xref: /linux/drivers/acpi/thermal.c (revision 3daee2e4b3568f0ed88b0598df96547fcf21cb9b)
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 #define ACPI_THERMAL_MAX_NR_TRIPS	(ACPI_THERMAL_MAX_ACTIVE + 3)
51 
52 /*
53  * This exception is thrown out in two cases:
54  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
55  *   when re-evaluating the AML code.
56  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
57  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
58  */
59 #define ACPI_THERMAL_TRIPS_EXCEPTION(tz, str) \
60 do { \
61 	acpi_handle_info(tz->device->handle, \
62 			 "ACPI thermal trip point %s changed\n" \
63 			 "Please report to linux-acpi@vger.kernel.org\n", str); \
64 } while (0)
65 
66 static int act;
67 module_param(act, int, 0644);
68 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
69 
70 static int crt;
71 module_param(crt, int, 0644);
72 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
73 
74 static int tzp;
75 module_param(tzp, int, 0444);
76 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
77 
78 static int off;
79 module_param(off, int, 0);
80 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
81 
82 static int psv;
83 module_param(psv, int, 0644);
84 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
85 
86 static struct workqueue_struct *acpi_thermal_pm_queue;
87 
88 struct acpi_thermal_trip {
89 	unsigned long temp_dk;
90 	struct acpi_handle_list devices;
91 };
92 
93 struct acpi_thermal_passive {
94 	struct acpi_thermal_trip trip;
95 	unsigned long tc1;
96 	unsigned long tc2;
97 	unsigned long delay;
98 };
99 
100 struct acpi_thermal_active {
101 	struct acpi_thermal_trip trip;
102 };
103 
104 struct acpi_thermal_trips {
105 	struct acpi_thermal_passive passive;
106 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
107 };
108 
109 struct acpi_thermal {
110 	struct acpi_device *device;
111 	acpi_bus_id name;
112 	unsigned long temp_dk;
113 	unsigned long last_temp_dk;
114 	unsigned long polling_frequency;
115 	volatile u8 zombie;
116 	struct acpi_thermal_trips trips;
117 	struct thermal_zone_device *thermal_zone;
118 	int kelvin_offset;	/* in millidegrees */
119 	struct work_struct thermal_check_work;
120 	struct mutex thermal_check_lock;
121 	refcount_t thermal_check_count;
122 };
123 
124 /* --------------------------------------------------------------------------
125                              Thermal Zone Management
126    -------------------------------------------------------------------------- */
127 
128 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
129 {
130 	acpi_status status = AE_OK;
131 	unsigned long long tmp;
132 
133 	if (!tz)
134 		return -EINVAL;
135 
136 	tz->last_temp_dk = tz->temp_dk;
137 
138 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
139 	if (ACPI_FAILURE(status))
140 		return -ENODEV;
141 
142 	tz->temp_dk = tmp;
143 
144 	acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
145 			  tz->temp_dk);
146 
147 	return 0;
148 }
149 
150 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
151 {
152 	acpi_status status = AE_OK;
153 	unsigned long long tmp;
154 
155 	if (!tz)
156 		return -EINVAL;
157 
158 	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
159 	if (ACPI_FAILURE(status))
160 		return -ENODEV;
161 
162 	tz->polling_frequency = tmp;
163 	acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
164 			  tz->polling_frequency);
165 
166 	return 0;
167 }
168 
169 static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k)
170 {
171 	int temp;
172 
173 	if (temp_deci_k == THERMAL_TEMP_INVALID)
174 		return THERMAL_TEMP_INVALID;
175 
176 	temp = deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
177 						       tz->kelvin_offset);
178 	if (temp <= 0)
179 		return THERMAL_TEMP_INVALID;
180 
181 	return temp;
182 }
183 
184 static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip)
185 {
186 	return acpi_trip->temp_dk != THERMAL_TEMP_INVALID;
187 }
188 
189 static int active_trip_index(struct acpi_thermal *tz,
190 			     struct acpi_thermal_trip *acpi_trip)
191 {
192 	struct acpi_thermal_active *active;
193 
194 	active = container_of(acpi_trip, struct acpi_thermal_active, trip);
195 	return active - tz->trips.active;
196 }
197 
198 static long get_passive_temp(struct acpi_thermal *tz)
199 {
200 	int temp;
201 
202 	if (acpi_passive_trip_temp(tz->device, &temp))
203 		return THERMAL_TEMP_INVALID;
204 
205 	return temp;
206 }
207 
208 static long get_active_temp(struct acpi_thermal *tz, int index)
209 {
210 	int temp;
211 
212 	if (acpi_active_trip_temp(tz->device, index, &temp))
213 		return THERMAL_TEMP_INVALID;
214 
215 	/*
216 	 * If an override has been provided, apply it so there are no active
217 	 * trips with thresholds greater than the override.
