xref: /linux/drivers/acpi/thermal.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  *
8  *  This driver fully implements the ACPI thermal policy as described in the
9  *  ACPI 2.0 Specification.
10  *
11  *  TBD: 1. Implement passive cooling hysteresis.
12  *       2. Enhance passive cooling (CPU) states/limit interface to support
13  *          concepts of 'multiple limiters', upper/lower limits, etc.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/dmi.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
21 #include <linux/types.h>
22 #include <linux/jiffies.h>
23 #include <linux/kmod.h>
24 #include <linux/reboot.h>
25 #include <linux/device.h>
26 #include <linux/thermal.h>
27 #include <linux/acpi.h>
28 #include <linux/workqueue.h>
29 #include <linux/uaccess.h>
30 #include <linux/units.h>
31 
32 #define PREFIX "ACPI: "
33 
34 #define ACPI_THERMAL_CLASS		"thermal_zone"
35 #define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
36 #define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
37 #define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
38 #define ACPI_THERMAL_NOTIFY_DEVICES	0x82
39 #define ACPI_THERMAL_NOTIFY_CRITICAL	0xF0
40 #define ACPI_THERMAL_NOTIFY_HOT		0xF1
41 #define ACPI_THERMAL_MODE_ACTIVE	0x00
42 
43 #define ACPI_THERMAL_MAX_ACTIVE	10
44 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
45 
46 #define _COMPONENT		ACPI_THERMAL_COMPONENT
47 ACPI_MODULE_NAME("thermal");
48 
49 MODULE_AUTHOR("Paul Diefenbaugh");
50 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
51 MODULE_LICENSE("GPL");
52 
53 static int act;
54 module_param(act, int, 0644);
55 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
56 
57 static int crt;
58 module_param(crt, int, 0644);
59 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
60 
61 static int tzp;
62 module_param(tzp, int, 0444);
63 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
64 
65 static int nocrt;
66 module_param(nocrt, int, 0);
67 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
68 
69 static int off;
70 module_param(off, int, 0);
71 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
72 
73 static int psv;
74 module_param(psv, int, 0644);
75 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
76 
77 static struct workqueue_struct *acpi_thermal_pm_queue;
78 
79 static int acpi_thermal_add(struct acpi_device *device);
80 static int acpi_thermal_remove(struct acpi_device *device);
81 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
82 
83 static const struct acpi_device_id  thermal_device_ids[] = {
84 	{ACPI_THERMAL_HID, 0},
85 	{"", 0},
86 };
87 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
88 
89 #ifdef CONFIG_PM_SLEEP
90 static int acpi_thermal_suspend(struct device *dev);
91 static int acpi_thermal_resume(struct device *dev);
92 #else
93 #define acpi_thermal_suspend NULL
94 #define acpi_thermal_resume NULL
95 #endif
96 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
97 
98 static struct acpi_driver acpi_thermal_driver = {
99 	.name = "thermal",
100 	.class = ACPI_THERMAL_CLASS,
101 	.ids = thermal_device_ids,
102 	.ops = {
103 		.add = acpi_thermal_add,
104 		.remove = acpi_thermal_remove,
105 		.notify = acpi_thermal_notify,
106 		},
107 	.drv.pm = &acpi_thermal_pm,
108 };
109 
110 struct acpi_thermal_state {
111 	u8 critical:1;
112 	u8 hot:1;
113 	u8 passive:1;
114 	u8 active:1;
115 	u8 reserved:4;
116 	int active_index;
117 };
118 
119 struct acpi_thermal_state_flags {
120 	u8 valid:1;
121 	u8 enabled:1;
122 	u8 reserved:6;
123 };
124 
125 struct acpi_thermal_critical {
126 	struct acpi_thermal_state_flags flags;
127 	unsigned long temperature;
128 };
129 
130 struct acpi_thermal_hot {
131 	struct acpi_thermal_state_flags flags;
132 	unsigned long temperature;
133 };
134 
135 struct acpi_thermal_passive {
136 	struct acpi_thermal_state_flags flags;
137 	unsigned long temperature;
138 	unsigned long tc1;
139 	unsigned long tc2;
140 	unsigned long tsp;
141 	struct acpi_handle_list devices;
142 };
143 
144 struct acpi_thermal_active {
145 	struct acpi_thermal_state_flags flags;
146 	unsigned long temperature;
