xref: /linux/drivers/acpi/thermal.c (revision 4ae68b26c3ab5a82aa271e6e9fc9b1a06e1d6b40)
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 #define ACPI_THERMAL_CLASS		"thermal_zone"
35 #define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
36 #define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
37 #define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
38 #define ACPI_THERMAL_NOTIFY_DEVICES	0x82
39 #define ACPI_THERMAL_NOTIFY_CRITICAL	0xF0
40 #define ACPI_THERMAL_NOTIFY_HOT		0xF1
41 #define ACPI_THERMAL_MODE_ACTIVE	0x00
42 
43 #define ACPI_THERMAL_MAX_ACTIVE		10
44 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN	65
45 
46 #define ACPI_TRIPS_CRITICAL	BIT(0)
47 #define ACPI_TRIPS_HOT		BIT(1)
48 #define ACPI_TRIPS_PASSIVE	BIT(2)
49 #define ACPI_TRIPS_ACTIVE	BIT(3)
50 #define ACPI_TRIPS_DEVICES	BIT(4)
51 
52 #define ACPI_TRIPS_THRESHOLDS	(ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
53 
54 #define ACPI_TRIPS_INIT		(ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT | \
55 				 ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE | \
56 				 ACPI_TRIPS_DEVICES)
57 
58 /*
59  * This exception is thrown out in two cases:
60  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
61  *   when re-evaluating the AML code.
62  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
63  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
64  */
65 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, tz, str) \
66 do { \
67 	if (flags != ACPI_TRIPS_INIT) \
68 		acpi_handle_info(tz->device->handle, \
69 			"ACPI thermal trip point %s changed\n" \
70 			"Please report to linux-acpi@vger.kernel.org\n", str); \
71 } while (0)
72 
73 static int act;
74 module_param(act, int, 0644);
75 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
76 
77 static int crt;
78 module_param(crt, int, 0644);
79 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
80 
81 static int tzp;
82 module_param(tzp, int, 0444);
83 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
84 
85 static int nocrt;
86 module_param(nocrt, int, 0);
87 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
88 
89 static int off;
90 module_param(off, int, 0);
91 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
92 
93 static int psv;
94 module_param(psv, int, 0644);
95 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
96 
97 static struct workqueue_struct *acpi_thermal_pm_queue;
98 
99 struct acpi_thermal_critical {
100 	unsigned long temperature;
101 	bool valid;
102 };
103 
104 struct acpi_thermal_hot {
105 	unsigned long temperature;
106 	bool valid;
107 };
108 
109 struct acpi_thermal_passive {
110 	struct acpi_handle_list devices;
111 	unsigned long temperature;
112 	unsigned long tc1;
113 	unsigned long tc2;
114 	unsigned long tsp;
115 	bool valid;
116 };
117 
118 struct acpi_thermal_active {
119 	struct acpi_handle_list devices;
120 	unsigned long temperature;
121 	bool valid;
122 	bool enabled;
123 };
124 
125 struct acpi_thermal_trips {
126 	struct acpi_thermal_critical critical;
127 	struct acpi_thermal_hot hot;
128 	struct acpi_thermal_passive passive;
129 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
130 };
131 
132 struct acpi_thermal {
133 	struct acpi_device *device;
134 	acpi_bus_id name;
135 	unsigned long temperature;
136 	unsigned long last_temperature;
137 	unsigned long polling_frequency;
138 	volatile u8 zombie;
139 	struct acpi_thermal_trips trips;
140 	struct acpi_handle_list devices;
141 	struct thermal_zone_device *thermal_zone;
142 	int kelvin_offset;	/* in millidegrees */
143 	struct work_struct thermal_check_work;
144 	struct mutex thermal_check_lock;
145 	refcount_t thermal_check_count;
146 };
147 
148 /* --------------------------------------------------------------------------
149                              Thermal Zone Management
150    -------------------------------------------------------------------------- */
151 
152 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
153 {
154 	acpi_status status = AE_OK;
155 	unsigned long long tmp;
156 
157 	if (!tz)
158 		return -EINVAL;
159 
160 	tz->last_temperature = tz->temperature;
161 
162 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
163 	if (ACPI_FAILURE(status))
164 		return -ENODEV;
165 
166 	tz->temperature = tmp;
167 
168 	acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
169 			  tz->temperature);
170 
171 	return 0;
172 }
173 
174 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
175 {
176 	acpi_status status = AE_OK;
177 	unsigned long long tmp;
178 
179 	if (!tz)
180 		return -EINVAL;
181 
182 	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
183 	if (ACPI_FAILURE(status))
184 		return -ENODEV;
185 
186 	tz->polling_frequency = tmp;
187 	acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
188 			  tz->polling_frequency);
189 
190 	return 0;
191 }
192 
193 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
194 {
195 	acpi_status status;
196 	unsigned long long tmp;
197 	struct acpi_handle_list devices;
198 	bool valid = false;
199 	int i;
200 
201 	/* Critical Shutdown */
202 	if (flag & ACPI_TRIPS_CRITICAL) {
203 		status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
204 		tz->trips.critical.temperature = tmp;
205 		/*
206 		 * Treat freezing temperatures as invalid as well; some
207 		 * BIOSes return really low values and cause reboots at startup.
