xref: /linux/drivers/acpi/thermal.c (revision 1a20a9a0ddef17c0bd67eece34a7439b02a7b0ba)
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 	if (temp_deci_k == THERMAL_TEMP_INVALID)
172 		return THERMAL_TEMP_INVALID;
173 
174 	return deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
175 						       tz->kelvin_offset);
176 }
177 
178 static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip)
179 {
180 	return acpi_trip->temp_dk != THERMAL_TEMP_INVALID;
181 }
182 
183 static int active_trip_index(struct acpi_thermal *tz,
184 			     struct acpi_thermal_trip *acpi_trip)
185 {
186 	struct acpi_thermal_active *active;
187 
188 	active = container_of(acpi_trip, struct acpi_thermal_active, trip);
189 	return active - tz->trips.active;
190 }
191 
192 static long get_passive_temp(struct acpi_thermal *tz)
193 {
194 	int temp;
195 
196 	if (acpi_passive_trip_temp(tz->device, &temp))
197 		return THERMAL_TEMP_INVALID;
198 
199 	return temp;
200 }
201 
202 static long get_active_temp(struct acpi_thermal *tz, int index)
203 {
204 	int temp;
205 
206 	if (acpi_active_trip_temp(tz->device, index, &temp))
207 		return THERMAL_TEMP_INVALID;
208 
209 	/*
210 	 * If an override has been provided, apply it so there are no active
211 	 * trips with thresholds greater than the override.
212 	 */
213 	if (act > 0) {
214 		unsigned long long override = celsius_to_deci_kelvin(act);
215 
216 		if (temp > override)
217 			return override;
218 	}
219 	return temp;
220 }
221 
222 static void acpi_thermal_update_trip(struct acpi_thermal *tz,
223 				     const struct thermal_trip *trip)
224 {
225 	struct acpi_thermal_trip *acpi_trip = trip->priv;
226 
227 	if (trip->type == THERMAL_TRIP_PASSIVE) {
228 		if (psv > 0)
229 			return;
230 
231 		acpi_trip->temp_dk = get_passive_temp(tz);
232 	} else {
233 		int index = active_trip_index(tz, acpi_trip);
234 
235 		acpi_trip->temp_dk = get_active_temp(tz, index);
236 	}
237 
238 	if (!acpi_thermal_trip_valid(acpi_trip))
239 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
240 }
241 
242 static bool update_trip_devices(struct acpi_thermal *tz,
243 				struct acpi_thermal_trip *acpi_trip,
244 				int index, bool compare)
245 {
246 	struct acpi_handle_list devices = { 0 };
247 	char method[] = "_PSL";
248 
249 	if (index != ACPI_THERMAL_TRIP_PASSIVE) {
250 		method[1] = 'A';
251 		method[2] = 'L';
252 		method[3] = '0' + index;
253 	}
254 
255 	if (!acpi_evaluate_reference(tz->device->handle, method, NULL, &devices)) {
256 		acpi_handle_info(tz->device->handle, "%s evaluation failure\n", method);
257 		return false;
258 	}
259 
260 	if (acpi_handle_list_equal(&acpi_trip->devices, &devices)) {
261 		acpi_handle_list_free(&devices);
262 		return true;
263 	}
264 
265 	if (compare)
266 		ACPI_THERMAL_TRIPS_EXCEPTION(tz, "device");
267 
268 	acpi_handle_list_replace(&acpi_trip->devices, &devices);
269 	return true;
270 }
271 
272 static void acpi_thermal_update_trip_devices(struct acpi_thermal *tz,
273 					     const struct thermal_trip *trip)
274 {
275 	struct acpi_thermal_trip *acpi_trip = trip->priv;
276 	int index = trip->type == THERMAL_TRIP_PASSIVE ?
