iTCO_wdt.c 18.9 KB
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678
/*
 *	intel TCO Watchdog Driver
 *
 *	(c) Copyright 2006-2011 Wim Van Sebroeck <wim@iguana.be>.
 *
 *	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 Wim Van Sebroeck nor Iguana vzw. admit liability nor
 *	provide warranty for any of this software. This material is
 *	provided "AS-IS" and at no charge.
 *
 *	The TCO watchdog is implemented in the following I/O controller hubs:
 *	(See the intel documentation on http://developer.intel.com.)
 *	document number 290655-003, 290677-014: 82801AA (ICH), 82801AB (ICHO)
 *	document number 290687-002, 298242-027: 82801BA (ICH2)
 *	document number 290733-003, 290739-013: 82801CA (ICH3-S)
 *	document number 290716-001, 290718-007: 82801CAM (ICH3-M)
 *	document number 290744-001, 290745-025: 82801DB (ICH4)
 *	document number 252337-001, 252663-008: 82801DBM (ICH4-M)
 *	document number 273599-001, 273645-002: 82801E (C-ICH)
 *	document number 252516-001, 252517-028: 82801EB (ICH5), 82801ER (ICH5R)
 *	document number 300641-004, 300884-013: 6300ESB
 *	document number 301473-002, 301474-026: 82801F (ICH6)
 *	document number 313082-001, 313075-006: 631xESB, 632xESB
 *	document number 307013-003, 307014-024: 82801G (ICH7)
 *	document number 322896-001, 322897-001: NM10
 *	document number 313056-003, 313057-017: 82801H (ICH8)
 *	document number 316972-004, 316973-012: 82801I (ICH9)
 *	document number 319973-002, 319974-002: 82801J (ICH10)
 *	document number 322169-001, 322170-003: 5 Series, 3400 Series (PCH)
 *	document number 320066-003, 320257-008: EP80597 (IICH)
 *	document number 324645-001, 324646-001: Cougar Point (CPT)
 *	document number TBD                   : Patsburg (PBG)
 *	document number TBD                   : DH89xxCC
 *	document number TBD                   : Panther Point
 *	document number TBD                   : Lynx Point
 *	document number TBD                   : Lynx Point-LP
 */

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

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

/* Module and version information */
#define DRV_NAME	"iTCO_wdt"
#define DRV_VERSION	"1.11"

/* Includes */
#include <linux/acpi.h>			/* For ACPI support */
#include <linux/module.h>		/* For module specific items */
#include <linux/moduleparam.h>		/* For new moduleparam's */
#include <linux/types.h>		/* For standard types (like size_t) */
#include <linux/errno.h>		/* For the -ENODEV/... values */
#include <linux/kernel.h>		/* For printk/panic/... */
#include <linux/watchdog.h>		/* For the watchdog specific items */
#include <linux/init.h>			/* For __init/__exit/... */
#include <linux/fs.h>			/* For file operations */
#include <linux/platform_device.h>	/* For platform_driver framework */
#include <linux/pci.h>			/* For pci functions */
#include <linux/ioport.h>		/* For io-port access */
#include <linux/spinlock.h>		/* For spin_lock/spin_unlock/... */
#include <linux/uaccess.h>		/* For copy_to_user/put_user/... */
#include <linux/io.h>			/* For inb/outb/... */
#include <linux/platform_data/itco_wdt.h>

#include "iTCO_vendor.h"

/* Address definitions for the TCO */
/* TCO base address */
#define TCOBASE		(iTCO_wdt_private.tco_res->start)
/* SMI Control and Enable Register */
#define SMI_EN		(iTCO_wdt_private.smi_res->start)

