xref: /linux/drivers/watchdog/iTCO_wdt.c (revision 6f52b16c5b29b89d92c0e7236f4655dc8491ad70)
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/platform_data/itco_wdt.h>
70 
71 #include "iTCO_vendor.h"
72 
73 /* Address definitions for the TCO */
74 /* TCO base address */
75 #define TCOBASE(p)	((p)->tco_res->start)
76 /* SMI Control and Enable Register */
77 #define SMI_EN(p)	((p)->smi_res->start)
78 
79 #define TCO_RLD(p)	(TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */
80 #define TCOv1_TMR(p)	(TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/
81 #define TCO_DAT_IN(p)	(TCOBASE(p) + 0x02) /* TCO Data In Register	*/
82 #define TCO_DAT_OUT(p)	(TCOBASE(p) + 0x03) /* TCO Data Out Register	*/
83 #define TCO1_STS(p)	(TCOBASE(p) + 0x04) /* TCO1 Status Register	*/
84 #define TCO2_STS(p)	(TCOBASE(p) + 0x06) /* TCO2 Status Register	*/
85 #define TCO1_CNT(p)	(TCOBASE(p) + 0x08) /* TCO1 Control Register	*/
86 #define TCO2_CNT(p)	(TCOBASE(p) + 0x0a) /* TCO2 Control Register	*/
87 #define TCOv2_TMR(p)	(TCOBASE(p) + 0x12) /* TCOv2 Timer Initial Value*/
88 
89 /* internal variables */
90 struct iTCO_wdt_private {
91 	struct watchdog_device wddev;
92 
93 	/* TCO version/generation */
94 	unsigned int iTCO_version;
95 	struct resource *tco_res;
96 	struct resource *smi_res;
97 	/*
98 	 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
99 	 * or memory-mapped PMC register bit 4 (TCO version 3).
100 	 */
101 	struct resource *gcs_pmc_res;
102 	unsigned long __iomem *gcs_pmc;
103 	/* the lock for io operations */
104 	spinlock_t io_lock;
105 	/* the PCI-device */
106 	struct pci_dev *pci_dev;
107 	/* whether or not the watchdog has been suspended */
108 	bool suspended;
109 	/* no reboot API private data */
110 	void *no_reboot_priv;
111 	/* no reboot update function pointer */
112 	int (*update_no_reboot_bit)(void *p, bool set);
113 };
114 
115 /* module parameters */
116 #define WATCHDOG_TIMEOUT 30	/* 30 sec default heartbeat */
117 static int heartbeat = WATCHDOG_TIMEOUT;  /* in seconds */
118 module_param(heartbeat, int, 0);
119 MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
120 	"5..76 (TCO v1) or 3..614 (TCO v2), default="
121 				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
122 
123 static bool nowayout = WATCHDOG_NOWAYOUT;
124 module_param(nowayout, bool, 0);
125 MODULE_PARM_DESC(nowayout,
126 	"Watchdog cannot be stopped once started (default="
127 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
128 
129 static int turn_SMI_watchdog_clear_off = 1;
130 module_param(turn_SMI_watchdog_clear_off, int, 0);
131 MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
132 	"Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
133 
134 /*
135  * Some TCO specific functions
136  */
137 
138 /*
139  * The iTCO v1 and v2's internal timer is stored as ticks which decrement
140  * every 0.6 seconds.  v3's internal timer is stored as seconds (some
141  * datasheets incorrectly state 0.6 seconds).