277 			ACPI_THERMAL_TRIP_PASSIVE : active_trip_index(tz, acpi_trip);
278 
279 	if (update_trip_devices(tz, acpi_trip, index, true))
280 		return;
281 
282 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
283 	ACPI_THERMAL_TRIPS_EXCEPTION(tz, "state");
284 }
285 
286 struct adjust_trip_data {
287 	struct acpi_thermal *tz;
288 	u32 event;
289 };
290 
291 static int acpi_thermal_adjust_trip(struct thermal_trip *trip, void *data)
292 {
293 	struct acpi_thermal_trip *acpi_trip = trip->priv;
294 	struct adjust_trip_data *atd = data;
295 	struct acpi_thermal *tz = atd->tz;
296 	int temp;
297 
298 	if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
299 		return 0;
300 
301 	if (atd->event == ACPI_THERMAL_NOTIFY_THRESHOLDS)
302 		acpi_thermal_update_trip(tz, trip);
303 	else
304 		acpi_thermal_update_trip_devices(tz, trip);
305 
306 	if (acpi_thermal_trip_valid(acpi_trip))
307 		temp = acpi_thermal_temp(tz, acpi_trip->temp_dk);
308 	else
309 		temp = THERMAL_TEMP_INVALID;
310 
311 	thermal_zone_set_trip_temp(tz->thermal_zone, trip, temp);
312 
313 	return 0;
314 }
315 
316 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
317 {
318 	if (!work_pending(&tz->thermal_check_work))
319 		queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
320 }
321 
322 static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
323 {
324 	struct adjust_trip_data atd = { .tz = tz, .event = event };
325 	struct acpi_device *adev = tz->device;
326 
327 	/*
328 	 * Use thermal_zone_for_each_trip() to carry out the trip points
329 	 * update, so as to protect thermal_get_trend() from getting stale
330 	 * trip point temperatures and to prevent thermal_zone_device_update()
331 	 * invoked from acpi_thermal_check_fn() from producing inconsistent
332 	 * results.
333 	 */
334 	thermal_zone_for_each_trip(tz->thermal_zone,
335 				   acpi_thermal_adjust_trip, &atd);
336 	acpi_queue_thermal_check(tz);
337 	acpi_bus_generate_netlink_event(adev->pnp.device_class,
338 					dev_name(&adev->dev), event, 0);
339 }
340 
341 static int acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
342 {
343 	int temp;
344 
345 	if (crt > 0) {
346 		temp = celsius_to_deci_kelvin(crt);
347 		goto set;
348 	}
349 	if (crt == -1) {
350 		acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
351 		return THERMAL_TEMP_INVALID;
352 	}
353 
354 	if (acpi_critical_trip_temp(tz->device, &temp))
355 		return THERMAL_TEMP_INVALID;
356 
357 	if (temp <= 2732) {
358 		/*
359 		 * Below zero (Celsius) values clearly aren't right for sure,
360 		 * so discard them as invalid.
361 		 */
362 		pr_info(FW_BUG "Invalid critical threshold (%d)\n", temp);
363 		return THERMAL_TEMP_INVALID;
364 	}
365 
366 set:
367 	acpi_handle_debug(tz->device->handle, "Critical threshold [%d]\n", temp);
368 	return temp;
369 }
370 
371 static int acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
372 {
373 	int temp;
374 
375 	if (acpi_hot_trip_temp(tz->device, &temp) || temp == THERMAL_TEMP_INVALID) {
376 		acpi_handle_debug(tz->device->handle, "No hot threshold\n");
377 		return THERMAL_TEMP_INVALID;
378 	}
379 
380 	acpi_handle_debug(tz->device->handle, "Hot threshold [%d]\n", temp);
381 	return temp;
382 }
383 
384 static bool passive_trip_params_init(struct acpi_thermal *tz)
385 {
386 	unsigned long long tmp;
387 	acpi_status status;
388 
389 	status = acpi_evaluate_integer(tz->device->handle, "_TC1", NULL, &tmp);
390 	if (ACPI_FAILURE(status))
391 		return false;
392 
393 	tz->trips.passive.tc1 = tmp;
394 
395 	status = acpi_evaluate_integer(tz->device->handle, "_TC2", NULL, &tmp);
396 	if (ACPI_FAILURE(status))
397 		return false;
398 
399 	tz->trips.passive.tc2 = tmp;
400 
401 	status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
402 	if (ACPI_SUCCESS(status)) {
403 		tz->trips.passive.delay = tmp;
404 		return true;
405 	}
406 
407 	status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
408 	if (ACPI_FAILURE(status))
409 		return false;
410 
411 	tz->trips.passive.delay = tmp * 100;
412 
413 	return true;
414 }
415 
416 static bool acpi_thermal_init_trip(struct acpi_thermal *tz, int index)
417 {
418 	struct acpi_thermal_trip *acpi_trip;
419 	long temp;
420 
421 	if (index == ACPI_THERMAL_TRIP_PASSIVE) {
422 		acpi_trip = &tz->trips.passive.trip;
423 
424 		if (psv == -1)
425 			goto fail;
426 
427 		if (!passive_trip_params_init(tz))
