xref: /linux/drivers/acpi/thermal.c (revision eed4edda910fe34dfae8c6bfbcf57f4593a54295)
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 #define pr_fmt(fmt) "ACPI: thermal: " fmt
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/dmi.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/types.h>
24 #include <linux/jiffies.h>
25 #include <linux/kmod.h>
26 #include <linux/reboot.h>
27 #include <linux/device.h>
28 #include <linux/thermal.h>
29 #include <linux/acpi.h>
30 #include <linux/workqueue.h>
31 #include <linux/uaccess.h>
32 #include <linux/units.h>
33 
34 #include "internal.h"
35 
36 #define ACPI_THERMAL_CLASS		"thermal_zone"
37 #define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
38 #define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
39 #define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
40 #define ACPI_THERMAL_NOTIFY_DEVICES	0x82
41 #define ACPI_THERMAL_NOTIFY_CRITICAL	0xF0
42 #define ACPI_THERMAL_NOTIFY_HOT		0xF1
43 #define ACPI_THERMAL_MODE_ACTIVE	0x00
44 
45 #define ACPI_THERMAL_MAX_ACTIVE		10
46 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN	65
47 
48 #define ACPI_THERMAL_TRIP_PASSIVE	(-1)
49 
50 /*
51  * This exception is thrown out in two cases:
52  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
53  *   when re-evaluating the AML code.
54  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
55  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
56  */
57 #define ACPI_THERMAL_TRIPS_EXCEPTION(tz, str) \
58 do { \
59 	acpi_handle_info(tz->device->handle, \
60 			 "ACPI thermal trip point %s changed\n" \
61 			 "Please report to linux-acpi@vger.kernel.org\n", str); \
62 } while (0)
63 
64 static int act;
65 module_param(act, int, 0644);
66 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
67 
68 static int crt;
69 module_param(crt, int, 0644);
70 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
71 
72 static int tzp;
73 module_param(tzp, int, 0444);
74 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
75 
76 static int off;
77 module_param(off, int, 0);
78 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
79 
80 static int psv;
81 module_param(psv, int, 0644);
82 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
83 
84 static struct workqueue_struct *acpi_thermal_pm_queue;
85 
86 struct acpi_thermal_trip {
87 	unsigned long temp_dk;
88 	struct acpi_handle_list devices;
89 };
90 
91 struct acpi_thermal_passive {
92 	struct acpi_thermal_trip trip;
93 	unsigned long tc1;
94 	unsigned long tc2;
95 	unsigned long delay;
96 };
97 
98 struct acpi_thermal_active {
99 	struct acpi_thermal_trip trip;
100 };
101 
102 struct acpi_thermal_trips {
103 	struct acpi_thermal_passive passive;
104 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
105 };
106 
107 struct acpi_thermal {
108 	struct acpi_device *device;
109 	acpi_bus_id name;
110 	unsigned long temp_dk;
111 	unsigned long last_temp_dk;
112 	unsigned long polling_frequency;
113 	volatile u8 zombie;
114 	struct acpi_thermal_trips trips;
115 	struct thermal_trip *trip_table;
116 	struct thermal_zone_device *thermal_zone;
117 	int kelvin_offset;	/* in millidegrees */
118 	struct work_struct thermal_check_work;
119 	struct mutex thermal_check_lock;
120 	refcount_t thermal_check_count;
121 };
122 
123 /* --------------------------------------------------------------------------
124                              Thermal Zone Management
125    -------------------------------------------------------------------------- */
126 
127 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
128 {
129 	acpi_status status = AE_OK;
130 	unsigned long long tmp;
131 
132 	if (!tz)
133 		return -EINVAL;
134 
135 	tz->last_temp_dk = tz->temp_dk;
136 
137 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
