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v6.2
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 *	intel TCO Watchdog Driver
  4 *
  5 *	(c) Copyright 2006-2011 Wim Van Sebroeck <wim@iguana.be>.
  6 *
 
 
 
 
 
  7 *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  8 *	provide warranty for any of this software. This material is
  9 *	provided "AS-IS" and at no charge.
 10 *
 11 *	The TCO watchdog is implemented in the following I/O controller hubs:
 12 *	(See the intel documentation on http://developer.intel.com.)
 13 *	document number 290655-003, 290677-014: 82801AA (ICH), 82801AB (ICHO)
 14 *	document number 290687-002, 298242-027: 82801BA (ICH2)
 15 *	document number 290733-003, 290739-013: 82801CA (ICH3-S)
 16 *	document number 290716-001, 290718-007: 82801CAM (ICH3-M)
 17 *	document number 290744-001, 290745-025: 82801DB (ICH4)
 18 *	document number 252337-001, 252663-008: 82801DBM (ICH4-M)
 19 *	document number 273599-001, 273645-002: 82801E (C-ICH)
 20 *	document number 252516-001, 252517-028: 82801EB (ICH5), 82801ER (ICH5R)
 21 *	document number 300641-004, 300884-013: 6300ESB
 22 *	document number 301473-002, 301474-026: 82801F (ICH6)
 23 *	document number 313082-001, 313075-006: 631xESB, 632xESB
 24 *	document number 307013-003, 307014-024: 82801G (ICH7)
 25 *	document number 322896-001, 322897-001: NM10
 26 *	document number 313056-003, 313057-017: 82801H (ICH8)
 27 *	document number 316972-004, 316973-012: 82801I (ICH9)
 28 *	document number 319973-002, 319974-002: 82801J (ICH10)
 29 *	document number 322169-001, 322170-003: 5 Series, 3400 Series (PCH)
 30 *	document number 320066-003, 320257-008: EP80597 (IICH)
 31 *	document number 324645-001, 324646-001: Cougar Point (CPT)
 32 *	document number TBD                   : Patsburg (PBG)
 33 *	document number TBD                   : DH89xxCC
 34 *	document number TBD                   : Panther Point
 35 *	document number TBD                   : Lynx Point
 36 *	document number TBD                   : Lynx Point-LP
 37 */
 38
 39/*
 40 *	Includes, defines, variables, module parameters, ...
 41 */
 42
 
 
 43/* Module and version information */
 44#define DRV_NAME	"iTCO_wdt"
 45#define DRV_VERSION	"1.11"
 46
 47/* Includes */
 48#include <linux/acpi.h>			/* For ACPI support */
 49#include <linux/bits.h>			/* For BIT() */
 50#include <linux/module.h>		/* For module specific items */
 51#include <linux/moduleparam.h>		/* For new moduleparam's */
 52#include <linux/types.h>		/* For standard types (like size_t) */
 53#include <linux/errno.h>		/* For the -ENODEV/... values */
 54#include <linux/kernel.h>		/* For printk/panic/... */
 55#include <linux/watchdog.h>		/* For the watchdog specific items */
 56#include <linux/init.h>			/* For __init/__exit/... */
 57#include <linux/fs.h>			/* For file operations */
 58#include <linux/platform_device.h>	/* For platform_driver framework */
 59#include <linux/pci.h>			/* For pci functions */
 60#include <linux/ioport.h>		/* For io-port access */
 61#include <linux/spinlock.h>		/* For spin_lock/spin_unlock/... */
 62#include <linux/uaccess.h>		/* For copy_to_user/put_user/... */
 63#include <linux/io.h>			/* For inb/outb/... */
 64#include <linux/platform_data/itco_wdt.h>
 65#include <linux/mfd/intel_pmc_bxt.h>
 66
 67#include "iTCO_vendor.h"
 68
 69/* Address definitions for the TCO */
 70/* TCO base address */
 71#define TCOBASE(p)	((p)->tco_res->start)
 72/* SMI Control and Enable Register */
 73#define SMI_EN(p)	((p)->smi_res->start)
 74
 75#define TCO_RLD(p)	(TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */
 76#define TCOv1_TMR(p)	(TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/
 77#define TCO_DAT_IN(p)	(TCOBASE(p) + 0x02) /* TCO Data In Register	*/
 78#define TCO_DAT_OUT(p)	(TCOBASE(p) + 0x03) /* TCO Data Out Register	*/
 79#define TCO1_STS(p)	(TCOBASE(p) + 0x04) /* TCO1 Status Register	*/
 80#define TCO2_STS(p)	(TCOBASE(p) + 0x06) /* TCO2 Status Register	*/
 81#define TCO1_CNT(p)	(TCOBASE(p) + 0x08) /* TCO1 Control Register	*/
 82#define TCO2_CNT(p)	(TCOBASE(p) + 0x0a) /* TCO2 Control Register	*/
 83#define TCOv2_TMR(p)	(TCOBASE(p) + 0x12) /* TCOv2 Timer Initial Value*/
 84
 85/* internal variables */
 86struct iTCO_wdt_private {
 87	struct watchdog_device wddev;
 88
 89	/* TCO version/generation */
 90	unsigned int iTCO_version;
 91	struct resource *tco_res;
 92	struct resource *smi_res;
 93	/*
 94	 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
 95	 * or memory-mapped PMC register bit 4 (TCO version 3).
 96	 */
 