218 	 */
219 	if (act > 0) {
220 		unsigned long long override = celsius_to_deci_kelvin(act);
221 
222 		if (temp > override)
223 			return override;
224 	}
225 	return temp;
226 }
227 
228 static void acpi_thermal_update_trip(struct acpi_thermal *tz,
229 				     const struct thermal_trip *trip)
230 {
231 	struct acpi_thermal_trip *acpi_trip = trip->priv;
232 
233 	if (trip->type == THERMAL_TRIP_PASSIVE) {
234 		if (psv > 0)
235 			return;
236 
237 		acpi_trip->temp_dk = get_passive_temp(tz);
238 	} else {
239 		int index = active_trip_index(tz, acpi_trip);
240 
241 		acpi_trip->temp_dk = get_active_temp(tz, index);
242 	}
243 
244 	if (!acpi_thermal_trip_valid(acpi_trip))
245 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
246 }
247 
248 static bool update_trip_devices(struct acpi_thermal *tz,
249 				struct acpi_thermal_trip *acpi_trip,
250 				int index, bool compare)
251 {
252 	struct acpi_handle_list devices = { 0 };
253 	char method[] = "_PSL";
254 
255 	if (index != ACPI_THERMAL_TRIP_PASSIVE) {
256 		method[1] = 'A';
257 		method[2] = 'L';
258 		method[3] = '0' + index;
259 	}
260 
261 	if (!acpi_evaluate_reference(tz->device->handle, method, NULL, &devices)) {
262 		acpi_handle_info(tz->device->handle, "%s evaluation failure\n", method);
263 		return false;
264 	}
265 
266 	if (acpi_handle_list_equal(&acpi_trip->devices, &devices)) {
267 		acpi_handle_list_free(&devices);
268 		return true;
269 	}
270 
271 	if (compare)
272 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "device");
273 
274 	acpi_handle_list_replace(&acpi_trip->devices, &devices);
275 	return true;
276 }
277 
278 static void acpi_thermal_update_trip_devices(struct acpi_thermal *tz,
279 					     const struct thermal_trip *trip)
280 {
281 	struct acpi_thermal_trip *acpi_trip = trip->priv;
282 	int index = trip->type == THERMAL_TRIP_PASSIVE ?
