xref: /openbmc/linux/drivers/acpi/thermal.c (revision 26a9630c72ebac7c564db305a6aee54a8edde70e)
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 MODULE_AUTHOR("Paul Diefenbaugh");
47 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
48 MODULE_LICENSE("GPL");
49 
50 static int act;
51 module_param(act, int, 0644);
52 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
53 
54 static int crt;
55 module_param(crt, int, 0644);
56 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
57 
58 static int tzp;
59 module_param(tzp, int, 0444);
60 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
61 
62 static int nocrt;
63 module_param(nocrt, int, 0);
64 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
65 
66 static int off;
67 module_param(off, int, 0);
68 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
69 
70 static int psv;
71 module_param(psv, int, 0644);
72 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
73 
74 static struct workqueue_struct *acpi_thermal_pm_queue;
75 
76 static int acpi_thermal_add(struct acpi_device *device);
77 static int acpi_thermal_remove(struct acpi_device *device);
78 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
79 
80 static const struct acpi_device_id  thermal_device_ids[] = {
81 	{ACPI_THERMAL_HID, 0},
82 	{"", 0},
83 };
84 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
85 
86 #ifdef CONFIG_PM_SLEEP
87 static int acpi_thermal_suspend(struct device *dev);
88 static int acpi_thermal_resume(struct device *dev);
89 #else
90 #define acpi_thermal_suspend NULL
91 #define acpi_thermal_resume NULL
92 #endif
93 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
94 
95 static struct acpi_driver acpi_thermal_driver = {
96 	.name = "thermal",
97 	.class = ACPI_THERMAL_CLASS,
98 	.ids = thermal_device_ids,
99 	.ops = {
100 		.add = acpi_thermal_add,
101 		.remove = acpi_thermal_remove,
102 		.notify = acpi_thermal_notify,
103 		},
104 	.drv.pm = &acpi_thermal_pm,
105 };
106 
107 struct acpi_thermal_state {
108 	u8 critical:1;
109 	u8 hot:1;
110 	u8 passive:1;
111 	u8 active:1;
112 	u8 reserved:4;
113 	int active_index;
114 };
115 
116 struct acpi_thermal_state_flags {
117 	u8 valid:1;
118 	u8 enabled:1;
119 	u8 reserved:6;
120 };
121 
122 struct acpi_thermal_critical {
123 	struct acpi_thermal_state_flags flags;
124 	unsigned long temperature;
125 };
126 
127 struct acpi_thermal_hot {
128 	struct acpi_thermal_state_flags flags;
129 	unsigned long temperature;
130 };
131 
132 struct acpi_thermal_passive {
133 	struct acpi_thermal_state_flags flags;
134 	unsigned long temperature;
135 	unsigned long tc1;
136 	unsigned long tc2;
137 	unsigned long tsp;
138 	struct acpi_handle_list devices;
139 };
140 
141 struct acpi_thermal_active {
142 	struct acpi_thermal_state_flags flags;
143 	unsigned long temperature;
144 	struct acpi_handle_list devices;
145 };
146 
147 struct acpi_thermal_trips {
148 	struct acpi_thermal_critical critical;
149 	struct acpi_thermal_hot hot;
150 	struct acpi_thermal_passive passive;
151 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
152 };
153 
154 struct acpi_thermal_flags {
155 	u8 cooling_mode:1;	/* _SCP */
156 	u8 devices:1;		/* _TZD */
157 	u8 reserved:6;
158 };
159 
160 struct acpi_thermal {
161 	struct acpi_device * device;
162 	acpi_bus_id name;
163 	unsigned long temperature;
164 	unsigned long last_temperature;
165 	unsigned long polling_frequency;
166 	volatile u8 zombie;
167 	struct acpi_thermal_flags flags;
168 	struct acpi_thermal_state state;
169 	struct acpi_thermal_trips trips;
170 	struct acpi_handle_list devices;
171 	struct thermal_zone_device *thermal_zone;
172 	int kelvin_offset;	/* in millidegrees */
173 	struct work_struct thermal_check_work;
174 	struct mutex thermal_check_lock;
175 	refcount_t thermal_check_count;
176 };
177 
178 /* --------------------------------------------------------------------------
