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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44
45/* Module and version information */
46#define DRV_NAME "iTCO_wdt"
47#define DRV_VERSION "1.11"
48
49/* Includes */
50#include <linux/acpi.h> /* For ACPI support */
51#include <linux/bits.h> /* For BIT() */
52#include <linux/module.h> /* For module specific items */
53#include <linux/moduleparam.h> /* For new moduleparam's */
54#include <linux/types.h> /* For standard types (like size_t) */
55#include <linux/errno.h> /* For the -ENODEV/... values */
56#include <linux/kernel.h> /* For printk/panic/... */
57#include <linux/watchdog.h> /* For the watchdog specific items */
58#include <linux/init.h> /* For __init/__exit/... */
59#include <linux/fs.h> /* For file operations */
60#include <linux/platform_device.h> /* For platform_driver framework */
61#include <linux/pci.h> /* For pci functions */
62#include <linux/ioport.h> /* For io-port access */
63#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
64#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
65#include <linux/io.h> /* For inb/outb/... */
66#include <linux/platform_data/itco_wdt.h>
67#include <linux/mfd/intel_pmc_bxt.h>
68
69#include "iTCO_vendor.h"
70
71/* Address definitions for the TCO */
72/* TCO base address */
73#define TCOBASE(p) ((p)->tco_res->start)
74/* SMI Control and Enable Register */
75#define SMI_EN(p) ((p)->smi_res->start)
76
77#define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */
78#define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/
79#define TCO_DAT_IN(p) (TCOBASE(p) + 0x02) /* TCO Data In Register */
80#define TCO_DAT_OUT(p) (TCOBASE(p) + 0x03) /* TCO Data Out Register */
81#define TCO1_STS(p) (TCOBASE(p) + 0x04) /* TCO1 Status Register */
82#define TCO2_STS(p) (TCOBASE(p) + 0x06) /* TCO2 Status Register */
83#define TCO1_CNT(p) (TCOBASE(p) + 0x08) /* TCO1 Control Register */
84#define TCO2_CNT(p) (TCOBASE(p) + 0x0a) /* TCO2 Control Register */
85#define TCOv2_TMR(p) (TCOBASE(p) + 0x12) /* TCOv2 Timer Initial Value*/
86
87/* internal variables */
88struct iTCO_wdt_private {
89 struct watchdog_device wddev;
90
91 /* TCO version/generation */
92 unsigned int iTCO_version;
93 struct resource *tco_res;
94 struct resource *smi_res;
95 /*
96 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
97 * or memory-mapped PMC register bit 4 (TCO version 3).
98 */
99 struct resource *gcs_pmc_res;
100 unsigned long __iomem *gcs_pmc;
101 /* the lock for io operations */
102 spinlock_t io_lock;
103 /* the PCI-device */
104 struct pci_dev *pci_dev;
105 /* whether or not the watchdog has been suspended */
106 bool suspended;
107 /* no reboot API private data */
108 void *no_reboot_priv;
109 /* no reboot update function pointer */
110 int (*update_no_reboot_bit)(void *p, bool set);
111};
112
113/* module parameters */
114#define WATCHDOG_TIMEOUT 30 /* 30 sec default heartbeat */
115static int heartbeat = WATCHDOG_TIMEOUT; /* in seconds */
116module_param(heartbeat, int, 0);
117MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
118 "5..76 (TCO v1) or 3..614 (TCO v2), default="
119 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
120
121static bool nowayout = WATCHDOG_NOWAYOUT;
122module_param(nowayout, bool, 0);
123MODULE_PARM_DESC(nowayout,
124 "Watchdog cannot be stopped once started (default="
125 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
126
127static int turn_SMI_watchdog_clear_off = 1;
128module_param(turn_SMI_watchdog_clear_off, int, 0);
129MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
130 "Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
131
132/*
133 * Some TCO specific functions
134 */
135
136/*
137 * The iTCO v1 and v2's internal timer is stored as ticks which decrement
138 * every 0.6 seconds. v3's internal timer is stored as seconds (some
139 * datasheets incorrectly state 0.6 seconds).
