aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/watchdog/i8xx_tco.c
blob: c337978dc966b7e955a1ed736e8fd7bad47a062b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
/*
 *	i8xx_tco 0.07:	TCO timer driver for i8xx chipsets
 *
 *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights Reserved.
 *				http://www.kernelconcepts.de
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Neither kernel concepts nor Nils Faerber admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 2000	kernel concepts <nils@kernelconcepts.de>
 *				developed for
 *                              Jentro AG, Haar/Munich (Germany)
 *
 *	TCO timer driver for i8xx chipsets
 *	based on softdog.c by Alan Cox <alan@redhat.com>
 *
 *	The TCO timer is implemented in the following I/O controller hubs:
 *	(See the intel documentation on http://developer.intel.com.)
 *	82801AA  (ICH)    : document number 290655-003, 290677-014,
 *	82801AB  (ICHO)   : document number 290655-003, 290677-014,
 *	82801BA  (ICH2)   : document number 290687-002, 298242-027,
 *	82801BAM (ICH2-M) : document number 290687-002, 298242-027,
 *	82801CA  (ICH3-S) : document number 290733-003, 290739-013,
 *	82801CAM (ICH3-M) : document number 290716-001, 290718-007,
 *	82801DB  (ICH4)   : document number 290744-001, 290745-020,
 *	82801DBM (ICH4-M) : document number 252337-001, 252663-005,
 *	82801E   (C-ICH)  : document number 273599-001, 273645-002,
 *	82801EB  (ICH5)   : document number 252516-001, 252517-003,
 *	82801ER  (ICH5R)  : document number 252516-001, 252517-003,
 *	82801FB  (ICH6)   : document number 301473-002, 301474-007,
 *	82801FR  (ICH6R)  : document number 301473-002, 301474-007,
 *	82801FBM (ICH6-M) : document number 301473-002, 301474-007,
 *	82801FW  (ICH6W)  : document number 301473-001, 301474-007,
 *	82801FRW (ICH6RW) : document number 301473-001, 301474-007
 *
 *  20000710 Nils Faerber
 *	Initial Version 0.01
 *  20000728 Nils Faerber
 *	0.02 Fix for SMI_EN->TCO_EN bit, some cleanups
 *  20011214 Matt Domsch <Matt_Domsch@dell.com>
 *	0.03 Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *	     Didn't add timeout option as i810_margin already exists.
 *  20020224 Joel Becker, Wim Van Sebroeck
 *	0.04 Support for 82801CA(M) chipset, timer margin needs to be > 3,
 *	     add support for WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT.
 *  20020412 Rob Radez <rob@osinvestor.com>, Wim Van Sebroeck
 *	0.05 Fix possible timer_alive race, add expect close support,
 *	     clean up ioctls (WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS and
 *	     WDIOC_SETOPTIONS), made i810tco_getdevice __init,
 *	     removed boot_status, removed tco_timer_read,
 *	     added support for 82801DB and 82801E chipset,
 *	     added support for 82801EB and 8280ER chipset,
 *	     general cleanup.
 *  20030921 Wim Van Sebroeck <wim@iguana.be>
 *	0.06 change i810_margin to heartbeat, use module_param,
 *	     added notify system support, renamed module to i8xx_tco.
 *  20050128 Wim Van Sebroeck <wim@iguana.be>
 *	0.07 Added support for the ICH4-M, ICH6, ICH6R, ICH6-M, ICH6W and ICH6RW
 *	     chipsets. Also added support for the "undocumented" ICH7 chipset.
 */

/*
 *	Includes, defines, variables, module parameters, ...
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/ioport.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#include "i8xx_tco.h"

/* Module and version information */
#define TCO_VERSION "0.07"
#define TCO_MODULE_NAME "i8xx TCO timer"
#define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
#define PFX TCO_MODULE_NAME ": "

/* internal variables */
static unsigned int ACPIBASE;
static spinlock_t tco_lock;	/* Guards the hardware */
static unsigned long timer_alive;
static char tco_expect_close;
static struct pci_dev *i8xx_tco_pci;

/* module parameters */
#define WATCHDOG_HEARTBEAT 30	/* 30 sec default heartbeat (2<heartbeat<39) */
static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");