#define TCO_RLD		(TCOBASE + 0x00) /* TCO Timer Reload and Curr. Value */
#define TCOv1_TMR	(TCOBASE + 0x01) /* TCOv1 Timer Initial Value	*/
#define TCO_DAT_IN	(TCOBASE + 0x02) /* TCO Data In Register	*/
#define TCO_DAT_OUT	(TCOBASE + 0x03) /* TCO Data Out Register	*/
#define TCO1_STS	(TCOBASE + 0x04) /* TCO1 Status Register	*/
#define TCO2_STS	(TCOBASE + 0x06) /* TCO2 Status Register	*/
#define TCO1_CNT	(TCOBASE + 0x08) /* TCO1 Control Register	*/
#define TCO2_CNT	(TCOBASE + 0x0a) /* TCO2 Control Register	*/
#define TCOv2_TMR	(TCOBASE + 0x12) /* TCOv2 Timer Initial Value	*/

/* internal variables */
static struct {		/* this is private data for the iTCO_wdt device */
	/* TCO version/generation */
	unsigned int iTCO_version;
	struct resource *tco_res;
	struct resource *smi_res;
	/*
	 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
	 * or memory-mapped PMC register bit 4 (TCO version 3).
	 */
	struct resource *gcs_pmc_res;
	unsigned long __iomem *gcs_pmc;
	/* the lock for io operations */
	spinlock_t io_lock;
	struct platform_device *dev;
	/* the PCI-device */
	struct pci_dev *pdev;
	/* whether or not the watchdog has been suspended */
	bool suspended;
} iTCO_wdt_private;

/* module parameters */
#define WATCHDOG_TIMEOUT 30	/* 30 sec default heartbeat */
static int heartbeat = WATCHDOG_TIMEOUT;  /* in seconds */
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
	"5..76 (TCO v1) or 3..614 (TCO v2), default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int turn_SMI_watchdog_clear_off = 1;
module_param(turn_SMI_watchdog_clear_off, int, 0);
MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
	"Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");

/*
 * Some TCO specific functions
 */

/*
 * The iTCO v1 and v2's internal timer is stored as ticks which decrement
 * every 0.6 seconds.  v3's internal timer is stored as seconds (some
 * datasheets incorrectly state 0.6 seconds).
 */
static inline unsigned int seconds_to_ticks(int secs)
{
	return iTCO_wdt_private.iTCO_version == 3 ? secs : (secs * 10) / 6;
}

static inline unsigned int ticks_to_seconds(int ticks)
{
	return iTCO_wdt_private.iTCO_version == 3 ? ticks : (ticks * 6) / 10;
}

static inline u32 no_reboot_bit(void)
{
	u32 enable_bit;

	switch (iTCO_wdt_private.iTCO_version) {
	case 5:
	case 3:
		enable_bit = 0x00000010;
		break;
	case 2:
		enable_bit = 0x00000020;
		break;
	case 4:
	case 1:
	default:
		enable_bit = 0x00000002;
		break;
	}

	return enable_bit;
}

static void iTCO_wdt_set_NO_REBOOT_bit(void)
{
	u32 val32;

	/* Set the NO_REBOOT bit: this disables reboots */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		val32 = readl(iTCO_wdt_private.gcs_pmc);
		val32 |= no_reboot_bit();
		writel(val32, iTCO_wdt_private.gcs_pmc);
	} else if (iTCO_wdt_private.iTCO_version == 1) {
		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
		val32 |= no_reboot_bit();
		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);
	}
}

static int iTCO_wdt_unset_NO_REBOOT_bit(void)
{
	u32 enable_bit = no_reboot_bit();
	u32 val32 = 0;

	/* Unset the NO_REBOOT bit: this enables reboots */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		val32 = readl(iTCO_wdt_private.gcs_pmc);
		val32 &= ~enable_bit;
		writel(val32, iTCO_wdt_private.gcs_pmc);

		val32 = readl(iTCO_wdt_private.gcs_pmc);
	} else if (iTCO_wdt_private.iTCO_version == 1) {
		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
		val32 &= ~enable_bit;
		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);