428 			goto fail;
429 
430 		temp = psv > 0 ? celsius_to_deci_kelvin(psv) :
431 				 get_passive_temp(tz);
432 	} else {
433 		acpi_trip = &tz->trips.active[index].trip;
434 
435 		if (act == -1)
436 			goto fail;
437 
438 		temp = get_active_temp(tz, index);
439 	}
440 
441 	if (temp == THERMAL_TEMP_INVALID)
442 		goto fail;
443 
444 	if (!update_trip_devices(tz, acpi_trip, index, false))
445 		goto fail;
446 
447 	acpi_trip->temp_dk = temp;
448 	return true;
449 
450 fail:
451 	acpi_trip->temp_dk = THERMAL_TEMP_INVALID;
452 	return false;
453 }
454 
455 static void acpi_thermal_get_trip_points(struct acpi_thermal *tz)
456 {
457 	int i;
458 
459 	acpi_thermal_init_trip(tz, ACPI_THERMAL_TRIP_PASSIVE);
460 
461 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
462 		if (!acpi_thermal_init_trip(tz, i))
463 			break;
464 	}
465 
466 	while (++i < ACPI_THERMAL_MAX_ACTIVE)
467 		tz->trips.active[i].trip.temp_dk = THERMAL_TEMP_INVALID;
468 }
469 
470 /* sys I/F for generic thermal sysfs support */
471 
472 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
473 {
474 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
475 	int result;
476 
477 	if (!tz)
478 		return -EINVAL;
479 
480 	result = acpi_thermal_get_temperature(tz);
481 	if (result)
482 		return result;
483 
484 	*temp = deci_kelvin_to_millicelsius_with_offset(tz->temp_dk,
485 							tz->kelvin_offset);
486 	return 0;
487 }
488 
489 static int thermal_get_trend(struct thermal_zone_device *thermal,
490 			     const struct thermal_trip *trip,
491 			     enum thermal_trend *trend)
492 {
493 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
494 	struct acpi_thermal_trip *acpi_trip;
495 	int t;
496 
497 	if (!tz || !trip)
498 		return -EINVAL;
499 
500 	acpi_trip = trip->priv;
501 	if (!acpi_trip || !acpi_thermal_trip_valid(acpi_trip))
502 		return -EINVAL;
503 
504 	switch (trip->type) {
505 	case THERMAL_TRIP_PASSIVE:
506 		t = tz->trips.passive.tc1 * (tz->temp_dk -
507 						tz->last_temp_dk) +
508 			tz->trips.passive.tc2 * (tz->temp_dk -
509 						acpi_trip->temp_dk);
510 		if (t > 0)
511 			*trend = THERMAL_TREND_RAISING;
512 		else if (t < 0)
513 			*trend = THERMAL_TREND_DROPPING;
514 		else
515 			*trend = THERMAL_TREND_STABLE;
516 
517 		return 0;
518 
519 	case THERMAL_TRIP_ACTIVE:
520 		t = acpi_thermal_temp(tz, tz->temp_dk);
521 		if (t <= trip->temperature)
522 			break;
523 
524 		*trend = THERMAL_TREND_RAISING;
525 
526 		return 0;
527 
528 	default:
529 		break;
530 	}
531 
532 	return -EINVAL;
533 }
534 
535 static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
536 {
537 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
538 
539 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
540 					dev_name(&tz->device->dev),
541 					ACPI_THERMAL_NOTIFY_HOT, 1);
542 }
543 
544 static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)
545 {
546 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
547 
548 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
549 					dev_name(&tz->device->dev),
550 					ACPI_THERMAL_NOTIFY_CRITICAL, 1);
551 
552 	thermal_zone_device_critical(thermal);
553 }
554 
555 struct acpi_thermal_bind_data {
556 	struct thermal_zone_device *thermal;
557 	struct thermal_cooling_device *cdev;
558 	bool bind;
559 };
560 
561 static int bind_unbind_cdev_cb(struct thermal_trip *trip, void *arg)
562 {
563 	struct acpi_thermal_trip *acpi_trip = trip->priv;
564 	struct acpi_thermal_bind_data *bd = arg;
565 	struct thermal_zone_device *thermal = bd->thermal;
566 	struct thermal_cooling_device *cdev = bd->cdev;
567 	struct acpi_device *cdev_adev = cdev->devdata;
568 	int i;
569 
570 	/* Skip critical and hot trips. */
571 	if (!acpi_trip)
572 		return 0;
573 
574 	for (i = 0; i < acpi_trip->devices.count; i++) {
575 		acpi_handle handle = acpi_trip->devices.handles[i];
576 		struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
577 
578 		if (adev != cdev_adev)
579 			continue;
580 
581 		if (bd->bind) {
582 			int ret;
583 
584 			ret = thermal_bind_cdev_to_trip(thermal, trip, cdev,
585 							THERMAL_NO_LIMIT,
586 							THERMAL_NO_LIMIT,
587 							THERMAL_WEIGHT_DEFAULT);
588 			if (ret)
589 				return ret;
590 		} else {
591 			thermal_unbind_cdev_from_trip(thermal, trip, cdev);
592 		}
593 	}
594 
595 	return 0;
596 }
597 
598 static int acpi_thermal_bind_unbind_cdev(struct thermal_zone_device *thermal,