#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout = 0;
#endif

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/*
 * Some TCO specific functions
 */

static inline unsigned char seconds_to_ticks(int seconds)
{
	/* the internal timer is stored as ticks which decrement
	 * every 0.6 seconds */
	return (seconds * 10) / 6;
}

static int tco_timer_start (void)
{
	unsigned char val;

	spin_lock(&tco_lock);
	val = inb (TCO1_CNT + 1);
	val &= 0xf7;
	outb (val, TCO1_CNT + 1);
	val = inb (TCO1_CNT + 1);
	spin_unlock(&tco_lock);

	if (val & 0x08)
		return -1;
	return 0;
}

static int tco_timer_stop (void)
{
	unsigned char val;

	spin_lock(&tco_lock);
	val = inb (TCO1_CNT + 1);
	val |= 0x08;
	outb (val, TCO1_CNT + 1);
	val = inb (TCO1_CNT + 1);
	spin_unlock(&tco_lock);

	if ((val & 0x08) == 0)
		return -1;
	return 0;
}

static int tco_timer_keepalive (void)
{
	spin_lock(&tco_lock);
	outb (0x01, TCO1_RLD);
	spin_unlock(&tco_lock);
	return 0;
}

static int tco_timer_set_heartbeat (int t)
{
	unsigned char val;
	unsigned char tmrval;

	tmrval = seconds_to_ticks(t);
	/* from the specs: */
	/* "Values of 0h-3h are ignored and should not be attempted" */
	if (tmrval > 0x3f || tmrval < 0x04)
		return -EINVAL;

	/* Write new heartbeat to watchdog */
	spin_lock(&tco_lock);
	val = inb (TCO1_TMR);
	val &= 0xc0;
	val |= tmrval;
	outb (val, TCO1_TMR);
	val = inb (TCO1_TMR);
	spin_unlock(&tco_lock);

	if ((val & 0x3f) != tmrval)
		return -EINVAL;

	heartbeat = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */

static int i8xx_tco_open (struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &timer_alive))
		return -EBUSY;

	/*
	 *      Reload and activate timer
	 */
	tco_timer_keepalive ();
	tco_timer_start ();
	return nonseekable_open(inode, file);
}

static int i8xx_tco_release (struct inode *inode, struct file *file)
{
	/*
	 *      Shut off the timer.
	 */
	if (tco_expect_close == 42) {
		tco_timer_stop ();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		tco_timer_keepalive ();
	}
	clear_bit(0, &timer_alive);
	tco_expect_close = 0;
	return 0;
}

static ssize_t i8xx_tco_write (struct file *file, const char __user *data,
			      size_t len, loff_t * ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the magic character
			 * five months ago... */
			tco_expect_close = 0;

			/* scan to see whether or not we got the magic character */
			for (i = 0; i != len; i++) {
				char c;
				if(get_user(c, data+i))
					return -EFAULT;
				if (c == 'V')
					tco_expect_close = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		tco_timer_keepalive ();
	}
	return len;
}

static int i8xx_tco_ioctl (struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg)
{
	int new_options, retval = -EINVAL;
	int new_heartbeat;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.options =		WDIOF_SETTIMEOUT |
					WDIOF_KEEPALIVEPING |
					WDIOF_MAGICCLOSE,
		.firmware_version =	0,
		.identity =		TCO_MODULE_NAME,
	};

	switch (cmd) {
		case WDIOC_GETSUPPORT:
			return copy_to_user(argp, &ident,
				sizeof (ident)) ? -EFAULT : 0;

		case WDIOC_GETSTATUS:
		case WDIOC_GETBOOTSTATUS:
			return put_user (0, p);

		case WDIOC_KEEPALIVE:
			tco_timer_keepalive ();
			return 0;

		case WDIOC_SETOPTIONS:
		{
			if (get_user (new_options, p))
				return -EFAULT;

			if (new_options & WDIOS_DISABLECARD) {
				tco_timer_stop ();
				retval = 0;
			}

			if (new_options & WDIOS_ENABLECARD) {
				tco_timer_keepalive ();
				tco_timer_start ();
				retval = 0;
			}

			return retval;
		}

		case WDIOC_SETTIMEOUT:
		{
			if (get_user(new_heartbeat, p))
				return -EFAULT;

			if (tco_timer_set_heartbeat(new_heartbeat))
			    return -EINVAL;

			tco_timer_keepalive ();
			/* Fall */
		}

		case WDIOC_GETTIMEOUT:
			return put_user(heartbeat, p);

		default:
			return -ENOIOCTLCMD;
	}
}

/*
 *	Notify system
 */

static int i8xx_tco_notify_sys (struct notifier_block *this, unsigned long code, void *unused)
{
	if (code==SYS_DOWN || code==SYS_HALT) {
		/* Turn the WDT off */
		tco_timer_stop ();
	}

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations i8xx_tco_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.write =	i8xx_tco_write,
	.ioctl =	i8xx_tco_ioctl,
	.open =		i8xx_tco_open,
	.release =	i8xx_tco_release,
};

static struct miscdevice i8xx_tco_miscdev = {
	.minor =	WATCHDOG_MINOR,
	.name =		"watchdog",
	.fops =		&i8xx_tco_fops,
};

static struct notifier_block i8xx_tco_notifier = {
	.notifier_call =	i8xx_tco_notify_sys,
};