179                              Thermal Zone Management
180    -------------------------------------------------------------------------- */
181 
182 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
183 {
184 	acpi_status status = AE_OK;
185 	unsigned long long tmp;
186 
187 	if (!tz)
188 		return -EINVAL;
189 
190 	tz->last_temperature = tz->temperature;
191 
192 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
193 	if (ACPI_FAILURE(status))
194 		return -ENODEV;
195 
196 	tz->temperature = tmp;
197 
198 	acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
199 			  tz->temperature);
200 
201 	return 0;
202 }
203 
204 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
205 {
206 	acpi_status status = AE_OK;
207 	unsigned long long tmp;
208 
209 	if (!tz)
210 		return -EINVAL;
211 
212 	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
213 	if (ACPI_FAILURE(status))
214 		return -ENODEV;
215 
216 	tz->polling_frequency = tmp;
217 	acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
218 			  tz->polling_frequency);
219 
220 	return 0;
221 }
222 
223 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
224 {
225 	if (!tz)
226 		return -EINVAL;
227 
228 	if (ACPI_FAILURE(acpi_execute_simple_method(tz->device->handle,
229 						    "_SCP", mode)))
230 		return -ENODEV;
231 
232 	return 0;
233 }
234 
235 #define ACPI_TRIPS_CRITICAL	0x01
236 #define ACPI_TRIPS_HOT		0x02
237 #define ACPI_TRIPS_PASSIVE	0x04
238 #define ACPI_TRIPS_ACTIVE	0x08
239 #define ACPI_TRIPS_DEVICES	0x10
240 
241 #define ACPI_TRIPS_REFRESH_THRESHOLDS	(ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
242 #define ACPI_TRIPS_REFRESH_DEVICES	ACPI_TRIPS_DEVICES
243 
244 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |	\
245 			      ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |	\
246 			      ACPI_TRIPS_DEVICES)
247 
248 /*
249  * This exception is thrown out in two cases:
250  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
251  *   when re-evaluating the AML code.
252  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
253  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
254  */
255 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, tz, str)	\
256 do {	\
257 	if (flags != ACPI_TRIPS_INIT)	\
258 		acpi_handle_info(tz->device->handle,	\
259 		"ACPI thermal trip point %s changed\n"	\
260 		"Please report to linux-acpi@vger.kernel.org\n", str); \
261 } while (0)
262 
263 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
264 {
265 	acpi_status status = AE_OK;
266 	unsigned long long tmp;
267 	struct acpi_handle_list devices;
268 	int valid = 0;
269 	int i;
270 
271 	/* Critical Shutdown */
272 	if (flag & ACPI_TRIPS_CRITICAL) {
273 		status = acpi_evaluate_integer(tz->device->handle,
274 				"_CRT", NULL, &tmp);
275 		tz->trips.critical.temperature = tmp;
276 		/*
277 		 * Treat freezing temperatures as invalid as well; some
278 		 * BIOSes return really low values and cause reboots at startup.
279 		 * Below zero (Celsius) values clearly aren't right for sure..
280 		 * ... so lets discard those as invalid.
281 		 */
282 		if (ACPI_FAILURE(status)) {
283 			tz->trips.critical.flags.valid = 0;
284 			acpi_handle_debug(tz->device->handle,
285 					  "No critical threshold\n");
286 		} else if (tmp <= 2732) {
287 			pr_info(FW_BUG "Invalid critical threshold (%llu)\n",
288 				tmp);
289 			tz->trips.critical.flags.valid = 0;
290 		} else {
291 			tz->trips.critical.flags.valid = 1;
292 			acpi_handle_debug(tz->device->handle,
293 					  "Found critical threshold [%lu]\n",
294 					  tz->trips.critical.temperature);
295 		}
296 		if (tz->trips.critical.flags.valid == 1) {
297 			if (crt == -1) {
298 				tz->trips.critical.flags.valid = 0;
299 			} else if (crt > 0) {
300 				unsigned long crt_k = celsius_to_deci_kelvin(crt);
301 
302 				/*
303 				 * Allow override critical threshold
304 				 */
305 				if (crt_k > tz->trips.critical.temperature)