283 			ACPI_THERMAL_TRIP_PASSIVE : active_trip_index(tz, acpi_trip);
284 
285 	if (update_trip_devices(tz, acpi_trip, index, true))
286 		return;
287 
288 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
289 	ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
290 }
291 
292 struct adjust_trip_data {
293 	struct acpi_thermal *tz;
294 	u32 event;
295 };
296 
297 static int acpi_thermal_adjust_trip(struct thermal_trip *trip, void *data)
298 {
299 	struct acpi_thermal_trip *acpi_trip = trip->priv;
300 	struct adjust_trip_data *atd = data;
301 	struct acpi_thermal *tz = atd->tz;
302 	int temp;
303 
304 	if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
305 		return 0;
306 
307 	if (atd->event == ACPI_THERMAL_NOTIFY_THRESHOLDS)
308 		acpi_thermal_update_trip(tz, trip);
309 	else
310 		acpi_thermal_update_trip_devices(tz, trip);
311 
312 	if (acpi_thermal_trip_valid(acpi_trip))
313 		temp = acpi_thermal_temp(tz, acpi_trip->temp_dk);
314 	else
315 		temp = THERMAL_TEMP_INVALID;
316 
317 	thermal_zone_set_trip_temp(tz->thermal_zone, trip, temp);
318 
319 	return 0;
320 }
321 
322 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
323 {
324 	if (!work_pending(&tz->thermal_check_work))
325 		queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
326 }
327 
328 static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
329 {
330 	struct adjust_trip_data atd = { .tz = tz, .event = event };
331 	struct acpi_device *adev = tz->device;
332 
333 	/*
334 	 * Use thermal_zone_for_each_trip() to carry out the trip points
335 	 * update, so as to protect thermal_get_trend() from getting stale
336 	 * trip point temperatures and to prevent thermal_zone_device_update()
337 	 * invoked from acpi_thermal_check_fn() from producing inconsistent
338 	 * results.
339 	 */
340 	thermal_zone_for_each_trip(tz->thermal_zone,
341 				   acpi_thermal_adjust_trip, &atd);
342 	acpi_queue_thermal_check(tz);
343 	acpi_bus_generate_netlink_event(adev->pnp.device_class,
344 					dev_name(&adev->dev), event, 0);
345 }
346 
347 static int acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
348 {
349 	int temp;
350 
351 	if (crt > 0) {
352 		temp = celsius_to_deci_kelvin(crt);
353 		goto set;
354 	}
355 	if (crt == -1) {
356 		acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
357 		return THERMAL_TEMP_INVALID;
358 	}
359 
360 	if (acpi_critical_trip_temp(tz->device, &temp))
361 		return THERMAL_TEMP_INVALID;
362 
363 	if (temp <= 2732) {
364 		/*
365 		 * Below zero (Celsius) values clearly aren't right for sure,
366 		 * so discard them as invalid.
367 		 */
368 		pr_info(FW_BUG "Invalid critical threshold (%d)\n", temp);
369 		return THERMAL_TEMP_INVALID;
370 	}
371 
372 set:
373 	acpi_handle_debug(tz->device->handle, "Critical threshold [%d]\n", temp);
374 	return temp;
375 }
376 
377 static int acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
378 {
379 	int temp;
380 
381 	if (acpi_hot_trip_temp(tz->device, &temp) || temp == THERMAL_TEMP_INVALID) {
382 		acpi_handle_debug(tz->device->handle, "No hot threshold\n");
383 		return THERMAL_TEMP_INVALID;
384 	}
385 
386 	acpi_handle_debug(tz->device->handle, "Hot threshold [%d]\n", temp);
387 	return temp;
388 }
389 
390 static bool passive_trip_params_init(struct acpi_thermal *tz)
391 {
392 	unsigned long long tmp;
393 	acpi_status status;
394 
395 	status = acpi_evaluate_integer(tz->device->handle, "_TC1", NULL, &tmp);
396 	if (ACPI_FAILURE(status))
397 		return false;
398 
399 	tz->trips.passive.tc1 = tmp;
400 
401 	status = acpi_evaluate_integer(tz->device->handle, "_TC2", NULL, &tmp);
402 	if (ACPI_FAILURE(status))
403 		return false;
404 
405 	tz->trips.passive.tc2 = tmp;
406 
407 	status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
408 	if (ACPI_SUCCESS(status)) {
409 		tz->trips.passive.delay = tmp;
410 		return true;
411 	}
412 
413 	status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
414 	if (ACPI_FAILURE(status))
415 		return false;
416 
