xref: /openbmc/linux/drivers/acpi/thermal.c (revision 86db9f28)
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 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/dmi.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
21 #include <linux/types.h>
22 #include <linux/jiffies.h>
23 #include <linux/kmod.h>
24 #include <linux/reboot.h>
25 #include <linux/device.h>
26 #include <linux/thermal.h>
27 #include <linux/acpi.h>
28 #include <linux/workqueue.h>
29 #include <linux/uaccess.h>
30 
31 #define PREFIX "ACPI: "
32 
33 #define ACPI_THERMAL_CLASS		"thermal_zone"
34 #define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
35 #define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
36 #define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
37 #define ACPI_THERMAL_NOTIFY_DEVICES	0x82
38 #define ACPI_THERMAL_NOTIFY_CRITICAL	0xF0
39 #define ACPI_THERMAL_NOTIFY_HOT		0xF1
40 #define ACPI_THERMAL_MODE_ACTIVE	0x00
41 
42 #define ACPI_THERMAL_MAX_ACTIVE	10
43 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
44 
45 #define _COMPONENT		ACPI_THERMAL_COMPONENT
46 ACPI_MODULE_NAME("thermal");
47 
48 MODULE_AUTHOR("Paul Diefenbaugh");
49 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
50 MODULE_LICENSE("GPL");
51 
52 static int act;
53 module_param(act, int, 0644);
54 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
55 
56 static int crt;
57 module_param(crt, int, 0644);
58 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
59 
60 static int tzp;
61 module_param(tzp, int, 0444);
62 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
63 
64 static int nocrt;
65 module_param(nocrt, int, 0);
66 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
67 
68 static int off;
69 module_param(off, int, 0);
70 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
71 
72 static int psv;
73 module_param(psv, int, 0644);
74 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
75 
76 static struct workqueue_struct *acpi_thermal_pm_queue;
77 
78 static int acpi_thermal_add(struct acpi_device *device);
79 static int acpi_thermal_remove(struct acpi_device *device);
80 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
81 
82 static const struct acpi_device_id  thermal_device_ids[] = {
83 	{ACPI_THERMAL_HID, 0},
84 	{"", 0},
85 };
86 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
87 
88 #ifdef CONFIG_PM_SLEEP
89 static int acpi_thermal_suspend(struct device *dev);
90 static int acpi_thermal_resume(struct device *dev);
91 #else
92 #define acpi_thermal_suspend NULL
93 #define acpi_thermal_resume NULL
94 #endif
95 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
96 
97 static struct acpi_driver acpi_thermal_driver = {
98 	.name = "thermal",
99 	.class = ACPI_THERMAL_CLASS,
100 	.ids = thermal_device_ids,
101 	.ops = {
102 		.add = acpi_thermal_add,
103 		.remove = acpi_thermal_remove,
104 		.notify = acpi_thermal_notify,
105 		},
106 	.drv.pm = &acpi_thermal_pm,
107 };
108 
109 struct acpi_thermal_state {
110 	u8 critical:1;
111 	u8 hot:1;
112 	u8 passive:1;
113 	u8 active:1;
114 	u8 reserved:4;
115 	int active_index;
116 };
117 
118 struct acpi_thermal_state_flags {
119 	u8 valid:1;
120 	u8 enabled:1;
121 	u8 reserved:6;
122 };
123 
124 struct acpi_thermal_critical {
125 	struct acpi_thermal_state_flags flags;
126 	unsigned long temperature;
127 };
128 
129 struct acpi_thermal_hot {
130 	struct acpi_thermal_state_flags flags;
131 	unsigned long temperature;
132 };
133 
134 struct acpi_thermal_passive {
135 	struct acpi_thermal_state_flags flags;
136 	unsigned long temperature;
137 	unsigned long tc1;
138 	unsigned long tc2;
139 	unsigned long tsp;
140 	struct acpi_handle_list devices;
141 };
142 
143 struct acpi_thermal_active {
144 	struct acpi_thermal_state_flags flags;
145 	unsigned long temperature;
146 	struct acpi_handle_list devices;
147 };
148 
149 struct acpi_thermal_trips {