306 					pr_info("Critical threshold %d C\n", crt);
307 
308 				tz->trips.critical.temperature = crt_k;
309 			}
310 		}
311 	}
312 
313 	/* Critical Sleep (optional) */
314 	if (flag & ACPI_TRIPS_HOT) {
315 		status = acpi_evaluate_integer(tz->device->handle,
316 				"_HOT", NULL, &tmp);
317 		if (ACPI_FAILURE(status)) {
318 			tz->trips.hot.flags.valid = 0;
319 			acpi_handle_debug(tz->device->handle,
320 					  "No hot threshold\n");
321 		} else {
322 			tz->trips.hot.temperature = tmp;
323 			tz->trips.hot.flags.valid = 1;
324 			acpi_handle_debug(tz->device->handle,
325 					  "Found hot threshold [%lu]\n",
326 					  tz->trips.hot.temperature);
327 		}
328 	}
329 
330 	/* Passive (optional) */
331 	if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
332 		(flag == ACPI_TRIPS_INIT)) {
333 		valid = tz->trips.passive.flags.valid;
334 		if (psv == -1) {
335 			status = AE_SUPPORT;
336 		} else if (psv > 0) {
337 			tmp = celsius_to_deci_kelvin(psv);
338 			status = AE_OK;
339 		} else {
340 			status = acpi_evaluate_integer(tz->device->handle,
341 				"_PSV", NULL, &tmp);
342 		}
343 
344 		if (ACPI_FAILURE(status))
345 			tz->trips.passive.flags.valid = 0;
346 		else {
347 			tz->trips.passive.temperature = tmp;
348 			tz->trips.passive.flags.valid = 1;
349 			if (flag == ACPI_TRIPS_INIT) {
350 				status = acpi_evaluate_integer(
351 						tz->device->handle, "_TC1",
352 						NULL, &tmp);
353 				if (ACPI_FAILURE(status))
354 					tz->trips.passive.flags.valid = 0;
355 				else
356 					tz->trips.passive.tc1 = tmp;
357 				status = acpi_evaluate_integer(
358 						tz->device->handle, "_TC2",
359 						NULL, &tmp);
360 				if (ACPI_FAILURE(status))
361 					tz->trips.passive.flags.valid = 0;
362 				else
363 					tz->trips.passive.tc2 = tmp;
364 				status = acpi_evaluate_integer(
365 						tz->device->handle, "_TSP",
366 						NULL, &tmp);
367 				if (ACPI_FAILURE(status))
368 					tz->trips.passive.flags.valid = 0;
369 				else
370 					tz->trips.passive.tsp = tmp;
371 			}
372 		}
373 	}
374 	if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
375 		memset(&devices, 0, sizeof(struct acpi_handle_list));
376 		status = acpi_evaluate_reference(tz->device->handle, "_PSL",
377 							NULL, &devices);
378 		if (ACPI_FAILURE(status)) {
379 			acpi_handle_info(tz->device->handle,
380 					 "Invalid passive threshold\n");
381 			tz->trips.passive.flags.valid = 0;
382 		}
383 		else
384 			tz->trips.passive.flags.valid = 1;
385 
386 		if (memcmp(&tz->trips.passive.devices, &devices,
387 				sizeof(struct acpi_handle_list))) {
388 			memcpy(&tz->trips.passive.devices, &devices,
389 				sizeof(struct acpi_handle_list));
390 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
391 		}
392 	}
393 	if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
394 		if (valid != tz->trips.passive.flags.valid)
395 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
396 	}
397 
398 	/* Active (optional) */
399 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
400 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
401 		valid = tz->trips.active[i].flags.valid;
402 
403 		if (act == -1)
404 			break; /* disable all active trip points */
405 
406 		if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
407 			tz->trips.active[i].flags.valid)) {
408 			status = acpi_evaluate_integer(tz->device->handle,
409 							name, NULL, &tmp);
410 			if (ACPI_FAILURE(status)) {
411 				tz->trips.active[i].flags.valid = 0;
412 				if (i == 0)
413 					break;
414 				if (act <= 0)
415 					break;
416 				if (i == 1)
417 					tz->trips.active[0].temperature =
418 						celsius_to_deci_kelvin(act);
419 				else
420 					/*
421 					 * Don't allow override higher than
422 					 * the next higher trip point
423 					 */
424 					tz->trips.active[i - 1].temperature =
425 						(tz->trips.active[i - 2].temperature <
426 						celsius_to_deci_kelvin(act) ?