142  */
143 static inline unsigned int seconds_to_ticks(struct iTCO_wdt_private *p,
144 					    int secs)
145 {
146 	return p->iTCO_version == 3 ? secs : (secs * 10) / 6;
147 }
148 
149 static inline unsigned int ticks_to_seconds(struct iTCO_wdt_private *p,
150 					    int ticks)
151 {
152 	return p->iTCO_version == 3 ? ticks : (ticks * 6) / 10;
153 }
154 
155 static inline u32 no_reboot_bit(struct iTCO_wdt_private *p)
156 {
157 	u32 enable_bit;
158 
159 	switch (p->iTCO_version) {
160 	case 5:
161 	case 3:
162 		enable_bit = 0x00000010;
163 		break;
164 	case 2:
165 		enable_bit = 0x00000020;
166 		break;
167 	case 4:
168 	case 1:
169 	default:
170 		enable_bit = 0x00000002;
171 		break;
172 	}
173 
174 	return enable_bit;
175 }
176 
177 static int update_no_reboot_bit_def(void *priv, bool set)
178 {
179 	return 0;
180 }
181 
182 static int update_no_reboot_bit_pci(void *priv, bool set)
183 {
184 	struct iTCO_wdt_private *p = priv;
185 	u32 val32 = 0, newval32 = 0;
186 
187 	pci_read_config_dword(p->pci_dev, 0xd4, &val32);
188 	if (set)
189 		val32 |= no_reboot_bit(p);
190 	else
191 		val32 &= ~no_reboot_bit(p);
192 	pci_write_config_dword(p->pci_dev, 0xd4, val32);
193 	pci_read_config_dword(p->pci_dev, 0xd4, &newval32);
194 
195 	/* make sure the update is successful */
196 	if (val32 != newval32)
197 		return -EIO;
198 
199 	return 0;
200 }
201 
202 static int update_no_reboot_bit_mem(void *priv, bool set)
203 {
204 	struct iTCO_wdt_private *p = priv;
205 	u32 val32 = 0, newval32 = 0;
206 
207 	val32 = readl(p->gcs_pmc);
208 	if (set)
209 		val32 |= no_reboot_bit(p);
210 	else
211 		val32 &= ~no_reboot_bit(p);
212 	writel(val32, p->gcs_pmc);
213 	newval32 = readl(p->gcs_pmc);
214 
215 	/* make sure the update is successful */
216 	if (val32 != newval32)
217 		return -EIO;
218 
219 	return 0;
220 }
221 
222 static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
223 		struct itco_wdt_platform_data *pdata)
224 {
225 	if (pdata->update_no_reboot_bit) {
226 		p->update_no_reboot_bit = pdata->update_no_reboot_bit;
227 		p->no_reboot_priv = pdata->no_reboot_priv;
228 		return;
229 	}
230 
231 	if (p->iTCO_version >= 2)
232 		p->update_no_reboot_bit = update_no_reboot_bit_mem;
233 	else if (p->iTCO_version == 1)
234 		p->update_no_reboot_bit = update_no_reboot_bit_pci;
235 	else
236 		p->update_no_reboot_bit = update_no_reboot_bit_def;
237 
238 	p->no_reboot_priv = p;
239 }
240 
241 static int iTCO_wdt_start(struct watchdog_device *wd_dev)
242 {
243 	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
244 	unsigned int val;
245 
246 	spin_lock(&p->io_lock);
247 
248 	iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
249 
250 	/* disable chipset's NO_REBOOT bit */
251 	if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
252 		spin_unlock(&p->io_lock);
253 		pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
254 		return -EIO;
255 	}
256 
257 	/* Force the timer to its reload value by writing to the TCO_RLD
258 	   register */
259 	if (p->iTCO_version >= 2)
260 		outw(0x01, TCO_RLD(p));
261 	else if (p->iTCO_version == 1)
262 		outb(0x01, TCO_RLD(p));
263 
264 	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
265 	val = inw(TCO1_CNT(p));
266 	val &= 0xf7ff;
267 	outw(val, TCO1_CNT(p));
268 	val = inw(TCO1_CNT(p));
269 	spin_unlock(&p->io_lock);
270 
271 	if (val & 0x0800)
272 		return -1;
273 	return 0;
274 }
275 
276 static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
277 {
278 	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