417 	tz->trips.passive.delay = tmp * 100;
418 
419 	return true;
420 }
421 
422 static bool acpi_thermal_init_trip(struct acpi_thermal *tz, int index)
423 {
424 	struct acpi_thermal_trip *acpi_trip;
425 	long temp;
426 
427 	if (index == ACPI_THERMAL_TRIP_PASSIVE) {
428 		acpi_trip = &tz->trips.passive.trip;
429 
430 		if (psv == -1)
431 			goto fail;
432 
433 		if (!passive_trip_params_init(tz))
434 			goto fail;
435 
436 		temp = psv > 0 ? celsius_to_deci_kelvin(psv) :
437 				 get_passive_temp(tz);
438 	} else {
439 		acpi_trip = &tz->trips.active[index].trip;
440 
441 		if (act == -1)
442 			goto fail;
443 
444 		temp = get_active_temp(tz, index);
445 	}
446 
447 	if (temp == THERMAL_TEMP_INVALID)
448 		goto fail;
449 
450 	if (!update_trip_devices(tz, acpi_trip, index, false))
451 		goto fail;
452 
453 	acpi_trip->temp_dk = temp;
454 	return true;
455 
456 fail:
457 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
458 	return false;
459 }
460 
461 static void acpi_thermal_get_trip_points(struct acpi_thermal *tz)
462 {
463 	int i;
464 
465 	acpi_thermal_init_trip(tz, ACPI_THERMAL_TRIP_PASSIVE);
466 
467 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
468 		if (!acpi_thermal_init_trip(tz, i))
469 			break;
470 	}
471 
472 	while (++i < ACPI_THERMAL_MAX_ACTIVE)
473 		tz->trips.active[i].trip.temp_dk = THERMAL_TEMP_INVALID;
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 const 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 					      const struct thermal_trip *trip_table,
666 					      unsigned int trip_count,
667 					      int passive_delay)
668 {
669 	int result;
670 
671 	if (trip_count)
672 		tz->thermal_zone = thermal_zone_device_register_with_trips(
673 					"acpitz", trip_table, trip_count, tz,
674 					&acpi_thermal_zone_ops, NULL, passive_delay,
675 					tz->polling_frequency * 100);
676 	else
677 		tz->thermal_zone = thermal_tripless_zone_device_register(
678 					"acpitz", tz, &acpi_thermal_zone_ops, NULL);
679 
680 	if (IS_ERR(tz->thermal_zone))
681 		return PTR_ERR(tz->thermal_zone);
682 
683 	result = acpi_thermal_zone_sysfs_add(tz);
684 	if (result)
685 		goto unregister_tzd;
686 
687 	result = thermal_zone_device_enable(tz->thermal_zone);
688 	if (result)
689 		goto remove_links;
690 
691 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
692 		 thermal_zone_device_id(tz->thermal_zone));
693 
694 	return 0;
695 
696 remove_links:
697 	acpi_thermal_zone_sysfs_remove(tz);
698 unregister_tzd:
699 	thermal_zone_device_unregister(tz->thermal_zone);
700 
701 	return result;
702 }
703 
704 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
705 {
706 	thermal_zone_device_disable(tz->thermal_zone);
707 	acpi_thermal_zone_sysfs_remove(tz);
708 	thermal_zone_device_unregister(tz->thermal_zone);
709 	tz->thermal_zone = NULL;
710 }
711 
712 
713 /* --------------------------------------------------------------------------
714                                  Driver Interface
715    -------------------------------------------------------------------------- */
716 
717 static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
718 {
719 	struct acpi_device *device = data;
720 	struct acpi_thermal *tz = acpi_driver_data(device);
721 
722 	if (!tz)
723 		return;
724 
725 	switch (event) {
726 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
727 		acpi_queue_thermal_check(tz);
728 		break;
729 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
730 	case ACPI_THERMAL_NOTIFY_DEVICES:
731 		acpi_thermal_trips_update(tz, event);
732 		break;
733 	default:
734 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
735 				  event);
736 		break;
737 	}
738 }
739 
740 /*
741  * On some platforms, the AML code has dependency about
742  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
743  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
744  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
745  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
746  *    if _TMP has never been evaluated.