/*
 * Data for PCI driver interface
 *
 * This data only exists for exporting the supported
 * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 * register a pci_driver, because someone else might one day
 * want to register another driver on the same PCI id.
 */
static struct pci_device_id i8xx_tco_pci_tbl[] = {
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_10,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_12,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801E_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_2,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0,	PCI_ANY_ID, PCI_ANY_ID, },
	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1,	PCI_ANY_ID, PCI_ANY_ID, },
	{ 0, },			/* End of list */
};
MODULE_DEVICE_TABLE (pci, i8xx_tco_pci_tbl);

/*
 *	Init & exit routines
 */

static unsigned char __init i8xx_tco_getdevice (void)
{
	struct pci_dev *dev = NULL;
	u8 val1, val2;
	u16 badr;
	/*
	 *      Find the PCI device
	 */

	while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
		if (pci_match_device(i8xx_tco_pci_tbl, dev)) {
			i8xx_tco_pci = dev;
			break;
		}
	}

	if (i8xx_tco_pci) {
		/*
		 *      Find the ACPI base I/O address which is the base
		 *      for the TCO registers (TCOBASE=ACPIBASE + 0x60)
		 *      ACPIBASE is bits [15:7] from 0x40-0x43
		 */
		pci_read_config_byte (i8xx_tco_pci, 0x40, &val1);
		pci_read_config_byte (i8xx_tco_pci, 0x41, &val2);
		badr = ((val2 << 1) | (val1 >> 7)) << 7;
		ACPIBASE = badr;
		/* Something's wrong here, ACPIBASE has to be set */
		if (badr == 0x0001 || badr == 0x0000) {
			printk (KERN_ERR PFX "failed to get TCOBASE address\n");
			return 0;
		}
		/*
		 * Check chipset's NO_REBOOT bit
		 */
		pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
		if (val1 & 0x02) {
			val1 &= 0xfd;
			pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
			pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
			if (val1 & 0x02) {
				printk (KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
				return 0;	/* Cannot reset NO_REBOOT bit */
			}
		}
		/* Set the TCO_EN bit in SMI_EN register */
		if (!request_region (SMI_EN + 1, 1, "i8xx TCO")) {
			printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
				SMI_EN + 1);
			return 0;
		}
		val1 = inb (SMI_EN + 1);
		val1 &= 0xdf;
		outb (val1, SMI_EN + 1);
		release_region (SMI_EN + 1, 1);
		return 1;
	}
	return 0;
}

static int __init watchdog_init (void)
{
	int ret;

	spin_lock_init(&tco_lock);

	/* Check whether or not the hardware watchdog is there */
	if (!i8xx_tco_getdevice () || i8xx_tco_pci == NULL)
		return -ENODEV;

	if (!request_region (TCOBASE, 0x10, "i8xx TCO")) {
		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
			TCOBASE);
		ret = -EIO;
		goto out;
	}

	/* Clear out the (probably old) status */
	outb (0, TCO1_STS);
	outb (3, TCO2_STS);

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (tco_timer_set_heartbeat (heartbeat)) {
		heartbeat = WATCHDOG_HEARTBEAT;
		tco_timer_set_heartbeat (heartbeat);
		printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39, using %d\n",
			heartbeat);
	}

	ret = register_reboot_notifier(&i8xx_tco_notifier);
	if (ret != 0) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		goto unreg_region;
	}

	ret = misc_register(&i8xx_tco_miscdev);
	if (ret != 0) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		goto unreg_notifier;
	}

	tco_timer_stop ();

	printk (KERN_INFO PFX "initialized (0x%04x). heartbeat=%d sec (nowayout=%d)\n",
		TCOBASE, heartbeat, nowayout);

	return 0;

unreg_notifier:
	unregister_reboot_notifier(&i8xx_tco_notifier);
unreg_region:
	release_region (TCOBASE, 0x10);
out:
	return ret;
}

static void __exit watchdog_cleanup (void)
{
	u8 val;

	/* Stop the timer before we leave */
	if (!nowayout)
		tco_timer_stop ();

	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
	pci_read_config_byte (i8xx_tco_pci, 0xd4, &val);
	val |= 0x02;
	pci_write_config_byte (i8xx_tco_pci, 0xd4, val);

	/* Deregister */
	misc_deregister (&i8xx_tco_miscdev);
	unregister_reboot_notifier(&i8xx_tco_notifier);
	release_region (TCOBASE, 0x10);
}

module_init(watchdog_init);
module_exit(watchdog_cleanup);

MODULE_AUTHOR("Nils Faerber");
MODULE_DESCRIPTION("TCO timer driver for i8xx chipsets");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);