599 					 struct thermal_cooling_device *cdev,
600 					 bool bind)
601 {
602 	struct acpi_thermal_bind_data bd = {
603 		.thermal = thermal, .cdev = cdev, .bind = bind
604 	};
605 
606 	return for_each_thermal_trip(thermal, bind_unbind_cdev_cb, &bd);
607 }
608 
609 static int
610 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
611 				 struct thermal_cooling_device *cdev)
612 {
613 	return acpi_thermal_bind_unbind_cdev(thermal, cdev, true);
614 }
615 
616 static int
617 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
618 				   struct thermal_cooling_device *cdev)
619 {
620 	return acpi_thermal_bind_unbind_cdev(thermal, cdev, false);
621 }
622 
623 static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
624 	.bind = acpi_thermal_bind_cooling_device,
625 	.unbind	= acpi_thermal_unbind_cooling_device,
626 	.get_temp = thermal_get_temp,
627 	.get_trend = thermal_get_trend,
628 	.hot = acpi_thermal_zone_device_hot,
629 	.critical = acpi_thermal_zone_device_critical,
630 };
631 
632 static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
633 {
634 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
635 	int ret;
636 
637 	ret = sysfs_create_link(&tz->device->dev.kobj,
638 				&tzdev->kobj, "thermal_zone");
639 	if (ret)
640 		return ret;
641 
642 	ret = sysfs_create_link(&tzdev->kobj,
643 				   &tz->device->dev.kobj, "device");
644 	if (ret)
645 		sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
646 
647 	return ret;
648 }
649 
650 static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
651 {
652 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
653 
654 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
655 	sysfs_remove_link(&tzdev->kobj, "device");
656 }
657 
658 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz,
659 					      const struct thermal_trip *trip_table,
660 					      unsigned int trip_count,
661 					      int passive_delay)
662 {
663 	int result;
664 
665 	if (trip_count)
666 		tz->thermal_zone = thermal_zone_device_register_with_trips(
667 					"acpitz", trip_table, trip_count, tz,
668 					&acpi_thermal_zone_ops, NULL, passive_delay,
669 					tz->polling_frequency * 100);
670 	else
671 		tz->thermal_zone = thermal_tripless_zone_device_register(
672 					"acpitz", tz, &acpi_thermal_zone_ops, NULL);
673 
674 	if (IS_ERR(tz->thermal_zone))
675 		return PTR_ERR(tz->thermal_zone);
676 
677 	result = acpi_thermal_zone_sysfs_add(tz);
678 	if (result)
679 		goto unregister_tzd;
680 
681 	result = thermal_zone_device_enable(tz->thermal_zone);
682 	if (result)
683 		goto remove_links;
684 
685 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
686 		 thermal_zone_device_id(tz->thermal_zone));
687 
688 	return 0;
689 
690 remove_links:
691 	acpi_thermal_zone_sysfs_remove(tz);
692 unregister_tzd:
693 	thermal_zone_device_unregister(tz->thermal_zone);
694 
695 	return result;
696 }
697 
698 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
699 {
700 	thermal_zone_device_disable(tz->thermal_zone);
701 	acpi_thermal_zone_sysfs_remove(tz);
702 	thermal_zone_device_unregister(tz->thermal_zone);
703 	tz->thermal_zone = NULL;
704 }
705 
706 
707 /* --------------------------------------------------------------------------
708                                  Driver Interface
709    -------------------------------------------------------------------------- */
710 
711 static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
712 {
713 	struct acpi_device *device = data;
714 	struct acpi_thermal *tz = acpi_driver_data(device);
715 
716 	if (!tz)
717 		return;
718 
719 	switch (event) {
720 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
721 		acpi_queue_thermal_check(tz);
722 		break;
723 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
724 	case ACPI_THERMAL_NOTIFY_DEVICES:
725 		acpi_thermal_trips_update(tz, event);
726 		break;
727 	default:
728 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
729 				  event);
730 		break;
731 	}
732 }
733 
734 /*
735  * On some platforms, the AML code has dependency about
736  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
737  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
738  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
739  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
740  *    if _TMP has never been evaluated.
