xref: /linux/drivers/watchdog/iTCO_wdt.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 /*
2  *	intel TCO Watchdog Driver
3  *
4  *	(c) Copyright 2006-2011 Wim Van Sebroeck <wim@iguana.be>.
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
12  *	provide warranty for any of this software. This material is
13  *	provided "AS-IS" and at no charge.
14  *
15  *	The TCO watchdog is implemented in the following I/O controller hubs:
16  *	(See the intel documentation on http://developer.intel.com.)
17  *	document number 290655-003, 290677-014: 82801AA (ICH), 82801AB (ICHO)
18  *	document number 290687-002, 298242-027: 82801BA (ICH2)
19  *	document number 290733-003, 290739-013: 82801CA (ICH3-S)
20  *	document number 290716-001, 290718-007: 82801CAM (ICH3-M)
21  *	document number 290744-001, 290745-025: 82801DB (ICH4)
22  *	document number 252337-001, 252663-008: 82801DBM (ICH4-M)
23  *	document number 273599-001, 273645-002: 82801E (C-ICH)
24  *	document number 252516-001, 252517-028: 82801EB (ICH5), 82801ER (ICH5R)
25  *	document number 300641-004, 300884-013: 6300ESB
26  *	document number 301473-002, 301474-026: 82801F (ICH6)
27  *	document number 313082-001, 313075-006: 631xESB, 632xESB
28  *	document number 307013-003, 307014-024: 82801G (ICH7)
29  *	document number 322896-001, 322897-001: NM10
30  *	document number 313056-003, 313057-017: 82801H (ICH8)
31  *	document number 316972-004, 316973-012: 82801I (ICH9)
32  *	document number 319973-002, 319974-002: 82801J (ICH10)
33  *	document number 322169-001, 322170-003: 5 Series, 3400 Series (PCH)
34  *	document number 320066-003, 320257-008: EP80597 (IICH)
35  *	document number 324645-001, 324646-001: Cougar Point (CPT)
36  *	document number TBD                   : Patsburg (PBG)
37  *	document number TBD                   : DH89xxCC
38  *	document number TBD                   : Panther Point
39  *	document number TBD                   : Lynx Point
40  *	document number TBD                   : Lynx Point-LP
41  */
42 
43 /*
44  *	Includes, defines, variables, module parameters, ...
45  */
46 
47 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 
49 /* Module and version information */
50 #define DRV_NAME	"iTCO_wdt"
51 #define DRV_VERSION	"1.11"
52 
53 /* Includes */
54 #include <linux/acpi.h>			/* For ACPI support */
55 #include <linux/module.h>		/* For module specific items */
56 #include <linux/moduleparam.h>		/* For new moduleparam's */
57 #include <linux/types.h>		/* For standard types (like size_t) */
58 #include <linux/errno.h>		/* For the -ENODEV/... values */
59 #include <linux/kernel.h>		/* For printk/panic/... */
60 #include <linux/watchdog.h>		/* For the watchdog specific items */
61 #include <linux/init.h>			/* For __init/__exit/... */
62 #include <linux/fs.h>			/* For file operations */
63 #include <linux/platform_device.h>	/* For platform_driver framework */
64 #include <linux/pci.h>			/* For pci functions */