138 	if (ACPI_FAILURE(status))
139 		return -ENODEV;
140 
141 	tz->temp_dk = tmp;
142 
143 	acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
144 			  tz->temp_dk);
145 
146 	return 0;
147 }
148 
149 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
150 {
151 	acpi_status status = AE_OK;
152 	unsigned long long tmp;
153 
154 	if (!tz)
155 		return -EINVAL;
156 
157 	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
158 	if (ACPI_FAILURE(status))
159 		return -ENODEV;
160 
161 	tz->polling_frequency = tmp;
162 	acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
163 			  tz->polling_frequency);
164 
165 	return 0;
166 }
167 
168 static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k)
169 {
170 	if (temp_deci_k == THERMAL_TEMP_INVALID)
171 		return THERMAL_TEMP_INVALID;
172 
173 	return deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
174 						       tz->kelvin_offset);
175 }
176 
177 static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip)
178 {
179 	return acpi_trip->temp_dk != THERMAL_TEMP_INVALID;
180 }
181 
182 static int active_trip_index(struct acpi_thermal *tz,
183 			     struct acpi_thermal_trip *acpi_trip)
184 {
185 	struct acpi_thermal_active *active;
186 
187 	active = container_of(acpi_trip, struct acpi_thermal_active, trip);
188 	return active - tz->trips.active;
189 }
190 
191 static long get_passive_temp(struct acpi_thermal *tz)
192 {
193 	int temp;
194 
195 	if (acpi_passive_trip_temp(tz->device, &temp))
196 		return THERMAL_TEMP_INVALID;
197 
198 	return temp;
199 }
200 
201 static long get_active_temp(struct acpi_thermal *tz, int index)
202 {
203 	int temp;
204 
205 	if (acpi_active_trip_temp(tz->device, index, &temp))
206 		return THERMAL_TEMP_INVALID;
207 
208 	/*
209 	 * If an override has been provided, apply it so there are no active
210 	 * trips with thresholds greater than the override.
211 	 */
212 	if (act > 0) {
213 		unsigned long long override = celsius_to_deci_kelvin(act);
214 
215 		if (temp > override)
216 			return override;
217 	}
218 	return temp;
219 }
220 
221 static void acpi_thermal_update_trip(struct acpi_thermal *tz,
222 				     const struct thermal_trip *trip)
223 {
224 	struct acpi_thermal_trip *acpi_trip = trip->priv;
225 
226 	if (trip->type == THERMAL_TRIP_PASSIVE) {
227 		if (psv > 0)
228 			return;
229 
230 		acpi_trip->temp_dk = get_passive_temp(tz);
231 	} else {
232 		int index = active_trip_index(tz, acpi_trip);
233 
234 		acpi_trip->temp_dk = get_active_temp(tz, index);
235 	}
236 
237 	if (!acpi_thermal_trip_valid(acpi_trip))
238 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
239 }
240 
241 static bool update_trip_devices(struct acpi_thermal *tz,
242 				struct acpi_thermal_trip *acpi_trip,
243 				int index, bool compare)
244 {
245 	struct acpi_handle_list devices = { 0 };
246 	char method[] = "_PSL";
247 
248 	if (index != ACPI_THERMAL_TRIP_PASSIVE) {
249 		method[1] = 'A';
250 		method[2] = 'L';
251 		method[3] = '0' + index;
252 	}
253 
254 	if (!acpi_evaluate_reference(tz->device->handle, method, NULL, &devices)) {
255 		acpi_handle_info(tz->device->handle, "%s evaluation failure\n", method);
256 		return false;
257 	}
258 
259 	if (acpi_handle_list_equal(&acpi_trip->devices, &devices)) {
260 		acpi_handle_list_free(&devices);
261 		return true;
262 	}
263 
264 	if (compare)
265 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "device");
266 
267 	acpi_handle_list_replace(&acpi_trip->devices, &devices);
268 	return true;
269 }
270 
271 static void acpi_thermal_update_trip_devices(struct acpi_thermal *tz,
272 					     const struct thermal_trip *trip)
273 {
274 	struct acpi_thermal_trip *acpi_trip = trip->priv;
275 	int index = trip->type == THERMAL_TRIP_PASSIVE ?
