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/uaccess.h> /* For copy_to_user/put_user/... */
62 #include <linux/io.h> /* For inb/outb/... */
63 #include <linux/platform_data/itco_wdt.h>
64 #include <linux/mfd/intel_pmc_bxt.h>
65
66 #include "iTCO_vendor.h"
67
68 /* Address definitions for the TCO */
69 /* TCO base address */
70 #define TCOBASE(p) ((p)->tco_res->start)
71 /* SMI Control and Enable Register */
72 #define SMI_EN(p) ((p)->smi_res->start)
73
74 #define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */
75 #define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/
76 #define TCO_DAT_IN(p) (TCOBASE(p) + 0x02) /* TCO Data In Register */
77 #define TCO_DAT_OUT(p) (TCOBASE(p) + 0x03) /* TCO Data Out Register */
78 #define TCO1_STS(p) (TCOBASE(p) + 0x04) /* TCO1 Status Register */
79 #define TCO2_STS(p) (TCOBASE(p) + 0x06) /* TCO2 Status Register */
80 #define TCO1_CNT(p) (TCOBASE(p) + 0x08) /* TCO1 Control Register */
81 #define TCO2_CNT(p) (TCOBASE(p) + 0x0a) /* TCO2 Control Register */
82 #define TCOv2_TMR(p) (TCOBASE(p) + 0x12) /* TCOv2 Timer Initial Value*/
83
84 /*
85 * NMI_NOW is bit 8 of TCO1_CNT register
86 * Read/Write
87 * This bit is implemented as RW but has no effect on HW.
88 */
89 #define NMI_NOW BIT(8)
90
91 /* internal variables */
92 struct iTCO_wdt_private {
93 struct watchdog_device wddev;
94
95 /* TCO version/generation */
96 unsigned int iTCO_version;
97 struct resource *tco_res;
98 struct resource *smi_res;
99 /*
100 * NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2),
101 * or memory-mapped PMC register bit 4 (TCO version 3).
102 */
103 unsigned long __iomem *gcs_pmc;
104 /* the PCI-device */
105 struct pci_dev *pci_dev;
106 /* whether or not the watchdog has been suspended */
107 bool suspended;
108 /* no reboot API private data */
109 void *no_reboot_priv;
110 /* no reboot update function pointer */
111 int (*update_no_reboot_bit)(void *p, bool set);
112 };
113
114 /* module parameters */
115 #define WATCHDOG_TIMEOUT 30 /* 30 sec default heartbeat */
116 static int heartbeat = WATCHDOG_TIMEOUT; /* in seconds */
117 module_param(heartbeat, int, 0);
118 MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
119 "5..76 (TCO v1) or 3..614 (TCO v2), default="
120 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
121
122 static bool nowayout = WATCHDOG_NOWAYOUT;
123 module_param(nowayout, bool, 0);
124 MODULE_PARM_DESC(nowayout,
125 "Watchdog cannot be stopped once started (default="
126 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
127
128 static int turn_SMI_watchdog_clear_off = 1;
129 module_param(turn_SMI_watchdog_clear_off, int, 0);
130 MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
131 "Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
132
133 /*
134 * Some TCO specific functions
135 */
136
137 /*
138 * The iTCO v1 and v2's internal timer is stored as ticks which decrement
139 * every 0.6 seconds. v3's internal timer is stored as seconds (some
140 * datasheets incorrectly state 0.6 seconds).