		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
	}

	if (val32 & enable_bit)
		return -EIO;

	return 0;
}

static int iTCO_wdt_start(struct watchdog_device *wd_dev)
{
	unsigned int val;

	spin_lock(&iTCO_wdt_private.io_lock);

	iTCO_vendor_pre_start(iTCO_wdt_private.smi_res, wd_dev->timeout);

	/* disable chipset's NO_REBOOT bit */
	if (iTCO_wdt_unset_NO_REBOOT_bit()) {
		spin_unlock(&iTCO_wdt_private.io_lock);
		pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
		return -EIO;
	}

	/* Force the timer to its reload value by writing to the TCO_RLD
	   register */
	if (iTCO_wdt_private.iTCO_version >= 2)
		outw(0x01, TCO_RLD);
	else if (iTCO_wdt_private.iTCO_version == 1)
		outb(0x01, TCO_RLD);

	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
	val = inw(TCO1_CNT);
	val &= 0xf7ff;
	outw(val, TCO1_CNT);
	val = inw(TCO1_CNT);
	spin_unlock(&iTCO_wdt_private.io_lock);

	if (val & 0x0800)
		return -1;
	return 0;
}

static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
{
	unsigned int val;

	spin_lock(&iTCO_wdt_private.io_lock);

	iTCO_vendor_pre_stop(iTCO_wdt_private.smi_res);

	/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
	val = inw(TCO1_CNT);
	val |= 0x0800;
	outw(val, TCO1_CNT);
	val = inw(TCO1_CNT);

	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
	iTCO_wdt_set_NO_REBOOT_bit();

	spin_unlock(&iTCO_wdt_private.io_lock);

	if ((val & 0x0800) == 0)
		return -1;
	return 0;
}

static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
{
	spin_lock(&iTCO_wdt_private.io_lock);

	iTCO_vendor_pre_keepalive(iTCO_wdt_private.smi_res, wd_dev->timeout);

	/* Reload the timer by writing to the TCO Timer Counter register */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		outw(0x01, TCO_RLD);
	} else if (iTCO_wdt_private.iTCO_version == 1) {
		/* Reset the timeout status bit so that the timer
		 * needs to count down twice again before rebooting */
		outw(0x0008, TCO1_STS);	/* write 1 to clear bit */

		outb(0x01, TCO_RLD);
	}

	spin_unlock(&iTCO_wdt_private.io_lock);
	return 0;
}

static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
{
	unsigned int val16;
	unsigned char val8;
	unsigned int tmrval;

	tmrval = seconds_to_ticks(t);

	/* For TCO v1 the timer counts down twice before rebooting */
	if (iTCO_wdt_private.iTCO_version == 1)
		tmrval /= 2;

	/* from the specs: */
	/* "Values of 0h-3h are ignored and should not be attempted" */
	if (tmrval < 0x04)
		return -EINVAL;
	if (((iTCO_wdt_private.iTCO_version >= 2) && (tmrval > 0x3ff)) ||
	    ((iTCO_wdt_private.iTCO_version == 1) && (tmrval > 0x03f)))
		return -EINVAL;

	iTCO_vendor_pre_set_heartbeat(tmrval);

	/* Write new heartbeat to watchdog */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		spin_lock(&iTCO_wdt_private.io_lock);
		val16 = inw(TCOv2_TMR);
		val16 &= 0xfc00;
		val16 |= tmrval;
		outw(val16, TCOv2_TMR);
		val16 = inw(TCOv2_TMR);
		spin_unlock(&iTCO_wdt_private.io_lock);

		if ((val16 & 0x3ff) != tmrval)
			return -EINVAL;
	} else if (iTCO_wdt_private.iTCO_version == 1) {
		spin_lock(&iTCO_wdt_private.io_lock);
		val8 = inb(TCOv1_TMR);
		val8 &= 0xc0;
		val8 |= (tmrval & 0xff);
		outb(val8, TCOv1_TMR);
		val8 = inb(TCOv1_TMR);
		spin_unlock(&iTCO_wdt_private.io_lock);

		if ((val8 & 0x3f) != tmrval)
			return -EINVAL;
	}

	wd_dev->timeout = t;
	return 0;
}

static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
{
	unsigned int val16;
	unsigned char val8;
	unsigned int time_left = 0;