150 	struct acpi_thermal_critical critical;
151 	struct acpi_thermal_hot hot;
152 	struct acpi_thermal_passive passive;
153 	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
154 };
155 
156 struct acpi_thermal_flags {
157 	u8 cooling_mode:1;	/* _SCP */
158 	u8 devices:1;		/* _TZD */
159 	u8 reserved:6;
160 };
161 
162 struct acpi_thermal {
163 	struct acpi_device * device;
164 	acpi_bus_id name;
165 	unsigned long temperature;
166 	unsigned long last_temperature;
167 	unsigned long polling_frequency;
168 	volatile u8 zombie;
169 	struct acpi_thermal_flags flags;
170 	struct acpi_thermal_state state;
171 	struct acpi_thermal_trips trips;
172 	struct acpi_handle_list devices;
173 	struct thermal_zone_device *thermal_zone;
174 	int tz_enabled;
175 	int kelvin_offset;
176 	struct work_struct thermal_check_work;
177 };
178 
179 /* --------------------------------------------------------------------------
180                              Thermal Zone Management
181    -------------------------------------------------------------------------- */
182 
183 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
184 {
185 	acpi_status status = AE_OK;
186 	unsigned long long tmp;
187 
188 	if (!tz)
189 		return -EINVAL;
190 
191 	tz->last_temperature = tz->temperature;
192 
193 	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
194 	if (ACPI_FAILURE(status))
195 		return -ENODEV;
196 
197 	tz->temperature = tmp;
198 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "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_DEBUG_PRINT((ACPI_DB_INFO, "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, str)	\
256 do {	\
257 	if (flags != ACPI_TRIPS_INIT)	\
258 		ACPI_EXCEPTION((AE_INFO, AE_ERROR,	\
259 		"ACPI thermal trip point %s changed\n"	\
260 		"Please send acpidump to linux-acpi@vger.kernel.org", 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_DEBUG_PRINT((ACPI_DB_INFO,
285 					  "No critical threshold\n"));
286 		} else if (tmp <= 2732) {
287 			pr_warn(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_DEBUG_PRINT((ACPI_DB_INFO,
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 				 * Allow override critical threshold
303 				 */
304 				if (crt_k > tz->trips.critical.temperature)
305 					pr_warn(PREFIX "Critical threshold %d C\n",
306 						crt);
307 				tz->trips.critical.temperature = crt_k;
308 			}
309 		}
310 	}
311 
312 	/* Critical Sleep (optional) */
313 	if (flag & ACPI_TRIPS_HOT) {
314 		status = acpi_evaluate_integer(tz->device->handle,
315 				"_HOT", NULL, &tmp);
316 		if (ACPI_FAILURE(status)) {
317 			tz->trips.hot.flags.valid = 0;
318 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
319 					"No hot threshold\n"));
320 		} else {
321 			tz->trips.hot.temperature = tmp;
322 			tz->trips.hot.flags.valid = 1;
323 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
324 					"Found hot threshold [%lu]\n",
325 					tz->trips.hot.temperature));
326 		}
327 	}
328 
329 	/* Passive (optional) */
330 	if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
331 		(flag == ACPI_TRIPS_INIT)) {
332 		valid = tz->trips.passive.flags.valid;
333 		if (psv == -1) {
334 			status = AE_SUPPORT;
335 		} else if (psv > 0) {
336 			tmp = CELSIUS_TO_DECI_KELVIN(psv);
337 			status = AE_OK;
338 		} else {
339 			status = acpi_evaluate_integer(tz->device->handle,
340 				"_PSV", NULL, &tmp);
341 		}
342 
343 		if (ACPI_FAILURE(status))
344 			tz->trips.passive.flags.valid = 0;
345 		else {
346 			tz->trips.passive.temperature = tmp;
347 			tz->trips.passive.flags.valid = 1;
348 			if (flag == ACPI_TRIPS_INIT) {
349 				status = acpi_evaluate_integer(
350 						tz->device->handle, "_TC1",
351 						NULL, &tmp);
352 				if (ACPI_FAILURE(status))
353 					tz->trips.passive.flags.valid = 0;
354 				else
355 					tz->trips.passive.tc1 = tmp;
356 				status = acpi_evaluate_integer(