65 #include <linux/ioport.h>		/* For io-port access */
66 #include <linux/spinlock.h>		/* For spin_lock/spin_unlock/... */
67 #include <linux/uaccess.h>		/* For copy_to_user/put_user/... */
68 #include <linux/io.h>			/* For inb/outb/... */
69 #include <linux/mfd/core.h>
70 #include <linux/mfd/lpc_ich.h>
71 
72 #include "iTCO_vendor.h"
73 
74 /* Address definitions for the TCO */
75 /* TCO base address */
76 #define TCOBASE		(iTCO_wdt_private.tco_res->start)
77 /* SMI Control and Enable Register */
78 #define SMI_EN		(iTCO_wdt_private.smi_res->start)
79 
80 #define TCO_RLD		(TCOBASE + 0x00) /* TCO Timer Reload and Curr. Value */
81 #define TCOv1_TMR	(TCOBASE + 0x01) /* TCOv1 Timer Initial Value	*/
82 #define TCO_DAT_IN	(TCOBASE + 0x02) /* TCO Data In Register	*/
83 #define TCO_DAT_OUT	(TCOBASE + 0x03) /* TCO Data Out Register	*/
84 #define TCO1_STS	(TCOBASE + 0x04) /* TCO1 Status Register	*/
85 #define TCO2_STS	(TCOBASE + 0x06) /* TCO2 Status Register	*/
86 #define TCO1_CNT	(TCOBASE + 0x08) /* TCO1 Control Register	*/
87 #define TCO2_CNT	(TCOBASE + 0x0a) /* TCO2 Control Register	*/
88 #define TCOv2_TMR	(TCOBASE + 0x12) /* TCOv2 Timer Initial Value	*/
89 
90 /* internal variables */
91 static struct {		/* this is private data for the iTCO_wdt device */
92 	/* TCO version/generation */
93 	unsigned int iTCO_version;
94 	struct resource *tco_res;
95 	struct resource *smi_res;
96 	/*
97 	 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
98 	 * or memory-mapped PMC register bit 4 (TCO version 3).
99 	 */
100 	struct resource *gcs_pmc_res;
101 	unsigned long __iomem *gcs_pmc;
102 	/* the lock for io operations */
103 	spinlock_t io_lock;
104 	struct platform_device *dev;
105 	/* the PCI-device */
106 	struct pci_dev *pdev;
107 	/* whether or not the watchdog has been suspended */
108 	bool suspended;
109 } iTCO_wdt_private;
110 
111 /* module parameters */
112 #define WATCHDOG_TIMEOUT 30	/* 30 sec default heartbeat */
113 static int heartbeat = WATCHDOG_TIMEOUT;  /* in seconds */
114 module_param(heartbeat, int, 0);
115 MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
116 	"5..76 (TCO v1) or 3..614 (TCO v2), default="
117 				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
118 
119 static bool nowayout = WATCHDOG_NOWAYOUT;
120 module_param(nowayout, bool, 0);
121 MODULE_PARM_DESC(nowayout,
122 	"Watchdog cannot be stopped once started (default="
123 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
124 
125 static int turn_SMI_watchdog_clear_off = 1;
126 module_param(turn_SMI_watchdog_clear_off, int, 0);
127 MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
128 	"Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
129 
130 /*
131  * Some TCO specific functions
132  */
133 
134 /*
135  * The iTCO v1 and v2's internal timer is stored as ticks which decrement
136  * every 0.6 seconds.  v3's internal timer is stored as seconds (some
137  * datasheets incorrectly state 0.6 seconds).