427 						tz->trips.active[i - 2].temperature :
428 						celsius_to_deci_kelvin(act));
429 				break;
430 			} else {
431 				tz->trips.active[i].temperature = tmp;
432 				tz->trips.active[i].flags.valid = 1;
433 			}
434 		}
435 
436 		name[2] = 'L';
437 		if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
438 			memset(&devices, 0, sizeof(struct acpi_handle_list));
439 			status = acpi_evaluate_reference(tz->device->handle,
440 						name, NULL, &devices);
441 			if (ACPI_FAILURE(status)) {
442 				acpi_handle_info(tz->device->handle,
443 						 "Invalid active%d threshold\n", i);
444 				tz->trips.active[i].flags.valid = 0;
445 			}
446 			else
447 				tz->trips.active[i].flags.valid = 1;
448 
449 			if (memcmp(&tz->trips.active[i].devices, &devices,
450 					sizeof(struct acpi_handle_list))) {
451 				memcpy(&tz->trips.active[i].devices, &devices,
452 					sizeof(struct acpi_handle_list));
453 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
454 			}
455 		}
456 		if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
457 			if (valid != tz->trips.active[i].flags.valid)
458 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
459 
460 		if (!tz->trips.active[i].flags.valid)
461 			break;
462 	}
463 
464 	if (flag & ACPI_TRIPS_DEVICES) {
465 		memset(&devices, 0, sizeof(devices));
466 		status = acpi_evaluate_reference(tz->device->handle, "_TZD",
467 						NULL, &devices);
468 		if (ACPI_SUCCESS(status)
469 		    && memcmp(&tz->devices, &devices, sizeof(devices))) {
470 			tz->devices = devices;
471 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
472 		}
473 	}
474 
475 	return 0;
476 }
477 
478 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
479 {
480 	int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
481 
482 	if (ret)
483 		return ret;
484 
485 	valid = tz->trips.critical.flags.valid |
486 		tz->trips.hot.flags.valid |
487 		tz->trips.passive.flags.valid;
488 
489 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
490 		valid |= tz->trips.active[i].flags.valid;
491 
492 	if (!valid) {
493 		pr_warn(FW_BUG "No valid trip found\n");
494 		return -ENODEV;
495 	}
496 	return 0;
497 }
498 
499 /* sys I/F for generic thermal sysfs support */
500 
501 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
502 {
503 	struct acpi_thermal *tz = thermal->devdata;
504 	int result;
505 
506 	if (!tz)
507 		return -EINVAL;
508 
509 	result = acpi_thermal_get_temperature(tz);
510 	if (result)
511 		return result;
512 
513 	*temp = deci_kelvin_to_millicelsius_with_offset(tz->temperature,
514 							tz->kelvin_offset);
515 	return 0;
516 }
517 
518 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
519 				 int trip, enum thermal_trip_type *type)
520 {
521 	struct acpi_thermal *tz = thermal->devdata;
522 	int i;
523 
524 	if (!tz || trip < 0)
525 		return -EINVAL;
526 
527 	if (tz->trips.critical.flags.valid) {
528 		if (!trip) {
529 			*type = THERMAL_TRIP_CRITICAL;
530 			return 0;
531 		}
532 		trip--;
533 	}
534 
535 	if (tz->trips.hot.flags.valid) {
536 		if (!trip) {
537 			*type = THERMAL_TRIP_HOT;
538 			return 0;
539 		}
540 		trip--;
541 	}
542 
543 	if (tz->trips.passive.flags.valid) {
544 		if (!trip) {
545 			*type = THERMAL_TRIP_PASSIVE;
546 			return 0;
547 		}
548 		trip--;
549 	}
550 
551 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
552 		tz->trips.active[i].flags.valid; i++) {
553 		if (!trip) {
554 			*type = THERMAL_TRIP_ACTIVE;
555 			return 0;
556 		}
557 		trip--;
558 	}
559 
560 	return -EINVAL;
561 }
562 
563 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
564 				 int trip, int *temp)
565 {
566 	struct acpi_thermal *tz = thermal->devdata;
567 	int i;
568 
569 	if (!tz || trip < 0)
570 		return -EINVAL;
571 
572 	if (tz->trips.critical.flags.valid) {
573 		if (!trip) {
574 			*temp = deci_kelvin_to_millicelsius_with_offset(
575 				tz->trips.critical.temperature,
576 				tz->kelvin_offset);
577 			return 0;
578 		}
579 		trip--;
580 	}
581 
582 	if (tz->trips.hot.flags.valid) {
583 		if (!trip) {
584 			*temp = deci_kelvin_to_millicelsius_with_offset(
585 				tz->trips.hot.temperature,
586 				tz->kelvin_offset);
587 			return 0;
588 		}
589 		trip--;
590 	}
591 
592 	if (tz->trips.passive.flags.valid) {
593 		if (!trip) {
594 			*temp = deci_kelvin_to_millicelsius_with_offset(
595 				tz->trips.passive.temperature,
596 				tz->kelvin_offset);
597 			return 0;
598 		}
599 		trip--;
600 	}
601 
602 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
603 		tz->trips.active[i].flags.valid; i++) {
604 		if (!trip) {
605 			*temp = deci_kelvin_to_millicelsius_with_offset(
606 				tz->trips.active[i].temperature,
607 				tz->kelvin_offset);
608 			return 0;
609 		}
610 		trip--;
611 	}
612 
613 	return -EINVAL;
614 }
615 