741  *
742  * As this dependency is totally transparent to OS, evaluate
743  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
744  * _TMP, before they are actually used.
745  */
746 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
747 {
748 	acpi_handle handle = tz->device->handle;
749 	unsigned long long value;
750 	int i;
751 
752 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
753 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
754 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
755 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
756 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
757 		acpi_status status;
758 
759 		status = acpi_evaluate_integer(handle, name, NULL, &value);
760 		if (status == AE_NOT_FOUND)
761 			break;
762 	}
763 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
764 }
765 
766 /*
767  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
768  * handles temperature values with a single decimal place. As a consequence,
769  * some implementations use an offset of 273.1 and others use an offset of
770  * 273.2. Try to find out which one is being used, to present the most
771  * accurate and visually appealing number.
772  *
773  * The heuristic below should work for all ACPI thermal zones which have a
774  * critical trip point with a value being a multiple of 0.5 degree Celsius.
775  */
776 static void acpi_thermal_guess_offset(struct acpi_thermal *tz, long crit_temp)
777 {
778 	if (crit_temp != THERMAL_TEMP_INVALID && crit_temp % 5 == 1)
779 		tz->kelvin_offset = 273100;
780 	else
781 		tz->kelvin_offset = 273200;
782 }
783 
784 static void acpi_thermal_check_fn(struct work_struct *work)
785 {
786 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
787 					       thermal_check_work);
788 
789 	/*
790 	 * In general, it is not sufficient to check the pending bit, because
791 	 * subsequent instances of this function may be queued after one of them
792 	 * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
793 	 * one of them is running, though, because it may have done the actual
794 	 * check some time ago, so allow at least one of them to block on the
795 	 * mutex while another one is running the update.
796 	 */
797 	if (!refcount_dec_not_one(&tz->thermal_check_count))
798 		return;
799 
800 	mutex_lock(&tz->thermal_check_lock);
801 
802 	thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
803 
804 	refcount_inc(&tz->thermal_check_count);
805 
806 	mutex_unlock(&tz->thermal_check_lock);
807 }
808 
809 static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz)
810 {
811 	int i;
812 
813 	acpi_handle_list_free(&tz->trips.passive.trip.devices);
814 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
815 		acpi_handle_list_free(&tz->trips.active[i].trip.devices);
816 
817 	kfree(tz);
818 }
819 
820 static int acpi_thermal_add(struct acpi_device *device)
821 {
822 	struct thermal_trip trip_table[ACPI_THERMAL_MAX_NR_TRIPS] = { 0 };
823 	struct acpi_thermal_trip *acpi_trip;
824 	struct thermal_trip *trip;
825 	struct acpi_thermal *tz;
826 	int crit_temp, hot_temp;
827 	int passive_delay = 0;
828 	int result;
829 	int i;
830 
831 	if (!device)
832 		return -EINVAL;
833 
834 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
835 	if (!tz)
836 		return -ENOMEM;
837 
838 	tz->device = device;
839 	strcpy(tz->name, device->pnp.bus_id);
840 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
841 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
842 	device->driver_data = tz;
843 
844 	acpi_thermal_aml_dependency_fix(tz);
845 
846 	/* Get trip points [_CRT, _PSV, etc.] (required). */
847 	acpi_thermal_get_trip_points(tz);
848 
849 	crit_temp = acpi_thermal_get_critical_trip(tz);
850 	hot_temp = acpi_thermal_get_hot_trip(tz);
