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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/*
86 * NMI_NOW is bit 8 of TCO1_CNT register
87 * Read/Write
88 * This bit is implemented as RW but has no effect on HW.
89 */
90#define NMI_NOW BIT(8)
91
92/* internal variables */
93struct iTCO_wdt_private {
94 struct watchdog_device wddev;
95
96 /* TCO version/generation */
97 unsigned int iTCO_version;
98 struct resource *tco_res;
99 struct resource *smi_res;
100 /*
101 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
102 * or memory-mapped PMC register bit 4 (TCO version 3).
103 */
104 unsigned long __iomem *gcs_pmc;
105 /* the lock for io operations */
106 spinlock_t io_lock;
107 /* the PCI-device */
108 struct pci_dev *pci_dev;
109 /* whether or not the watchdog has been suspended */
110 bool suspended;
111 /* no reboot API private data */
112 void *no_reboot_priv;
113 /* no reboot update function pointer */
114 int (*update_no_reboot_bit)(void *p, bool set);
115};
116
117/* module parameters */
118#define WATCHDOG_TIMEOUT 30 /* 30 sec default heartbeat */
119static int heartbeat = WATCHDOG_TIMEOUT; /* in seconds */
120module_param(heartbeat, int, 0);
121MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
122 "5..76 (TCO v1) or 3..614 (TCO v2), default="
123 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
124
125static bool nowayout = WATCHDOG_NOWAYOUT;
126module_param(nowayout, bool, 0);
127MODULE_PARM_DESC(nowayout,
128 "Watchdog cannot be stopped once started (default="
129 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
130
131static int turn_SMI_watchdog_clear_off = 1;
132module_param(turn_SMI_watchdog_clear_off, int, 0);
133MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
134 "Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
135
136/*
137 * Some TCO specific functions
138 */
139
140/*
141 * The iTCO v1 and v2's internal timer is stored as ticks which decrement
142 * every 0.6 seconds. v3's internal timer is stored as seconds (some
143 * datasheets incorrectly state 0.6 seconds).
144 */
145static inline unsigned int seconds_to_ticks(struct iTCO_wdt_private *p,
146 int secs)
147{
148 return p->iTCO_version == 3 ? secs : (secs * 10) / 6;
149}
150
151static inline unsigned int ticks_to_seconds(struct iTCO_wdt_private *p,
152 int ticks)
153{
154 return p->iTCO_version == 3 ? ticks : (ticks * 6) / 10;
155}
156
157static inline u32 no_reboot_bit(struct iTCO_wdt_private *p)
158{
159 u32 enable_bit;
160
161 switch (p->iTCO_version) {
162 case 5:
163 case 3:
164 enable_bit = 0x00000010;
165 break;
166 case 2:
167 enable_bit = 0x00000020;
168 break;
169 case 4:
170 case 1:
171 default:
172 enable_bit = 0x00000002;
173 break;
174 }
175
176 return enable_bit;
177}
178
179static int update_no_reboot_bit_def(void *priv, bool set)
180{
181 return 0;
182}
183
184static int update_no_reboot_bit_pci(void *priv, bool set)
185{
186 struct iTCO_wdt_private *p = priv;
187 u32 val32 = 0, newval32 = 0;
188
189 pci_read_config_dword(p->pci_dev, 0xd4, &val32);
190 if (set)
191 val32 |= no_reboot_bit(p);
192 else
193 val32 &= ~no_reboot_bit(p);
194 pci_write_config_dword(p->pci_dev, 0xd4, val32);
195 pci_read_config_dword(p->pci_dev, 0xd4, &newval32);
196
197 /* make sure the update is successful */
198 if (val32 != newval32)
199 return -EIO;
200
201 return 0;
202}
203
204static int update_no_reboot_bit_mem(void *priv, bool set)
205{
206 struct iTCO_wdt_private *p = priv;
207 u32 val32 = 0, newval32 = 0;
208
209 val32 = readl(p->gcs_pmc);
210 if (set)
211 val32 |= no_reboot_bit(p);
212 else
213 val32 &= ~no_reboot_bit(p);
214 writel(val32, p->gcs_pmc);
215 newval32 = readl(p->gcs_pmc);
216
217 /* make sure the update is successful */
218 if (val32 != newval32)
219 return -EIO;
220
221 return 0;
222}
223
224static int update_no_reboot_bit_cnt(void *priv, bool set)
225{
226 struct iTCO_wdt_private *p = priv;
227 u16 val, newval;
228
229 /*
230 * writing back 1b1 to NMI_NOW of TCO1_CNT register
231 * causes NMI_NOW bit inversion what consequently does
232 * not allow to perform the register's value comparison
233 * properly.