141 */
seconds_to_ticks(struct iTCO_wdt_private * p,int secs)142 static inline unsigned int seconds_to_ticks(struct iTCO_wdt_private *p,
143 int secs)
144 {
145 return p->iTCO_version == 3 ? secs : (secs * 10) / 6;
146 }
147
ticks_to_seconds(struct iTCO_wdt_private * p,int ticks)148 static inline unsigned int ticks_to_seconds(struct iTCO_wdt_private *p,
149 int ticks)
150 {
151 return p->iTCO_version == 3 ? ticks : (ticks * 6) / 10;
152 }
153
no_reboot_bit(struct iTCO_wdt_private * p)154 static inline u32 no_reboot_bit(struct iTCO_wdt_private *p)
155 {
156 u32 enable_bit;
157
158 switch (p->iTCO_version) {
159 case 5:
160 case 3:
161 enable_bit = 0x00000010;
162 break;
163 case 2:
164 enable_bit = 0x00000020;
165 break;
166 case 4:
167 case 1:
168 default:
169 enable_bit = 0x00000002;
170 break;
171 }
172
173 return enable_bit;
174 }
175
update_no_reboot_bit_def(void * priv,bool set)176 static int update_no_reboot_bit_def(void *priv, bool set)
177 {
178 return 0;
179 }
180
update_no_reboot_bit_pci(void * priv,bool set)181 static int update_no_reboot_bit_pci(void *priv, bool set)
182 {
183 struct iTCO_wdt_private *p = priv;
184 u32 val32 = 0, newval32 = 0;
185
186 pci_read_config_dword(p->pci_dev, 0xd4, &val32);
187 if (set)
188 val32 |= no_reboot_bit(p);
189 else
190 val32 &= ~no_reboot_bit(p);
191 pci_write_config_dword(p->pci_dev, 0xd4, val32);
192 pci_read_config_dword(p->pci_dev, 0xd4, &newval32);
193
194 /* make sure the update is successful */
195 if (val32 != newval32)
196 return -EIO;
197
198 return 0;
199 }
200
update_no_reboot_bit_mem(void * priv,bool set)201 static int update_no_reboot_bit_mem(void *priv, bool set)
202 {
203 struct iTCO_wdt_private *p = priv;
204 u32 val32 = 0, newval32 = 0;
205
206 val32 = readl(p->gcs_pmc);
207 if (set)
208 val32 |= no_reboot_bit(p);
209 else
210 val32 &= ~no_reboot_bit(p);
211 writel(val32, p->gcs_pmc);
212 newval32 = readl(p->gcs_pmc);
213
214 /* make sure the update is successful */
215 if (val32 != newval32)
216 return -EIO;
217
218 return 0;
219 }
220
update_no_reboot_bit_cnt(void * priv,bool set)221 static int update_no_reboot_bit_cnt(void *priv, bool set)
222 {
223 struct iTCO_wdt_private *p = priv;
224 u16 val, newval;
225
226 /*
227 * writing back 1b1 to NMI_NOW of TCO1_CNT register
228 * causes NMI_NOW bit inversion what consequently does
229 * not allow to perform the register's value comparison
230 * properly.
231 *
232 * NMI_NOW bit masking for TCO1_CNT register values
233 * helps to avoid possible NMI_NOW bit inversions on
234 * following write operation.
235 */
236 val = inw(TCO1_CNT(p)) & ~NMI_NOW;
237 if (set)
238 val |= BIT(0);
239 else
240 val &= ~BIT(0);
241 outw(val, TCO1_CNT(p));
242 newval = inw(TCO1_CNT(p)) & ~NMI_NOW;
243
244 /* make sure the update is successful */
245 return val != newval ? -EIO : 0;
246 }
247
update_no_reboot_bit_pmc(void * priv,bool set)248 static int update_no_reboot_bit_pmc(void *priv, bool set)
249 {
250 struct intel_pmc_dev *pmc = priv;
251 u32 bits = PMC_CFG_NO_REBOOT_EN;
252 u32 value = set ? bits : 0;
253
254 return intel_pmc_gcr_update(pmc, PMC_GCR_PMC_CFG_REG, bits, value);
255 }
256
iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private * p,struct platform_device * pdev,struct itco_wdt_platform_data * pdata)257 static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
258 struct platform_device *pdev,
259 struct itco_wdt_platform_data *pdata)
260 {
261 if (pdata->no_reboot_use_pmc) {
262 struct intel_pmc_dev *pmc = dev_get_drvdata(pdev->dev.parent);
263
264 p->update_no_reboot_bit = update_no_reboot_bit_pmc;
265 p->no_reboot_priv = pmc;
266 return;
267 }
268
269 if (p->iTCO_version >= 6)
270 p->update_no_reboot_bit = update_no_reboot_bit_cnt;
271 else if (p->iTCO_version >= 2)
272 p->update_no_reboot_bit = update_no_reboot_bit_mem;
273 else if (p->iTCO_version == 1)
274 p->update_no_reboot_bit = update_no_reboot_bit_pci;
275 else
276 p->update_no_reboot_bit = update_no_reboot_bit_def;
277
278 p->no_reboot_priv = p;
279 }
280
iTCO_wdt_start(struct watchdog_device * wd_dev)281 static int iTCO_wdt_start(struct watchdog_device *wd_dev)
282 {
283 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
284 unsigned int val;
285
286 iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
287
288 /* disable chipset's NO_REBOOT bit */
289 if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
290 dev_err(wd_dev->parent, "failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
291 return -EIO;
292 }
293
294 /* Force the timer to its reload value by writing to the TCO_RLD
295 register */
296 if (p->iTCO_version >= 2)
297 outw(0x01, TCO_RLD(p));
298 else if (p->iTCO_version == 1)
299 outb(0x01, TCO_RLD(p));
300
301 /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
302 val = inw(TCO1_CNT(p));
303 val &= 0xf7ff;
304 outw(val, TCO1_CNT(p));
305 val = inw(TCO1_CNT(p));
306
307 if (val & 0x0800)
308 return -1;
309 return 0;
310 }
311
iTCO_wdt_stop(struct watchdog_device * wd_dev)312 static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
313 {
314 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
315 unsigned int val;
316
317 iTCO_vendor_pre_stop(p->smi_res);
318
319 /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
320 val = inw(TCO1_CNT(p));
321 val |= 0x0800;
322 outw(val, TCO1_CNT(p));
323 val = inw(TCO1_CNT(p));
324
325 /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
326 p->update_no_reboot_bit(p->no_reboot_priv, true);
327
328 if ((val & 0x0800) == 0)
329 return -1;
330 return 0;
331 }
332
iTCO_wdt_ping(struct watchdog_device * wd_dev)333 static int iTCO_wdt_ping(struct watchdog_device *wd_dev)
334 {
335 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
336
337 /* Reload the timer by writing to the TCO Timer Counter register */
338 if (p->iTCO_version >= 2) {
339 outw(0x01, TCO_RLD(p));
340 } else if (p->iTCO_version == 1) {
341 /* Reset the timeout status bit so that the timer
342 * needs to count down twice again before rebooting */
343 outw(0x0008, TCO1_STS(p)); /* write 1 to clear bit */
344
345 outb(0x01, TCO_RLD(p));
346 }
347
348 return 0;
349 }
350
iTCO_wdt_set_timeout(struct watchdog_device * wd_dev,unsigned int t)351 static 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 val16 = inw(TCOv2_TMR(p));
375 val16 &= 0xfc00;
376 val16 |= tmrval;
377 outw(val16, TCOv2_TMR(p));
378 val16 = inw(TCOv2_TMR(p));
