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