276 			ACPI_THERMAL_TRIP_PASSIVE : active_trip_index(tz, acpi_trip);
277 
278 	if (update_trip_devices(tz, acpi_trip, index, true))
279 		return;
280 
281 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
282 	ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
283 }
284 
285 struct adjust_trip_data {
286 	struct acpi_thermal *tz;
287 	u32 event;
288 };
289 
290 static int acpi_thermal_adjust_trip(struct thermal_trip *trip, void *data)
291 {
292 	struct acpi_thermal_trip *acpi_trip = trip->priv;
293 	struct adjust_trip_data *atd = data;
294 	struct acpi_thermal *tz = atd->tz;
295 	int temp;
296 
297 	if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
298 		return 0;
299 
300 	if (atd->event == ACPI_THERMAL_NOTIFY_THRESHOLDS)
301 		acpi_thermal_update_trip(tz, trip);
302 	else
303 		acpi_thermal_update_trip_devices(tz, trip);
304 
305 	if (acpi_thermal_trip_valid(acpi_trip))
306 		temp = acpi_thermal_temp(tz, acpi_trip->temp_dk);
307 	else
308 		temp = THERMAL_TEMP_INVALID;
309 
310 	thermal_zone_set_trip_temp(tz->thermal_zone, trip, temp);
311 
312 	return 0;
313 }
314 
315 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
316 {
317 	if (!work_pending(&tz->thermal_check_work))
318 		queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
319 }
320 
321 static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
322 {
323 	struct adjust_trip_data atd = { .tz = tz, .event = event };
324 	struct acpi_device *adev = tz->device;
325 
326 	/*
327 	 * Use thermal_zone_for_each_trip() to carry out the trip points
328 	 * update, so as to protect thermal_get_trend() from getting stale
329 	 * trip point temperatures and to prevent thermal_zone_device_update()
330 	 * invoked from acpi_thermal_check_fn() from producing inconsistent
331 	 * results.
332 	 */
333 	thermal_zone_for_each_trip(tz->thermal_zone,
334 				   acpi_thermal_adjust_trip, &atd);
335 	acpi_queue_thermal_check(tz);
336 	acpi_bus_generate_netlink_event(adev->pnp.device_class,
337 					dev_name(&adev->dev), event, 0);
338 }
339 
340 static int acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
341 {
342 	int temp;
343 
344 	if (crt > 0) {
345 		temp = celsius_to_deci_kelvin(crt);
346 		goto set;
347 	}
348 	if (crt == -1) {
349 		acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
350 		return THERMAL_TEMP_INVALID;
351 	}
352 
353 	if (acpi_critical_trip_temp(tz->device, &temp))
354 		return THERMAL_TEMP_INVALID;
355 
356 	if (temp <= 2732) {
357 		/*
358 		 * Below zero (Celsius) values clearly aren't right for sure,
359 		 * so discard them as invalid.
360 		 */
361 		pr_info(FW_BUG "Invalid critical threshold (%d)\n", temp);
362 		return THERMAL_TEMP_INVALID;
363 	}
364 
365 set:
366 	acpi_handle_debug(tz->device->handle, "Critical threshold [%d]\n", temp);
367 	return temp;
368 }
369 
370 static int acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
371 {
372 	int temp;
373 
374 	if (acpi_hot_trip_temp(tz->device, &temp) || temp == THERMAL_TEMP_INVALID) {
375 		acpi_handle_debug(tz->device->handle, "No hot threshold\n");
376 		return THERMAL_TEMP_INVALID;
377 	}
378 
379 	acpi_handle_debug(tz->device->handle, "Hot threshold [%d]\n", temp);
380 	return temp;
381 }
382 
383 static bool passive_trip_params_init(struct acpi_thermal *tz)
384 {
385 	unsigned long long tmp;
386 	acpi_status status;
387 
388 	status = acpi_evaluate_integer(tz->device->handle, "_TC1", NULL, &tmp);
389 	if (ACPI_FAILURE(status))
390 		return false;
391 
392 	tz->trips.passive.tc1 = tmp;
393 
394 	status = acpi_evaluate_integer(tz->device->handle, "_TC2", NULL, &tmp);
395 	if (ACPI_FAILURE(status))
396 		return false;
397 
398 	tz->trips.passive.tc2 = tmp;
399 
400 	status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
401 	if (ACPI_SUCCESS(status)) {
402 		tz->trips.passive.delay = tmp;
403 		return true;
404 	}
405 
406 	status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
407 	if (ACPI_FAILURE(status))
408 		return false;
409 
410 	tz->trips.passive.delay = tmp * 100;
411 
412 	return true;
413 }
414 
415 static bool acpi_thermal_init_trip(struct acpi_thermal *tz, int index)
416 {
417 	struct acpi_thermal_trip *acpi_trip;
418 	long temp;
419 
420 	if (index == ACPI_THERMAL_TRIP_PASSIVE) {
421 		acpi_trip = &tz->trips.passive.trip;
422 
423 		if (psv == -1)
424 			goto fail;
425 