357 						tz->device->handle, "_TC2",
358 						NULL, &tmp);
359 				if (ACPI_FAILURE(status))
360 					tz->trips.passive.flags.valid = 0;
361 				else
362 					tz->trips.passive.tc2 = tmp;
363 				status = acpi_evaluate_integer(
364 						tz->device->handle, "_TSP",
365 						NULL, &tmp);
366 				if (ACPI_FAILURE(status))
367 					tz->trips.passive.flags.valid = 0;
368 				else
369 					tz->trips.passive.tsp = tmp;
370 			}
371 		}
372 	}
373 	if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
374 		memset(&devices, 0, sizeof(struct acpi_handle_list));
375 		status = acpi_evaluate_reference(tz->device->handle, "_PSL",
376 							NULL, &devices);
377 		if (ACPI_FAILURE(status)) {
378 			pr_warn(PREFIX "Invalid passive threshold\n");
379 			tz->trips.passive.flags.valid = 0;
380 		}
381 		else
382 			tz->trips.passive.flags.valid = 1;
383 
384 		if (memcmp(&tz->trips.passive.devices, &devices,
385 				sizeof(struct acpi_handle_list))) {
386 			memcpy(&tz->trips.passive.devices, &devices,
387 				sizeof(struct acpi_handle_list));
388 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
389 		}
390 	}
391 	if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
392 		if (valid != tz->trips.passive.flags.valid)
393 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
394 	}
395 
396 	/* Active (optional) */
397 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
398 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
399 		valid = tz->trips.active[i].flags.valid;
400 
401 		if (act == -1)
402 			break; /* disable all active trip points */
403 
404 		if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
405 			tz->trips.active[i].flags.valid)) {
406 			status = acpi_evaluate_integer(tz->device->handle,
407 							name, NULL, &tmp);
408 			if (ACPI_FAILURE(status)) {
409 				tz->trips.active[i].flags.valid = 0;
410 				if (i == 0)
411 					break;
412 				if (act <= 0)
413 					break;
414 				if (i == 1)
415 					tz->trips.active[0].temperature =
416 						CELSIUS_TO_DECI_KELVIN(act);
417 				else
418 					/*
419 					 * Don't allow override higher than
420 					 * the next higher trip point
421 					 */
422 					tz->trips.active[i - 1].temperature =
423 						(tz->trips.active[i - 2].temperature <
424 						CELSIUS_TO_DECI_KELVIN(act) ?
425 						tz->trips.active[i - 2].temperature :
426 						CELSIUS_TO_DECI_KELVIN(act));
427 				break;
428 			} else {
429 				tz->trips.active[i].temperature = tmp;
430 				tz->trips.active[i].flags.valid = 1;
431 			}
432 		}
433 
434 		name[2] = 'L';
435 		if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
436 			memset(&devices, 0, sizeof(struct acpi_handle_list));
437 			status = acpi_evaluate_reference(tz->device->handle,
438 						name, NULL, &devices);
439 			if (ACPI_FAILURE(status)) {
440 				pr_warn(PREFIX "Invalid active%d threshold\n",
441 					i);
442 				tz->trips.active[i].flags.valid = 0;
443 			}
444 			else
445 				tz->trips.active[i].flags.valid = 1;
446 
447 			if (memcmp(&tz->trips.active[i].devices, &devices,
448 					sizeof(struct acpi_handle_list))) {
449 				memcpy(&tz->trips.active[i].devices, &devices,
450 					sizeof(struct acpi_handle_list));
451 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
452 			}
453 		}
454 		if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
455 			if (valid != tz->trips.active[i].flags.valid)
456 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
457 
458 		if (!tz->trips.active[i].flags.valid)
459 			break;
460 	}
461 
462 	if (flag & ACPI_TRIPS_DEVICES) {
463 		memset(&devices, 0, sizeof(devices));
464 		status = acpi_evaluate_reference(tz->device->handle, "_TZD",
465 						NULL, &devices);
466 		if (ACPI_SUCCESS(status)
467 		    && memcmp(&tz->devices, &devices, sizeof(devices))) {
468 			tz->devices = devices;
469 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