379
380 if ((val16 & 0x3ff) != tmrval)
381 return -EINVAL;
382 } else if (p->iTCO_version == 1) {
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
389 if ((val8 & 0x3f) != tmrval)
390 return -EINVAL;
391 }
392
393 wd_dev->timeout = t;
394 return 0;
395 }
396
iTCO_wdt_get_timeleft(struct watchdog_device * wd_dev)397 static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev)
398 {
399 struct iTCO_wdt_private *p = watchdog_get_drvdata(wd_dev);
400 unsigned int val16;
401 unsigned char val8;
402 unsigned int time_left = 0;
403
404 /* read the TCO Timer */
405 if (p->iTCO_version >= 2) {
406 val16 = inw(TCO_RLD(p));
407 val16 &= 0x3ff;
408
409 time_left = ticks_to_seconds(p, val16);
410 } else if (p->iTCO_version == 1) {
411 val8 = inb(TCO_RLD(p));
412 val8 &= 0x3f;
413 if (!(inw(TCO1_STS(p)) & 0x0008))
414 val8 += (inb(TCOv1_TMR(p)) & 0x3f);
415
416 time_left = ticks_to_seconds(p, val8);
417 }
418 return time_left;
419 }
420
421 /* Returns true if the watchdog was running */
iTCO_wdt_set_running(struct iTCO_wdt_private * p)422 static bool iTCO_wdt_set_running(struct iTCO_wdt_private *p)
423 {
424 u16 val;
425
426 /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled */
427 val = inw(TCO1_CNT(p));
428 if (!(val & BIT(11))) {
429 set_bit(WDOG_HW_RUNNING, &p->wddev.status);
430 return true;
431 }
432 return false;
433 }
434
435 /*
436 * Kernel Interfaces
437 */
438
439 static struct watchdog_info ident = {
440 .options = WDIOF_SETTIMEOUT |
441 WDIOF_KEEPALIVEPING |
442 WDIOF_MAGICCLOSE,
443 .identity = DRV_NAME,
444 };
445
446 static const struct watchdog_ops iTCO_wdt_ops = {
447 .owner = THIS_MODULE,
448 .start = iTCO_wdt_start,
449 .stop = iTCO_wdt_stop,
450 .ping = iTCO_wdt_ping,
451 .set_timeout = iTCO_wdt_set_timeout,
452 .get_timeleft = iTCO_wdt_get_timeleft,
453 };
454
455 /*
456 * Init & exit routines
457 */
458
iTCO_wdt_probe(struct platform_device * pdev)459 static int iTCO_wdt_probe(struct platform_device *pdev)
460 {
461 struct device *dev = &pdev->dev;
462 struct itco_wdt_platform_data *pdata = dev_get_platdata(dev);
463 struct iTCO_wdt_private *p;
464 unsigned long val32;
465 int ret;
466
467 if (!pdata)
468 return -ENODEV;
469
470 p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
471 if (!p)
472 return -ENOMEM;
473
474 p->tco_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_TCO);
475 if (!p->tco_res)
476 return -ENODEV;
477
478 p->iTCO_version = pdata->version;
479 p->pci_dev = to_pci_dev(dev->parent);
480
481 p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
482 if (p->smi_res) {
483 /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
484 if (!devm_request_region(dev, p->smi_res->start,
485 resource_size(p->smi_res),
486 pdev->name)) {
487 dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
488 (u64)SMI_EN(p));
489 return -EBUSY;
490 }
491 } else if (iTCO_vendorsupport ||
492 turn_SMI_watchdog_clear_off >= p->iTCO_version) {
493 dev_err(dev, "SMI I/O resource is missing\n");
494 return -ENODEV;
495 }
496
497 iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
498
499 /*
500 * Get the Memory-Mapped GCS or PMC register, we need it for the
501 * NO_REBOOT flag (TCO v2 and v3).