426 		if (!passive_trip_params_init(tz))
427 			goto fail;
428 
429 		temp = psv > 0 ? celsius_to_deci_kelvin(psv) :
430 				 get_passive_temp(tz);
431 	} else {
432 		acpi_trip = &tz->trips.active[index].trip;
433 
434 		if (act == -1)
435 			goto fail;
436 
437 		temp = get_active_temp(tz, index);
438 	}
439 
440 	if (temp == THERMAL_TEMP_INVALID)
441 		goto fail;
442 
443 	if (!update_trip_devices(tz, acpi_trip, index, false))
444 		goto fail;
445 
446 	acpi_trip->temp_dk = temp;
447 	return true;
448 
449 fail:
450 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
451 	return false;
452 }
453 
454 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
455 {
456 	unsigned int count = 0;
457 	int i;
458 
459 	if (acpi_thermal_init_trip(tz, ACPI_THERMAL_TRIP_PASSIVE))
460 		count++;
461 
462 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
463 		if (acpi_thermal_init_trip(tz, i))
464 			count++;
465 		else
466 			break;
467 
468 	}
469 
470 	while (++i < ACPI_THERMAL_MAX_ACTIVE)
471 		tz->trips.active[i].trip.temp_dk = THERMAL_TEMP_INVALID;
472 
473 	return count;
474 }
475 
476 /* sys I/F for generic thermal sysfs support */
477 
478 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
479 {
480 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
481 	int result;
482 
483 	if (!tz)
484 		return -EINVAL;
485 
486 	result = acpi_thermal_get_temperature(tz);
487 	if (result)
488 		return result;
489 
490 	*temp = deci_kelvin_to_millicelsius_with_offset(tz->temp_dk,
491 							tz->kelvin_offset);
492 	return 0;
493 }
494 
495 static int thermal_get_trend(struct thermal_zone_device *thermal,
496 			     const struct thermal_trip *trip,
497 			     enum thermal_trend *trend)
498 {
499 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
500 	struct acpi_thermal_trip *acpi_trip;
501 	int t;
502 
503 	if (!tz || !trip)
504 		return -EINVAL;
505 
506 	acpi_trip = trip->priv;
507 	if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
508 		return -EINVAL;
509 
510 	switch (trip->type) {
511 	case THERMAL_TRIP_PASSIVE:
512 		t = tz->trips.passive.tc1 * (tz->temp_dk -
513 						tz->last_temp_dk) +
514 			tz->trips.passive.tc2 * (tz->temp_dk -
515 						acpi_trip->temp_dk);
516 		if (t > 0)
517 			*trend = THERMAL_TREND_RAISING;
518 		else if (t < 0)
519 			*trend = THERMAL_TREND_DROPPING;
520 		else
521 			*trend = THERMAL_TREND_STABLE;
522 
523 		return 0;
524 
525 	case THERMAL_TRIP_ACTIVE:
526 		t = acpi_thermal_temp(tz, tz->temp_dk);
527 		if (t <= trip->temperature)
528 			break;
529 
530 		*trend = THERMAL_TREND_RAISING;
531 
532 		return 0;
533 
534 	default:
535 		break;
536 	}
537 
538 	return -EINVAL;
539 }
540 
541 static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
542 {
543 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
544 
545 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
546 					dev_name(&tz->device->dev),
547 					ACPI_THERMAL_NOTIFY_HOT, 1);
548 }
549 
550 static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)
551 {
552 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
553 
554 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
555 					dev_name(&tz->device->dev),
556 					ACPI_THERMAL_NOTIFY_CRITICAL, 1);
557 
558 	thermal_zone_device_critical(thermal);
559 }
560 
561 struct acpi_thermal_bind_data {
562 	struct thermal_zone_device *thermal;
563 	struct thermal_cooling_device *cdev;
564 	bool bind;
565 };
566 
567 static int bind_unbind_cdev_cb(struct thermal_trip *trip, void *arg)
568 {
569 	struct acpi_thermal_trip *acpi_trip = trip->priv;
570 	struct acpi_thermal_bind_data *bd = arg;
571 	struct thermal_zone_device *thermal = bd->thermal;
572 	struct thermal_cooling_device *cdev = bd->cdev;
573 	struct acpi_device *cdev_adev = cdev->devdata;
574 	int i;
575 
576 	/* Skip critical and hot trips. */
577 	if (!acpi_trip)
578 		return 0;
579 
580 	for (i = 0; i < acpi_trip->devices.count; i++) {
581 		acpi_handle handle = acpi_trip->devices.handles[i];
582 		struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
583 
584 		if (adev != cdev_adev)
585 			continue;
586 
587 		if (bd->bind) {
588 			int ret;
589 
590 			ret = thermal_bind_cdev_to_trip(thermal, trip, cdev,
591 							THERMAL_NO_LIMIT,
592 							THERMAL_NO_LIMIT,
593 							THERMAL_WEIGHT_DEFAULT);
594 			if (ret)
595 				return ret;
596 		} else {