208 		 * Below zero (Celsius) values clearly aren't right for sure..
209 		 * ... so lets discard those as invalid.
210 		 */
211 		if (ACPI_FAILURE(status)) {
212 			tz->trips.critical.valid = false;
213 			acpi_handle_debug(tz->device->handle,
214 					  "No critical threshold\n");
215 		} else if (tmp <= 2732) {
216 			pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
217 			tz->trips.critical.valid = false;
218 		} else {
219 			tz->trips.critical.valid = true;
220 			acpi_handle_debug(tz->device->handle,
221 					  "Found critical threshold [%lu]\n",
222 					  tz->trips.critical.temperature);
223 		}
224 		if (tz->trips.critical.valid) {
225 			if (crt == -1) {
226 				tz->trips.critical.valid = false;
227 			} else if (crt > 0) {
228 				unsigned long crt_k = celsius_to_deci_kelvin(crt);
229 
230 				/*
231 				 * Allow override critical threshold
232 				 */
233 				if (crt_k > tz->trips.critical.temperature)
234 					pr_info("Critical threshold %d C\n", crt);
235 
236 				tz->trips.critical.temperature = crt_k;
237 			}
238 		}
239 	}
240 
241 	/* Critical Sleep (optional) */
242 	if (flag & ACPI_TRIPS_HOT) {
243 		status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
244 		if (ACPI_FAILURE(status)) {
245 			tz->trips.hot.valid = false;
246 			acpi_handle_debug(tz->device->handle,
247 					  "No hot threshold\n");
248 		} else {
249 			tz->trips.hot.temperature = tmp;
250 			tz->trips.hot.valid = true;
251 			acpi_handle_debug(tz->device->handle,
252 					  "Found hot threshold [%lu]\n",
253 					  tz->trips.hot.temperature);
254 		}
255 	}
256 
257 	/* Passive (optional) */
258 	if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.valid) ||
259 	    flag == ACPI_TRIPS_INIT) {
260 		valid = tz->trips.passive.valid;
261 		if (psv == -1) {
262 			status = AE_SUPPORT;
263 		} else if (psv > 0) {
264 			tmp = celsius_to_deci_kelvin(psv);
265 			status = AE_OK;
266 		} else {
267 			status = acpi_evaluate_integer(tz->device->handle,
268 						       "_PSV", NULL, &tmp);
269 		}
270 
271 		if (ACPI_FAILURE(status)) {
272 			tz->trips.passive.valid = false;
273 		} else {
274 			tz->trips.passive.temperature = tmp;
275 			tz->trips.passive.valid = true;
276 			if (flag == ACPI_TRIPS_INIT) {
277 				status = acpi_evaluate_integer(tz->device->handle,
278 							       "_TC1", NULL, &tmp);
279 				if (ACPI_FAILURE(status))
280 					tz->trips.passive.valid = false;
281 				else
282 					tz->trips.passive.tc1 = tmp;
283 
284 				status = acpi_evaluate_integer(tz->device->handle,
285 							       "_TC2", NULL, &tmp);
286 				if (ACPI_FAILURE(status))
287 					tz->trips.passive.valid = false;
288 				else
289 					tz->trips.passive.tc2 = tmp;
290 
291 				status = acpi_evaluate_integer(tz->device->handle,
292 							       "_TSP", NULL, &tmp);
293 				if (ACPI_FAILURE(status))
294 					tz->trips.passive.valid = false;
295 				else
296 					tz->trips.passive.tsp = tmp;
297 			}
298 		}
299 	}
300 	if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.valid) {
301 		memset(&devices, 0, sizeof(struct acpi_handle_list));
302 		status = acpi_evaluate_reference(tz->device->handle, "_PSL",
303 						 NULL, &devices);
304 		if (ACPI_FAILURE(status)) {
305 			acpi_handle_info(tz->device->handle,
306 					 "Invalid passive threshold\n");
307 			tz->trips.passive.valid = false;
308 		} else {
309 			tz->trips.passive.valid = true;
310 		}
311 
312 		if (memcmp(&tz->trips.passive.devices, &devices,
313 			   sizeof(struct acpi_handle_list))) {
314 			memcpy(&tz->trips.passive.devices, &devices,
315 			       sizeof(struct acpi_handle_list));
316 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
317 		}
318 	}
319 	if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
320 		if (valid != tz->trips.passive.valid)