747  *
748  * As this dependency is totally transparent to OS, evaluate
749  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
750  * _TMP, before they are actually used.
751  */
752 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
753 {
754 	acpi_handle handle = tz->device->handle;
755 	unsigned long long value;
756 	int i;
757 
758 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
759 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
760 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
761 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
762 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
763 		acpi_status status;
764 
765 		status = acpi_evaluate_integer(handle, name, NULL, &value);
766 		if (status == AE_NOT_FOUND)
767 			break;
768 	}
769 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
770 }
771 
772 /*
773  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
774  * handles temperature values with a single decimal place. As a consequence,
775  * some implementations use an offset of 273.1 and others use an offset of
776  * 273.2. Try to find out which one is being used, to present the most
777  * accurate and visually appealing number.
778  *
779  * The heuristic below should work for all ACPI thermal zones which have a
780  * critical trip point with a value being a multiple of 0.5 degree Celsius.
781  */
782 static void acpi_thermal_guess_offset(struct acpi_thermal *tz, long crit_temp)
783 {
784 	if (crit_temp != THERMAL_TEMP_INVALID && crit_temp % 5 == 1)
785 		tz->kelvin_offset = 273100;
786 	else
787 		tz->kelvin_offset = 273200;
788 }
789 
790 static void acpi_thermal_check_fn(struct work_struct *work)
791 {
792 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
793 					       thermal_check_work);
794 
795 	/*
796 	 * In general, it is not sufficient to check the pending bit, because
797 	 * subsequent instances of this function may be queued after one of them
798 	 * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
799 	 * one of them is running, though, because it may have done the actual
800 	 * check some time ago, so allow at least one of them to block on the
801 	 * mutex while another one is running the update.
802 	 */
803 	if (!refcount_dec_not_one(&tz->thermal_check_count))
804 		return;
805 
806 	mutex_lock(&tz->thermal_check_lock);
807 
808 	thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
809 
810 	refcount_inc(&tz->thermal_check_count);
811 
812 	mutex_unlock(&tz->thermal_check_lock);
813 }
814 
815 static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz)
816 {
817 	int i;
818 
819 	acpi_handle_list_free(&tz->trips.passive.trip.devices);
820 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
821 		acpi_handle_list_free(&tz->trips.active[i].trip.devices);
822 
823 	kfree(tz);
824 }
825 
826 static int acpi_thermal_add(struct acpi_device *device)
827 {
828 	struct thermal_trip trip_table[ACPI_THERMAL_MAX_NR_TRIPS] = { 0 };
829 	struct acpi_thermal_trip *acpi_trip;
830 	struct thermal_trip *trip;
831 	struct acpi_thermal *tz;
832 	int crit_temp, hot_temp;
833 	int passive_delay = 0;
834 	int result;
835 	int i;
836 
837 	if (!device)
838 		return -EINVAL;
839 
840 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
841 	if (!tz)
842 		return -ENOMEM;
843 
844 	tz->device = device;
845 	strcpy(tz->name, device->pnp.bus_id);
846 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
847 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
848 	device->driver_data = tz;
849 
850 	acpi_thermal_aml_dependency_fix(tz);
851 
852 	/* Get trip points [_CRT, _PSV, etc.] (required). */
853 	acpi_thermal_get_trip_points(tz);
854 
855 	crit_temp = acpi_thermal_get_critical_trip(tz);
856 	hot_temp = acpi_thermal_get_hot_trip(tz);