140 */
141static inline unsigned int seconds_to_ticks(struct iTCO_wdt_private *p,
142 int secs)
143{
144 return p->iTCO_version == 3 ? secs : (secs * 10) / 6;
145}
146
147static inline unsigned int ticks_to_seconds(struct iTCO_wdt_private *p,
148 int ticks)
149{
150 return p->iTCO_version == 3 ? ticks : (ticks * 6) / 10;
151}
152
153static inline u32 no_reboot_bit(struct iTCO_wdt_private *p)
154{
155 u32 enable_bit;
156
157 switch (p->iTCO_version) {
158 case 5:
159 case 3:
160 enable_bit = 0x00000010;
161 break;
162 case 2:
163 enable_bit = 0x00000020;
164 break;
165 case 4:
166 case 1:
167 default:
168 enable_bit = 0x00000002;
169 break;
170 }
171
172 return enable_bit;
173}
174
175static int update_no_reboot_bit_def(void *priv, bool set)
176{
177 return 0;
178}
179
180static int update_no_reboot_bit_pci(void *priv, bool set)
181{
182 struct iTCO_wdt_private *p = priv;
183 u32 val32 = 0, newval32 = 0;
184
185 pci_read_config_dword(p->pci_dev, 0xd4, &val32);
186 if (set)
187 val32 |= no_reboot_bit(p);
188 else
189 val32 &= ~no_reboot_bit(p);
190 pci_write_config_dword(p->pci_dev, 0xd4, val32);
191 pci_read_config_dword(p->pci_dev, 0xd4, &newval32);
192
193 /* make sure the update is successful */
194 if (val32 != newval32)
195 return -EIO;
196
197 return 0;
198}
199
200static int update_no_reboot_bit_mem(void *priv, bool set)
201{
202 struct iTCO_wdt_private *p = priv;
203 u32 val32 = 0, newval32 = 0;
204
205 val32 = readl(p->gcs_pmc);
206 if (set)
207 val32 |= no_reboot_bit(p);
208 else
209 val32 &= ~no_reboot_bit(p);
210 writel(val32, p->gcs_pmc);
211 newval32 = readl(p->gcs_pmc);
212
213 /* make sure the update is successful */
214 if (val32 != newval32)
215 return -EIO;
216
217 return 0;
218}
219
220static int update_no_reboot_bit_cnt(void *priv, bool set)
221{
222 struct iTCO_wdt_private *p = priv;
223 u16 val, newval;
224
225 val = inw(TCO1_CNT(p));
226 if (set)
227 val |= BIT(0);
228 else
229 val &= ~BIT(0);
230 outw(val, TCO1_CNT(p));
231 newval = inw(TCO1_CNT(p));
232
233 /* make sure the update is successful */
234 return val != newval ? -EIO : 0;
235}
236
237static int update_no_reboot_bit_pmc(void *priv, bool set)
238{
239 struct intel_pmc_dev *pmc = priv;
240 u32 bits = PMC_CFG_NO_REBOOT_EN;
241 u32 value = set ? bits : 0;
242
243 return intel_pmc_gcr_update(pmc, PMC_GCR_PMC_CFG_REG, bits, value);
244}
245
246static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
247 struct platform_device *pdev,
248 struct itco_wdt_platform_data *pdata)
249{
250 if (pdata->no_reboot_use_pmc) {
251 struct intel_pmc_dev *pmc = dev_get_drvdata(pdev->dev.parent);
252
253 p->update_no_reboot_bit = update_no_reboot_bit_pmc;
254 p->no_reboot_priv = pmc;
255 return;
256 }
257
258 if (p->iTCO_version >= 6)
259 p->update_no_reboot_bit = update_no_reboot_bit_cnt;
260 else if (p->iTCO_version >= 2)
261 p->update_no_reboot_bit = update_no_reboot_bit_mem;
262 else if (p->iTCO_version == 1)
263 p->update_no_reboot_bit = update_no_reboot_bit_pci;
264 else
265 p->update_no_reboot_bit = update_no_reboot_bit_def;
266
267 p->no_reboot_priv = p;
268}
269
270static int iTCO_wdt_start(struct watchdog_device *wd_dev)
271{
272 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
273 unsigned int val;
274
275 spin_lock(&p->io_lock);
276
277 iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
278
279 /* disable chipset's NO_REBOOT bit */
280 if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
281 spin_unlock(&p->io_lock);
282 pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