	/* read the TCO Timer */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		spin_lock(&iTCO_wdt_private.io_lock);
		val16 = inw(TCO_RLD);
		val16 &= 0x3ff;
		spin_unlock(&iTCO_wdt_private.io_lock);

		time_left = ticks_to_seconds(val16);
	} else if (iTCO_wdt_private.iTCO_version == 1) {
		spin_lock(&iTCO_wdt_private.io_lock);
		val8 = inb(TCO_RLD);
		val8 &= 0x3f;
		if (!(inw(TCO1_STS) & 0x0008))
			val8 += (inb(TCOv1_TMR) & 0x3f);
		spin_unlock(&iTCO_wdt_private.io_lock);

		time_left = ticks_to_seconds(val8);
	}
	return time_left;
}

/*
 *	Kernel Interfaces
 */

static const struct watchdog_info ident = {
	.options =		WDIOF_SETTIMEOUT |
				WDIOF_KEEPALIVEPING |
				WDIOF_MAGICCLOSE,
	.firmware_version =	0,
	.identity =		DRV_NAME,
};

static const struct watchdog_ops iTCO_wdt_ops = {
	.owner =		THIS_MODULE,
	.start =		iTCO_wdt_start,
	.stop =			iTCO_wdt_stop,
	.ping =			iTCO_wdt_ping,
	.set_timeout =		iTCO_wdt_set_timeout,
	.get_timeleft =		iTCO_wdt_get_timeleft,
};

static struct watchdog_device iTCO_wdt_watchdog_dev = {
	.info =		&ident,
	.ops =		&iTCO_wdt_ops,
};

/*
 *	Init & exit routines
 */

static void iTCO_wdt_cleanup(void)
{
	/* Stop the timer before we leave */
	if (!nowayout)
		iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);

	/* Deregister */
	watchdog_unregister_device(&iTCO_wdt_watchdog_dev);

	/* release resources */
	release_region(iTCO_wdt_private.tco_res->start,
			resource_size(iTCO_wdt_private.tco_res));
	release_region(iTCO_wdt_private.smi_res->start,
			resource_size(iTCO_wdt_private.smi_res));
	if (iTCO_wdt_private.iTCO_version >= 2) {
		iounmap(iTCO_wdt_private.gcs_pmc);
		release_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
				resource_size(iTCO_wdt_private.gcs_pmc_res));
	}

	iTCO_wdt_private.tco_res = NULL;
	iTCO_wdt_private.smi_res = NULL;
	iTCO_wdt_private.gcs_pmc_res = NULL;
	iTCO_wdt_private.gcs_pmc = NULL;
}

static int iTCO_wdt_probe(struct platform_device *dev)
{
	int ret = -ENODEV;
	unsigned long val32;
	struct itco_wdt_platform_data *pdata = dev_get_platdata(&dev->dev);

	if (!pdata)
		goto out;

	spin_lock_init(&iTCO_wdt_private.io_lock);

	iTCO_wdt_private.tco_res =
		platform_get_resource(dev, IORESOURCE_IO, ICH_RES_IO_TCO);
	if (!iTCO_wdt_private.tco_res)
		goto out;

	iTCO_wdt_private.smi_res =
		platform_get_resource(dev, IORESOURCE_IO, ICH_RES_IO_SMI);
	if (!iTCO_wdt_private.smi_res)
		goto out;

	iTCO_wdt_private.iTCO_version = pdata->version;
	iTCO_wdt_private.dev = dev;
	iTCO_wdt_private.pdev = to_pci_dev(dev->dev.parent);