851 
852 	/* Get temperature [_TMP] (required). */
853 	result = acpi_thermal_get_temperature(tz);
854 	if (result)
855 		goto free_memory;
856 
857 	/* Set the cooling mode [_SCP] to active cooling. */
858 	acpi_execute_simple_method(tz->device->handle, "_SCP",
859 				   ACPI_THERMAL_MODE_ACTIVE);
860 
861 	/* Determine the default polling frequency [_TZP]. */
862 	if (tzp)
863 		tz->polling_frequency = tzp;
864 	else
865 		acpi_thermal_get_polling_frequency(tz);
866 
867 	acpi_thermal_guess_offset(tz, crit_temp);
868 
869 	trip = trip_table;
870 
871 	if (crit_temp != THERMAL_TEMP_INVALID) {
872 		trip->type = THERMAL_TRIP_CRITICAL;
873 		trip->temperature = acpi_thermal_temp(tz, crit_temp);
874 		trip++;
875 	}
876 
877 	if (hot_temp != THERMAL_TEMP_INVALID) {
878 		trip->type = THERMAL_TRIP_HOT;
879 		trip->temperature = acpi_thermal_temp(tz, hot_temp);
880 		trip++;
881 	}
882 
883 	acpi_trip = &tz->trips.passive.trip;
884 	if (acpi_thermal_trip_valid(acpi_trip)) {
885 		passive_delay = tz->trips.passive.delay;
886 
887 		trip->type = THERMAL_TRIP_PASSIVE;
888 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
889 		trip->priv = acpi_trip;
890 		trip++;
891 	}
892 
893 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
894 		acpi_trip =  &tz->trips.active[i].trip;
895 
896 		if (!acpi_thermal_trip_valid(acpi_trip))
897 			break;
898 
899 		trip->type = THERMAL_TRIP_ACTIVE;
900 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
901 		trip->priv = acpi_trip;
902 		trip++;
903 	}
904 
905 	if (trip == trip_table)
906 		pr_warn(FW_BUG "No valid trip points!\n");
907 
908 	result = acpi_thermal_register_thermal_zone(tz, trip_table,
909 						    trip - trip_table,
910 						    passive_delay);
911 	if (result)
912 		goto free_memory;
913 
914 	refcount_set(&tz->thermal_check_count, 3);
915 	mutex_init(&tz->thermal_check_lock);
916 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
917 
918 	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
919 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temp_dk));
920 
921 	result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
922 						 acpi_thermal_notify, device);
923 	if (result)
924 		goto flush_wq;
925 
926 	return 0;
927 
928 flush_wq:
929 	flush_workqueue(acpi_thermal_pm_queue);
930 	acpi_thermal_unregister_thermal_zone(tz);
931 free_memory:
932 	acpi_thermal_free_thermal_zone(tz);
933 
934 	return result;
935 }
936 
937 static void acpi_thermal_remove(struct acpi_device *device)
938 {
939 	struct acpi_thermal *tz;
940 
941 	if (!device || !acpi_driver_data(device))
942 		return;
943 
944 	tz = acpi_driver_data(device);
945 
946 	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
947 				       acpi_thermal_notify);
948 
949 	flush_workqueue(acpi_thermal_pm_queue);
950 	acpi_thermal_unregister_thermal_zone(tz);
951 	acpi_thermal_free_thermal_zone(tz);
952 }
953 
954 #ifdef CONFIG_PM_SLEEP
955 static int acpi_thermal_suspend(struct device *dev)
956 {
957 	/* Make sure the previously queued thermal check work has been done */
958 	flush_workqueue(acpi_thermal_pm_queue);
959 	return 0;
960 }
961 
962 static int acpi_thermal_resume(struct device *dev)
963 {
964 	struct acpi_thermal *tz;
965 	int i, j, power_state;
966 
967 	if (!dev)
968 		return -EINVAL;
969 
970 	tz = acpi_driver_data(to_acpi_device(dev));
971 	if (!tz)
972 		return -EINVAL;
973 
974 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
975 		struct acpi_thermal_trip *acpi_trip = &tz->trips.active[i].trip;
976 
977 		if (!acpi_thermal_trip_valid(acpi_trip))
978 			break;
979 
980 		for (j = 0; j < acpi_trip->devices.count; j++) {
981 			acpi_bus_update_power(acpi_trip->devices.handles[j],
982 					      &power_state);
983 		}
984 	}
985 
986 	acpi_queue_thermal_check(tz);