597 			thermal_unbind_cdev_from_trip(thermal, trip, cdev);
598 		}
599 	}
600 
601 	return 0;
602 }
603 
604 static int acpi_thermal_bind_unbind_cdev(struct thermal_zone_device *thermal,
605 					 struct thermal_cooling_device *cdev,
606 					 bool bind)
607 {
608 	struct acpi_thermal_bind_data bd = {
609 		.thermal = thermal, .cdev = cdev, .bind = bind
610 	};
611 
612 	return for_each_thermal_trip(thermal, bind_unbind_cdev_cb, &bd);
613 }
614 
615 static int
616 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
617 				 struct thermal_cooling_device *cdev)
618 {
619 	return acpi_thermal_bind_unbind_cdev(thermal, cdev, true);
620 }
621 
622 static int
623 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
624 				   struct thermal_cooling_device *cdev)
625 {
626 	return acpi_thermal_bind_unbind_cdev(thermal, cdev, false);
627 }
628 
629 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
630 	.bind = acpi_thermal_bind_cooling_device,
631 	.unbind	= acpi_thermal_unbind_cooling_device,
632 	.get_temp = thermal_get_temp,
633 	.get_trend = thermal_get_trend,
634 	.hot = acpi_thermal_zone_device_hot,
635 	.critical = acpi_thermal_zone_device_critical,
636 };
637 
638 static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
639 {
640 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
641 	int ret;
642 
643 	ret = sysfs_create_link(&tz->device->dev.kobj,
644 				&tzdev->kobj, "thermal_zone");
645 	if (ret)
646 		return ret;
647 
648 	ret = sysfs_create_link(&tzdev->kobj,
649 				   &tz->device->dev.kobj, "device");
650 	if (ret)
651 		sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
652 
653 	return ret;
654 }
655 
656 static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
657 {
658 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
659 
660 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
661 	sysfs_remove_link(&tzdev->kobj, "device");
662 }
663 
664 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz,
665 					      unsigned int trip_count,
666 					      int passive_delay)
667 {
668 	int result;
669 
670 	tz->thermal_zone = thermal_zone_device_register_with_trips("acpitz",
671 								   tz->trip_table,
672 								   trip_count,
673 								   0, tz,
674 								   &acpi_thermal_zone_ops,
675 								   NULL,
676 								   passive_delay,
677 								   tz->polling_frequency * 100);
678 	if (IS_ERR(tz->thermal_zone))
679 		return PTR_ERR(tz->thermal_zone);
680 
681 	result = acpi_thermal_zone_sysfs_add(tz);
682 	if (result)
683 		goto unregister_tzd;
684 
685 	result = thermal_zone_device_enable(tz->thermal_zone);
686 	if (result)
687 		goto remove_links;
688 
689 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
690 		 thermal_zone_device_id(tz->thermal_zone));
691 
692 	return 0;
693 
694 remove_links:
695 	acpi_thermal_zone_sysfs_remove(tz);
696 unregister_tzd:
697 	thermal_zone_device_unregister(tz->thermal_zone);
698 
699 	return result;
700 }
701 
702 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
703 {
704 	thermal_zone_device_disable(tz->thermal_zone);
705 	acpi_thermal_zone_sysfs_remove(tz);
706 	thermal_zone_device_unregister(tz->thermal_zone);
707 	tz->thermal_zone = NULL;
708 }
709 
710 
711 /* --------------------------------------------------------------------------
712                                  Driver Interface
713    -------------------------------------------------------------------------- */
714 
715 static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
716 {
717 	struct acpi_device *device = data;
718 	struct acpi_thermal *tz = acpi_driver_data(device);
719 
720 	if (!tz)
721 		return;
722 
723 	switch (event) {
724 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
725 		acpi_queue_thermal_check(tz);
726 		break;
727 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
728 	case ACPI_THERMAL_NOTIFY_DEVICES:
729 		acpi_thermal_trips_update(tz, event);
730 		break;
731 	default:
732 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
733 				  event);
734 		break;
735 	}
736 }
737 
738 /*
739  * On some platforms, the AML code has dependency about
740  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
741  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
742  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
743  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
744  *    if _TMP has never been evaluated.