279 	unsigned int val;
280 
281 	spin_lock(&p->io_lock);
282 
283 	iTCO_vendor_pre_stop(p->smi_res);
284 
285 	/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
286 	val = inw(TCO1_CNT(p));
287 	val |= 0x0800;
288 	outw(val, TCO1_CNT(p));
289 	val = inw(TCO1_CNT(p));
290 
291 	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
292 	p->update_no_reboot_bit(p->no_reboot_priv, true);
293 
294 	spin_unlock(&p->io_lock);
295 
296 	if ((val & 0x0800) == 0)
297 		return -1;
298 	return 0;
299 }
300 
301 static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
302 {
303 	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
304 
305 	spin_lock(&p->io_lock);
306 
307 	iTCO_vendor_pre_keepalive(p->smi_res, wd_dev->timeout);
308 
309 	/* Reload the timer by writing to the TCO Timer Counter register */
310 	if (p->iTCO_version >= 2) {
311 		outw(0x01, TCO_RLD(p));
312 	} else if (p->iTCO_version == 1) {
313 		/* Reset the timeout status bit so that the timer
314 		 * needs to count down twice again before rebooting */
315 		outw(0x0008, TCO1_STS(p));	/* write 1 to clear bit */
316 
317 		outb(0x01, TCO_RLD(p));
318 	}
319 
320 	spin_unlock(&p->io_lock);
321 	return 0;
322 }
323 
324 static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
325 {
326 	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
327 	unsigned int val16;
328 	unsigned char val8;
329 	unsigned int tmrval;
330 
331 	tmrval = seconds_to_ticks(p, t);
332 
333 	/* For TCO v1 the timer counts down twice before rebooting */
334 	if (p->iTCO_version == 1)
335 		tmrval /= 2;
336 
337 	/* from the specs: */
338 	/* "Values of 0h-3h are ignored and should not be attempted" */
339 	if (tmrval < 0x04)
340 		return -EINVAL;
341 	if ((p->iTCO_version >= 2 && tmrval > 0x3ff) ||
342 	    (p->iTCO_version == 1 && tmrval > 0x03f))
343 		return -EINVAL;
344 
345 	iTCO_vendor_pre_set_heartbeat(tmrval);
346 
347 	/* Write new heartbeat to watchdog */
348 	if (p->iTCO_version >= 2) {
349 		spin_lock(&p->io_lock);
350 		val16 = inw(TCOv2_TMR(p));
351 		val16 &= 0xfc00;
352 		val16 |= tmrval;
353 		outw(val16, TCOv2_TMR(p));
354 		val16 = inw(TCOv2_TMR(p));
355 		spin_unlock(&p->io_lock);
356 
357 		if ((val16 & 0x3ff) != tmrval)
358 			return -EINVAL;
359 	} else if (p->iTCO_version == 1) {
360 		spin_lock(&p->io_lock);
361 		val8 = inb(TCOv1_TMR(p));
362 		val8 &= 0xc0;
363 		val8 |= (tmrval & 0xff);
364 		outb(val8, TCOv1_TMR(p));
365 		val8 = inb(TCOv1_TMR(p));
366 		spin_unlock(&p->io_lock);
367 
368 		if ((val8 & 0x3f) != tmrval)
369 			return -EINVAL;
370 	}
371 
372 	wd_dev->timeout = t;
373 	return 0;
374 }
375 
376 static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
377 {
378 	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
379 	unsigned int val16;
380 	unsigned char val8;
381 	unsigned int time_left = 0;
382 
383 	/* read the TCO Timer */
384 	if (p->iTCO_version >= 2) {
385 		spin_lock(&p->io_lock);
386 		val16 = inw(TCO_RLD(p));
387 		val16 &= 0x3ff;
388 		spin_unlock(&p->io_lock);
389 
390 		time_left = ticks_to_seconds(p, val16);
391 	} else if (p->iTCO_version == 1) {
392 		spin_lock(&p->io_lock);
393 		val8 = inb(TCO_RLD(p));
394 		val8 &= 0x3f;
395 		if (!(inw(TCO1_STS(p)) & 0x0008))
396 			val8 += (inb(TCOv1_TMR(p)) & 0x3f);
397 		spin_unlock(&p->io_lock);
398 
399 		time_left = ticks_to_seconds(p, val8);
400 	}
401 	return time_left;
402 }
403 
404 /*
405  *	Kernel Interfaces
406  */
407 
408 static const struct watchdog_info ident = {