321 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
322 	}
323 
324 	/* Active (optional) */
325 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
326 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
327 		valid = tz->trips.active[i].valid;
328 
329 		if (act == -1)
330 			break; /* disable all active trip points */
331 
332 		if (flag == ACPI_TRIPS_INIT || ((flag & ACPI_TRIPS_ACTIVE) &&
333 		    tz->trips.active[i].valid)) {
334 			status = acpi_evaluate_integer(tz->device->handle,
335 						       name, NULL, &tmp);
336 			if (ACPI_FAILURE(status)) {
337 				tz->trips.active[i].valid = false;
338 				if (i == 0)
339 					break;
340 
341 				if (act <= 0)
342 					break;
343 
344 				if (i == 1)
345 					tz->trips.active[0].temperature = celsius_to_deci_kelvin(act);
346 				else
347 					/*
348 					 * Don't allow override higher than
349 					 * the next higher trip point
350 					 */
351 					tz->trips.active[i-1].temperature =
352 						min_t(unsigned long,
353 						      tz->trips.active[i-2].temperature,
354 						      celsius_to_deci_kelvin(act));
355 
356 				break;
357 			} else {
358 				tz->trips.active[i].temperature = tmp;
359 				tz->trips.active[i].valid = true;
360 			}
361 		}
362 
363 		name[2] = 'L';
364 		if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].valid) {
365 			memset(&devices, 0, sizeof(struct acpi_handle_list));
366 			status = acpi_evaluate_reference(tz->device->handle,
367 							 name, NULL, &devices);
368 			if (ACPI_FAILURE(status)) {
369 				acpi_handle_info(tz->device->handle,
370 						 "Invalid active%d threshold\n", i);
371 				tz->trips.active[i].valid = false;
372 			} else {
373 				tz->trips.active[i].valid = true;
374 			}
375 
376 			if (memcmp(&tz->trips.active[i].devices, &devices,
377 				   sizeof(struct acpi_handle_list))) {
378 				memcpy(&tz->trips.active[i].devices, &devices,
379 				       sizeof(struct acpi_handle_list));
380 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
381 			}
382 		}
383 		if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
384 			if (valid != tz->trips.active[i].valid)
385 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
386 
387 		if (!tz->trips.active[i].valid)
388 			break;
389 	}
390 
391 	if (flag & ACPI_TRIPS_DEVICES) {
392 		memset(&devices, 0, sizeof(devices));
393 		status = acpi_evaluate_reference(tz->device->handle, "_TZD",
394 						 NULL, &devices);
395 		if (ACPI_SUCCESS(status) &&
396 		    memcmp(&tz->devices, &devices, sizeof(devices))) {
397 			tz->devices = devices;
398 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
399 		}
400 	}
401 
402 	return 0;
403 }
404 
405 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
406 {
407 	int i, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
408 	bool valid;
409 
410 	if (ret)
411 		return ret;
412 
413 	valid = tz->trips.critical.valid |
414 		tz->trips.hot.valid |
415 		tz->trips.passive.valid;
416 
417 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
418 		valid = valid || tz->trips.active[i].valid;
419 
420 	if (!valid) {
421 		pr_warn(FW_BUG "No valid trip found\n");
422 		return -ENODEV;
423 	}
424 	return 0;
425 }
426 
427 /* sys I/F for generic thermal sysfs support */
428 
429 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
430 {
431 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
432 	int result;
433 
434 	if (!tz)
435 		return -EINVAL;
436 
437 	result = acpi_thermal_get_temperature(tz);
438 	if (result)
439 		return result;
440 
441 	*temp = deci_kelvin_to_millicelsius_with_offset(tz->temperature,
442 							tz->kelvin_offset);
443 	return 0;
444 }
445 
446 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
447 				 int trip, enum thermal_trip_type *type)
448 {
449 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
450 	int i;
451 