745  *
746  * As this dependency is totally transparent to OS, evaluate
747  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
748  * _TMP, before they are actually used.
749  */
750 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
751 {
752 	acpi_handle handle = tz->device->handle;
753 	unsigned long long value;
754 	int i;
755 
756 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
757 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
758 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
759 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
760 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
761 		acpi_status status;
762 
763 		status = acpi_evaluate_integer(handle, name, NULL, &value);
764 		if (status == AE_NOT_FOUND)
765 			break;
766 	}
767 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
768 }
769 
770 /*
771  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
772  * handles temperature values with a single decimal place. As a consequence,
773  * some implementations use an offset of 273.1 and others use an offset of
774  * 273.2. Try to find out which one is being used, to present the most
775  * accurate and visually appealing number.
776  *
777  * The heuristic below should work for all ACPI thermal zones which have a
778  * critical trip point with a value being a multiple of 0.5 degree Celsius.
779  */
780 static void acpi_thermal_guess_offset(struct acpi_thermal *tz, long crit_temp)
781 {
782 	if (crit_temp != THERMAL_TEMP_INVALID && crit_temp % 5 == 1)
783 		tz->kelvin_offset = 273100;
784 	else
785 		tz->kelvin_offset = 273200;
786 }
787 
788 static void acpi_thermal_check_fn(struct work_struct *work)
789 {
790 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
791 					       thermal_check_work);
792 
793 	/*
794 	 * In general, it is not sufficient to check the pending bit, because
795 	 * subsequent instances of this function may be queued after one of them
796 	 * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
797 	 * one of them is running, though, because it may have done the actual
798 	 * check some time ago, so allow at least one of them to block on the
799 	 * mutex while another one is running the update.
800 	 */
801 	if (!refcount_dec_not_one(&tz->thermal_check_count))
802 		return;
803 
804 	mutex_lock(&tz->thermal_check_lock);
805 
806 	thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
807 
808 	refcount_inc(&tz->thermal_check_count);
809 
810 	mutex_unlock(&tz->thermal_check_lock);
811 }
812 
813 static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz)
814 {
815 	int i;
816 
817 	acpi_handle_list_free(&tz->trips.passive.trip.devices);
818 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
819 		acpi_handle_list_free(&tz->trips.active[i].trip.devices);
820 
821 	kfree(tz);
822 }
823 
824 static int acpi_thermal_add(struct acpi_device *device)
825 {
826 	struct acpi_thermal_trip *acpi_trip;
827 	struct thermal_trip *trip;
828 	struct acpi_thermal *tz;
829 	unsigned int trip_count;
830 	int crit_temp, hot_temp;
831 	int passive_delay = 0;
832 	int result;
833 	int i;
834 
835 	if (!device)
836 		return -EINVAL;
837 
838 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
839 	if (!tz)
840 		return -ENOMEM;
841 
842 	tz->device = device;
843 	strcpy(tz->name, device->pnp.bus_id);
844 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
845 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
846 	device->driver_data = tz;
847 
848 	acpi_thermal_aml_dependency_fix(tz);
849 
850 	/* Get trip points [_CRT, _PSV, etc.] (required). */
851 	trip_count = acpi_thermal_get_trip_points(tz);
852 
853 	crit_temp = acpi_thermal_get_critical_trip(tz);
854 	if (crit_temp != THERMAL_TEMP_INVALID)
855 		trip_count++;
856 
857 	hot_temp = acpi_thermal_get_hot_trip(tz);
858 	if (hot_temp != THERMAL_TEMP_INVALID)
859 		trip_count++;
860 