147 	struct acpi_handle_list devices;
148 };
149 
150 struct acpi_thermal_trips {
151 	struct acpi_thermal_critical critical;
152 	struct acpi_thermal_hot hot;
153 	struct acpi_thermal_passive passive;
154 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
155 };
156 
157 struct acpi_thermal_flags {
158 	u8 cooling_mode:1;	/* _SCP */
159 	u8 devices:1;		/* _TZD */
160 	u8 reserved:6;
161 };
162 
163 struct acpi_thermal {
164 	struct acpi_device * device;
165 	acpi_bus_id name;
166 	unsigned long temperature;
167 	unsigned long last_temperature;
168 	unsigned long polling_frequency;
169 	volatile u8 zombie;
170 	struct acpi_thermal_flags flags;
171 	struct acpi_thermal_state state;
172 	struct acpi_thermal_trips trips;
173 	struct acpi_handle_list devices;
174 	struct thermal_zone_device *thermal_zone;
175 	int tz_enabled;
176 	int kelvin_offset;	/* in millidegrees */
177 	struct work_struct thermal_check_work;
178 };
179 
180 /* --------------------------------------------------------------------------
181                              Thermal Zone Management
182    -------------------------------------------------------------------------- */
183 
184 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
185 {
186 	acpi_status status = AE_OK;
187 	unsigned long long tmp;
188 
189 	if (!tz)
190 		return -EINVAL;
191 
192 	tz->last_temperature = tz->temperature;
193 
194 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
195 	if (ACPI_FAILURE(status))
196 		return -ENODEV;
197 
198 	tz->temperature = tmp;
199 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
200 			  tz->temperature));
201 
202 	return 0;
203 }
204 
205 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
206 {
207 	acpi_status status = AE_OK;
208 	unsigned long long tmp;
209 
210 	if (!tz)
211 		return -EINVAL;
212 
213 	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
214 	if (ACPI_FAILURE(status))
215 		return -ENODEV;
216 
217 	tz->polling_frequency = tmp;
218 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
219 			  tz->polling_frequency));
220 
221 	return 0;
222 }
223 
224 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
225 {
226 	if (!tz)
227 		return -EINVAL;
228 
229 	if (ACPI_FAILURE(acpi_execute_simple_method(tz->device->handle,
230 						    "_SCP", mode)))
231 		return -ENODEV;
232 
233 	return 0;
234 }
235 
236 #define ACPI_TRIPS_CRITICAL	0x01
237 #define ACPI_TRIPS_HOT		0x02
238 #define ACPI_TRIPS_PASSIVE	0x04
239 #define ACPI_TRIPS_ACTIVE	0x08
240 #define ACPI_TRIPS_DEVICES	0x10
241 
242 #define ACPI_TRIPS_REFRESH_THRESHOLDS	(ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
243 #define ACPI_TRIPS_REFRESH_DEVICES	ACPI_TRIPS_DEVICES
244 
245 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |	\
246 			      ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |	\
247 			      ACPI_TRIPS_DEVICES)
248 
249 /*
250  * This exception is thrown out in two cases:
251  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
252  *   when re-evaluating the AML code.
253  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
254  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
255  */
256 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)	\
257 do {	\
258 	if (flags != ACPI_TRIPS_INIT)	\
259 		ACPI_EXCEPTION((AE_INFO, AE_ERROR,	\
260 		"ACPI thermal trip point %s changed\n"	\
261 		"Please send acpidump to linux-acpi@vger.kernel.org", str)); \
262 } while (0)
263 
264 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
265 {
266 	acpi_status status = AE_OK;
267 	unsigned long long tmp;
268 	struct acpi_handle_list devices;
269 	int valid = 0;
270 	int i;
271 
272 	/* Critical Shutdown */
273 	if (flag & ACPI_TRIPS_CRITICAL) {
274 		status = acpi_evaluate_integer(tz->device->handle,
275 				"_CRT", NULL, &tmp);
276 		tz->trips.critical.temperature = tmp;
277 		/*
278 		 * Treat freezing temperatures as invalid as well; some
279 		 * BIOSes return really low values and cause reboots at startup.
280 		 * Below zero (Celsius) values clearly aren't right for sure..
281 		 * ... so lets discard those as invalid.