 97	unsigned long __iomem *gcs_pmc;
 98	/* the lock for io operations */
 99	spinlock_t io_lock;
100	/* the PCI-device */
101	struct pci_dev *pci_dev;
102	/* whether or not the watchdog has been suspended */
103	bool suspended;
104	/* no reboot API private data */
105	void *no_reboot_priv;
106	/* no reboot update function pointer */
107	int (*update_no_reboot_bit)(void *p, bool set);
108};
109
110/* module parameters */
111#define WATCHDOG_TIMEOUT 30	/* 30 sec default heartbeat */
112static int heartbeat = WATCHDOG_TIMEOUT;  /* in seconds */
113module_param(heartbeat, int, 0);
114MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
115	"5..76 (TCO v1) or 3..614 (TCO v2), default="
116				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
117
118static bool nowayout = WATCHDOG_NOWAYOUT;
119module_param(nowayout, bool, 0);
120MODULE_PARM_DESC(nowayout,
121	"Watchdog cannot be stopped once started (default="
122				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
123
124static int turn_SMI_watchdog_clear_off = 1;
125module_param(turn_SMI_watchdog_clear_off, int, 0);
126MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
127	"Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
128
129/*
130 * Some TCO specific functions
131 */
132
133/*
134 * The iTCO v1 and v2's internal timer is stored as ticks which decrement
135 * every 0.6 seconds.  v3's internal timer is stored as seconds (some
136 * datasheets incorrectly state 0.6 seconds).
137 */
138static inline unsigned int seconds_to_ticks(struct iTCO_wdt_private *p,
139					    int secs)
140{
141	return p->iTCO_version == 3 ? secs : (secs * 10) / 6;
142}
143
144static inline unsigned int ticks_to_seconds(struct iTCO_wdt_private *p,
145					    int ticks)
146{
147	return p->iTCO_version == 3 ? ticks : (ticks * 6) / 10;
148}
149
150static inline u32 no_reboot_bit(struct iTCO_wdt_private *p)
151{
152	u32 enable_bit;
153
154	switch (p->iTCO_version) {
155	case 5:
156	case 3:
157		enable_bit = 0x00000010;
158		break;
159	case 2:
160		enable_bit = 0x00000020;
161		break;
162	case 4:
163	case 1:
164	default:
165		enable_bit = 0x00000002;
166		break;
167	}
168
169	return enable_bit;
170}
171
172static int update_no_reboot_bit_def(void *priv, bool set)
173{
174	return 0;
175}
176
177static int update_no_reboot_bit_pci(void *priv, bool set)
178{
179	struct iTCO_wdt_private *p = priv;
180	u32 val32 = 0, newval32 = 0;
181
182	pci_read_config_dword(p->pci_dev, 0xd4, &val32);
183	if (set)
184		val32 |= no_reboot_bit(p);
185	else
186		val32 &= ~no_reboot_bit(p);
187	pci_write_config_dword(p->pci_dev, 0xd4, val32);
188	pci_read_config_dword(p->pci_dev, 0xd4, &newval32);
189
190	/* make sure the update is successful */
191	if (val32 != newval32)
192		return -EIO;
193
194	return 0;
195}
196
197static int update_no_reboot_bit_mem(void *priv, bool set)
198{
199	struct iTCO_wdt_private *p = priv;
200	u32 val32 = 0, newval32 = 0;
201
202	val32 = readl(p->gcs_pmc);
203	if (set)
204		val32 |= no_reboot_bit(p);
205	else
206		val32 &= ~no_reboot_bit(p);
207	writel(val32, p->gcs_pmc);
208	newval32 = readl(p->gcs_pmc);
209
210	/* make sure the update is successful */
211	if (val32 != newval32)