138  */
139 static inline unsigned int seconds_to_ticks(int secs)
140 {
141 	return iTCO_wdt_private.iTCO_version == 3 ? secs : (secs * 10) / 6;
142 }
143 
144 static inline unsigned int ticks_to_seconds(int ticks)
145 {
146 	return iTCO_wdt_private.iTCO_version == 3 ? ticks : (ticks * 6) / 10;
147 }
148 
149 static void iTCO_wdt_set_NO_REBOOT_bit(void)
150 {
151 	u32 val32;
152 
153 	/* Set the NO_REBOOT bit: this disables reboots */
154 	if (iTCO_wdt_private.iTCO_version == 3) {
155 		val32 = readl(iTCO_wdt_private.gcs_pmc);
156 		val32 |= 0x00000010;
157 		writel(val32, iTCO_wdt_private.gcs_pmc);
158 	} else if (iTCO_wdt_private.iTCO_version == 2) {
159 		val32 = readl(iTCO_wdt_private.gcs_pmc);
160 		val32 |= 0x00000020;
161 		writel(val32, iTCO_wdt_private.gcs_pmc);
162 	} else if (iTCO_wdt_private.iTCO_version == 1) {
163 		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
164 		val32 |= 0x00000002;
165 		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);
166 	}
167 }
168 
169 static int iTCO_wdt_unset_NO_REBOOT_bit(void)
170 {
171 	int ret = 0;
172 	u32 val32;
173 
174 	/* Unset the NO_REBOOT bit: this enables reboots */
175 	if (iTCO_wdt_private.iTCO_version == 3) {
176 		val32 = readl(iTCO_wdt_private.gcs_pmc);
177 		val32 &= 0xffffffef;
178 		writel(val32, iTCO_wdt_private.gcs_pmc);
179 
180 		val32 = readl(iTCO_wdt_private.gcs_pmc);
181 		if (val32 & 0x00000010)
182 			ret = -EIO;
183 	} else if (iTCO_wdt_private.iTCO_version == 2) {
184 		val32 = readl(iTCO_wdt_private.gcs_pmc);
185 		val32 &= 0xffffffdf;
186 		writel(val32, iTCO_wdt_private.gcs_pmc);
187 
188 		val32 = readl(iTCO_wdt_private.gcs_pmc);
189 		if (val32 & 0x00000020)
190 			ret = -EIO;
191 	} else if (iTCO_wdt_private.iTCO_version == 1) {
192 		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
193 		val32 &= 0xfffffffd;
194 		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);
195 
196 		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
197 		if (val32 & 0x00000002)
198 			ret = -EIO;
199 	}
200 
201 	return ret; /* returns: 0 = OK, -EIO = Error */
202 }
203 
204 static int iTCO_wdt_start(struct watchdog_device *wd_dev)
205 {
206 	unsigned int val;
207 
208 	spin_lock(&iTCO_wdt_private.io_lock);
209 
210 	iTCO_vendor_pre_start(iTCO_wdt_private.smi_res, wd_dev->timeout);
211 
212 	/* disable chipset's NO_REBOOT bit */
213 	if (iTCO_wdt_unset_NO_REBOOT_bit()) {
214 		spin_unlock(&iTCO_wdt_private.io_lock);
215 		pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
216 		return -EIO;
217 	}
218 
219 	/* Force the timer to its reload value by writing to the TCO_RLD
220 	   register */
221 	if (iTCO_wdt_private.iTCO_version >= 2)
222 		outw(0x01, TCO_RLD);
223 	else if (iTCO_wdt_private.iTCO_version == 1)
224 		outb(0x01, TCO_RLD);
225 
226 	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
227 	val = inw(TCO1_CNT);
228 	val &= 0xf7ff;
229 	outw(val, TCO1_CNT);
230 	val = inw(TCO1_CNT);
231 	spin_unlock(&iTCO_wdt_private.io_lock);
232 
233 	if (val & 0x0800)