282 		 */
283 		if (ACPI_FAILURE(status)) {
284 			tz->trips.critical.flags.valid = 0;
285 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
286 					  "No critical threshold\n"));
287 		} else if (tmp <= 2732) {
288 			pr_warn(FW_BUG "Invalid critical threshold (%llu)\n",
289 				tmp);
290 			tz->trips.critical.flags.valid = 0;
291 		} else {
292 			tz->trips.critical.flags.valid = 1;
293 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
294 					  "Found critical threshold [%lu]\n",
295 					  tz->trips.critical.temperature));
296 		}
297 		if (tz->trips.critical.flags.valid == 1) {
298 			if (crt == -1) {
299 				tz->trips.critical.flags.valid = 0;
300 			} else if (crt > 0) {
301 				unsigned long crt_k = celsius_to_deci_kelvin(crt);
302 
303 				/*
304 				 * Allow override critical threshold
305 				 */
306 				if (crt_k > tz->trips.critical.temperature)
307 					pr_warn(PREFIX "Critical threshold %d C\n",
308 						crt);
309 				tz->trips.critical.temperature = crt_k;
310 			}
311 		}
312 	}
313 
314 	/* Critical Sleep (optional) */
315 	if (flag & ACPI_TRIPS_HOT) {
316 		status = acpi_evaluate_integer(tz->device->handle,
317 				"_HOT", NULL, &tmp);
318 		if (ACPI_FAILURE(status)) {
319 			tz->trips.hot.flags.valid = 0;
320 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
321 					"No hot threshold\n"));
322 		} else {
323 			tz->trips.hot.temperature = tmp;
324 			tz->trips.hot.flags.valid = 1;
325 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
326 					"Found hot threshold [%lu]\n",
327 					tz->trips.hot.temperature));
328 		}
329 	}
330 
331 	/* Passive (optional) */
332 	if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
333 		(flag == ACPI_TRIPS_INIT)) {
334 		valid = tz->trips.passive.flags.valid;
335 		if (psv == -1) {
336 			status = AE_SUPPORT;
337 		} else if (psv > 0) {
338 			tmp = celsius_to_deci_kelvin(psv);
339 			status = AE_OK;
340 		} else {
341 			status = acpi_evaluate_integer(tz->device->handle,
342 				"_PSV", NULL, &tmp);
343 		}
344 
345 		if (ACPI_FAILURE(status))
346 			tz->trips.passive.flags.valid = 0;
347 		else {
348 			tz->trips.passive.temperature = tmp;
349 			tz->trips.passive.flags.valid = 1;
350 			if (flag == ACPI_TRIPS_INIT) {
351 				status = acpi_evaluate_integer(
352 						tz->device->handle, "_TC1",
353 						NULL, &tmp);
354 				if (ACPI_FAILURE(status))
355 					tz->trips.passive.flags.valid = 0;
356 				else
357 					tz->trips.passive.tc1 = tmp;
358 				status = acpi_evaluate_integer(
359 						tz->device->handle, "_TC2",
360 						NULL, &tmp);
361 				if (ACPI_FAILURE(status))
362 					tz->trips.passive.flags.valid = 0;
363 				else
364 					tz->trips.passive.tc2 = tmp;
365 				status = acpi_evaluate_integer(
366 						tz->device->handle, "_TSP",
367 						NULL, &tmp);
368 				if (ACPI_FAILURE(status))
369 					tz->trips.passive.flags.valid = 0;
370 				else
371 					tz->trips.passive.tsp = tmp;
372 			}
373 		}
374 	}
375 	if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
376 		memset(&devices, 0, sizeof(struct acpi_handle_list));
377 		status = acpi_evaluate_reference(tz->device->handle, "_PSL",
378 							NULL, &devices);
379 		if (ACPI_FAILURE(status)) {
380 			pr_warn(PREFIX "Invalid passive threshold\n");
381 			tz->trips.passive.flags.valid = 0;
382 		}
383 		else
384 			tz->trips.passive.flags.valid = 1;
385 
386 		if (memcmp(&tz->trips.passive.devices, &devices,
387 				sizeof(struct acpi_handle_list))) {
388 			memcpy(&tz->trips.passive.devices, &devices,
389 				sizeof(struct acpi_handle_list));
390 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
391 		}
392 	}
393 	if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
394 		if (valid != tz->trips.passive.flags.valid)
395 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
396 	}
397 
398 	/* Active (optional) */
399 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
400 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
401 		valid = tz->trips.active[i].flags.valid;
402 
403 		if (act == -1)
404 			break; /* disable all active trip points */
405 
406 		if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
407 			tz->trips.active[i].flags.valid)) {
408 			status = acpi_evaluate_integer(tz->device->handle,
409 							name, NULL, &tmp);
410 			if (ACPI_FAILURE(status)) {
411 				tz->trips.active[i].flags.valid = 0;
412 				if (i == 0)
413 					break;
414 				if (act <= 0)
415 					break;
416 				if (i == 1)
417 					tz->trips.active[0].temperature =
418 						celsius_to_deci_kelvin(act);
419 				else
420 					/*
421 					 * Don't allow override higher than
422 					 * the next higher trip point
423 					 */
424 					tz->trips.active[i - 1].temperature =
425 						(tz->trips.active[i - 2].temperature <
426 						celsius_to_deci_kelvin(act) ?
