifier_block wdt977_notifier = {
440	.notifier_call = wdt977_notify_sys,
441};
442
443static int __init wd977_init(void)
444{
445	int rc;
446
447	pr_info("driver v%s\n", WATCHDOG_VERSION);
448
449	/* Check that the timeout value is within its range;
450	   if not reset to the default */
451	if (wdt977_set_timeout(timeout)) {
452		wdt977_set_timeout(DEFAULT_TIMEOUT);
453		pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
454			DEFAULT_TIMEOUT);
455	}
456
457	/* on Netwinder the IOports are already reserved by
458	 * arch/arm/mach-footbridge/netwinder-hw.c
459	 */
460	if (!machine_is_netwinder()) {
461		if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
462			pr_err("I/O address 0x%04x already in use\n",
463			       IO_INDEX_PORT);
464			rc = -EIO;
465			goto err_out;
466		}
467	}
468
469	rc = register_reboot_notifier(&wdt977_notifier);
470	if (rc) {
471		pr_err("cannot register reboot notifier (err=%d)\n", rc);
472		goto err_out_region;
473	}
474
475	rc = misc_register(&wdt977_miscdev);
476	if (rc) {
477		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
478		       wdt977_miscdev.minor, rc);
479		goto err_out_reboot;
480	}
481
482	pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
483		timeout, nowayout, testmode);
484
485	return 0;
486
487err_out_reboot:
488	unregister_reboot_notifier(&wdt977_notifier);
489err_out_region:
490	if (!machine_is_netwinder())
491		release_region(IO_INDEX_PORT, 2);
492err_out:
493	return rc;
494}
495
496static void __exit wd977_exit(void)
497{
498	wdt977_stop();
499	misc_deregister(&wdt977_miscdev);
500	unregister_reboot_notifier(&wdt977_notifier);
501	release_region(IO_INDEX_PORT, 2);
502}
503
504module_init(wd977_init);
505module_exit(wd977_exit);
506
507MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
508MODULE_DESCRIPTION("W83977AF Watchdog driver");
509MODULE_LICENSE("GPL");
510