409 	.options =		WDIOF_SETTIMEOUT |
410 				WDIOF_KEEPALIVEPING |
411 				WDIOF_MAGICCLOSE,
412 	.firmware_version =	0,
413 	.identity =		DRV_NAME,
414 };
415 
416 static const struct watchdog_ops iTCO_wdt_ops = {
417 	.owner =		THIS_MODULE,
418 	.start =		iTCO_wdt_start,
419 	.stop =			iTCO_wdt_stop,
420 	.ping =			iTCO_wdt_ping,
421 	.set_timeout =		iTCO_wdt_set_timeout,
422 	.get_timeleft =		iTCO_wdt_get_timeleft,
423 };
424 
425 /*
426  *	Init & exit routines
427  */
428 
429 static int iTCO_wdt_probe(struct platform_device *pdev)
430 {
431 	struct device *dev = &pdev->dev;
432 	struct itco_wdt_platform_data *pdata = dev_get_platdata(dev);
433 	struct iTCO_wdt_private *p;
434 	unsigned long val32;
435 	int ret;
436 
437 	if (!pdata)
438 		return -ENODEV;
439 
440 	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
441 	if (!p)
442 		return -ENOMEM;
443 
444 	spin_lock_init(&p->io_lock);
445 
446 	p->tco_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_TCO);
447 	if (!p->tco_res)
448 		return -ENODEV;
449 
450 	p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
451 	if (!p->smi_res)
452 		return -ENODEV;
453 
454 	p->iTCO_version = pdata->version;
455 	p->pci_dev = to_pci_dev(dev->parent);
456 
457 	iTCO_wdt_no_reboot_bit_setup(p, pdata);
458 
459 	/*
460 	 * Get the Memory-Mapped GCS or PMC register, we need it for the
461 	 * NO_REBOOT flag (TCO v2 and v3).
462 	 */
463 	if (p->iTCO_version >= 2 && !pdata->update_no_reboot_bit) {
464 		p->gcs_pmc_res = platform_get_resource(pdev,
465 						       IORESOURCE_MEM,
466 						       ICH_RES_MEM_GCS_PMC);
467 		p->gcs_pmc = devm_ioremap_resource(dev, p->gcs_pmc_res);
468 		if (IS_ERR(p->gcs_pmc))
469 			return PTR_ERR(p->gcs_pmc);
470 	}
471 
472 	/* Check chipset's NO_REBOOT bit */
473 	if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
474 	    iTCO_vendor_check_noreboot_on()) {
475 		pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
476 		return -ENODEV;	/* Cannot reset NO_REBOOT bit */
477 	}
478 
479 	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
480 	p->update_no_reboot_bit(p->no_reboot_priv, true);
481 
482 	/* The TCO logic uses the TCO_EN bit in the SMI_EN register */
483 	if (!devm_request_region(dev, p->smi_res->start,
484 				 resource_size(p->smi_res),
485 				 pdev->name)) {
486 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
487 		       (u64)SMI_EN(p));
488 		return -EBUSY;
489 	}
490 	if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
491 		/*
492 		 * Bit 13: TCO_EN -> 0
493 		 * Disables TCO logic generating an SMI#
494 		 */
495 		val32 = inl(SMI_EN(p));
496 		val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
497 		outl(val32, SMI_EN(p));
498 	}
499 
500 	if (!devm_request_region(dev, p->tco_res->start,
501 				 resource_size(p->tco_res),
502 				 pdev->name)) {
503 		pr_err("I/O address 0x%04llx already in use, device disabled\n",
504 		       (u64)TCOBASE(p));
505 		return -EBUSY;
506 	}
507 
508 	pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
509 		pdata->name, pdata->version, (u64)TCOBASE(p));
510 
511 	/* Clear out the (probably old) status */
512 	switch (p->iTCO_version) {
513 	case 5:
514 	case 4:
515 		outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
516 		outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
517 		break;
518 	case 3:
519 		outl(0x20008, TCO1_STS(p));
520 		break;
521 	case 2:
522 	case 1:
523 	default:
524 		outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