616 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
617 				int *temperature)
618 {
619 	struct acpi_thermal *tz = thermal->devdata;
620 
621 	if (tz->trips.critical.flags.valid) {
622 		*temperature = deci_kelvin_to_millicelsius_with_offset(
623 				tz->trips.critical.temperature,
624 				tz->kelvin_offset);
625 		return 0;
626 	} else
627 		return -EINVAL;
628 }
629 
630 static int thermal_get_trend(struct thermal_zone_device *thermal,
631 				int trip, enum thermal_trend *trend)
632 {
633 	struct acpi_thermal *tz = thermal->devdata;
634 	enum thermal_trip_type type;
635 	int i;
636 
637 	if (thermal_get_trip_type(thermal, trip, &type))
638 		return -EINVAL;
639 
640 	if (type == THERMAL_TRIP_ACTIVE) {
641 		int trip_temp;
642 		int temp = deci_kelvin_to_millicelsius_with_offset(
643 					tz->temperature, tz->kelvin_offset);
644 		if (thermal_get_trip_temp(thermal, trip, &trip_temp))
645 			return -EINVAL;
646 
647 		if (temp > trip_temp) {
648 			*trend = THERMAL_TREND_RAISING;
649 			return 0;
650 		} else {
651 			/* Fall back on default trend */
652 			return -EINVAL;
653 		}
654 	}
655 
656 	/*
657 	 * tz->temperature has already been updated by generic thermal layer,
658 	 * before this callback being invoked
659 	 */
660 	i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
661 		+ (tz->trips.passive.tc2
662 		* (tz->temperature - tz->trips.passive.temperature));
663 
664 	if (i > 0)
665 		*trend = THERMAL_TREND_RAISING;
666 	else if (i < 0)
667 		*trend = THERMAL_TREND_DROPPING;
668 	else
669 		*trend = THERMAL_TREND_STABLE;
670 	return 0;
671 }
672 
673 
674 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
675 			   enum thermal_trip_type trip_type)
676 {
677 	u8 type = 0;
678 	struct acpi_thermal *tz = thermal->devdata;
679 
680 	if (trip_type == THERMAL_TRIP_CRITICAL)
681 		type = ACPI_THERMAL_NOTIFY_CRITICAL;
682 	else if (trip_type == THERMAL_TRIP_HOT)
683 		type = ACPI_THERMAL_NOTIFY_HOT;
684 	else
685 		return 0;
686 
687 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
688 					dev_name(&tz->device->dev), type, 1);
689 
690 	if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
691 		return 1;
692 
693 	return 0;
694 }
695 
696 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
697 					struct thermal_cooling_device *cdev,
698 					bool bind)
699 {
700 	struct acpi_device *device = cdev->devdata;
701 	struct acpi_thermal *tz = thermal->devdata;
702 	struct acpi_device *dev;
703 	acpi_status status;
704 	acpi_handle handle;
705 	int i;
706 	int j;
707 	int trip = -1;
708 	int result = 0;
709 
710 	if (tz->trips.critical.flags.valid)
711 		trip++;
712 
713 	if (tz->trips.hot.flags.valid)
714 		trip++;
715 
716 	if (tz->trips.passive.flags.valid) {
717 		trip++;
718 		for (i = 0; i < tz->trips.passive.devices.count;
719 		    i++) {
720 			handle = tz->trips.passive.devices.handles[i];
721 			status = acpi_bus_get_device(handle, &dev);
722 			if (ACPI_FAILURE(status) || dev != device)
723 				continue;
724 			if (bind)
725 				result =
726 					thermal_zone_bind_cooling_device
727 					(thermal, trip, cdev,
728 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
729 					 THERMAL_WEIGHT_DEFAULT);
730 			else
731 				result =
732 					thermal_zone_unbind_cooling_device
733 					(thermal, trip, cdev);
734 			if (result)
735 				goto failed;
736 		}
737 	}
738 
739 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
740 		if (!tz->trips.active[i].flags.valid)
741 			break;
742 		trip++;
743 		for (j = 0;
744 		    j < tz->trips.active[i].devices.count;
745 		    j++) {
746 			handle = tz->trips.active[i].devices.handles[j];
747 			status = acpi_bus_get_device(handle, &dev);
748 			if (ACPI_FAILURE(status) || dev != device)
749 				continue;
750 			if (bind)
751 				result = thermal_zone_bind_cooling_device
752 					(thermal, trip, cdev,
753 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
754 					 THERMAL_WEIGHT_DEFAULT);
755 			else
756 				result = thermal_zone_unbind_cooling_device
757 					(thermal, trip, cdev);
758 			if (result)
759 				goto failed;
760 		}
761 	}
762 
763 	for (i = 0; i < tz->devices.count; i++) {
764 		handle = tz->devices.handles[i];
765 		status = acpi_bus_get_device(handle, &dev);
766 		if (ACPI_SUCCESS(status) && (dev == device)) {
767 			if (bind)
768 				result = thermal_zone_bind_cooling_device
769 						(thermal, THERMAL_TRIPS_NONE,
770 						 cdev, THERMAL_NO_LIMIT,
771 						 THERMAL_NO_LIMIT,
772 						 THERMAL_WEIGHT_DEFAULT);
773 			else
774 				result = thermal_zone_unbind_cooling_device
775 						(thermal, THERMAL_TRIPS_NONE,
776 						 cdev);
777 			if (result)
778 				goto failed;
779 		}
780 	}
781 
782 failed:
783 	return result;
784 }
785 
786 static int
787 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