427 						tz->trips.active[i - 2].temperature :
428 						celsius_to_deci_kelvin(act));
429 				break;
430 			} else {
431 				tz->trips.active[i].temperature = tmp;
432 				tz->trips.active[i].flags.valid = 1;
433 			}
434 		}
435 
436 		name[2] = 'L';
437 		if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
438 			memset(&devices, 0, sizeof(struct acpi_handle_list));
439 			status = acpi_evaluate_reference(tz->device->handle,
440 						name, NULL, &devices);
441 			if (ACPI_FAILURE(status)) {
442 				pr_warn(PREFIX "Invalid active%d threshold\n",
443 					i);
444 				tz->trips.active[i].flags.valid = 0;
445 			}
446 			else
447 				tz->trips.active[i].flags.valid = 1;
448 
449 			if (memcmp(&tz->trips.active[i].devices, &devices,
450 					sizeof(struct acpi_handle_list))) {
451 				memcpy(&tz->trips.active[i].devices, &devices,
452 					sizeof(struct acpi_handle_list));
453 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
454 			}
455 		}
456 		if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
457 			if (valid != tz->trips.active[i].flags.valid)
458 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
459 
460 		if (!tz->trips.active[i].flags.valid)
461 			break;
462 	}
463 
464 	if (flag & ACPI_TRIPS_DEVICES) {
465 		memset(&devices, 0, sizeof(devices));
466 		status = acpi_evaluate_reference(tz->device->handle, "_TZD",
467 						NULL, &devices);
468 		if (ACPI_SUCCESS(status)
469 		    && memcmp(&tz->devices, &devices, sizeof(devices))) {
470 			tz->devices = devices;
471 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
472 		}
473 	}
474 
475 	return 0;
476 }
477 
478 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
479 {
480 	int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
481 
482 	if (ret)
483 		return ret;
484 
485 	valid = tz->trips.critical.flags.valid |
486 		tz->trips.hot.flags.valid |
487 		tz->trips.passive.flags.valid;
488 
489 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
490 		valid |= tz->trips.active[i].flags.valid;
491 
492 	if (!valid) {
493 		pr_warn(FW_BUG "No valid trip found\n");
494 		return -ENODEV;
495 	}
496 	return 0;
497 }
498 
499 static void acpi_thermal_check(void *data)
500 {
501 	struct acpi_thermal *tz = data;
502 
503 	if (!tz->tz_enabled)
504 		return;
505 
506 	thermal_zone_device_update(tz->thermal_zone,
507 				   THERMAL_EVENT_UNSPECIFIED);
508 }
509 
510 /* sys I/F for generic thermal sysfs support */
511 
512 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
513 {
514 	struct acpi_thermal *tz = thermal->devdata;
515 	int result;
516 
517 	if (!tz)
518 		return -EINVAL;
519 
520 	result = acpi_thermal_get_temperature(tz);
521 	if (result)
522 		return result;
523 
524 	*temp = deci_kelvin_to_millicelsius_with_offset(tz->temperature,
525 							tz->kelvin_offset);
526 	return 0;
527 }
528 
529 static int thermal_get_mode(struct thermal_zone_device *thermal,
530 				enum thermal_device_mode *mode)
531 {
532 	struct acpi_thermal *tz = thermal->devdata;
533 
534 	if (!tz)
535 		return -EINVAL;
536 
537 	*mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
538 		THERMAL_DEVICE_DISABLED;
539 
540 	return 0;
541 }
542 
543 static int thermal_set_mode(struct thermal_zone_device *thermal,
544 				enum thermal_device_mode mode)
545 {
546 	struct acpi_thermal *tz = thermal->devdata;
547 	int enable;
548 
549 	if (!tz)
550 		return -EINVAL;
551 
552 	/*
553 	 * enable/disable thermal management from ACPI thermal driver
554 	 */
555 	if (mode == THERMAL_DEVICE_ENABLED)
556 		enable = 1;
557 	else if (mode == THERMAL_DEVICE_DISABLED) {
558 		enable = 0;
559 		pr_warn("thermal zone will be disabled\n");
560 	} else
561 		return -EINVAL;
562 
563 	if (enable != tz->tz_enabled) {
564 		tz->tz_enabled = enable;
565 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
566 			"%s kernel ACPI thermal control\n",
567 			tz->tz_enabled ? "Enable" : "Disable"));
568 		acpi_thermal_check(tz);
569 	}
570 	return 0;
571 }
572 
573 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
574 				 int trip, enum thermal_trip_type *type)
575 {
576 	struct acpi_thermal *tz = thermal->devdata;
577 	int i;
578 
579 	if (!tz || trip < 0)
580 		return -EINVAL;
581 
582 	if (tz->trips.critical.flags.valid) {
583 		if (!trip) {
584 			*type = THERMAL_TRIP_CRITICAL;
585 			return 0;
586 		}
587 		trip--;
588 	}
589 
590 	if (tz->trips.hot.flags.valid) {
591 		if (!trip) {
592 			*type = THERMAL_TRIP_HOT;
593 			return 0;
594 		}
595 		trip--;
596 	}
597 
598 	if (tz->trips.passive.flags.valid) {
599 		if (!trip) {
600 			*type = THERMAL_TRIP_PASSIVE;
601 			return 0;
602 		}
603 		trip--;
604 	}
605 
606 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
607 		tz->trips.active[i].flags.valid; i++) {
608 		if (!trip) {
609 			*type = THERMAL_TRIP_ACTIVE;
610 			return 0;
611 		}
612 		trip--;
613 	}
614 
615 	return -EINVAL;
616 }
617 
618 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
619 				 int trip, int *temp)
620 {
621 	struct acpi_thermal *tz = thermal->devdata;
622 	int i;
623 