525 		outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
526 		outw(0x0004, TCO2_STS(p)); /* Clear BOOT_STS bit */
527 		break;
528 	}
529 
530 	p->wddev.info =	&ident,
531 	p->wddev.ops = &iTCO_wdt_ops,
532 	p->wddev.bootstatus = 0;
533 	p->wddev.timeout = WATCHDOG_TIMEOUT;
534 	watchdog_set_nowayout(&p->wddev, nowayout);
535 	p->wddev.parent = dev;
536 
537 	watchdog_set_drvdata(&p->wddev, p);
538 	platform_set_drvdata(pdev, p);
539 
540 	/* Make sure the watchdog is not running */
541 	iTCO_wdt_stop(&p->wddev);
542 
543 	/* Check that the heartbeat value is within it's range;
544 	   if not reset to the default */
545 	if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
546 		iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
547 		pr_info("timeout value out of range, using %d\n",
548 			WATCHDOG_TIMEOUT);
549 	}
550 
551 	watchdog_stop_on_reboot(&p->wddev);
552 	ret = devm_watchdog_register_device(dev, &p->wddev);
553 	if (ret != 0) {
554 		pr_err("cannot register watchdog device (err=%d)\n", ret);
555 		return ret;
556 	}
557 
558 	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
559 		heartbeat, nowayout);
560 
561 	return 0;
562 }
563 
564 static int iTCO_wdt_remove(struct platform_device *pdev)
565 {
566 	struct iTCO_wdt_private *p = platform_get_drvdata(pdev);
567 
568 	/* Stop the timer before we leave */
569 	if (!nowayout)
570 		iTCO_wdt_stop(&p->wddev);
571 
572 	return 0;
573 }
574 
575 #ifdef CONFIG_PM_SLEEP
576 /*
577  * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
578  * the watchdog cannot be pinged while in that state.  In ACPI sleep states the
579  * watchdog is stopped by the platform firmware.
580  */
581 
582 #ifdef CONFIG_ACPI
583 static inline bool need_suspend(void)
584 {
585 	return acpi_target_system_state() == ACPI_STATE_S0;
586 }
587 #else
588 static inline bool need_suspend(void) { return true; }
589 #endif
590 
591 static int iTCO_wdt_suspend_noirq(struct device *dev)
592 {
593 	struct iTCO_wdt_private *p = dev_get_drvdata(dev);
594 	int ret = 0;
595 
596 	p->suspended = false;
597 	if (watchdog_active(&p->wddev) && need_suspend()) {
598 		ret = iTCO_wdt_stop(&p->wddev);
599 		if (!ret)
600 			p->suspended = true;
601 	}
602 	return ret;
603 }
604 
605 static int iTCO_wdt_resume_noirq(struct device *dev)
606 {
607 	struct iTCO_wdt_private *p = dev_get_drvdata(dev);
608 
609 	if (p->suspended)
610 		iTCO_wdt_start(&p->wddev);
611 
612 	return 0;
613 }
614 
615 static const struct dev_pm_ops iTCO_wdt_pm = {
616 	.suspend_noirq = iTCO_wdt_suspend_noirq,
617 	.resume_noirq = iTCO_wdt_resume_noirq,
618 };
619 
620 #define ITCO_WDT_PM_OPS	(&iTCO_wdt_pm)
621 #else
622 #define ITCO_WDT_PM_OPS	NULL
623 #endif /* CONFIG_PM_SLEEP */
624 
625 static struct platform_driver iTCO_wdt_driver = {
626 	.probe          = iTCO_wdt_probe,
627 	.remove         = iTCO_wdt_remove,
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 	pr_info("Intel TCO WatchDog Timer Driver v%s\n", DRV_VERSION);
637 
638 	return platform_driver_register(&iTCO_wdt_driver);
639 }
640 
641 static void __exit iTCO_wdt_cleanup_module(void)
642 {
643 	platform_driver_unregister(&iTCO_wdt_driver);
644 	pr_info("Watchdog Module Unloaded\n");
645 }
646 
647 module_init(iTCO_wdt_init_module);
648 module_exit(iTCO_wdt_cleanup_module);
649 
650 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
651 MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
652 MODULE_VERSION(DRV_VERSION);
653 MODULE_LICENSE("GPL");
654 MODULE_ALIAS("platform:" DRV_NAME);
655