788 					struct thermal_cooling_device *cdev)
789 {
790 	return acpi_thermal_cooling_device_cb(thermal, cdev, true);
791 }
792 
793 static int
794 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
795 					struct thermal_cooling_device *cdev)
796 {
797 	return acpi_thermal_cooling_device_cb(thermal, cdev, false);
798 }
799 
800 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
801 	.bind = acpi_thermal_bind_cooling_device,
802 	.unbind	= acpi_thermal_unbind_cooling_device,
803 	.get_temp = thermal_get_temp,
804 	.get_trip_type = thermal_get_trip_type,
805 	.get_trip_temp = thermal_get_trip_temp,
806 	.get_crit_temp = thermal_get_crit_temp,
807 	.get_trend = thermal_get_trend,
808 	.notify = thermal_notify,
809 };
810 
811 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
812 {
813 	int trips = 0;
814 	int result;
815 	acpi_status status;
816 	int i;
817 
818 	if (tz->trips.critical.flags.valid)
819 		trips++;
820 
821 	if (tz->trips.hot.flags.valid)
822 		trips++;
823 
824 	if (tz->trips.passive.flags.valid)
825 		trips++;
826 
827 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
828 			tz->trips.active[i].flags.valid; i++, trips++);
829 
830 	if (tz->trips.passive.flags.valid)
831 		tz->thermal_zone =
832 			thermal_zone_device_register("acpitz", trips, 0, tz,
833 						&acpi_thermal_zone_ops, NULL,
834 						     tz->trips.passive.tsp*100,
835 						     tz->polling_frequency*100);
836 	else
837 		tz->thermal_zone =
838 			thermal_zone_device_register("acpitz", trips, 0, tz,
839 						&acpi_thermal_zone_ops, NULL,
840 						0, tz->polling_frequency*100);
841 	if (IS_ERR(tz->thermal_zone))
842 		return -ENODEV;
843 
844 	result = sysfs_create_link(&tz->device->dev.kobj,
845 				   &tz->thermal_zone->device.kobj, "thermal_zone");
846 	if (result)
847 		goto unregister_tzd;
848 
849 	result = sysfs_create_link(&tz->thermal_zone->device.kobj,
850 				   &tz->device->dev.kobj, "device");
851 	if (result)
852 		goto remove_tz_link;
853 
854 	status =  acpi_bus_attach_private_data(tz->device->handle,
855 					       tz->thermal_zone);
856 	if (ACPI_FAILURE(status)) {
857 		result = -ENODEV;
858 		goto remove_dev_link;
859 	}
860 
861 	result = thermal_zone_device_enable(tz->thermal_zone);
862 	if (result)
863 		goto acpi_bus_detach;
864 
865 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
866 		 tz->thermal_zone->id);
867 
868 	return 0;
869 
870 acpi_bus_detach:
871 	acpi_bus_detach_private_data(tz->device->handle);
872 remove_dev_link:
873 	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
874 remove_tz_link:
875 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
876 unregister_tzd:
877 	thermal_zone_device_unregister(tz->thermal_zone);
878 
879 	return result;
880 }
881 
882 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
883 {
884 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
885 	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
886 	thermal_zone_device_unregister(tz->thermal_zone);
887 	tz->thermal_zone = NULL;
888 	acpi_bus_detach_private_data(tz->device->handle);
889 }
890 
891 
892 /* --------------------------------------------------------------------------
893                                  Driver Interface
894    -------------------------------------------------------------------------- */
895 
896 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
897 {
898 	if (!work_pending(&tz->thermal_check_work))
899 		queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
900 }
901 
902 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
903 {
904 	struct acpi_thermal *tz = acpi_driver_data(device);
905 
906 
907 	if (!tz)
908 		return;
909 
910 	switch (event) {
911 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
912 		acpi_queue_thermal_check(tz);
913 		break;
914 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
915 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
916 		acpi_queue_thermal_check(tz);
917 		acpi_bus_generate_netlink_event(device->pnp.device_class,
918 						  dev_name(&device->dev), event, 0);
919 		break;
920 	case ACPI_THERMAL_NOTIFY_DEVICES:
921 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
922 		acpi_queue_thermal_check(tz);
923 		acpi_bus_generate_netlink_event(device->pnp.device_class,
924 						  dev_name(&device->dev), event, 0);
925 		break;
926 	default:
927 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
928 				  event);
929 		break;
930 	}
931 }
932 
933 /*
934  * On some platforms, the AML code has dependency about
935  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
936  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
937  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
938  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
939  *    if _TMP has never been evaluated.