624 	if (!tz || trip < 0)
625 		return -EINVAL;
626 
627 	if (tz->trips.critical.flags.valid) {
628 		if (!trip) {
629 			*temp = deci_kelvin_to_millicelsius_with_offset(
630 				tz->trips.critical.temperature,
631 				tz->kelvin_offset);
632 			return 0;
633 		}
634 		trip--;
635 	}
636 
637 	if (tz->trips.hot.flags.valid) {
638 		if (!trip) {
639 			*temp = deci_kelvin_to_millicelsius_with_offset(
640 				tz->trips.hot.temperature,
641 				tz->kelvin_offset);
642 			return 0;
643 		}
644 		trip--;
645 	}
646 
647 	if (tz->trips.passive.flags.valid) {
648 		if (!trip) {
649 			*temp = deci_kelvin_to_millicelsius_with_offset(
650 				tz->trips.passive.temperature,
651 				tz->kelvin_offset);
652 			return 0;
653 		}
654 		trip--;
655 	}
656 
657 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
658 		tz->trips.active[i].flags.valid; i++) {
659 		if (!trip) {
660 			*temp = deci_kelvin_to_millicelsius_with_offset(
661 				tz->trips.active[i].temperature,
662 				tz->kelvin_offset);
663 			return 0;
664 		}
665 		trip--;
666 	}
667 
668 	return -EINVAL;
669 }
670 
671 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
672 				int *temperature)
673 {
674 	struct acpi_thermal *tz = thermal->devdata;
675 
676 	if (tz->trips.critical.flags.valid) {
677 		*temperature = deci_kelvin_to_millicelsius_with_offset(
678 				tz->trips.critical.temperature,
679 				tz->kelvin_offset);
680 		return 0;
681 	} else
682 		return -EINVAL;
683 }
684 
685 static int thermal_get_trend(struct thermal_zone_device *thermal,
686 				int trip, enum thermal_trend *trend)
687 {
688 	struct acpi_thermal *tz = thermal->devdata;
689 	enum thermal_trip_type type;
690 	int i;
691 
692 	if (thermal_get_trip_type(thermal, trip, &type))
693 		return -EINVAL;
694 
695 	if (type == THERMAL_TRIP_ACTIVE) {
696 		int trip_temp;
697 		int temp = deci_kelvin_to_millicelsius_with_offset(
698 					tz->temperature, tz->kelvin_offset);
699 		if (thermal_get_trip_temp(thermal, trip, &trip_temp))
700 			return -EINVAL;
701 
702 		if (temp > trip_temp) {
703 			*trend = THERMAL_TREND_RAISING;
704 			return 0;
705 		} else {
706 			/* Fall back on default trend */
707 			return -EINVAL;
708 		}
709 	}
710 
711 	/*
712 	 * tz->temperature has already been updated by generic thermal layer,
713 	 * before this callback being invoked
714 	 */
715 	i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
716 		+ (tz->trips.passive.tc2
717 		* (tz->temperature - tz->trips.passive.temperature));
718 
719 	if (i > 0)
720 		*trend = THERMAL_TREND_RAISING;
721 	else if (i < 0)
722 		*trend = THERMAL_TREND_DROPPING;
723 	else
724 		*trend = THERMAL_TREND_STABLE;
725 	return 0;
726 }
727 
728 
729 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
730 			   enum thermal_trip_type trip_type)
731 {
732 	u8 type = 0;
733 	struct acpi_thermal *tz = thermal->devdata;
734 
735 	if (trip_type == THERMAL_TRIP_CRITICAL)
736 		type = ACPI_THERMAL_NOTIFY_CRITICAL;
737 	else if (trip_type == THERMAL_TRIP_HOT)
738 		type = ACPI_THERMAL_NOTIFY_HOT;
739 	else
740 		return 0;
741 
742 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
743 					dev_name(&tz->device->dev), type, 1);
744 
745 	if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
746 		return 1;
747 
748 	return 0;
749 }
750 
751 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
752 					struct thermal_cooling_device *cdev,
753 					bool bind)
754 {
755 	struct acpi_device *device = cdev->devdata;
756 	struct acpi_thermal *tz = thermal->devdata;
757 	struct acpi_device *dev;
758 	acpi_status status;
759 	acpi_handle handle;
760 	int i;
761 	int j;
762 	int trip = -1;
763 	int result = 0;
764 
765 	if (tz->trips.critical.flags.valid)
766 		trip++;
767 
768 	if (tz->trips.hot.flags.valid)
769 		trip++;
770 
771 	if (tz->trips.passive.flags.valid) {
772 		trip++;
773 		for (i = 0; i < tz->trips.passive.devices.count;
774 		    i++) {
775 			handle = tz->trips.passive.devices.handles[i];
776 			status = acpi_bus_get_device(handle, &dev);
777 			if (ACPI_FAILURE(status) || dev != device)
778 				continue;
779 			if (bind)
780 				result =
781 					thermal_zone_bind_cooling_device
782 					(thermal, trip, cdev,
783 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
784 					 THERMAL_WEIGHT_DEFAULT);
785 			else
786 				result =
787 					thermal_zone_unbind_cooling_device
788 					(thermal, trip, cdev);
789 			if (result)
790 				goto failed;
791 		}
792 	}
793 
794 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
795 		if (!tz->trips.active[i].flags.valid)
796 			break;
797 		trip++;
798 		for (j = 0;
799 		    j < tz->trips.active[i].devices.count;
800 		    j++) {
801 			handle = tz->trips.active[i].devices.handles[j];
802 			status = acpi_bus_get_device(handle, &dev);
803 			if (ACPI_FAILURE(status) || dev != device)
804 				continue;
805 			if (bind)
806 				result = thermal_zone_bind_cooling_device
807 					(thermal, trip, cdev,
808 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
809 					 THERMAL_WEIGHT_DEFAULT);
810 			else