234 		return -1;
235 	return 0;
236 }
237 
238 static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
239 {
240 	unsigned int val;
241 
242 	spin_lock(&iTCO_wdt_private.io_lock);
243 
244 	iTCO_vendor_pre_stop(iTCO_wdt_private.smi_res);
245 
246 	/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
247 	val = inw(TCO1_CNT);
248 	val |= 0x0800;
249 	outw(val, TCO1_CNT);
250 	val = inw(TCO1_CNT);
251 
252 	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
253 	iTCO_wdt_set_NO_REBOOT_bit();
254 
255 	spin_unlock(&iTCO_wdt_private.io_lock);
256 
257 	if ((val & 0x0800) == 0)
258 		return -1;
259 	return 0;
260 }
261 
262 static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
263 {
264 	spin_lock(&iTCO_wdt_private.io_lock);
265 
266 	iTCO_vendor_pre_keepalive(iTCO_wdt_private.smi_res, wd_dev->timeout);
267 
268 	/* Reload the timer by writing to the TCO Timer Counter register */
269 	if (iTCO_wdt_private.iTCO_version >= 2) {
270 		outw(0x01, TCO_RLD);
271 	} else if (iTCO_wdt_private.iTCO_version == 1) {
272 		/* Reset the timeout status bit so that the timer
273 		 * needs to count down twice again before rebooting */
274 		outw(0x0008, TCO1_STS);	/* write 1 to clear bit */
275 
276 		outb(0x01, TCO_RLD);
277 	}
278 
279 	spin_unlock(&iTCO_wdt_private.io_lock);
280 	return 0;
281 }
282 
283 static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
284 {
285 	unsigned int val16;
286 	unsigned char val8;
287 	unsigned int tmrval;
288 
289 	tmrval = seconds_to_ticks(t);
290 
291 	/* For TCO v1 the timer counts down twice before rebooting */
292 	if (iTCO_wdt_private.iTCO_version == 1)
293 		tmrval /= 2;
294 
295 	/* from the specs: */
296 	/* "Values of 0h-3h are ignored and should not be attempted" */
297 	if (tmrval < 0x04)
298 		return -EINVAL;
299 	if (((iTCO_wdt_private.iTCO_version >= 2) && (tmrval > 0x3ff)) ||
300 	    ((iTCO_wdt_private.iTCO_version == 1) && (tmrval > 0x03f)))
301 		return -EINVAL;
302 
303 	iTCO_vendor_pre_set_heartbeat(tmrval);
304 
305 	/* Write new heartbeat to watchdog */
306 	if (iTCO_wdt_private.iTCO_version >= 2) {
307 		spin_lock(&iTCO_wdt_private.io_lock);
308 		val16 = inw(TCOv2_TMR);
309 		val16 &= 0xfc00;
310 		val16 |= tmrval;
311 		outw(val16, TCOv2_TMR);
312 		val16 = inw(TCOv2_TMR);
313 		spin_unlock(&iTCO_wdt_private.io_lock);
314 
315 		if ((val16 & 0x3ff) != tmrval)
316 			return -EINVAL;
317 	} else if (iTCO_wdt_private.iTCO_version == 1) {
318 		spin_lock(&iTCO_wdt_private.io_lock);
319 		val8 = inb(TCOv1_TMR);
320 		val8 &= 0xc0;
321 		val8 |= (tmrval & 0xff);
322 		outb(val8, TCOv1_TMR);
323 		val8 = inb(TCOv1_TMR);
324 		spin_unlock(&iTCO_wdt_private.io_lock);
325 
326 		if ((val8 & 0x3f) != tmrval)
327 			return -EINVAL;
328 	}
329 
330 	wd_dev->timeout = t;
331 	return 0;
332 }
333 
334 static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
335 {
336 	unsigned int val16;
337 	unsigned char val8;
338 	unsigned int time_left = 0;
339 
340 	/* read the TCO Timer */