452 	if (!tz || trip < 0)
453 		return -EINVAL;
454 
455 	if (tz->trips.critical.valid) {
456 		if (!trip) {
457 			*type = THERMAL_TRIP_CRITICAL;
458 			return 0;
459 		}
460 		trip--;
461 	}
462 
463 	if (tz->trips.hot.valid) {
464 		if (!trip) {
465 			*type = THERMAL_TRIP_HOT;
466 			return 0;
467 		}
468 		trip--;
469 	}
470 
471 	if (tz->trips.passive.valid) {
472 		if (!trip) {
473 			*type = THERMAL_TRIP_PASSIVE;
474 			return 0;
475 		}
476 		trip--;
477 	}
478 
479 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE && tz->trips.active[i].valid; i++) {
480 		if (!trip) {
481 			*type = THERMAL_TRIP_ACTIVE;
482 			return 0;
483 		}
484 		trip--;
485 	}
486 
487 	return -EINVAL;
488 }
489 
490 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
491 				 int trip, int *temp)
492 {
493 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
494 	int i;
495 
496 	if (!tz || trip < 0)
497 		return -EINVAL;
498 
499 	if (tz->trips.critical.valid) {
500 		if (!trip) {
501 			*temp = deci_kelvin_to_millicelsius_with_offset(
502 					tz->trips.critical.temperature,
503 					tz->kelvin_offset);
504 			return 0;
505 		}
506 		trip--;
507 	}
508 
509 	if (tz->trips.hot.valid) {
510 		if (!trip) {
511 			*temp = deci_kelvin_to_millicelsius_with_offset(
512 					tz->trips.hot.temperature,
513 					tz->kelvin_offset);
514 			return 0;
515 		}
516 		trip--;
517 	}
518 
519 	if (tz->trips.passive.valid) {
520 		if (!trip) {
521 			*temp = deci_kelvin_to_millicelsius_with_offset(
522 					tz->trips.passive.temperature,
523 					tz->kelvin_offset);
524 			return 0;
525 		}
526 		trip--;
527 	}
528 
529 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
530 		tz->trips.active[i].valid; i++) {
531 		if (!trip) {
532 			*temp = deci_kelvin_to_millicelsius_with_offset(
533 					tz->trips.active[i].temperature,
534 					tz->kelvin_offset);
535 			return 0;
536 		}
537 		trip--;
538 	}
539 
540 	return -EINVAL;
541 }
542 
543 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
544 				int *temperature)
545 {
546 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
547 
548 	if (tz->trips.critical.valid) {
549 		*temperature = deci_kelvin_to_millicelsius_with_offset(
550 					tz->trips.critical.temperature,
551 					tz->kelvin_offset);
552 		return 0;
553 	}
554 
555 	return -EINVAL;
556 }
557 
558 static int thermal_get_trend(struct thermal_zone_device *thermal,
559 			     int trip, enum thermal_trend *trend)
560 {
561 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
562 	enum thermal_trip_type type;
563 	int i;
564 
565 	if (thermal_get_trip_type(thermal, trip, &type))
566 		return -EINVAL;
567 
568 	if (type == THERMAL_TRIP_ACTIVE) {
569 		int trip_temp;
570 		int temp = deci_kelvin_to_millicelsius_with_offset(
571 					tz->temperature, tz->kelvin_offset);
572 		if (thermal_get_trip_temp(thermal, trip, &trip_temp))
573 			return -EINVAL;
574 
575 		if (temp > trip_temp) {
576 			*trend = THERMAL_TREND_RAISING;
577 			return 0;
578 		} else {
579 			/* Fall back on default trend */
580 			return -EINVAL;
581 		}
582 	}
583 
584 	/*
585 	 * tz->temperature has already been updated by generic thermal layer,
586 	 * before this callback being invoked
587 	 */
588 	i = tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature) +
589 	    tz->trips.passive.tc2 * (tz->temperature - tz->trips.passive.temperature);
590 
591 	if (i > 0)
592 		*trend = THERMAL_TREND_RAISING;
593 	else if (i < 0)
594 		*trend = THERMAL_TREND_DROPPING;
595 	else
596 		*trend = THERMAL_TREND_STABLE;
597 
598 	return 0;
599 }
600 
601 static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
602 {
603 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
604 
605 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
606 					dev_name(&tz->device->dev),