283 return -EIO;
284 }
285
286 /* Force the timer to its reload value by writing to the TCO_RLD
287 register */
288 if (p->iTCO_version >= 2)
289 outw(0x01, TCO_RLD(p));
290 else if (p->iTCO_version == 1)
291 outb(0x01, TCO_RLD(p));
292
293 /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
294 val = inw(TCO1_CNT(p));
295 val &= 0xf7ff;
296 outw(val, TCO1_CNT(p));
297 val = inw(TCO1_CNT(p));
298 spin_unlock(&p->io_lock);
299
300 if (val & 0x0800)
301 return -1;
302 return 0;
303}
304
305static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
306{
307 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
308 unsigned int val;
309
310 spin_lock(&p->io_lock);
311
312 iTCO_vendor_pre_stop(p->smi_res);
313
314 /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
315 val = inw(TCO1_CNT(p));
316 val |= 0x0800;
317 outw(val, TCO1_CNT(p));
318 val = inw(TCO1_CNT(p));
319
320 /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
321 p->update_no_reboot_bit(p->no_reboot_priv, true);
322
323 spin_unlock(&p->io_lock);
324
325 if ((val & 0x0800) == 0)
326 return -1;
327 return 0;
328}
329
330static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
331{
332 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
333
334 spin_lock(&p->io_lock);
335
336 /* Reload the timer by writing to the TCO Timer Counter register */
337 if (p->iTCO_version >= 2) {
338 outw(0x01, TCO_RLD(p));
339 } else if (p->iTCO_version == 1) {
340 /* Reset the timeout status bit so that the timer
341 * needs to count down twice again before rebooting */
342 outw(0x0008, TCO1_STS(p)); /* write 1 to clear bit */
343
344 outb(0x01, TCO_RLD(p));
345 }
346
347 spin_unlock(&p->io_lock);
348 return 0;
349}
350
351static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
352{
353 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
354 unsigned int val16;
355 unsigned char val8;
356 unsigned int tmrval;
357
358 tmrval = seconds_to_ticks(p, t);
359
360 /* For TCO v1 the timer counts down twice before rebooting */
361 if (p->iTCO_version == 1)
362 tmrval /= 2;
363
364 /* from the specs: */
365 /* "Values of 0h-3h are ignored and should not be attempted" */
366 if (tmrval < 0x04)
367 return -EINVAL;
368 if ((p->iTCO_version >= 2 && tmrval > 0x3ff) ||
369 (p->iTCO_version == 1 && tmrval > 0x03f))
370 return -EINVAL;
371
372 /* Write new heartbeat to watchdog */
373 if (p->iTCO_version >= 2) {
374 spin_lock(&p->io_lock);
375 val16 = inw(TCOv2_TMR(p));
376 val16 &= 0xfc00;
377 val16 |= tmrval;
378 outw(val16, TCOv2_TMR(p));
379 val16 = inw(TCOv2_TMR(p));
380 spin_unlock(&p->io_lock);
381
382 if ((val16 & 0x3ff) != tmrval)
383 return -EINVAL;
384 } else if (p->iTCO_version == 1) {
385 spin_lock(&p->io_lock);
386 val8 = inb(TCOv1_TMR(p));
387 val8 &= 0xc0;
388 val8 |= (tmrval & 0xff);
389 outb(val8, TCOv1_TMR(p));
390 val8 = inb(TCOv1_TMR(p));
391 spin_unlock(&p->io_lock);
392
393 if ((val8 & 0x3f) != tmrval)
394 return -EINVAL;
395 }
396
397 wd_dev->timeout = t;
398 return 0;
399}
400
401static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
402{
403 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
404 unsigned int val16;
405 unsigned char val8;
406 unsigned int time_left = 0;
407
408 /* read the TCO Timer */
409 if (p->iTCO_version >= 2) {
410 spin_lock(&p->io_lock);
411 val16 = inw(TCO_RLD(p));
412 val16 &= 0x3ff;
413 spin_unlock(&p->io_lock);
414
415 time_left = ticks_to_seconds(p, val16);
416 } else if (p->iTCO_version == 1) {
417 spin_lock(&p->io_lock);
418 val8 = inb(TCO_RLD(p));