212		return -EIO;
213
214	return 0;
215}
216
217static int update_no_reboot_bit_cnt(void *priv, bool set)
218{
219	struct iTCO_wdt_private *p = priv;
220	u16 val, newval;
221
222	val = inw(TCO1_CNT(p));
223	if (set)
224		val |= BIT(0);
225	else
226		val &= ~BIT(0);
227	outw(val, TCO1_CNT(p));
228	newval = inw(TCO1_CNT(p));
229
230	/* make sure the update is successful */
231	return val != newval ? -EIO : 0;
232}
233
234static int update_no_reboot_bit_pmc(void *priv, bool set)
235{
236	struct intel_pmc_dev *pmc = priv;
237	u32 bits = PMC_CFG_NO_REBOOT_EN;
238	u32 value = set ? bits : 0;
239
240	return intel_pmc_gcr_update(pmc, PMC_GCR_PMC_CFG_REG, bits, value);
241}
242
243static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
244					 struct platform_device *pdev,
245					 struct itco_wdt_platform_data *pdata)
246{
247	if (pdata->no_reboot_use_pmc) {
248		struct intel_pmc_dev *pmc = dev_get_drvdata(pdev->dev.parent);
249
250		p->update_no_reboot_bit = update_no_reboot_bit_pmc;
251		p->no_reboot_priv = pmc;
252		return;
253	}
254
255	if (p->iTCO_version >= 6)
256		p->update_no_reboot_bit = update_no_reboot_bit_cnt;
257	else if (p->iTCO_version >= 2)
258		p->update_no_reboot_bit = update_no_reboot_bit_mem;
259	else if (p->iTCO_version == 1)
260		p->update_no_reboot_bit = update_no_reboot_bit_pci;
261	else
262		p->update_no_reboot_bit = update_no_reboot_bit_def;
263
264	p->no_reboot_priv = p;
265}
266
267static int iTCO_wdt_start(struct watchdog_device *wd_dev)
268{
269	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
270	unsigned int val;
271
272	spin_lock(&p->io_lock);
273
274	iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
275
276	/* disable chipset's NO_REBOOT bit */
277	if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
278		spin_unlock(&p->io_lock);
279		dev_err(wd_dev->parent, "failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
280		return -EIO;
281	}
282
283	/* Force the timer to its reload value by writing to the TCO_RLD
284	   register */
285	if (p->iTCO_version >= 2)
286		outw(0x01, TCO_RLD(p));
287	else if (p->iTCO_version == 1)
288		outb(0x01, TCO_RLD(p));
289
290	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
291	val = inw(TCO1_CNT(p));
292	val &= 0xf7ff;
293	outw(val, TCO1_CNT(p));
294	val = inw(TCO1_CNT(p));
295	spin_unlock(&p->io_lock);
296
297	if (val & 0x0800)
298		return -1;
299	return 0;
300}
301
302static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
303{
304	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
305	unsigned int val;
306
307	spin_lock(&p->io_lock);
308
309	iTCO_vendor_pre_stop(p->smi_res);
310
311	/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
312	val = inw(TCO1_CNT(p));
313	val |= 0x0800;
314	outw(val, TCO1_CNT(p));
315	val = inw(TCO1_CNT(p));
316
317	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
318	p->update_no_reboot_bit(p->no_reboot_priv, true);
319
320	spin_unlock(&p->io_lock);
321
322	if ((val & 0x0800) == 0)
323		return -1;
324	return 0;
325}
326
327static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
328{
329	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
330
331	spin_lock(&p->io_lock);
332
 