861 	if (!trip_count) {
862 		pr_warn(FW_BUG "No valid trip points!\n");
863 		result = -ENODEV;
864 		goto free_memory;
865 	}
866 
867 	/* Get temperature [_TMP] (required). */
868 	result = acpi_thermal_get_temperature(tz);
869 	if (result)
870 		goto free_memory;
871 
872 	/* Set the cooling mode [_SCP] to active cooling. */
873 	acpi_execute_simple_method(tz->device->handle, "_SCP",
874 				   ACPI_THERMAL_MODE_ACTIVE);
875 
876 	/* Determine the default polling frequency [_TZP]. */
877 	if (tzp)
878 		tz->polling_frequency = tzp;
879 	else
880 		acpi_thermal_get_polling_frequency(tz);
881 
882 	acpi_thermal_guess_offset(tz, crit_temp);
883 
884 	trip = kcalloc(trip_count, sizeof(*trip), GFP_KERNEL);
885 	if (!trip) {
886 		result = -ENOMEM;
887 		goto free_memory;
888 	}
889 
890 	tz->trip_table = trip;
891 
892 	if (crit_temp != THERMAL_TEMP_INVALID) {
893 		trip->type = THERMAL_TRIP_CRITICAL;
894 		trip->temperature = acpi_thermal_temp(tz, crit_temp);
895 		trip++;
896 	}
897 
898 	if (hot_temp != THERMAL_TEMP_INVALID) {
899 		trip->type = THERMAL_TRIP_HOT;
900 		trip->temperature = acpi_thermal_temp(tz, hot_temp);
901 		trip++;
902 	}
903 
904 	acpi_trip = &tz->trips.passive.trip;
905 	if (acpi_thermal_trip_valid(acpi_trip)) {
906 		passive_delay = tz->trips.passive.delay;
907 
908 		trip->type = THERMAL_TRIP_PASSIVE;
909 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
910 		trip->priv = acpi_trip;
911 		trip++;
912 	}
913 
914 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
915 		acpi_trip =  &tz->trips.active[i].trip;
916 
917 		if (!acpi_thermal_trip_valid(acpi_trip))
918 			break;
919 
920 		trip->type = THERMAL_TRIP_ACTIVE;
921 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
922 		trip->priv = acpi_trip;
923 		trip++;
924 	}
925 
926 	result = acpi_thermal_register_thermal_zone(tz, trip_count, passive_delay);
927 	if (result)
928 		goto free_trips;
929 
930 	refcount_set(&tz->thermal_check_count, 3);
931 	mutex_init(&tz->thermal_check_lock);
932 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
933 
934 	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
935 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temp_dk));
936 
937 	result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
938 						 acpi_thermal_notify, device);
939 	if (result)
940 		goto flush_wq;
941 
942 	return 0;
943 
944 flush_wq:
945 	flush_workqueue(acpi_thermal_pm_queue);
946 	acpi_thermal_unregister_thermal_zone(tz);
947 free_trips:
948 	kfree(tz->trip_table);
949 free_memory:
950 	acpi_thermal_free_thermal_zone(tz);
951 
952 	return result;
953 }
954 
955 static void acpi_thermal_remove(struct acpi_device *device)
956 {
957 	struct acpi_thermal *tz;
958 
959 	if (!device || !acpi_driver_data(device))
960 		return;
961 
962 	tz = acpi_driver_data(device);
963 
964 	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
965 				       acpi_thermal_notify);
966 
967 	flush_workqueue(acpi_thermal_pm_queue);
968 	acpi_thermal_unregister_thermal_zone(tz);
969 	kfree(tz->trip_table);
970 	acpi_thermal_free_thermal_zone(tz);
971 }
972 
973 #ifdef CONFIG_PM_SLEEP
974 static int acpi_thermal_suspend(struct device *dev)
975 {
976 	/* Make sure the previously queued thermal check work has been done */
977 	flush_workqueue(acpi_thermal_pm_queue);
978 	return 0;
979 }
980 
981 static int acpi_thermal_resume(struct device *dev)
982 {
983 	struct acpi_thermal *tz;
984 	int i, j, power_state;
985 
986 	if (!dev)
987 		return -EINVAL;
988 
989 	tz = acpi_driver_data(to_acpi_device(dev));
990 	if (!tz)
991 		return -EINVAL;
992 
993 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
994 		struct acpi_thermal_trip *acpi_trip = &tz->trips.active[i].trip;
995 
996 		if (!acpi_thermal_trip_valid(acpi_trip))
997 			break;
998 
999 		for (j = 0; j < acpi_trip->devices.count; j++) {
1000 			acpi_bus_update_power(acpi_trip->devices.handles[j],