419 val8 &= 0x3f;
420 if (!(inw(TCO1_STS(p)) & 0x0008))
421 val8 += (inb(TCOv1_TMR(p)) & 0x3f);
422 spin_unlock(&p->io_lock);
423
424 time_left = ticks_to_seconds(p, val8);
425 }
426 return time_left;
427}
428
429/*
430 * Kernel Interfaces
431 */
432
433static const struct watchdog_info ident = {
434 .options = WDIOF_SETTIMEOUT |
435 WDIOF_KEEPALIVEPING |
436 WDIOF_MAGICCLOSE,
437 .firmware_version = 0,
438 .identity = DRV_NAME,
439};
440
441static const struct watchdog_ops iTCO_wdt_ops = {
442 .owner = THIS_MODULE,
443 .start = iTCO_wdt_start,
444 .stop = iTCO_wdt_stop,
445 .ping = iTCO_wdt_ping,
446 .set_timeout = iTCO_wdt_set_timeout,
447 .get_timeleft = iTCO_wdt_get_timeleft,
448};
449
450/*
451 * Init & exit routines
452 */
453
454static int iTCO_wdt_probe(struct platform_device *pdev)
455{
456 struct device *dev = &pdev->dev;
457 struct itco_wdt_platform_data *pdata = dev_get_platdata(dev);
458 struct iTCO_wdt_private *p;
459 unsigned long val32;
460 int ret;
461
462 if (!pdata)
463 return -ENODEV;
464
465 p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
466 if (!p)
467 return -ENOMEM;
468
469 spin_lock_init(&p->io_lock);
470
471 p->tco_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_TCO);
472 if (!p->tco_res)
473 return -ENODEV;
474
475 p->iTCO_version = pdata->version;
476 p->pci_dev = to_pci_dev(dev->parent);
477
478 p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
479 if (p->smi_res) {
480 /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
481 if (!devm_request_region(dev, p->smi_res->start,
482 resource_size(p->smi_res),
483 pdev->name)) {
484 pr_err("I/O address 0x%04llx already in use, device disabled\n",
485 (u64)SMI_EN(p));
486 return -EBUSY;
487 }
488 } else if (iTCO_vendorsupport ||
489 turn_SMI_watchdog_clear_off >= p->iTCO_version) {
490 pr_err("SMI I/O resource is missing\n");
491 return -ENODEV;
492 }
493
494 iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
495
496 /*
497 * Get the Memory-Mapped GCS or PMC register, we need it for the
498 * NO_REBOOT flag (TCO v2 and v3).
499 */
500 if (p->iTCO_version >= 2 && p->iTCO_version < 6 &&
501 !pdata->no_reboot_use_pmc) {
502 p->gcs_pmc_res = platform_get_resource(pdev,
503 IORESOURCE_MEM,
504 ICH_RES_MEM_GCS_PMC);
505 p->gcs_pmc = devm_ioremap_resource(dev, p->gcs_pmc_res);
506 if (IS_ERR(p->gcs_pmc))
507 return PTR_ERR(p->gcs_pmc);
508 }
509
510 /* Check chipset's NO_REBOOT bit */
511 if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
512 iTCO_vendor_check_noreboot_on()) {
513 pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
514 return -ENODEV; /* Cannot reset NO_REBOOT bit */
515 }
516
517 /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
518 p->update_no_reboot_bit(p->no_reboot_priv, true);
519
520 if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
521 /*
522 * Bit 13: TCO_EN -> 0
523 * Disables TCO logic generating an SMI#
524 */
525 val32 = inl(SMI_EN(p));
526 val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
527 outl(val32, SMI_EN(p));
528 }
529
530 if (!devm_request_region(dev, p->tco_res->start,
531 resource_size(p->tco_res),
532 pdev->name)) {
533 pr_err("I/O address 0x%04llx already in use, device disabled\n",
534 (u64)TCOBASE(p));
535 return -EBUSY;
536 }
537
538 pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
539 pdata->name, pdata->version, (u64)TCOBASE(p));
540
541 /* Clear out the (probably old) status */
542 switch (p->iTCO_version) {
543 case 6:
544 case 5:
545 case 4:
546 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