 
333	/* Reload the timer by writing to the TCO Timer Counter register */
334	if (p->iTCO_version >= 2) {
335		outw(0x01, TCO_RLD(p));
336	} else if (p->iTCO_version == 1) {
337		/* Reset the timeout status bit so that the timer
338		 * needs to count down twice again before rebooting */
339		outw(0x0008, TCO1_STS(p));	/* write 1 to clear bit */
340
341		outb(0x01, TCO_RLD(p));
342	}
343
344	spin_unlock(&p->io_lock);
345	return 0;
346}
347
348static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
349{
350	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
351	unsigned int val16;
352	unsigned char val8;
353	unsigned int tmrval;
354
355	tmrval = seconds_to_ticks(p, t);
356
357	/* For TCO v1 the timer counts down twice before rebooting */
358	if (p->iTCO_version == 1)
359		tmrval /= 2;
360
361	/* from the specs: */
362	/* "Values of 0h-3h are ignored and should not be attempted" */
363	if (tmrval < 0x04)
364		return -EINVAL;
365	if ((p->iTCO_version >= 2 && tmrval > 0x3ff) ||
366	    (p->iTCO_version == 1 && tmrval > 0x03f))
367		return -EINVAL;
368
 
 
369	/* Write new heartbeat to watchdog */
370	if (p->iTCO_version >= 2) {
371		spin_lock(&p->io_lock);
372		val16 = inw(TCOv2_TMR(p));
373		val16 &= 0xfc00;
374		val16 |= tmrval;
375		outw(val16, TCOv2_TMR(p));
376		val16 = inw(TCOv2_TMR(p));
377		spin_unlock(&p->io_lock);
378
379		if ((val16 & 0x3ff) != tmrval)
380			return -EINVAL;
381	} else if (p->iTCO_version == 1) {
382		spin_lock(&p->io_lock);
383		val8 = inb(TCOv1_TMR(p));
384		val8 &= 0xc0;
385		val8 |= (tmrval & 0xff);
386		outb(val8, TCOv1_TMR(p));
387		val8 = inb(TCOv1_TMR(p));
388		spin_unlock(&p->io_lock);
389
390		if ((val8 & 0x3f) != tmrval)
391			return -EINVAL;
392	}
393
394	wd_dev->timeout = t;
395	return 0;
396}
397
398static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
399{
400	struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
401	unsigned int val16;
402	unsigned char val8;
403	unsigned int time_left = 0;
404
405	/* read the TCO Timer */
406	if (p->iTCO_version >= 2) {
407		spin_lock(&p->io_lock);
408		val16 = inw(TCO_RLD(p));
409		val16 &= 0x3ff;
410		spin_unlock(&p->io_lock);
411
412		time_left = ticks_to_seconds(p, val16);
413	} else if (p->iTCO_version == 1) {
414		spin_lock(&p->io_lock);
415		val8 = inb(TCO_RLD(p));
416		val8 &= 0x3f;
417		if (!(inw(TCO1_STS(p)) & 0x0008))
418			val8 += (inb(TCOv1_TMR(p)) & 0x3f);
419		spin_unlock(&p->io_lock);
420
421		time_left = ticks_to_seconds(p, val8);
422	}
423	return time_left;
424}
425
426/* Returns true if the watchdog was running */
427static bool iTCO_wdt_set_running(struct iTCO_wdt_private *p)
428{
429	u16 val;
430
431	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled */
432	val = inw(TCO1_CNT(p));
433	if (!(val & BIT(11))) {
434		set_bit(WDOG_HW_RUNNING, &p->wddev.status);
435		return true;
436	}
437	return false;
438}
439
440/*
441 *	Kernel Interfaces
442 */
443
444static const struct watchdog_info ident = {
445	.options =		WDIOF_SETTIMEOUT |
446				WDIOF_KEEPALIVEPING |
447				WDIOF_MAGICCLOSE,
448	.firmware_version =	0,
449	.identity =		DRV_NAME,
450};
451
452static const struct watchdog_ops iTCO_wdt_ops = {
453	.owner =		THIS_MODULE,
454	.start =		iTCO_wdt_start,
455	.stop =			iTCO_wdt_stop,
456	.ping =			iTCO_wdt_ping,
457	.set_timeout =		iTCO_wdt_set_timeout,
458	.get_timeleft =		iTCO_wdt_get_timeleft,
459};
460
461/*
462 *	Init & exit routines
463 */
464
465static int iTCO_wdt_probe(struct platform_device *pdev)
466{
467	struct device *dev = &pdev->dev;
468	struct itco_wdt_platform_data *pdata = dev_get_platdata(dev);
469	struct iTCO_wdt_private *p;
470	unsigned long val32;
471	int ret;
472
473	if (!pdata)
474		return -ENODEV;
475
476	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
477	if (!p)
478		return -ENOMEM;
479
480	spin_lock_init(&p->io_lock);
481
482	p->tco_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_TCO);
483	if (!p->tco_res)
484		return -ENODEV;
485
486	p->iTCO_version = pdata->version;
487	p->pci_dev = to_pci_dev(dev->parent);
488
489	p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
490	if (p->smi_res) {
491		/* The TCO logic uses the TCO_EN bit in the SMI_EN register */
492		if (!devm_request_region(dev, p->smi_res->start,
493					 resource_size(p->smi_res),
494					 pdev->name)) {
495			dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
496			       (u64)SMI_EN(p));
497			return -EBUSY;
498		}
499	} else if (iTCO_vendorsupport ||
500		   turn_SMI_watchdog_clear_off >= p->iTCO_version) {
501		dev_err(dev, "SMI I/O resource is missing\n");
502		return -ENODEV;
503	}
504
505	iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
 