341 	if (iTCO_wdt_private.iTCO_version >= 2) {
342 		spin_lock(&iTCO_wdt_private.io_lock);
343 		val16 = inw(TCO_RLD);
344 		val16 &= 0x3ff;
345 		spin_unlock(&iTCO_wdt_private.io_lock);
346 
347 		time_left = ticks_to_seconds(val16);
348 	} else if (iTCO_wdt_private.iTCO_version == 1) {
349 		spin_lock(&iTCO_wdt_private.io_lock);
350 		val8 = inb(TCO_RLD);
351 		val8 &= 0x3f;
352 		if (!(inw(TCO1_STS) & 0x0008))
353 			val8 += (inb(TCOv1_TMR) & 0x3f);
354 		spin_unlock(&iTCO_wdt_private.io_lock);
355 
356 		time_left = ticks_to_seconds(val8);
357 	}
358 	return time_left;
359 }
360 
361 /*
362  *	Kernel Interfaces
363  */
364 
365 static const struct watchdog_info ident = {
366 	.options =		WDIOF_SETTIMEOUT |
367 				WDIOF_KEEPALIVEPING |
368 				WDIOF_MAGICCLOSE,
369 	.firmware_version =	0,
370 	.identity =		DRV_NAME,
371 };
372 
373 static const struct watchdog_ops iTCO_wdt_ops = {
374 	.owner =		THIS_MODULE,
375 	.start =		iTCO_wdt_start,
376 	.stop =			iTCO_wdt_stop,
377 	.ping =			iTCO_wdt_ping,
378 	.set_timeout =		iTCO_wdt_set_timeout,
379 	.get_timeleft =		iTCO_wdt_get_timeleft,
380 };
381 
382 static struct watchdog_device iTCO_wdt_watchdog_dev = {
383 	.info =		&ident,
384 	.ops =		&iTCO_wdt_ops,
385 };
386 
387 /*
388  *	Init & exit routines
389  */
390 
391 static void iTCO_wdt_cleanup(void)
392 {
393 	/* Stop the timer before we leave */
394 	if (!nowayout)
395 		iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);
396 
397 	/* Deregister */
398 	watchdog_unregister_device(&iTCO_wdt_watchdog_dev);
399 
400 	/* release resources */
401 	release_region(iTCO_wdt_private.tco_res->start,
402 			resource_size(iTCO_wdt_private.tco_res));
403 	release_region(iTCO_wdt_private.smi_res->start,
404 			resource_size(iTCO_wdt_private.smi_res));
405 	if (iTCO_wdt_private.iTCO_version >= 2) {
406 		iounmap(iTCO_wdt_private.gcs_pmc);
407 		release_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
408 				resource_size(iTCO_wdt_private.gcs_pmc_res));
409 	}
410 
411 	iTCO_wdt_private.tco_res = NULL;
412 	iTCO_wdt_private.smi_res = NULL;
413 	iTCO_wdt_private.gcs_pmc_res = NULL;
414 	iTCO_wdt_private.gcs_pmc = NULL;
415 }
416 
417 static int iTCO_wdt_probe(struct platform_device *dev)
418 {
419 	int ret = -ENODEV;
420 	unsigned long val32;
421 	struct lpc_ich_info *ich_info = dev_get_platdata(&dev->dev);
422 
423 	if (!ich_info)
424 		goto out;
425 
426 	spin_lock_init(&iTCO_wdt_private.io_lock);
427 
428 	iTCO_wdt_private.tco_res =
429 		platform_get_resource(dev, IORESOURCE_IO, ICH_RES_IO_TCO);
430 	if (!iTCO_wdt_private.tco_res)
431 		goto out;
432 
433 	iTCO_wdt_private.smi_res =
434 		platform_get_resource(dev, IORESOURCE_IO, ICH_RES_IO_SMI);
435 	if (!iTCO_wdt_private.smi_res)
436 		goto out;
437 
438 	iTCO_wdt_private.iTCO_version = ich_info->iTCO_version;
439 	iTCO_wdt_private.dev = dev;
440 	iTCO_wdt_private.pdev = to_pci_dev(dev->dev.parent);
441 
442 	/*
443 	 * Get the Memory-Mapped GCS or PMC register, we need it for the
444 	 * NO_REBOOT flag (TCO v2 and v3).