470 		}
471 	}
472 
473 	return 0;
474 }
475 
476 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
477 {
478 	int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
479 
480 	if (ret)
481 		return ret;
482 
483 	valid = tz->trips.critical.flags.valid |
484 		tz->trips.hot.flags.valid |
485 		tz->trips.passive.flags.valid;
486 
487 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
488 		valid |= tz->trips.active[i].flags.valid;
489 
490 	if (!valid) {
491 		pr_warn(FW_BUG "No valid trip found\n");
492 		return -ENODEV;
493 	}
494 	return 0;
495 }
496 
497 static void acpi_thermal_check(void *data)
498 {
499 	struct acpi_thermal *tz = data;
500 
501 	if (!tz->tz_enabled)
502 		return;
503 
504 	thermal_zone_device_update(tz->thermal_zone,
505 				   THERMAL_EVENT_UNSPECIFIED);
506 }
507 
508 /* sys I/F for generic thermal sysfs support */
509 
510 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
511 {
512 	struct acpi_thermal *tz = thermal->devdata;
513 	int result;
514 
515 	if (!tz)
516 		return -EINVAL;
517 
518 	result = acpi_thermal_get_temperature(tz);
519 	if (result)
520 		return result;
521 
522 	*temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(tz->temperature,
523 							tz->kelvin_offset);
524 	return 0;
525 }
526 
527 static int thermal_get_mode(struct thermal_zone_device *thermal,
528 				enum thermal_device_mode *mode)
529 {
530 	struct acpi_thermal *tz = thermal->devdata;
531 
532 	if (!tz)
533 		return -EINVAL;
534 
535 	*mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
536 		THERMAL_DEVICE_DISABLED;
537 
538 	return 0;
539 }
540 
541 static int thermal_set_mode(struct thermal_zone_device *thermal,
542 				enum thermal_device_mode mode)
543 {
544 	struct acpi_thermal *tz = thermal->devdata;
545 	int enable;
546 
547 	if (!tz)
548 		return -EINVAL;
549 
550 	/*
551 	 * enable/disable thermal management from ACPI thermal driver
552 	 */
553 	if (mode == THERMAL_DEVICE_ENABLED)
554 		enable = 1;
555 	else if (mode == THERMAL_DEVICE_DISABLED) {
556 		enable = 0;
557 		pr_warn("thermal zone will be disabled\n");
558 	} else
559 		return -EINVAL;
560 
561 	if (enable != tz->tz_enabled) {
562 		tz->tz_enabled = enable;
563 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
564 			"%s kernel ACPI thermal control\n",
565 			tz->tz_enabled ? "Enable" : "Disable"));
566 		acpi_thermal_check(tz);
567 	}
568 	return 0;
569 }
570 
571 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
572 				 int trip, enum thermal_trip_type *type)
573 {
574 	struct acpi_thermal *tz = thermal->devdata;
575 	int i;
576 
577 	if (!tz || trip < 0)
578 		return -EINVAL;
579 
580 	if (tz->trips.critical.flags.valid) {
581 		if (!trip) {
582 			*type = THERMAL_TRIP_CRITICAL;
583 			return 0;
584 		}
585 		trip--;
586 	}
587 
588 	if (tz->trips.hot.flags.valid) {
589 		if (!trip) {
590 			*type = THERMAL_TRIP_HOT;
591 			return 0;
592 		}
593 		trip--;
594 	}
595 
596 	if (tz->trips.passive.flags.valid) {
597 		if (!trip) {
598 			*type = THERMAL_TRIP_PASSIVE;
599 			return 0;
600 		}
601 		trip--;
602 	}
603 
604 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
605 		tz->trips.active[i].flags.valid; i++) {
606 		if (!trip) {
607 			*type = THERMAL_TRIP_ACTIVE;
608 			return 0;
609 		}
610 		trip--;
611 	}
612 
613 	return -EINVAL;
614 }
615 
616 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
617 				 int trip, int *temp)
618 {
619 	struct acpi_thermal *tz = thermal->devdata;
620 	int i;
621 
622 	if (!tz || trip < 0)
623 		return -EINVAL;
624 
625 	if (tz->trips.critical.flags.valid) {
626 		if (!trip) {
627 			*temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
628 				tz->trips.critical.temperature,
629 				tz->kelvin_offset);
630 			return 0;
631 		}
632 		trip--;
633 	}
634 
635 	if (tz->trips.hot.flags.valid) {
636 		if (!trip) {