857 
858 	/* Get temperature [_TMP] (required). */
859 	result = acpi_thermal_get_temperature(tz);
860 	if (result)
861 		goto free_memory;
862 
863 	/* Set the cooling mode [_SCP] to active cooling. */
864 	acpi_execute_simple_method(tz->device->handle, "_SCP",
865 				   ACPI_THERMAL_MODE_ACTIVE);
866 
867 	/* Determine the default polling frequency [_TZP]. */
868 	if (tzp)
869 		tz->polling_frequency = tzp;
870 	else
871 		acpi_thermal_get_polling_frequency(tz);
872 
873 	acpi_thermal_guess_offset(tz, crit_temp);
874 
875 	trip = trip_table;
876 
877 	if (crit_temp != THERMAL_TEMP_INVALID) {
878 		trip->type = THERMAL_TRIP_CRITICAL;
879 		trip->temperature = acpi_thermal_temp(tz, crit_temp);
880 		trip++;
881 	}
882 
883 	if (hot_temp != THERMAL_TEMP_INVALID) {
884 		trip->type = THERMAL_TRIP_HOT;
885 		trip->temperature = acpi_thermal_temp(tz, hot_temp);
886 		trip++;
887 	}
888 
889 	acpi_trip = &tz->trips.passive.trip;
890 	if (acpi_thermal_trip_valid(acpi_trip)) {
891 		passive_delay = tz->trips.passive.delay;
892 
893 		trip->type = THERMAL_TRIP_PASSIVE;
894 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
895 		trip->priv = acpi_trip;
896 		trip++;
897 	}
898 
899 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
900 		acpi_trip =  &tz->trips.active[i].trip;
901 
902 		if (!acpi_thermal_trip_valid(acpi_trip))
903 			break;
904 
905 		trip->type = THERMAL_TRIP_ACTIVE;
906 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
907 		trip->priv = acpi_trip;
908 		trip++;
909 	}
910 
911 	if (trip == trip_table)
912 		pr_warn(FW_BUG "No valid trip points!\n");
913 
914 	result = acpi_thermal_register_thermal_zone(tz, trip_table,
915 						    trip - trip_table,
916 						    passive_delay);
917 	if (result)
918 		goto free_memory;
919 
920 	refcount_set(&tz->thermal_check_count, 3);
921 	mutex_init(&tz->thermal_check_lock);
922 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
923 
924 	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
925 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temp_dk));
926 
927 	result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
928 						 acpi_thermal_notify, device);
929 	if (result)
930 		goto flush_wq;
931 
932 	return 0;
933 
934 flush_wq:
935 	flush_workqueue(acpi_thermal_pm_queue);
936 	acpi_thermal_unregister_thermal_zone(tz);
937 free_memory:
938 	acpi_thermal_free_thermal_zone(tz);
939 
940 	return result;
941 }
942 
943 static void acpi_thermal_remove(struct acpi_device *device)
944 {
945 	struct acpi_thermal *tz;
946 
947 	if (!device || !acpi_driver_data(device))
948 		return;
949 
950 	tz = acpi_driver_data(device);
951 
952 	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
953 				       acpi_thermal_notify);
954 
955 	flush_workqueue(acpi_thermal_pm_queue);
956 	acpi_thermal_unregister_thermal_zone(tz);
957 	acpi_thermal_free_thermal_zone(tz);
958 }
959 
960 #ifdef CONFIG_PM_SLEEP
961 static int acpi_thermal_suspend(struct device *dev)
962 {
963 	/* Make sure the previously queued thermal check work has been done */
964 	flush_workqueue(acpi_thermal_pm_queue);
965 	return 0;
966 }
967 
968 static int acpi_thermal_resume(struct device *dev)
969 {
970 	struct acpi_thermal *tz;
971 	int i, j, power_state;
972 
973 	if (!dev)
974 		return -EINVAL;
975 
976 	tz = acpi_driver_data(to_acpi_device(dev));
977 	if (!tz)
978 		return -EINVAL;
979 
980 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
981 		struct acpi_thermal_trip *acpi_trip = &tz->trips.active[i].trip;
982 
983 		if (!acpi_thermal_trip_valid(acpi_trip))
984 			break;
985 
986 		for (j = 0; j < acpi_trip->devices.count; j++) {
987 			acpi_bus_update_power(acpi_trip->devices.handles[j],
988 					      &power_state);
989 		}
990 	}
991 
992 	acpi_queue_thermal_check(tz);