445 	 */
446 	if (iTCO_wdt_private.iTCO_version >= 2) {
447 		iTCO_wdt_private.gcs_pmc_res = platform_get_resource(dev,
448 							IORESOURCE_MEM,
449 							ICH_RES_MEM_GCS_PMC);
450 
451 		if (!iTCO_wdt_private.gcs_pmc_res)
452 			goto out;
453 
454 		if (!request_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
455 			resource_size(iTCO_wdt_private.gcs_pmc_res), dev->name)) {
456 			ret = -EBUSY;
457 			goto out;
458 		}
459 		iTCO_wdt_private.gcs_pmc = ioremap(iTCO_wdt_private.gcs_pmc_res->start,
460 			resource_size(iTCO_wdt_private.gcs_pmc_res));
461 		if (!iTCO_wdt_private.gcs_pmc) {
462 			ret = -EIO;
463 			goto unreg_gcs_pmc;
464 		}
465 	}
466 
467 	/* Check chipset's NO_REBOOT bit */
468 	if (iTCO_wdt_unset_NO_REBOOT_bit() && iTCO_vendor_check_noreboot_on()) {
469 		pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
470 		ret = -ENODEV;	/* Cannot reset NO_REBOOT bit */
471 		goto unmap_gcs_pmc;
472 	}
473 
474 	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
475 	iTCO_wdt_set_NO_REBOOT_bit();
476 
477 	/* The TCO logic uses the TCO_EN bit in the SMI_EN register */
478 	if (!request_region(iTCO_wdt_private.smi_res->start,
479 			resource_size(iTCO_wdt_private.smi_res), dev->name)) {
480 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
481 		       (u64)SMI_EN);
482 		ret = -EBUSY;
483 		goto unmap_gcs_pmc;
484 	}
485 	if (turn_SMI_watchdog_clear_off >= iTCO_wdt_private.iTCO_version) {
486 		/*
487 		 * Bit 13: TCO_EN -> 0
488 		 * Disables TCO logic generating an SMI#
489 		 */
490 		val32 = inl(SMI_EN);
491 		val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
492 		outl(val32, SMI_EN);
493 	}
494 
495 	if (!request_region(iTCO_wdt_private.tco_res->start,
496 			resource_size(iTCO_wdt_private.tco_res), dev->name)) {
497 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
498 		       (u64)TCOBASE);
499 		ret = -EBUSY;
500 		goto unreg_smi;
501 	}
502 
503 	pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
504 		ich_info->name, ich_info->iTCO_version, (u64)TCOBASE);
505 
506 	/* Clear out the (probably old) status */
507 	if (iTCO_wdt_private.iTCO_version == 3) {
508 		outl(0x20008, TCO1_STS);
509 	} else {
510 		outw(0x0008, TCO1_STS);	/* Clear the Time Out Status bit */
511 		outw(0x0002, TCO2_STS);	/* Clear SECOND_TO_STS bit */
512 		outw(0x0004, TCO2_STS);	/* Clear BOOT_STS bit */
513 	}
514 
515 	iTCO_wdt_watchdog_dev.bootstatus = 0;
516 	iTCO_wdt_watchdog_dev.timeout = WATCHDOG_TIMEOUT;
517 	watchdog_set_nowayout(&iTCO_wdt_watchdog_dev, nowayout);
518 	iTCO_wdt_watchdog_dev.parent = &dev->dev;
519 
520 	/* Make sure the watchdog is not running */
521 	iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);
522 
523 	/* Check that the heartbeat value is within it's range;
524 	   if not reset to the default */
525 	if (iTCO_wdt_set_timeout(&iTCO_wdt_watchdog_dev, heartbeat)) {
526 		iTCO_wdt_set_timeout(&iTCO_wdt_watchdog_dev, WATCHDOG_TIMEOUT);
527 		pr_info("timeout value out of range, using %d\n",
528 			WATCHDOG_TIMEOUT);
529 	}
530 
531 	ret = watchdog_register_device(&iTCO_wdt_watchdog_dev);
532 	if (ret != 0) {
533 		pr_err("cannot register watchdog device (err=%d)\n", ret);
534 		goto unreg_tco;
535 	}
536 
537 	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
538 		heartbeat, nowayout);
539 
540 	return 0;
541 
542 unreg_tco:
543 	release_region(iTCO_wdt_private.tco_res->start,
544 			resource_size(iTCO_wdt_private.tco_res));
545 unreg_smi:
546 	release_region(iTCO_wdt_private.smi_res->start,
547 			resource_size(iTCO_wdt_private.smi_res));
548 unmap_gcs_pmc:
549 	if (iTCO_wdt_private.iTCO_version >= 2)
550 		iounmap(iTCO_wdt_private.gcs_pmc);
551 unreg_gcs_pmc:
552 	if (iTCO_wdt_private.iTCO_version >= 2)
553 		release_mem_region(iTCO_wdt_private.gcs_pmc_res->start,
554 				resource_size(iTCO_wdt_private.gcs_pmc_res));
555 out:
556 	iTCO_wdt_private.tco_res = NULL;
557 	iTCO_wdt_private.smi_res = NULL;
558 	iTCO_wdt_private.gcs_pmc_res = NULL;
559 	iTCO_wdt_private.gcs_pmc = NULL;
560 
561 	return ret;
562 }
563 
564 static int iTCO_wdt_remove(struct platform_device *dev)
565 {
566 	if (iTCO_wdt_private.tco_res || iTCO_wdt_private.smi_res)
567 		iTCO_wdt_cleanup();
568 
569 	return 0;
570 }
571 
572 static void iTCO_wdt_shutdown(struct platform_device *dev)
573 {
574 	iTCO_wdt_stop(NULL);
575 }
576 
577 #ifdef CONFIG_PM_SLEEP
578 /*
579  * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
580  * the watchdog cannot be pinged while in that state.  In ACPI sleep states the
581  * watchdog is stopped by the platform firmware.