502 */
503 if (p->iTCO_version >= 2 && p->iTCO_version < 6 &&
504 !pdata->no_reboot_use_pmc) {
505 p->gcs_pmc = devm_platform_ioremap_resource(pdev, ICH_RES_MEM_GCS_PMC);
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 dev_info(dev, "unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
514 return -ENODEV; /* Cannot reset NO_REBOOT bit */
515 }
516
517 if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
518 /*
519 * Bit 13: TCO_EN -> 0
520 * Disables TCO logic generating an SMI#
521 */
522 val32 = inl(SMI_EN(p));
523 val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
524 outl(val32, SMI_EN(p));
525 }
526
527 if (!devm_request_region(dev, p->tco_res->start,
528 resource_size(p->tco_res),
529 pdev->name)) {
530 dev_err(dev, "I/O address 0x%04llx already in use, device disabled\n",
531 (u64)TCOBASE(p));
532 return -EBUSY;
533 }
534
535 dev_info(dev, "Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
536 pdata->name, pdata->version, (u64)TCOBASE(p));
537
538 /* Clear out the (probably old) status */
539 switch (p->iTCO_version) {
540 case 6:
541 case 5:
542 case 4:
543 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
544 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
545 break;
546 case 3:
547 outl(0x20008, TCO1_STS(p));
548 break;
549 case 2:
550 case 1:
551 default:
552 outw(0x0008, TCO1_STS(p)); /* Clear the Time Out Status bit */
553 outw(0x0002, TCO2_STS(p)); /* Clear SECOND_TO_STS bit */
554 outw(0x0004, TCO2_STS(p)); /* Clear BOOT_STS bit */
555 break;
556 }
557
558 ident.firmware_version = p->iTCO_version;
559 p->wddev.info = &ident;
560 p->wddev.ops = &iTCO_wdt_ops;
561 p->wddev.bootstatus = 0;
562 p->wddev.timeout = WATCHDOG_TIMEOUT;
563 watchdog_set_nowayout(&p->wddev, nowayout);
564 p->wddev.parent = dev;
565
566 watchdog_set_drvdata(&p->wddev, p);
567 platform_set_drvdata(pdev, p);
568
569 if (!iTCO_wdt_set_running(p)) {
570 /*
571 * If the watchdog was not running set NO_REBOOT now to
572 * prevent later reboots.
573 */
574 p->update_no_reboot_bit(p->no_reboot_priv, true);
575 }
576
577 /* Check that the heartbeat value is within it's range;
578 if not reset to the default */
579 if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
580 iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
581 dev_info(dev, "timeout value out of range, using %d\n",
582 WATCHDOG_TIMEOUT);
583 heartbeat = WATCHDOG_TIMEOUT;
584 }
585
586 watchdog_stop_on_reboot(&p->wddev);
587 watchdog_stop_on_unregister(&p->wddev);
588 ret = devm_watchdog_register_device(dev, &p->wddev);
589 if (ret != 0)
590 return ret;
591
592 dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
593 heartbeat, nowayout);
594
595 return 0;
596 }
597
598 /*
599 * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so
600 * the watchdog cannot be pinged while in that state. In ACPI sleep states the
601 * watchdog is stopped by the platform firmware.
602 */
603
604 #ifdef CONFIG_ACPI
need_suspend(void)605 static inline bool __maybe_unused need_suspend(void)
606 {
607 return acpi_target_system_state() == ACPI_STATE_S0;
608 }
609 #else
need_suspend(void)610 static inline bool __maybe_unused need_suspend(void) { return true; }
611 #endif
612
iTCO_wdt_suspend_noirq(struct device * dev)613 static int __maybe_unused iTCO_wdt_suspend_noirq(struct device *dev)
614 {
615 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
616 int ret = 0;
617
618 p->suspended = false;
619 if (watchdog_active(&p->wddev) && need_suspend()) {
620 ret = iTCO_wdt_stop(&p->wddev);
621 if (!ret)
622 p->suspended = true;
623 }
624 return ret;
625 }
626
iTCO_wdt_resume_noirq(struct device * dev)627 static int __maybe_unused iTCO_wdt_resume_noirq(struct device *dev)
628 {
629 struct iTCO_wdt_private *p = dev_get_drvdata(dev);
630
631 if (p->suspended)
632 iTCO_wdt_start(&p->wddev);
633
634 return 0;
635 }
636
637 static const struct dev_pm_ops iTCO_wdt_pm = {
638 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(iTCO_wdt_suspend_noirq,
639 iTCO_wdt_resume_noirq)
640 };
641
642 static struct platform_driver iTCO_wdt_driver = {
643 .probe = iTCO_wdt_probe,
644 .driver = {
645 .name = DRV_NAME,
646 .pm = &iTCO_wdt_pm,
647 },
648 };
649
650 module_platform_driver(iTCO_wdt_driver);
651
652 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
653 MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
654 MODULE_VERSION(DRV_VERSION);
655 MODULE_LICENSE("GPL");
656 MODULE_ALIAS("platform:" DRV_NAME);
657