607 					ACPI_THERMAL_NOTIFY_HOT, 1);
608 }
609 
610 static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)
611 {
612 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
613 
614 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
615 					dev_name(&tz->device->dev),
616 					ACPI_THERMAL_NOTIFY_CRITICAL, 1);
617 
618 	thermal_zone_device_critical(thermal);
619 }
620 
621 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
622 					  struct thermal_cooling_device *cdev,
623 					  bool bind)
624 {
625 	struct acpi_device *device = cdev->devdata;
626 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
627 	struct acpi_device *dev;
628 	acpi_handle handle;
629 	int i;
630 	int j;
631 	int trip = -1;
632 	int result = 0;
633 
634 	if (tz->trips.critical.valid)
635 		trip++;
636 
637 	if (tz->trips.hot.valid)
638 		trip++;
639 
640 	if (tz->trips.passive.valid) {
641 		trip++;
642 		for (i = 0; i < tz->trips.passive.devices.count; i++) {
643 			handle = tz->trips.passive.devices.handles[i];
644 			dev = acpi_fetch_acpi_dev(handle);
645 			if (dev != device)
646 				continue;
647 
648 			if (bind)
649 				result = thermal_zone_bind_cooling_device(
650 						thermal, trip, cdev,
651 						THERMAL_NO_LIMIT,
652 						THERMAL_NO_LIMIT,
653 						THERMAL_WEIGHT_DEFAULT);
654 			else
655 				result =
656 					thermal_zone_unbind_cooling_device(
657 						thermal, trip, cdev);
658 
659 			if (result)
660 				goto failed;
661 		}
662 	}
663 
664 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
665 		if (!tz->trips.active[i].valid)
666 			break;
667 
668 		trip++;
669 		for (j = 0; j < tz->trips.active[i].devices.count; j++) {
670 			handle = tz->trips.active[i].devices.handles[j];
671 			dev = acpi_fetch_acpi_dev(handle);
672 			if (dev != device)
673 				continue;
674 
675 			if (bind)
676 				result = thermal_zone_bind_cooling_device(
677 						thermal, trip, cdev,
678 						THERMAL_NO_LIMIT,
679 						THERMAL_NO_LIMIT,
680 						THERMAL_WEIGHT_DEFAULT);
681 			else
682 				result = thermal_zone_unbind_cooling_device(
683 						thermal, trip, cdev);
684 
685 			if (result)
686 				goto failed;
687 		}
688 	}
689 
690 failed:
691 	return result;
692 }
693 
694 static int
695 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
696 				 struct thermal_cooling_device *cdev)
697 {
698 	return acpi_thermal_cooling_device_cb(thermal, cdev, true);
699 }
700 
701 static int
702 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
703 				   struct thermal_cooling_device *cdev)
704 {
705 	return acpi_thermal_cooling_device_cb(thermal, cdev, false);
706 }
707 
708 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
709 	.bind = acpi_thermal_bind_cooling_device,
710 	.unbind	= acpi_thermal_unbind_cooling_device,
711 	.get_temp = thermal_get_temp,
712 	.get_trip_type = thermal_get_trip_type,
713 	.get_trip_temp = thermal_get_trip_temp,
714 	.get_crit_temp = thermal_get_crit_temp,
715 	.get_trend = thermal_get_trend,
716 	.hot = acpi_thermal_zone_device_hot,
717 	.critical = acpi_thermal_zone_device_critical,
718 };
719 
720 static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
721 {
722 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
723 	int ret;
724 
725 	ret = sysfs_create_link(&tz->device->dev.kobj,
726 				&tzdev->kobj, "thermal_zone");
727 	if (ret)
728 		return ret;
729 
730 	ret = sysfs_create_link(&tzdev->kobj,
731 				   &tz->device->dev.kobj, "device");
732 	if (ret)
733 		sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
734 
735 	return ret;
736 }
737 
738 static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
739 {
740 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
741 
742 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
743 	sysfs_remove_link(&tzdev->kobj, "device");
744 }
745 