993 
994 	return AE_OK;
995 }
996 #else
997 #define acpi_thermal_suspend	NULL
998 #define acpi_thermal_resume	NULL
999 #endif
1000 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
1001 
1002 static const struct acpi_device_id  thermal_device_ids[] = {
1003 	{ACPI_THERMAL_HID, 0},
1004 	{"", 0},
1005 };
1006 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
1007 
1008 static struct acpi_driver acpi_thermal_driver = {
1009 	.name = "thermal",
1010 	.class = ACPI_THERMAL_CLASS,
1011 	.ids = thermal_device_ids,
1012 	.ops = {
1013 		.add = acpi_thermal_add,
1014 		.remove = acpi_thermal_remove,
1015 		},
1016 	.drv.pm = &acpi_thermal_pm,
1017 };
1018 
1019 static int thermal_act(const struct dmi_system_id *d)
1020 {
1021 	if (act == 0) {
1022 		pr_notice("%s detected: disabling all active thermal trip points\n",
1023 			  d->ident);
1024 		act = -1;
1025 	}
1026 	return 0;
1027 }
1028 
1029 static int thermal_nocrt(const struct dmi_system_id *d)
1030 {
1031 	pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1032 		  d->ident);
1033 	crt = -1;
1034 	return 0;
1035 }
1036 
1037 static int thermal_tzp(const struct dmi_system_id *d)
1038 {
1039 	if (tzp == 0) {
1040 		pr_notice("%s detected: enabling thermal zone polling\n",
1041 			  d->ident);
1042 		tzp = 300;	/* 300 dS = 30 Seconds */
1043 	}
1044 	return 0;
1045 }
1046 
1047 static int thermal_psv(const struct dmi_system_id *d)
1048 {
1049 	if (psv == 0) {
1050 		pr_notice("%s detected: disabling all passive thermal trip points\n",
1051 			  d->ident);
1052 		psv = -1;
1053 	}
1054 	return 0;
1055 }
1056 
1057 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1058 	/*
1059 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1060 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1061 	 */
1062 	{
1063 	 .callback = thermal_act,
1064 	 .ident = "AOpen i915GMm-HFS",
1065 	 .matches = {
1066 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1067 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1068 		},
1069 	},
1070 	{
1071 	 .callback = thermal_psv,
1072 	 .ident = "AOpen i915GMm-HFS",
1073 	 .matches = {
1074 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1075 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1076 		},
1077 	},
1078 	{
1079 	 .callback = thermal_tzp,
1080 	 .ident = "AOpen i915GMm-HFS",
1081 	 .matches = {
1082 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1083 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1084 		},
1085 	},
1086 	{
1087 	 .callback = thermal_nocrt,
1088 	 .ident = "Gigabyte GA-7ZX",
1089 	 .matches = {
1090 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1091 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1092 		},
1093 	},
1094 	{}
1095 };
1096 
1097 static int __init acpi_thermal_init(void)
1098 {
1099 	int result;
1100 
1101 	dmi_check_system(thermal_dmi_table);
1102 
1103 	if (off) {
1104 		pr_notice("thermal control disabled\n");
1105 		return -ENODEV;
1106 	}
1107 
1108 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1109 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1110 	if (!acpi_thermal_pm_queue)
1111 		return -ENODEV;
1112 
1113 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1114 	if (result < 0) {
1115 		destroy_workqueue(acpi_thermal_pm_queue);
1116 		return -ENODEV;
1117 	}
1118 
1119 	return 0;
1120 }
1121 
1122 static void __exit acpi_thermal_exit(void)
1123 {
1124 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1125 	destroy_workqueue(acpi_thermal_pm_queue);
1126 }
1127 
1128 module_init(acpi_thermal_init);
1129 module_exit(acpi_thermal_exit);
1130 
1131 MODULE_IMPORT_NS(ACPI_THERMAL);
1132 MODULE_AUTHOR("Paul Diefenbaugh");
1133 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
1134 MODULE_LICENSE("GPL");
1135