234 *
235 * NMI_NOW bit masking for TCO1_CNT register values
236 * helps to avoid possible NMI_NOW bit inversions on
237 * following write operation.
238 */
239 val = inw(TCO1_CNT(p)) & ~NMI_NOW;
240 if (set)
241 val |= BIT(0);
242 else
243 val &= ~BIT(0);
244 outw(val, TCO1_CNT(p));
245 newval = inw(TCO1_CNT(p)) & ~NMI_NOW;
246
247 /* make sure the update is successful */
248 return val != newval ? -EIO : 0;
249}
250
251static int update_no_reboot_bit_pmc(void *priv, bool set)
252{
253 struct intel_pmc_dev *pmc = priv;
254 u32 bits = PMC_CFG_NO_REBOOT_EN;
255 u32 value = set ? bits : 0;
256
257 return intel_pmc_gcr_update(pmc, PMC_GCR_PMC_CFG_REG, bits, value);
258}
259
260static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
261 struct platform_device *pdev,
262 struct itco_wdt_platform_data *pdata)
263{
264 if (pdata->no_reboot_use_pmc) {
265 struct intel_pmc_dev *pmc = dev_get_drvdata(pdev->dev.parent);
266
267 p->update_no_reboot_bit = update_no_reboot_bit_pmc;
268 p->no_reboot_priv = pmc;
269 return;
270 }
271
272 if (p->iTCO_version >= 6)
273 p->update_no_reboot_bit = update_no_reboot_bit_cnt;
274 else if (p->iTCO_version >= 2)
275 p->update_no_reboot_bit = update_no_reboot_bit_mem;
276 else if (p->iTCO_version == 1)
277 p->update_no_reboot_bit = update_no_reboot_bit_pci;
278 else
279 p->update_no_reboot_bit = update_no_reboot_bit_def;
280
281 p->no_reboot_priv = p;
282}
283
284static int iTCO_wdt_start(struct watchdog_device *wd_dev)
285{
286 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
287 unsigned int val;
288
289 spin_lock(&p->io_lock);
290
291 iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
292
293 /* disable chipset's NO_REBOOT bit */
294 if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
295 spin_unlock(&p->io_lock);
296 dev_err(wd_dev->parent, "failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
297 return -EIO;
298 }
299
300 /* Force the timer to its reload value by writing to the TCO_RLD
301 register */
302 if (p->iTCO_version >= 2)
303 outw(0x01, TCO_RLD(p));
304 else if (p->iTCO_version == 1)
305 outb(0x01, TCO_RLD(p));
306
307 /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
308 val = inw(TCO1_CNT(p));
309 val &= 0xf7ff;
310 outw(val, TCO1_CNT(p));
311 val = inw(TCO1_CNT(p));
312 spin_unlock(&p->io_lock);
313
314 if (val & 0x0800)
315 return -1;
316 return 0;
317}
318
319static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
320{
321 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
322 unsigned int val;
323
324 spin_lock(&p->io_lock);
325
326 iTCO_vendor_pre_stop(p->smi_res);
327
328 /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
329 val = inw(TCO1_CNT(p));
330 val |= 0x0800;
331 outw(val, TCO1_CNT(p));
332 val = inw(TCO1_CNT(p));
333
334 /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
335 p->update_no_reboot_bit(p->no_reboot_priv, true);
336
337 spin_unlock(&p->io_lock);
338
339 if ((val & 0x0800) == 0)
340 return -1;
341 return 0;
342}
343
344static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
345{
346 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
347
348 spin_lock(&p->io_lock);
349
350 /* Reload the timer by writing to the TCO Timer Counter register */
351 if (p->iTCO_version >= 2) {
352 outw(0x01, TCO_RLD(p));
353 } else if (p->iTCO_version == 1) {
354 /* Reset the timeout status bit so that the timer
355 * needs to count down twice again before rebooting */
356 outw(0x0008, TCO1_STS(p)); /* write 1 to clear bit */
357
358 outb(0x01, TCO_RLD(p));
359 }
360
361 spin_unlock(&p->io_lock);
362 return 0;
363}
364
365static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
366{
367 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
368 unsigned int val16;
369 unsigned char val8;
370 unsigned int tmrval;
371
372 tmrval = seconds_to_ticks(p, t);
373
374 /* For TCO v1 the timer counts down twice before rebooting */