 
 
506
507	/*
508	 * Get the Memory-Mapped GCS or PMC register, we need it for the
509	 * NO_REBOOT flag (TCO v2 and v3).
510	 */
511	if (p->iTCO_version >= 2 && p->iTCO_version < 6 &&
512	    !pdata->no_reboot_use_pmc) {
513		p->gcs_pmc = devm_platform_ioremap_resource(pdev, ICH_RES_MEM_GCS_PMC);
 
 
514		if (IS_ERR(p->gcs_pmc))
515			return PTR_ERR(p->gcs_pmc);
516	}
517
518	/* Check chipset's NO_REBOOT bit */
519	if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
520	    iTCO_vendor_check_noreboot_on()) {
521		dev_info(dev, "unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
522		return -ENODEV;	/* Cannot reset NO_REBOOT bit */
523	}
524
 
 
 
 
 
 
 
 
 
 
 
525	if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
526		/*
527		 * Bit 13: TCO_EN -> 0
528		 * Disables TCO logic generating an SMI#
529		 */
530		val32 = inl(SMI_EN(p));
531		val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
532		outl(val32, SMI_EN(p));
533	}
534
535	if (!devm_request_region(dev, p->tco_res->start,
536				 resource_size(p->tco_res),
537				 pdev->name)) {
538		dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
539		       (u64)TCOBASE(p));
540		return -EBUSY;
541	}
542
543	dev_info(dev, "Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
544		pdata->name, pdata->version, (u64)TCOBASE(p));
545
546	/* Clear out the (probably old) status */
547	switch (p->iTCO_version) {
548	case 6:
549	case 5:
550	case 4:
551		outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
552		outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
553		break;
554	case 3:
555		outl(0x20008, TCO1_STS(p));
556		break;
557	case 2:
558	case 1:
559	default:
560		outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
561		outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
562		outw(0x0004, TCO2_STS(p)); /* Clear BOOT_STS bit */
563		break;
564	}
565
566	p->wddev.info = &ident,
567	p->wddev.ops = &iTCO_wdt_ops,
568	p->wddev.bootstatus = 0;
569	p->wddev.timeout = WATCHDOG_TIMEOUT;
570	watchdog_set_nowayout(&p->wddev, nowayout);
571	p->wddev.parent = dev;
572
573	watchdog_set_drvdata(&p->wddev, p);
574	platform_set_drvdata(pdev, p);
575
576	if (!iTCO_wdt_set_running(p)) {
577		/*
578		 * If the watchdog was not running set NO_REBOOT now to
579		 * prevent later reboots.
580		 */
581		p->update_no_reboot_bit(p->no_reboot_priv, true);
582	}
583
584	/* Check that the heartbeat value is within it's range;
585	   if not reset to the default */
586	if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
587		iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
588		dev_info(dev, "timeout value out of range, using %d\n",
589			WATCHDOG_TIMEOUT);
590	}
591
592	watchdog_stop_on_reboot(&p->wddev);
593	watchdog_stop_on_unregister(&p->wddev);
594	ret = devm_watchdog_register_device(dev, &p->wddev);
595	if (ret != 0) {
596		dev_err(dev, "cannot register watchdog device (err=%d)\n", ret);
597		return ret;
598	}
599
600	dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
601		heartbeat, nowayout);
602
603	return 0;
604}
605
 