1001 					      &power_state);
1002 		}
1003 	}
1004 
1005 	acpi_queue_thermal_check(tz);
1006 
1007 	return AE_OK;
1008 }
1009 #else
1010 #define acpi_thermal_suspend	NULL
1011 #define acpi_thermal_resume	NULL
1012 #endif
1013 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
1014 
1015 static const struct acpi_device_id  thermal_device_ids[] = {
1016 	{ACPI_THERMAL_HID, 0},
1017 	{"", 0},
1018 };
1019 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
1020 
1021 static struct acpi_driver acpi_thermal_driver = {
1022 	.name = "thermal",
1023 	.class = ACPI_THERMAL_CLASS,
1024 	.ids = thermal_device_ids,
1025 	.ops = {
1026 		.add = acpi_thermal_add,
1027 		.remove = acpi_thermal_remove,
1028 		},
1029 	.drv.pm = &acpi_thermal_pm,
1030 };
1031 
1032 static int thermal_act(const struct dmi_system_id *d)
1033 {
1034 	if (act == 0) {
1035 		pr_notice("%s detected: disabling all active thermal trip points\n",
1036 			  d->ident);
1037 		act = -1;
1038 	}
1039 	return 0;
1040 }
1041 
1042 static int thermal_nocrt(const struct dmi_system_id *d)
1043 {
1044 	pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1045 		  d->ident);
1046 	crt = -1;
1047 	return 0;
1048 }
1049 
1050 static int thermal_tzp(const struct dmi_system_id *d)
1051 {
1052 	if (tzp == 0) {
1053 		pr_notice("%s detected: enabling thermal zone polling\n",
1054 			  d->ident);
1055 		tzp = 300;	/* 300 dS = 30 Seconds */
1056 	}
1057 	return 0;
1058 }
1059 
1060 static int thermal_psv(const struct dmi_system_id *d)
1061 {
1062 	if (psv == 0) {
1063 		pr_notice("%s detected: disabling all passive thermal trip points\n",
1064 			  d->ident);
1065 		psv = -1;
1066 	}
1067 	return 0;
1068 }
1069 
1070 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1071 	/*
1072 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1073 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1074 	 */
1075 	{
1076 	 .callback = thermal_act,
1077 	 .ident = "AOpen i915GMm-HFS",
1078 	 .matches = {
1079 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1080 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1081 		},
1082 	},
1083 	{
1084 	 .callback = thermal_psv,
1085 	 .ident = "AOpen i915GMm-HFS",
1086 	 .matches = {
1087 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1088 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1089 		},
1090 	},
1091 	{
1092 	 .callback = thermal_tzp,
1093 	 .ident = "AOpen i915GMm-HFS",
1094 	 .matches = {
1095 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1096 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1097 		},
1098 	},
1099 	{
1100 	 .callback = thermal_nocrt,
1101 	 .ident = "Gigabyte GA-7ZX",
1102 	 .matches = {
1103 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1104 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1105 		},
1106 	},
1107 	{}
1108 };
1109 
1110 static int __init acpi_thermal_init(void)
1111 {
1112 	int result;
1113 
1114 	dmi_check_system(thermal_dmi_table);
1115 
1116 	if (off) {
1117 		pr_notice("thermal control disabled\n");
1118 		return -ENODEV;
1119 	}
1120 
1121 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1122 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1123 	if (!acpi_thermal_pm_queue)
1124 		return -ENODEV;
1125 
1126 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1127 	if (result < 0) {
1128 		destroy_workqueue(acpi_thermal_pm_queue);
1129 		return -ENODEV;
1130 	}
1131 
1132 	return 0;
1133 }
1134 
1135 static void __exit acpi_thermal_exit(void)
1136 {
1137 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1138 	destroy_workqueue(acpi_thermal_pm_queue);
1139 }
1140 
1141 module_init(acpi_thermal_init);
1142 module_exit(acpi_thermal_exit);
1143 
1144 MODULE_IMPORT_NS(ACPI_THERMAL);
1145 MODULE_AUTHOR("Paul Diefenbaugh");
1146 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
1147 MODULE_LICENSE("GPL");
1148