811 				result = thermal_zone_unbind_cooling_device
812 					(thermal, trip, cdev);
813 			if (result)
814 				goto failed;
815 		}
816 	}
817 
818 	for (i = 0; i < tz->devices.count; i++) {
819 		handle = tz->devices.handles[i];
820 		status = acpi_bus_get_device(handle, &dev);
821 		if (ACPI_SUCCESS(status) && (dev == device)) {
822 			if (bind)
823 				result = thermal_zone_bind_cooling_device
824 						(thermal, THERMAL_TRIPS_NONE,
825 						 cdev, THERMAL_NO_LIMIT,
826 						 THERMAL_NO_LIMIT,
827 						 THERMAL_WEIGHT_DEFAULT);
828 			else
829 				result = thermal_zone_unbind_cooling_device
830 						(thermal, THERMAL_TRIPS_NONE,
831 						 cdev);
832 			if (result)
833 				goto failed;
834 		}
835 	}
836 
837 failed:
838 	return result;
839 }
840 
841 static int
842 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
843 					struct thermal_cooling_device *cdev)
844 {
845 	return acpi_thermal_cooling_device_cb(thermal, cdev, true);
846 }
847 
848 static int
849 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
850 					struct thermal_cooling_device *cdev)
851 {
852 	return acpi_thermal_cooling_device_cb(thermal, cdev, false);
853 }
854 
855 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
856 	.bind = acpi_thermal_bind_cooling_device,
857 	.unbind	= acpi_thermal_unbind_cooling_device,
858 	.get_temp = thermal_get_temp,
859 	.get_mode = thermal_get_mode,
860 	.set_mode = thermal_set_mode,
861 	.get_trip_type = thermal_get_trip_type,
862 	.get_trip_temp = thermal_get_trip_temp,
863 	.get_crit_temp = thermal_get_crit_temp,
864 	.get_trend = thermal_get_trend,
865 	.notify = thermal_notify,
866 };
867 
868 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
869 {
870 	int trips = 0;
871 	int result;
872 	acpi_status status;
873 	int i;
874 
875 	if (tz->trips.critical.flags.valid)
876 		trips++;
877 
878 	if (tz->trips.hot.flags.valid)
879 		trips++;
880 
881 	if (tz->trips.passive.flags.valid)
882 		trips++;
883 
884 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
885 			tz->trips.active[i].flags.valid; i++, trips++);
886 
887 	if (tz->trips.passive.flags.valid)
888 		tz->thermal_zone =
889 			thermal_zone_device_register("acpitz", trips, 0, tz,
890 						&acpi_thermal_zone_ops, NULL,
891 						     tz->trips.passive.tsp*100,
892 						     tz->polling_frequency*100);
893 	else
894 		tz->thermal_zone =
895 			thermal_zone_device_register("acpitz", trips, 0, tz,
896 						&acpi_thermal_zone_ops, NULL,
897 						0, tz->polling_frequency*100);
898 	if (IS_ERR(tz->thermal_zone))
899 		return -ENODEV;
900 
901 	result = sysfs_create_link(&tz->device->dev.kobj,
902 				   &tz->thermal_zone->device.kobj, "thermal_zone");
903 	if (result)
904 		return result;
905 
906 	result = sysfs_create_link(&tz->thermal_zone->device.kobj,
907 				   &tz->device->dev.kobj, "device");
908 	if (result)
909 		return result;
910 
911 	status =  acpi_bus_attach_private_data(tz->device->handle,
912 					       tz->thermal_zone);
913 	if (ACPI_FAILURE(status))
914 		return -ENODEV;
915 
916 	tz->tz_enabled = 1;
917 
918 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
919 		 tz->thermal_zone->id);
920 	return 0;
921 }
922 
923 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
924 {
925 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
926 	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
927 	thermal_zone_device_unregister(tz->thermal_zone);
928 	tz->thermal_zone = NULL;
929 	acpi_bus_detach_private_data(tz->device->handle);
930 }
931 
932 
933 /* --------------------------------------------------------------------------
934                                  Driver Interface
935    -------------------------------------------------------------------------- */
936 
937 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
938 {
939 	struct acpi_thermal *tz = acpi_driver_data(device);
940 
941 
942 	if (!tz)
943 		return;
944 
945 	switch (event) {
946 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
947 		acpi_thermal_check(tz);
948 		break;
949 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
950 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
951 		acpi_thermal_check(tz);
952 		acpi_bus_generate_netlink_event(device->pnp.device_class,
953 						  dev_name(&device->dev), event, 0);
954 		break;
955 	case ACPI_THERMAL_NOTIFY_DEVICES:
956 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
957 		acpi_thermal_check(tz);
958 		acpi_bus_generate_netlink_event(device->pnp.device_class,
959 						  dev_name(&device->dev), event, 0);
960 		break;
961 	default:
962 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
963 				  "Unsupported event [0x%x]\n", event));
964 		break;
965 	}
966 }
967 
968 /*
969  * On some platforms, the AML code has dependency about
970  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
971  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
972  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
973  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
974  *    if _TMP has never been evaluated.