987 
988 	return AE_OK;
989 }
990 #else
991 #define acpi_thermal_suspend	NULL
992 #define acpi_thermal_resume	NULL
993 #endif
994 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
995 
996 static const struct acpi_device_id  thermal_device_ids[] = {
997 	{ACPI_THERMAL_HID, 0},
998 	{"", 0},
999 };
1000 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
1001 
1002 static struct acpi_driver acpi_thermal_driver = {
1003 	.name = "thermal",
1004 	.class = ACPI_THERMAL_CLASS,
1005 	.ids = thermal_device_ids,
1006 	.ops = {
1007 		.add = acpi_thermal_add,
1008 		.remove = acpi_thermal_remove,
1009 		},
1010 	.drv.pm = &acpi_thermal_pm,
1011 };
1012 
1013 static int thermal_act(const struct dmi_system_id *d)
1014 {
1015 	if (act == 0) {
1016 		pr_notice("%s detected: disabling all active thermal trip points\n",
1017 			  d->ident);
1018 		act = -1;
1019 	}
1020 	return 0;
1021 }
1022 
1023 static int thermal_nocrt(const struct dmi_system_id *d)
1024 {
1025 	pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1026 		  d->ident);
1027 	crt = -1;
1028 	return 0;
1029 }
1030 
1031 static int thermal_tzp(const struct dmi_system_id *d)
1032 {
1033 	if (tzp == 0) {
1034 		pr_notice("%s detected: enabling thermal zone polling\n",
1035 			  d->ident);
1036 		tzp = 300;	/* 300 dS = 30 Seconds */
1037 	}
1038 	return 0;
1039 }
1040 
1041 static int thermal_psv(const struct dmi_system_id *d)
1042 {
1043 	if (psv == 0) {
1044 		pr_notice("%s detected: disabling all passive thermal trip points\n",
1045 			  d->ident);
1046 		psv = -1;
1047 	}
1048 	return 0;
1049 }
1050 
1051 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1052 	/*
1053 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1054 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1055 	 */
1056 	{
1057 	 .callback = thermal_act,
1058 	 .ident = "AOpen i915GMm-HFS",
1059 	 .matches = {
1060 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1061 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1062 		},
1063 	},
1064 	{
1065 	 .callback = thermal_psv,
1066 	 .ident = "AOpen i915GMm-HFS",
1067 	 .matches = {
1068 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1069 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1070 		},
1071 	},
1072 	{
1073 	 .callback = thermal_tzp,
1074 	 .ident = "AOpen i915GMm-HFS",
1075 	 .matches = {
1076 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1077 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1078 		},
1079 	},
1080 	{
1081 	 .callback = thermal_nocrt,
1082 	 .ident = "Gigabyte GA-7ZX",
1083 	 .matches = {
1084 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1085 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1086 		},
1087 	},
1088 	{}
1089 };
1090 
1091 static int __init acpi_thermal_init(void)
1092 {
1093 	int result;
1094 
1095 	dmi_check_system(thermal_dmi_table);
1096 
1097 	if (off) {
1098 		pr_notice("thermal control disabled\n");
1099 		return -ENODEV;
1100 	}
1101 
1102 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1103 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1104 	if (!acpi_thermal_pm_queue)
1105 		return -ENODEV;
1106 
1107 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1108 	if (result < 0) {
1109 		destroy_workqueue(acpi_thermal_pm_queue);
1110 		return -ENODEV;
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 static void __exit acpi_thermal_exit(void)
1117 {
1118 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1119 	destroy_workqueue(acpi_thermal_pm_queue);
1120 }
1121 
1122 module_init(acpi_thermal_init);
1123 module_exit(acpi_thermal_exit);
1124 
1125 MODULE_IMPORT_NS(ACPI_THERMAL);
1126 MODULE_AUTHOR("Paul Diefenbaugh");
1127 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
1128 MODULE_LICENSE("GPL");
1129