746 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
747 {
748 	int trips = 0;
749 	int result;
750 	acpi_status status;
751 	int i;
752 
753 	if (tz->trips.critical.valid)
754 		trips++;
755 
756 	if (tz->trips.hot.valid)
757 		trips++;
758 
759 	if (tz->trips.passive.valid)
760 		trips++;
761 
762 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE && tz->trips.active[i].valid;
763 	     i++, trips++);
764 
765 	if (tz->trips.passive.valid)
766 		tz->thermal_zone = thermal_zone_device_register("acpitz", trips, 0, tz,
767 								&acpi_thermal_zone_ops, NULL,
768 								tz->trips.passive.tsp * 100,
769 								tz->polling_frequency * 100);
770 	else
771 		tz->thermal_zone =
772 			thermal_zone_device_register("acpitz", trips, 0, tz,
773 						     &acpi_thermal_zone_ops, NULL,
774 						     0, tz->polling_frequency * 100);
775 
776 	if (IS_ERR(tz->thermal_zone))
777 		return -ENODEV;
778 
779 	result = acpi_thermal_zone_sysfs_add(tz);
780 	if (result)
781 		goto unregister_tzd;
782 
783 	status =  acpi_bus_attach_private_data(tz->device->handle,
784 					       tz->thermal_zone);
785 	if (ACPI_FAILURE(status)) {
786 		result = -ENODEV;
787 		goto remove_links;
788 	}
789 
790 	result = thermal_zone_device_enable(tz->thermal_zone);
791 	if (result)
792 		goto acpi_bus_detach;
793 
794 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
795 		 thermal_zone_device_id(tz->thermal_zone));
796 
797 	return 0;
798 
799 acpi_bus_detach:
800 	acpi_bus_detach_private_data(tz->device->handle);
801 remove_links:
802 	acpi_thermal_zone_sysfs_remove(tz);
803 unregister_tzd:
804 	thermal_zone_device_unregister(tz->thermal_zone);
805 
806 	return result;
807 }
808 
809 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
810 {
811 	acpi_thermal_zone_sysfs_remove(tz);
812 	thermal_zone_device_unregister(tz->thermal_zone);
813 	tz->thermal_zone = NULL;
814 	acpi_bus_detach_private_data(tz->device->handle);
815 }
816 
817 
818 /* --------------------------------------------------------------------------
819                                  Driver Interface
820    -------------------------------------------------------------------------- */
821 
822 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
823 {
824 	if (!work_pending(&tz->thermal_check_work))
825 		queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
826 }
827 
828 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
829 {
830 	struct acpi_thermal *tz = acpi_driver_data(device);
831 
832 	if (!tz)
833 		return;
834 
835 	switch (event) {
836 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
837 		acpi_queue_thermal_check(tz);
838 		break;
839 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
840 		acpi_thermal_trips_update(tz, ACPI_TRIPS_THRESHOLDS);
841 		acpi_queue_thermal_check(tz);
842 		acpi_bus_generate_netlink_event(device->pnp.device_class,
843 						dev_name(&device->dev), event, 0);
844 		break;
845 	case ACPI_THERMAL_NOTIFY_DEVICES:
846 		acpi_thermal_trips_update(tz, ACPI_TRIPS_DEVICES);
847 		acpi_queue_thermal_check(tz);
848 		acpi_bus_generate_netlink_event(device->pnp.device_class,
849 						dev_name(&device->dev), event, 0);
850 		break;
851 	default:
852 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
853 				  event);
854 		break;
855 	}
856 }
857 
858 /*
859  * On some platforms, the AML code has dependency about
860  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
861  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
862  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
863  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
864  *    if _TMP has never been evaluated.
865  *
866  * As this dependency is totally transparent to OS, evaluate
867  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
868  * _TMP, before they are actually used.