975  *
976  * As this dependency is totally transparent to OS, evaluate
977  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
978  * _TMP, before they are actually used.
979  */
980 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
981 {
982 	acpi_handle handle = tz->device->handle;
983 	unsigned long long value;
984 	int i;
985 
986 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
987 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
988 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
989 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
990 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
991 		acpi_status status;
992 
993 		status = acpi_evaluate_integer(handle, name, NULL, &value);
994 		if (status == AE_NOT_FOUND)
995 			break;
996 	}
997 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
998 }
999 
1000 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1001 {
1002 	int result = 0;
1003 
1004 
1005 	if (!tz)
1006 		return -EINVAL;
1007 
1008 	acpi_thermal_aml_dependency_fix(tz);
1009 
1010 	/* Get trip points [_CRT, _PSV, etc.] (required) */
1011 	result = acpi_thermal_get_trip_points(tz);
1012 	if (result)
1013 		return result;
1014 
1015 	/* Get temperature [_TMP] (required) */
1016 	result = acpi_thermal_get_temperature(tz);
1017 	if (result)
1018 		return result;
1019 
1020 	/* Set the cooling mode [_SCP] to active cooling (default) */
1021 	result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1022 	if (!result)
1023 		tz->flags.cooling_mode = 1;
1024 
1025 	/* Get default polling frequency [_TZP] (optional) */
1026 	if (tzp)
1027 		tz->polling_frequency = tzp;
1028 	else
1029 		acpi_thermal_get_polling_frequency(tz);
1030 
1031 	return 0;
1032 }
1033 
1034 /*
1035  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1036  * handles temperature values with a single decimal place. As a consequence,
1037  * some implementations use an offset of 273.1 and others use an offset of
1038  * 273.2. Try to find out which one is being used, to present the most
1039  * accurate and visually appealing number.
1040  *
1041  * The heuristic below should work for all ACPI thermal zones which have a
1042  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1043  */
1044 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1045 {
1046 	if (tz->trips.critical.flags.valid &&
1047 	    (tz->trips.critical.temperature % 5) == 1)
1048 		tz->kelvin_offset = 273100;
1049 	else
1050 		tz->kelvin_offset = 273200;
1051 }
1052 
1053 static void acpi_thermal_check_fn(struct work_struct *work)
1054 {
1055 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
1056 					       thermal_check_work);
1057 	acpi_thermal_check(tz);
1058 }
1059 
1060 static int acpi_thermal_add(struct acpi_device *device)
1061 {
1062 	int result = 0;
1063 	struct acpi_thermal *tz = NULL;
1064 
1065 
1066 	if (!device)
1067 		return -EINVAL;
1068 
1069 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1070 	if (!tz)
1071 		return -ENOMEM;
1072 
1073 	tz->device = device;
1074 	strcpy(tz->name, device->pnp.bus_id);
1075 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1076 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1077 	device->driver_data = tz;
1078 
1079 	result = acpi_thermal_get_info(tz);
1080 	if (result)
1081 		goto free_memory;
1082 
1083 	acpi_thermal_guess_offset(tz);
1084 
1085 	result = acpi_thermal_register_thermal_zone(tz);
1086 	if (result)
1087 		goto free_memory;
1088 
1089 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
1090 
1091 	pr_info(PREFIX "%s [%s] (%ld C)\n", acpi_device_name(device),
1092 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temperature));
1093 	goto end;
1094 
1095 free_memory:
1096 	kfree(tz);
1097 end:
1098 	return result;
1099 }
1100 
1101 static int acpi_thermal_remove(struct acpi_device *device)
1102 {
1103 	struct acpi_thermal *tz = NULL;
1104 
1105 	if (!device || !acpi_driver_data(device))
1106 		return -EINVAL;
1107 
1108 	flush_workqueue(acpi_thermal_pm_queue);
1109 	tz = acpi_driver_data(device);
1110 
1111 	acpi_thermal_unregister_thermal_zone(tz);
1112 	kfree(tz);
1113 	return 0;
1114 }
1115 
1116 #ifdef CONFIG_PM_SLEEP