	/*
	 * Get the Memory-Mapped GCS or PMC register, we need it for the
	 * NO_REBOOT flag (TCO v2 and v3).
	 */
	if (iTCO_wdt_private.iTCO_version >= 2) {
		iTCO_wdt_private.gcs_pmc_res = platform_get_resource(dev,
							IORESOURCE_MEM,
							ICH_RES_MEM_GCS_PMC);

		if (!iTCO_wdt_private.gcs_pmc_res)
			goto out;

		if (!request_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
			resource_size(iTCO_wdt_private.gcs_pmc_res), dev->name)) {
			ret = -EBUSY;
			goto out;
		}
		iTCO_wdt_private.gcs_pmc = ioremap(iTCO_wdt_private.gcs_pmc_res->start,
			resource_size(iTCO_wdt_private.gcs_pmc_res));
		if (!iTCO_wdt_private.gcs_pmc) {
			ret = -EIO;
			goto unreg_gcs_pmc;
		}
	}

	/* Check chipset's NO_REBOOT bit */
	if (iTCO_wdt_unset_NO_REBOOT_bit() && iTCO_vendor_check_noreboot_on()) {
		pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
		ret = -ENODEV;	/* Cannot reset NO_REBOOT bit */
		goto unmap_gcs_pmc;
	}

	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
	iTCO_wdt_set_NO_REBOOT_bit();

	/* The TCO logic uses the TCO_EN bit in the SMI_EN register */
	if (!request_region(iTCO_wdt_private.smi_res->start,
			resource_size(iTCO_wdt_private.smi_res), dev->name)) {
		pr_err("I/O address 0x%04llx already in use, device disabled\n",
		       (u64)SMI_EN);
		ret = -EBUSY;
		goto unmap_gcs_pmc;
	}
	if (turn_SMI_watchdog_clear_off >= iTCO_wdt_private.iTCO_version) {
		/*
		 * Bit 13: TCO_EN -> 0
		 * Disables TCO logic generating an SMI#
		 */
		val32 = inl(SMI_EN);
		val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
		outl(val32, SMI_EN);
	}

	if (!request_region(iTCO_wdt_private.tco_res->start,
			resource_size(iTCO_wdt_private.tco_res), dev->name)) {
		pr_err("I/O address 0x%04llx already in use, device disabled\n",
		       (u64)TCOBASE);
		ret = -EBUSY;
		goto unreg_smi;
	}

	pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
		pdata->name, pdata->version, (u64)TCOBASE);

	/* Clear out the (probably old) status */
	switch (iTCO_wdt_private.iTCO_version) {
	case 5:
	case 4:
		outw(0x0008, TCO1_STS);	/* Clear the Time Out Status bit */
		outw(0x0002, TCO2_STS);	/* Clear SECOND_TO_STS bit */
		break;
	case 3:
		outl(0x20008, TCO1_STS);
		break;
	case 2:
	case 1:
	default:
		outw(0x0008, TCO1_STS);	/* Clear the Time Out Status bit */
		outw(0x0002, TCO2_STS);	/* Clear SECOND_TO_STS bit */
		outw(0x0004, TCO2_STS);	/* Clear BOOT_STS bit */
		break;
	}

	iTCO_wdt_watchdog_dev.bootstatus = 0;
	iTCO_wdt_watchdog_dev.timeout = WATCHDOG_TIMEOUT;
	watchdog_set_nowayout(&iTCO_wdt_watchdog_dev, nowayout);
	iTCO_wdt_watchdog_dev.parent = &dev->dev;

	/* Make sure the watchdog is not running */
	iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);

	/* Check that the heartbeat value is within it's range;
	   if not reset to the default */
	if (iTCO_wdt_set_timeout(&iTCO_wdt_watchdog_dev, heartbeat)) {
		iTCO_wdt_set_timeout(&iTCO_wdt_watchdog_dev, WATCHDOG_TIMEOUT);
		pr_info("timeout value out of range, using %d\n",
			WATCHDOG_TIMEOUT);
	}

	ret = watchdog_register_device(&iTCO_wdt_watchdog_dev);
	if (ret != 0) {
		pr_err("cannot register watchdog device (err=%d)\n", ret);
		goto unreg_tco;
	}