940  *
941  * As this dependency is totally transparent to OS, evaluate
942  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
943  * _TMP, before they are actually used.
944  */
945 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
946 {
947 	acpi_handle handle = tz->device->handle;
948 	unsigned long long value;
949 	int i;
950 
951 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
952 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
953 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
954 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
955 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
956 		acpi_status status;
957 
958 		status = acpi_evaluate_integer(handle, name, NULL, &value);
959 		if (status == AE_NOT_FOUND)
960 			break;
961 	}
962 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
963 }
964 
965 static int acpi_thermal_get_info(struct acpi_thermal *tz)
966 {
967 	int result = 0;
968 
969 
970 	if (!tz)
971 		return -EINVAL;
972 
973 	acpi_thermal_aml_dependency_fix(tz);
974 
975 	/* Get trip points [_CRT, _PSV, etc.] (required) */
976 	result = acpi_thermal_get_trip_points(tz);
977 	if (result)
978 		return result;
979 
980 	/* Get temperature [_TMP] (required) */
981 	result = acpi_thermal_get_temperature(tz);
982 	if (result)
983 		return result;
984 
985 	/* Set the cooling mode [_SCP] to active cooling (default) */
986 	result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
987 	if (!result)
988 		tz->flags.cooling_mode = 1;
989 
990 	/* Get default polling frequency [_TZP] (optional) */
991 	if (tzp)
992 		tz->polling_frequency = tzp;
993 	else
994 		acpi_thermal_get_polling_frequency(tz);
995 
996 	return 0;
997 }
998 
999 /*
1000  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1001  * handles temperature values with a single decimal place. As a consequence,
1002  * some implementations use an offset of 273.1 and others use an offset of
1003  * 273.2. Try to find out which one is being used, to present the most
1004  * accurate and visually appealing number.
1005  *
1006  * The heuristic below should work for all ACPI thermal zones which have a
1007  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1008  */
1009 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1010 {
1011 	if (tz->trips.critical.flags.valid &&
1012 	    (tz->trips.critical.temperature % 5) == 1)
1013 		tz->kelvin_offset = 273100;
1014 	else
1015 		tz->kelvin_offset = 273200;
1016 }
1017 
1018 static void acpi_thermal_check_fn(struct work_struct *work)
1019 {
1020 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
1021 					       thermal_check_work);
1022 
1023 	/*
1024 	 * In general, it is not sufficient to check the pending bit, because
1025 	 * subsequent instances of this function may be queued after one of them
1026 	 * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
1027 	 * one of them is running, though, because it may have done the actual
1028 	 * check some time ago, so allow at least one of them to block on the
1029 	 * mutex while another one is running the update.
1030 	 */
1031 	if (!refcount_dec_not_one(&tz->thermal_check_count))
1032 		return;
1033 
1034 	mutex_lock(&tz->thermal_check_lock);
1035 
1036 	thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
1037 
1038 	refcount_inc(&tz->thermal_check_count);
1039 
1040 	mutex_unlock(&tz->thermal_check_lock);
1041 }
1042 
1043 static int acpi_thermal_add(struct acpi_device *device)
1044 {
1045 	int result = 0;
1046 	struct acpi_thermal *tz = NULL;
1047 
1048 
1049 	if (!device)
1050 		return -EINVAL;
1051 
1052 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1053 	if (!tz)
1054 		return -ENOMEM;
1055 
1056 	tz->device = device;
1057 	strcpy(tz->name, device->pnp.bus_id);
1058 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1059 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1060 	device->driver_data = tz;
1061 
1062 	result = acpi_thermal_get_info(tz);
1063 	if (result)
1064 		goto free_memory;
1065 
1066 	acpi_thermal_guess_offset(tz);
1067 
1068 	result = acpi_thermal_register_thermal_zone(tz);
1069 	if (result)
1070 		goto free_memory;
1071 
1072 	refcount_set(&tz->thermal_check_count, 3);
1073 	mutex_init(&tz->thermal_check_lock);
1074 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
1075 
1076 	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
1077 		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temperature));
1078 	goto end;
1079 
1080 free_memory:
1081 	kfree(tz);
1082 end:
1083 	return result;
1084 }