582  */
583 
584 #ifdef CONFIG_ACPI
585 static inline bool need_suspend(void)
586 {
587 	return acpi_target_system_state() == ACPI_STATE_S0;
588 }
589 #else
590 static inline bool need_suspend(void) { return true; }
591 #endif
592 
593 static int iTCO_wdt_suspend_noirq(struct device *dev)
594 {
595 	int ret = 0;
596 
597 	iTCO_wdt_private.suspended = false;
598 	if (watchdog_active(&iTCO_wdt_watchdog_dev) && need_suspend()) {
599 		ret = iTCO_wdt_stop(&iTCO_wdt_watchdog_dev);
600 		if (!ret)
601 			iTCO_wdt_private.suspended = true;
602 	}
603 	return ret;
604 }
605 
606 static int iTCO_wdt_resume_noirq(struct device *dev)
607 {
608 	if (iTCO_wdt_private.suspended)
609 		iTCO_wdt_start(&iTCO_wdt_watchdog_dev);
610 
611 	return 0;
612 }
613 
614 static struct dev_pm_ops iTCO_wdt_pm = {
615 	.suspend_noirq = iTCO_wdt_suspend_noirq,
616 	.resume_noirq = iTCO_wdt_resume_noirq,
617 };
618 
619 #define ITCO_WDT_PM_OPS	(&iTCO_wdt_pm)
620 #else
621 #define ITCO_WDT_PM_OPS	NULL
622 #endif /* CONFIG_PM_SLEEP */
623 
624 static struct platform_driver iTCO_wdt_driver = {
625 	.probe          = iTCO_wdt_probe,
626 	.remove         = iTCO_wdt_remove,
627 	.shutdown       = iTCO_wdt_shutdown,
628 	.driver         = {
629 		.name   = DRV_NAME,
630 		.pm     = ITCO_WDT_PM_OPS,
631 	},
632 };
633 
634 static int __init iTCO_wdt_init_module(void)
635 {
636 	int err;
637 
638 	pr_info("Intel TCO WatchDog Timer Driver v%s\n", DRV_VERSION);
639 
640 	err = platform_driver_register(&iTCO_wdt_driver);
641 	if (err)
642 		return err;
643 
644 	return 0;
645 }
646 
647 static void __exit iTCO_wdt_cleanup_module(void)
648 {
649 	platform_driver_unregister(&iTCO_wdt_driver);
650 	pr_info("Watchdog Module Unloaded\n");
651 }
652 
653 module_init(iTCO_wdt_init_module);
654 module_exit(iTCO_wdt_cleanup_module);
655 
656 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
657 MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
658 MODULE_VERSION(DRV_VERSION);
659 MODULE_LICENSE("GPL");
660 MODULE_ALIAS("platform:" DRV_NAME);
661