869  */
870 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
871 {
872 	acpi_handle handle = tz->device->handle;
873 	unsigned long long value;
874 	int i;
875 
876 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
877 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
878 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
879 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
880 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
881 		acpi_status status;
882 
883 		status = acpi_evaluate_integer(handle, name, NULL, &value);
884 		if (status == AE_NOT_FOUND)
885 			break;
886 	}
887 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
888 }
889 
890 static int acpi_thermal_get_info(struct acpi_thermal *tz)
891 {
892 	int result;
893 
894 	if (!tz)
895 		return -EINVAL;
896 
897 	acpi_thermal_aml_dependency_fix(tz);
898 
899 	/* Get trip points [_CRT, _PSV, etc.] (required) */
900 	result = acpi_thermal_get_trip_points(tz);
901 	if (result)
902 		return result;
903 
904 	/* Get temperature [_TMP] (required) */
905 	result = acpi_thermal_get_temperature(tz);
906 	if (result)
907 		return result;
908 
909 	/* Set the cooling mode [_SCP] to active cooling (default) */
910 	acpi_execute_simple_method(tz->device->handle, "_SCP",
911 				   ACPI_THERMAL_MODE_ACTIVE);
912 
913 	/* Get default polling frequency [_TZP] (optional) */
914 	if (tzp)
915 		tz->polling_frequency = tzp;
916 	else
917 		acpi_thermal_get_polling_frequency(tz);
918 
919 	return 0;
920 }
921 
922 /*
923  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
924  * handles temperature values with a single decimal place. As a consequence,
925  * some implementations use an offset of 273.1 and others use an offset of
926  * 273.2. Try to find out which one is being used, to present the most
927  * accurate and visually appealing number.
928  *
929  * The heuristic below should work for all ACPI thermal zones which have a
930  * critical trip point with a value being a multiple of 0.5 degree Celsius.
931  */
932 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
933 {
934 	if (tz->trips.critical.valid &&
935 	    (tz->trips.critical.temperature % 5) == 1)
936 		tz->kelvin_offset = 273100;
937 	else
938 		tz->kelvin_offset = 273200;
939 }
940 
941 static void acpi_thermal_check_fn(struct work_struct *work)
942 {
943 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
944 					       thermal_check_work);
945 
946 	/*
947 	 * In general, it is not sufficient to check the pending bit, because
948 	 * subsequent instances of this function may be queued after one of them
949 	 * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
950 	 * one of them is running, though, because it may have done the actual
951 	 * check some time ago, so allow at least one of them to block on the
952 	 * mutex while another one is running the update.
953 	 */
954 	if (!refcount_dec_not_one(&tz->thermal_check_count))
955 		return;
956 
957 	mutex_lock(&tz->thermal_check_lock);
958 
959 	thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
960 
961 	refcount_inc(&tz->thermal_check_count);
962 
963 	mutex_unlock(&tz->thermal_check_lock);
964 }
965 
966 static int acpi_thermal_add(struct acpi_device *device)
967 {
968 	struct acpi_thermal *tz;
969 	int result;
970 
971 	if (!device)
972 		return -EINVAL;
973 
974 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
975 	if (!tz)
976 		return -ENOMEM;
977 
978 	tz->device = device;
979 	strcpy(tz->name, device->pnp.bus_id);
980 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
981 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
982 	device->driver_data = tz;
983 
984 	result = acpi_thermal_get_info(tz);
985 	if (result)
986 		goto free_memory;
987 
988 	acpi_thermal_guess_offset(tz);
989 
990 	result = acpi_thermal_register_thermal_zone(tz);
991 	if (result)
992 		goto free_memory;
993 
994 	refcount_set(&tz->thermal_check_count, 3);
995 	mutex_init(&tz->thermal_check_lock);
996 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
997 
998 	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
999 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temperature));
1000 	goto end;
1001 
1002 free_memory:
1003 	kfree(tz);
1004 end:
1005 	return result;
1006 }
1007 
1008 static void acpi_thermal_remove(struct acpi_device *device)
1009 {
1010 	struct acpi_thermal *tz;
1011 
1012 	if (!device || !acpi_driver_data(device))
1013 		return;
1014 
1015 	flush_workqueue(acpi_thermal_pm_queue);
1016 	tz = acpi_driver_data(device);
1017 
1018 	acpi_thermal_unregister_thermal_zone(tz);
1019 	kfree(tz);
1020 }
1021 
1022 #ifdef CONFIG_PM_SLEEP
1023 static int acpi_thermal_suspend(struct device *dev)