1085 
1086 static int acpi_thermal_remove(struct acpi_device *device)
1087 {
1088 	struct acpi_thermal *tz = NULL;
1089 
1090 	if (!device || !acpi_driver_data(device))
1091 		return -EINVAL;
1092 
1093 	flush_workqueue(acpi_thermal_pm_queue);
1094 	tz = acpi_driver_data(device);
1095 
1096 	acpi_thermal_unregister_thermal_zone(tz);
1097 	kfree(tz);
1098 	return 0;
1099 }
1100 
1101 #ifdef CONFIG_PM_SLEEP
1102 static int acpi_thermal_suspend(struct device *dev)
1103 {
1104 	/* Make sure the previously queued thermal check work has been done */
1105 	flush_workqueue(acpi_thermal_pm_queue);
1106 	return 0;
1107 }
1108 
1109 static int acpi_thermal_resume(struct device *dev)
1110 {
1111 	struct acpi_thermal *tz;
1112 	int i, j, power_state, result;
1113 
1114 	if (!dev)
1115 		return -EINVAL;
1116 
1117 	tz = acpi_driver_data(to_acpi_device(dev));
1118 	if (!tz)
1119 		return -EINVAL;
1120 
1121 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1122 		if (!(&tz->trips.active[i]))
1123 			break;
1124 		if (!tz->trips.active[i].flags.valid)
1125 			break;
1126 		tz->trips.active[i].flags.enabled = 1;
1127 		for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1128 			result = acpi_bus_update_power(
1129 					tz->trips.active[i].devices.handles[j],
1130 					&power_state);
1131 			if (result || (power_state != ACPI_STATE_D0)) {
1132 				tz->trips.active[i].flags.enabled = 0;
1133 				break;
1134 			}
1135 		}
1136 		tz->state.active |= tz->trips.active[i].flags.enabled;
1137 	}
1138 
1139 	acpi_queue_thermal_check(tz);
1140 
1141 	return AE_OK;
1142 }
1143 #endif
1144 
1145 static int thermal_act(const struct dmi_system_id *d) {
1146 
1147 	if (act == 0) {
1148 		pr_notice("%s detected: disabling all active thermal trip points\n",
1149 			  d->ident);
1150 		act = -1;
1151 	}
1152 	return 0;
1153 }
1154 static int thermal_nocrt(const struct dmi_system_id *d) {
1155 
1156 	pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1157 		  d->ident);
1158 	nocrt = 1;
1159 	return 0;
1160 }
1161 static int thermal_tzp(const struct dmi_system_id *d) {
1162 
1163 	if (tzp == 0) {
1164 		pr_notice("%s detected: enabling thermal zone polling\n",
1165 			  d->ident);
1166 		tzp = 300;	/* 300 dS = 30 Seconds */
1167 	}
1168 	return 0;
1169 }
1170 static int thermal_psv(const struct dmi_system_id *d) {
1171 
1172 	if (psv == 0) {
1173 		pr_notice("%s detected: disabling all passive thermal trip points\n",
1174 			  d->ident);
1175 		psv = -1;
1176 	}
1177 	return 0;
1178 }
1179 
1180 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1181 	/*
1182 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1183 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1184 	 */
1185 	{
1186 	 .callback = thermal_act,
1187 	 .ident = "AOpen i915GMm-HFS",
1188 	 .matches = {
1189 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1190 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1191 		},
1192 	},
1193 	{
1194 	 .callback = thermal_psv,
1195 	 .ident = "AOpen i915GMm-HFS",
1196 	 .matches = {
1197 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1198 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1199 		},
1200 	},
1201 	{
1202 	 .callback = thermal_tzp,
1203 	 .ident = "AOpen i915GMm-HFS",
1204 	 .matches = {
1205 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1206 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1207 		},
1208 	},
1209 	{
1210 	 .callback = thermal_nocrt,
1211 	 .ident = "Gigabyte GA-7ZX",
1212 	 .matches = {
1213 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1214 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1215 		},
1216 	},
1217 	{}
1218 };
1219 
1220 static int __init acpi_thermal_init(void)
1221 {
1222 	int result = 0;
1223 
1224 	dmi_check_system(thermal_dmi_table);
1225 
1226 	if (off) {
1227 		pr_notice("thermal control disabled\n");
1228 		return -ENODEV;
1229 	}
1230 
1231 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1232 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1233 	if (!acpi_thermal_pm_queue)
1234 		return -ENODEV;
1235 
1236 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1237 	if (result < 0) {
1238 		destroy_workqueue(acpi_thermal_pm_queue);
1239 		return -ENODEV;
1240 	}
1241 
1242 	return 0;
1243 }
1244 
1245 static void __exit acpi_thermal_exit(void)
1246 {
1247 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1248 	destroy_workqueue(acpi_thermal_pm_queue);
1249 
1250 	return;
1251 }
1252 
1253 module_init(acpi_thermal_init);
1254 module_exit(acpi_thermal_exit);
1255