 
 
 
 
 
 
 
 
 
 
 
606/*
607 * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
608 * the watchdog cannot be pinged while in that state.  In ACPI sleep states the
609 * watchdog is stopped by the platform firmware.
610 */
611
612#ifdef CONFIG_ACPI
613static inline bool __maybe_unused need_suspend(void)
614{
615	return acpi_target_system_state() == ACPI_STATE_S0;
616}
617#else
618static inline bool __maybe_unused need_suspend(void) { return true; }
619#endif
620
621static int __maybe_unused iTCO_wdt_suspend_noirq(struct device *dev)
622{
623	struct iTCO_wdt_private *p = dev_get_drvdata(dev);
624	int ret = 0;
625
626	p->suspended = false;
627	if (watchdog_active(&p->wddev) && need_suspend()) {
628		ret = iTCO_wdt_stop(&p->wddev);
629		if (!ret)
630			p->suspended = true;
631	}
632	return ret;
633}
634
635static int __maybe_unused iTCO_wdt_resume_noirq(struct device *dev)
636{
637	struct iTCO_wdt_private *p = dev_get_drvdata(dev);
638
639	if (p->suspended)
640		iTCO_wdt_start(&p->wddev);
641
642	return 0;
643}
644
645static const struct dev_pm_ops iTCO_wdt_pm = {
646	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(iTCO_wdt_suspend_noirq,
647				      iTCO_wdt_resume_noirq)
648};
649
 
 
 
 
 
650static struct platform_driver iTCO_wdt_driver = {
651	.probe          = iTCO_wdt_probe,
 
652	.driver         = {
653		.name   = DRV_NAME,
654		.pm     = &iTCO_wdt_pm,
655	},
656};
657
658module_platform_driver(iTCO_wdt_driver);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
659
660MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
661MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
662MODULE_VERSION(DRV_VERSION);
663MODULE_LICENSE("GPL");
664MODULE_ALIAS("platform:" DRV_NAME);
v4.17
 
  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 */
 90struct 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 */
117static int heartbeat = WATCHDOG_TIMEOUT;  /* in seconds */
118module_param(heartbeat, int, 0);
119MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
120	"5..76 (TCO v1) or 3..614 (TCO v2), default="
121				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
122
123static bool nowayout = WATCHDOG_NOWAYOUT;
124module_param(nowayout, bool, 0);
125MODULE_PARM_DESC(nowayout,
126	"Watchdog cannot be stopped once started (default="
127				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
128
129static int turn_SMI_watchdog_clear_off = 1;
130module_param(turn_SMI_watchdog_clear_off, int, 0);
131MODULE_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 */
143static 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
149static 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
155static 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
177static int update_no_reboot_bit_def(void *priv, bool set)
178{
179	return 0;
180}
181
182static 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
202static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
222static 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
241static 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
276static 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
301static 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
324static 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
376static 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
408static 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
416static 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
429static 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
564static 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
583static inline bool need_suspend(void)
584{
585	return acpi_target_system_state() == ACPI_STATE_S0;
586}
587#else
588static inline bool need_suspend(void) { return true; }
589#endif
590
591static 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
605static 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
615static 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
625static 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
634static 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
641static void __exit iTCO_wdt_cleanup_module(void)
642{
643	platform_driver_unregister(&iTCO_wdt_driver);
644	pr_info("Watchdog Module Unloaded\n");
645}
646
647module_init(iTCO_wdt_init_module);
648module_exit(iTCO_wdt_cleanup_module);
649
650MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
651MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
652MODULE_VERSION(DRV_VERSION);
653MODULE_LICENSE("GPL");
654MODULE_ALIAS("platform:" DRV_NAME);