375 if (p->iTCO_version == 1)
376 tmrval /= 2;
377
378 /* from the specs: */
379 /* "Values of 0h-3h are ignored and should not be attempted" */
380 if (tmrval < 0x04)
381 return -EINVAL;
382 if ((p->iTCO_version >= 2 && tmrval > 0x3ff) ||
383 (p->iTCO_version == 1 && tmrval > 0x03f))
384 return -EINVAL;
385
386 /* Write new heartbeat to watchdog */
387 if (p->iTCO_version >= 2) {
388 spin_lock(&p->io_lock);
389 val16 = inw(TCOv2_TMR(p));
390 val16 &= 0xfc00;
391 val16 |= tmrval;
392 outw(val16, TCOv2_TMR(p));
393 val16 = inw(TCOv2_TMR(p));
394 spin_unlock(&p->io_lock);
395
396 if ((val16 & 0x3ff) != tmrval)
397 return -EINVAL;
398 } else if (p->iTCO_version == 1) {
399 spin_lock(&p->io_lock);
400 val8 = inb(TCOv1_TMR(p));
401 val8 &= 0xc0;
402 val8 |= (tmrval & 0xff);
403 outb(val8, TCOv1_TMR(p));
404 val8 = inb(TCOv1_TMR(p));
405 spin_unlock(&p->io_lock);
406
407 if ((val8 & 0x3f) != tmrval)
408 return -EINVAL;
409 }
410
411 wd_dev->timeout = t;
412 return 0;
413}
414
415static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
416{
417 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
418 unsigned int val16;
419 unsigned char val8;
420 unsigned int time_left = 0;
421
422 /* read the TCO Timer */
423 if (p->iTCO_version >= 2) {
424 spin_lock(&p->io_lock);
425 val16 = inw(TCO_RLD(p));
426 val16 &= 0x3ff;
427 spin_unlock(&p->io_lock);
428
429 time_left = ticks_to_seconds(p, val16);
430 } else if (p->iTCO_version == 1) {
431 spin_lock(&p->io_lock);
432 val8 = inb(TCO_RLD(p));
433 val8 &= 0x3f;
434 if (!(inw(TCO1_STS(p)) & 0x0008))
435 val8 += (inb(TCOv1_TMR(p)) & 0x3f);
436 spin_unlock(&p->io_lock);
437
438 time_left = ticks_to_seconds(p, val8);
439 }
440 return time_left;
441}
442
443/* Returns true if the watchdog was running */
444static bool iTCO_wdt_set_running(struct iTCO_wdt_private *p)
445{
446 u16 val;
447
448 /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled */
449 val = inw(TCO1_CNT(p));
450 if (!(val & BIT(11))) {
451 set_bit(WDOG_HW_RUNNING, &p->wddev.status);
452 return true;
453 }
454 return false;
455}
456
457/*
458 * Kernel Interfaces
459 */
460
461static struct watchdog_info ident = {
462 .options = WDIOF_SETTIMEOUT |
463 WDIOF_KEEPALIVEPING |
464 WDIOF_MAGICCLOSE,
465 .identity = DRV_NAME,
466};
467
468static const struct watchdog_ops iTCO_wdt_ops = {
469 .owner = THIS_MODULE,
470 .start = iTCO_wdt_start,
471 .stop = iTCO_wdt_stop,
472 .ping = iTCO_wdt_ping,
473 .set_timeout = iTCO_wdt_set_timeout,
474 .get_timeleft = iTCO_wdt_get_timeleft,
475};
476
477/*
478 * Init & exit routines
479 */
480
481static int iTCO_wdt_probe(struct platform_device *pdev)
482{
483 struct device *dev = &pdev->dev;
484 struct itco_wdt_platform_data *pdata = dev_get_platdata(dev);
485 struct iTCO_wdt_private *p;
486 unsigned long val32;
487 int ret;
488
489 if (!pdata)
490 return -ENODEV;
491
492 p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
493 if (!p)
494 return -ENOMEM;
495
496 spin_lock_init(&p->io_lock);
497
498 p->tco_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_TCO);
499 if (!p->tco_res)
500 return -ENODEV;
501
502 p->iTCO_version = pdata->version;
503 p->pci_dev = to_pci_dev(dev->parent);
504
505 p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
506 if (p->smi_res) {
507 /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
508 if (!devm_request_region(dev, p->smi_res->start,
509 resource_size(p->smi_res),
510 pdev->name)) {
511 dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
512 (u64)SMI_EN(p));
513 return -EBUSY;
514 }
515 } else if (iTCO_vendorsupport ||
516 turn_SMI_watchdog_clear_off >= p->iTCO_version) {
517 dev_err(dev, "SMI I/O resource is missing\n");
518 return -ENODEV;
519 }
520
521 iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
522
523 /*
524 * Get the Memory-Mapped GCS or PMC register, we need it for the
525 * NO_REBOOT flag (TCO v2 and v3).