1024 {
1025 	/* Make sure the previously queued thermal check work has been done */
1026 	flush_workqueue(acpi_thermal_pm_queue);
1027 	return 0;
1028 }
1029 
1030 static int acpi_thermal_resume(struct device *dev)
1031 {
1032 	struct acpi_thermal *tz;
1033 	int i, j, power_state, result;
1034 
1035 	if (!dev)
1036 		return -EINVAL;
1037 
1038 	tz = acpi_driver_data(to_acpi_device(dev));
1039 	if (!tz)
1040 		return -EINVAL;
1041 
1042 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1043 		if (!tz->trips.active[i].valid)
1044 			break;
1045 
1046 		tz->trips.active[i].enabled = true;
1047 		for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1048 			result = acpi_bus_update_power(
1049 					tz->trips.active[i].devices.handles[j],
1050 					&power_state);
1051 			if (result || (power_state != ACPI_STATE_D0)) {
1052 				tz->trips.active[i].enabled = false;
1053 				break;
1054 			}
1055 		}
1056 	}
1057 
1058 	acpi_queue_thermal_check(tz);
1059 
1060 	return AE_OK;
1061 }
1062 #else
1063 #define acpi_thermal_suspend	NULL
1064 #define acpi_thermal_resume	NULL
1065 #endif
1066 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
1067 
1068 static const struct acpi_device_id  thermal_device_ids[] = {
1069 	{ACPI_THERMAL_HID, 0},
1070 	{"", 0},
1071 };
1072 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
1073 
1074 static struct acpi_driver acpi_thermal_driver = {
1075 	.name = "thermal",
1076 	.class = ACPI_THERMAL_CLASS,
1077 	.ids = thermal_device_ids,
1078 	.ops = {
1079 		.add = acpi_thermal_add,
1080 		.remove = acpi_thermal_remove,
1081 		.notify = acpi_thermal_notify,
1082 		},
1083 	.drv.pm = &acpi_thermal_pm,
1084 };
1085 
1086 static int thermal_act(const struct dmi_system_id *d) {
1087 	if (act == 0) {
1088 		pr_notice("%s detected: disabling all active thermal trip points\n",
1089 			  d->ident);
1090 		act = -1;
1091 	}
1092 	return 0;
1093 }
1094 static int thermal_nocrt(const struct dmi_system_id *d) {
1095 	pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1096 		  d->ident);
1097 	nocrt = 1;
1098 	return 0;
1099 }
1100 static int thermal_tzp(const struct dmi_system_id *d) {
1101 	if (tzp == 0) {
1102 		pr_notice("%s detected: enabling thermal zone polling\n",
1103 			  d->ident);
1104 		tzp = 300;	/* 300 dS = 30 Seconds */
1105 	}
1106 	return 0;
1107 }
1108 static int thermal_psv(const struct dmi_system_id *d) {
1109 	if (psv == 0) {
1110 		pr_notice("%s detected: disabling all passive thermal trip points\n",
1111 			  d->ident);
1112 		psv = -1;
1113 	}
1114 	return 0;
1115 }
1116 
1117 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1118 	/*
1119 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1120 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1121 	 */
1122 	{
1123 	 .callback = thermal_act,
1124 	 .ident = "AOpen i915GMm-HFS",
1125 	 .matches = {
1126 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1127 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1128 		},
1129 	},
1130 	{
1131 	 .callback = thermal_psv,
1132 	 .ident = "AOpen i915GMm-HFS",
1133 	 .matches = {
1134 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1135 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1136 		},
1137 	},
1138 	{
1139 	 .callback = thermal_tzp,
1140 	 .ident = "AOpen i915GMm-HFS",
1141 	 .matches = {
1142 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1143 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1144 		},
1145 	},
1146 	{
1147 	 .callback = thermal_nocrt,
1148 	 .ident = "Gigabyte GA-7ZX",
1149 	 .matches = {
1150 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1151 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1152 		},
1153 	},
1154 	{}
1155 };
1156 
1157 static int __init acpi_thermal_init(void)
1158 {
1159 	int result;
1160 
1161 	dmi_check_system(thermal_dmi_table);
1162 
1163 	if (off) {
1164 		pr_notice("thermal control disabled\n");
1165 		return -ENODEV;
1166 	}
1167 
1168 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1169 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1170 	if (!acpi_thermal_pm_queue)
1171 		return -ENODEV;
1172 
1173 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1174 	if (result < 0) {
1175 		destroy_workqueue(acpi_thermal_pm_queue);
1176 		return -ENODEV;
1177 	}
1178 
1179 	return 0;
1180 }
1181 
1182 static void __exit acpi_thermal_exit(void)
1183 {
1184 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1185 	destroy_workqueue(acpi_thermal_pm_queue);
1186 }
1187 
1188 module_init(acpi_thermal_init);
1189 module_exit(acpi_thermal_exit);
1190 
1191 MODULE_AUTHOR("Paul Diefenbaugh");
1192 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
1193 MODULE_LICENSE("GPL");
1194