	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
		heartbeat, nowayout);

	return 0;

unreg_tco:
	release_region(iTCO_wdt_private.tco_res->start,
			resource_size(iTCO_wdt_private.tco_res));
unreg_smi:
	release_region(iTCO_wdt_private.smi_res->start,
			resource_size(iTCO_wdt_private.smi_res));
unmap_gcs_pmc:
	if (iTCO_wdt_private.iTCO_version >= 2)
		iounmap(iTCO_wdt_private.gcs_pmc);
unreg_gcs_pmc:
	if (iTCO_wdt_private.iTCO_version >= 2)
		release_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
				resource_size(iTCO_wdt_private.gcs_pmc_res));
out:
	iTCO_wdt_private.tco_res = NULL;
	iTCO_wdt_private.smi_res = NULL;
	iTCO_wdt_private.gcs_pmc_res = NULL;
	iTCO_wdt_private.gcs_pmc = NULL;

	return ret;
}

static int iTCO_wdt_remove(struct platform_device *dev)
{
	if (iTCO_wdt_private.tco_res || iTCO_wdt_private.smi_res)
		iTCO_wdt_cleanup();

	return 0;
}

static void iTCO_wdt_shutdown(struct platform_device *dev)
{
	iTCO_wdt_stop(NULL);
}

#ifdef CONFIG_PM_SLEEP
/*
 * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
 * the watchdog cannot be pinged while in that state.  In ACPI sleep states the
 * watchdog is stopped by the platform firmware.
 */

#ifdef CONFIG_ACPI
static inline bool need_suspend(void)
{
	return acpi_target_system_state() == ACPI_STATE_S0;
}
#else
static inline bool need_suspend(void) { return true; }
#endif

static int iTCO_wdt_suspend_noirq(struct device *dev)
{
	int ret = 0;

	iTCO_wdt_private.suspended = false;
	if (watchdog_active(&iTCO_wdt_watchdog_dev) && need_suspend()) {
		ret = iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);
		if (!ret)
			iTCO_wdt_private.suspended = true;
	}
	return ret;
}

static int iTCO_wdt_resume_noirq(struct device *dev)
{
	if (iTCO_wdt_private.suspended)
		iTCO_wdt_start(&iTCO_wdt_watchdog_dev);

	return 0;
}

static const struct dev_pm_ops iTCO_wdt_pm = {
	.suspend_noirq = iTCO_wdt_suspend_noirq,
	.resume_noirq = iTCO_wdt_resume_noirq,
};

#define ITCO_WDT_PM_OPS	(&iTCO_wdt_pm)
#else
#define ITCO_WDT_PM_OPS	NULL
#endif /* CONFIG_PM_SLEEP */

static struct platform_driver iTCO_wdt_driver = {
	.probe          = iTCO_wdt_probe,
	.remove         = iTCO_wdt_remove,
	.shutdown       = iTCO_wdt_shutdown,
	.driver         = {
		.name   = DRV_NAME,
		.pm     = ITCO_WDT_PM_OPS,
	},
};

static int __init iTCO_wdt_init_module(void)
{
	int err;

	pr_info("Intel TCO WatchDog Timer Driver v%s\n", DRV_VERSION);

	err = platform_driver_register(&iTCO_wdt_driver);
	if (err)
		return err;

	return 0;
}

static void __exit iTCO_wdt_cleanup_module(void)
{
	platform_driver_unregister(&iTCO_wdt_driver);
	pr_info("Watchdog Module Unloaded\n");
}

module_init(iTCO_wdt_init_module);
module_exit(iTCO_wdt_cleanup_module);

MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);