526 */
527 if (p->iTCO_version >= 2 && p->iTCO_version < 6 &&
528 !pdata->no_reboot_use_pmc) {
529 p->gcs_pmc = devm_platform_ioremap_resource(pdev, ICH_RES_MEM_GCS_PMC);
530 if (IS_ERR(p->gcs_pmc))
531 return PTR_ERR(p->gcs_pmc);
532 }
533
534 /* Check chipset's NO_REBOOT bit */
535 if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
536 iTCO_vendor_check_noreboot_on()) {
537 dev_info(dev, "unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
538 return -ENODEV; /* Cannot reset NO_REBOOT bit */
539 }
540
541 if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
542 /*
543 * Bit 13: TCO_EN -> 0
544 * Disables TCO logic generating an SMI#
545 */
546 val32 = inl(SMI_EN(p));
547 val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
548 outl(val32, SMI_EN(p));
549 }
550
551 if (!devm_request_region(dev, p->tco_res->start,
552 resource_size(p->tco_res),
553 pdev->name)) {
554 dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
555 (u64)TCOBASE(p));
556 return -EBUSY;
557 }
558
559 dev_info(dev, "Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
560 pdata->name, pdata->version, (u64)TCOBASE(p));
561
562 /* Clear out the (probably old) status */
563 switch (p->iTCO_version) {
564 case 6:
565 case 5:
566 case 4:
567 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
568 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
569 break;
570 case 3:
571 outl(0x20008, TCO1_STS(p));
572 break;
573 case 2:
574 case 1:
575 default:
576 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
577 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
578 outw(0x0004, TCO2_STS(p)); /* Clear BOOT_STS bit */
579 break;
580 }
581
582 ident.firmware_version = p->iTCO_version;
583 p->wddev.info = &ident;
584 p->wddev.ops = &iTCO_wdt_ops;
585 p->wddev.bootstatus = 0;
586 p->wddev.timeout = WATCHDOG_TIMEOUT;
587 watchdog_set_nowayout(&p->wddev, nowayout);
588 p->wddev.parent = dev;
589
590 watchdog_set_drvdata(&p->wddev, p);
591 platform_set_drvdata(pdev, p);
592
593 if (!iTCO_wdt_set_running(p)) {
594 /*
595 * If the watchdog was not running set NO_REBOOT now to
596 * prevent later reboots.
597 */
598 p->update_no_reboot_bit(p->no_reboot_priv, true);
599 }
600
601 /* Check that the heartbeat value is within it's range;
602 if not reset to the default */
603 if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
604 iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
605 dev_info(dev, "timeout value out of range, using %d\n",
606 WATCHDOG_TIMEOUT);
607 }
608
609 watchdog_stop_on_reboot(&p->wddev);
610 watchdog_stop_on_unregister(&p->wddev);
611 ret = devm_watchdog_register_device(dev, &p->wddev);
612 if (ret != 0)
613 return ret;
614
615 dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
616 heartbeat, nowayout);
617
618 return 0;
619}
620
621/*
622 * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
623 * the watchdog cannot be pinged while in that state. In ACPI sleep states the
624 * watchdog is stopped by the platform firmware.
625 */
626
627#ifdef CONFIG_ACPI
628static inline bool __maybe_unused need_suspend(void)
629{
630 return acpi_target_system_state() == ACPI_STATE_S0;
631}
632#else
633static inline bool __maybe_unused need_suspend(void) { return true; }
634#endif
635
636static int __maybe_unused iTCO_wdt_suspend_noirq(struct device *dev)
637{
638 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
639 int ret = 0;
640
641 p->suspended = false;
642 if (watchdog_active(&p->wddev) && need_suspend()) {
643 ret = iTCO_wdt_stop(&p->wddev);
644 if (!ret)
645 p->suspended = true;
646 }
647 return ret;
648}
649
650static int __maybe_unused iTCO_wdt_resume_noirq(struct device *dev)
651{
652 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
653
654 if (p->suspended)
655 iTCO_wdt_start(&p->wddev);
656
657 return 0;
658}
659
660static const struct dev_pm_ops iTCO_wdt_pm = {
661 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(iTCO_wdt_suspend_noirq,
662 iTCO_wdt_resume_noirq)
663};
664
665static struct platform_driver iTCO_wdt_driver = {
666 .probe = iTCO_wdt_probe,
667 .driver = {
668 .name = DRV_NAME,
669 .pm = &iTCO_wdt_pm,
670 },
671};
672
673module_platform_driver(iTCO_wdt_driver);
674
675MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
676MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
677MODULE_VERSION(DRV_VERSION);
678MODULE_LICENSE("GPL");
679MODULE_ALIAS("platform:" DRV_NAME);