1117 static int acpi_thermal_suspend(struct device *dev)
1118 {
1119 	/* Make sure the previously queued thermal check work has been done */
1120 	flush_workqueue(acpi_thermal_pm_queue);
1121 	return 0;
1122 }
1123 
1124 static int acpi_thermal_resume(struct device *dev)
1125 {
1126 	struct acpi_thermal *tz;
1127 	int i, j, power_state, result;
1128 
1129 	if (!dev)
1130 		return -EINVAL;
1131 
1132 	tz = acpi_driver_data(to_acpi_device(dev));
1133 	if (!tz)
1134 		return -EINVAL;
1135 
1136 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1137 		if (!(&tz->trips.active[i]))
1138 			break;
1139 		if (!tz->trips.active[i].flags.valid)
1140 			break;
1141 		tz->trips.active[i].flags.enabled = 1;
1142 		for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1143 			result = acpi_bus_update_power(
1144 					tz->trips.active[i].devices.handles[j],
1145 					&power_state);
1146 			if (result || (power_state != ACPI_STATE_D0)) {
1147 				tz->trips.active[i].flags.enabled = 0;
1148 				break;
1149 			}
1150 		}
1151 		tz->state.active |= tz->trips.active[i].flags.enabled;
1152 	}
1153 
1154 	queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
1155 
1156 	return AE_OK;
1157 }
1158 #endif
1159 
1160 static int thermal_act(const struct dmi_system_id *d) {
1161 
1162 	if (act == 0) {
1163 		pr_notice(PREFIX "%s detected: "
1164 			  "disabling all active thermal trip points\n", d->ident);
1165 		act = -1;
1166 	}
1167 	return 0;
1168 }
1169 static int thermal_nocrt(const struct dmi_system_id *d) {
1170 
1171 	pr_notice(PREFIX "%s detected: "
1172 		  "disabling all critical thermal trip point actions.\n", d->ident);
1173 	nocrt = 1;
1174 	return 0;
1175 }
1176 static int thermal_tzp(const struct dmi_system_id *d) {
1177 
1178 	if (tzp == 0) {
1179 		pr_notice(PREFIX "%s detected: "
1180 			  "enabling thermal zone polling\n", d->ident);
1181 		tzp = 300;	/* 300 dS = 30 Seconds */
1182 	}
1183 	return 0;
1184 }
1185 static int thermal_psv(const struct dmi_system_id *d) {
1186 
1187 	if (psv == 0) {
1188 		pr_notice(PREFIX "%s detected: "
1189 			  "disabling all passive thermal trip points\n", d->ident);
1190 		psv = -1;
1191 	}
1192 	return 0;
1193 }
1194 
1195 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1196 	/*
1197 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1198 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1199 	 */
1200 	{
1201 	 .callback = thermal_act,
1202 	 .ident = "AOpen i915GMm-HFS",
1203 	 .matches = {
1204 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1205 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1206 		},
1207 	},
1208 	{
1209 	 .callback = thermal_psv,
1210 	 .ident = "AOpen i915GMm-HFS",
1211 	 .matches = {
1212 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1213 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1214 		},
1215 	},
1216 	{
1217 	 .callback = thermal_tzp,
1218 	 .ident = "AOpen i915GMm-HFS",
1219 	 .matches = {
1220 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1221 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1222 		},
1223 	},
1224 	{
1225 	 .callback = thermal_nocrt,
1226 	 .ident = "Gigabyte GA-7ZX",
1227 	 .matches = {
1228 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1229 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1230 		},
1231 	},
1232 	{}
1233 };
1234 
1235 static int __init acpi_thermal_init(void)
1236 {
1237 	int result = 0;
1238 
1239 	dmi_check_system(thermal_dmi_table);
1240 
1241 	if (off) {
1242 		pr_notice(PREFIX "thermal control disabled\n");
1243 		return -ENODEV;
1244 	}
1245 
1246 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1247 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1248 	if (!acpi_thermal_pm_queue)
1249 		return -ENODEV;
1250 
1251 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1252 	if (result < 0) {
1253 		destroy_workqueue(acpi_thermal_pm_queue);
1254 		return -ENODEV;
1255 	}
1256 
1257 	return 0;
1258 }
1259 
1260 static void __exit acpi_thermal_exit(void)
1261 {
1262 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1263 	destroy_workqueue(acpi_thermal_pm_queue);
1264 
1265 	return;
1266 }
1267 
1268 module_init(acpi_thermal_init);
1269 module_exit(acpi_thermal_exit);
1270