547 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
548 break;
549 case 3:
550 outl(0x20008, TCO1_STS(p));
551 break;
552 case 2:
553 case 1:
554 default:
555 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
556 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
557 outw(0x0004, TCO2_STS(p)); /* Clear BOOT_STS bit */
558 break;
559 }
560
561 p->wddev.info = &ident,
562 p->wddev.ops = &iTCO_wdt_ops,
563 p->wddev.bootstatus = 0;
564 p->wddev.timeout = WATCHDOG_TIMEOUT;
565 watchdog_set_nowayout(&p->wddev, nowayout);
566 p->wddev.parent = dev;
567
568 watchdog_set_drvdata(&p->wddev, p);
569 platform_set_drvdata(pdev, p);
570
571 /* Make sure the watchdog is not running */
572 iTCO_wdt_stop(&p->wddev);
573
574 /* Check that the heartbeat value is within it's range;
575 if not reset to the default */
576 if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
577 iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
578 pr_info("timeout value out of range, using %d\n",
579 WATCHDOG_TIMEOUT);
580 }
581
582 watchdog_stop_on_reboot(&p->wddev);
583 watchdog_stop_on_unregister(&p->wddev);
584 ret = devm_watchdog_register_device(dev, &p->wddev);
585 if (ret != 0) {
586 pr_err("cannot register watchdog device (err=%d)\n", ret);
587 return ret;
588 }
589
590 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
591 heartbeat, nowayout);
592
593 return 0;
594}
595
596#ifdef CONFIG_PM_SLEEP
597/*
598 * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
599 * the watchdog cannot be pinged while in that state. In ACPI sleep states the
600 * watchdog is stopped by the platform firmware.
601 */
602
603#ifdef CONFIG_ACPI
604static inline bool need_suspend(void)
605{
606 return acpi_target_system_state() == ACPI_STATE_S0;
607}
608#else
609static inline bool need_suspend(void) { return true; }
610#endif
611
612static int iTCO_wdt_suspend_noirq(struct device *dev)
613{
614 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
615 int ret = 0;
616
617 p->suspended = false;
618 if (watchdog_active(&p->wddev) && need_suspend()) {
619 ret = iTCO_wdt_stop(&p->wddev);
620 if (!ret)
621 p->suspended = true;
622 }
623 return ret;
624}
625
626static int iTCO_wdt_resume_noirq(struct device *dev)
627{
628 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
629
630 if (p->suspended)
631 iTCO_wdt_start(&p->wddev);
632
633 return 0;
634}
635
636static const struct dev_pm_ops iTCO_wdt_pm = {
637 .suspend_noirq = iTCO_wdt_suspend_noirq,
638 .resume_noirq = iTCO_wdt_resume_noirq,
639};
640
641#define ITCO_WDT_PM_OPS (&iTCO_wdt_pm)
642#else
643#define ITCO_WDT_PM_OPS NULL
644#endif /* CONFIG_PM_SLEEP */
645
646static struct platform_driver iTCO_wdt_driver = {
647 .probe = iTCO_wdt_probe,
648 .driver = {
649 .name = DRV_NAME,
650 .pm = ITCO_WDT_PM_OPS,
651 },
652};
653
654static int __init iTCO_wdt_init_module(void)
655{
656 pr_info("Intel TCO WatchDog Timer Driver v%s\n", DRV_VERSION);
657
658 return platform_driver_register(&iTCO_wdt_driver);
659}
660
661static void __exit iTCO_wdt_cleanup_module(void)
662{
663 platform_driver_unregister(&iTCO_wdt_driver);
664 pr_info("Watchdog Module Unloaded\n");
665}
666
667module_init(iTCO_wdt_init_module);
668module_exit(iTCO_wdt_cleanup_module);
669
670MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
671MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
672MODULE_VERSION(DRV_VERSION);
673MODULE_LICENSE("GPL");
674MODULE_ALIAS("platform:" DRV_NAME);
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);