637 			*temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
638 				tz->trips.hot.temperature,
639 				tz->kelvin_offset);
640 			return 0;
641 		}
642 		trip--;
643 	}
644 
645 	if (tz->trips.passive.flags.valid) {
646 		if (!trip) {
647 			*temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
648 				tz->trips.passive.temperature,
649 				tz->kelvin_offset);
650 			return 0;
651 		}
652 		trip--;
653 	}
654 
655 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
656 		tz->trips.active[i].flags.valid; i++) {
657 		if (!trip) {
658 			*temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
659 				tz->trips.active[i].temperature,
660 				tz->kelvin_offset);
661 			return 0;
662 		}
663 		trip--;
664 	}
665 
666 	return -EINVAL;
667 }
668 
669 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
670 				int *temperature)
671 {
672 	struct acpi_thermal *tz = thermal->devdata;
673 
674 	if (tz->trips.critical.flags.valid) {
675 		*temperature = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
676 				tz->trips.critical.temperature,
677 				tz->kelvin_offset);
678 		return 0;
679 	} else
680 		return -EINVAL;
681 }
682 
683 static int thermal_get_trend(struct thermal_zone_device *thermal,
684 				int trip, enum thermal_trend *trend)
685 {
686 	struct acpi_thermal *tz = thermal->devdata;
687 	enum thermal_trip_type type;
688 	int i;
689 
690 	if (thermal_get_trip_type(thermal, trip, &type))
691 		return -EINVAL;
692 
693 	if (type == THERMAL_TRIP_ACTIVE) {
694 		int trip_temp;
695 		int temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
696 					tz->temperature, tz->kelvin_offset);
697 		if (thermal_get_trip_temp(thermal, trip, &trip_temp))
698 			return -EINVAL;
699 
700 		if (temp > trip_temp) {
701 			*trend = THERMAL_TREND_RAISING;
702 			return 0;
703 		} else {
704 			/* Fall back on default trend */
705 			return -EINVAL;
706 		}
707 	}
708 
709 	/*
710 	 * tz->temperature has already been updated by generic thermal layer,
711 	 * before this callback being invoked
712 	 */
713 	i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
714 		+ (tz->trips.passive.tc2
715 		* (tz->temperature - tz->trips.passive.temperature));
716 
717 	if (i > 0)
718 		*trend = THERMAL_TREND_RAISING;
719 	else if (i < 0)
720 		*trend = THERMAL_TREND_DROPPING;
721 	else
722 		*trend = THERMAL_TREND_STABLE;
723 	return 0;
724 }
725 
726 
727 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
728 			   enum thermal_trip_type trip_type)
729 {
730 	u8 type = 0;
731 	struct acpi_thermal *tz = thermal->devdata;
732 
733 	if (trip_type == THERMAL_TRIP_CRITICAL)
734 		type = ACPI_THERMAL_NOTIFY_CRITICAL;
735 	else if (trip_type == THERMAL_TRIP_HOT)
736 		type = ACPI_THERMAL_NOTIFY_HOT;
737 	else
738 		return 0;
739 
740 	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
741 					dev_name(&tz->device->dev), type, 1);
742 
743 	if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
744 		return 1;
745 
746 	return 0;
747 }
748 
749 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
750 					struct thermal_cooling_device *cdev,
751 					bool bind)
752 {
753 	struct acpi_device *device = cdev->devdata;
754 	struct acpi_thermal *tz = thermal->devdata;
755 	struct acpi_device *dev;
756 	acpi_status status;
757 	acpi_handle handle;
758 	int i;
759 	int j;
760 	int trip = -1;
761 	int result = 0;
762 
763 	if (tz->trips.critical.flags.valid)
764 		trip++;
765 
766 	if (tz->trips.hot.flags.valid)
767 		trip++;
768 
769 	if (tz->trips.passive.flags.valid) {
770 		trip++;
771 		for (i = 0; i < tz->trips.passive.devices.count;
772 		    i++) {
773 			handle = tz->trips.passive.devices.handles[i];
774 			status = acpi_bus_get_device(handle, &dev);
775 			if (ACPI_FAILURE(status) || dev != device)
776 				continue;
777 			if (bind)
778 				result =
779 					thermal_zone_bind_cooling_device
780 					(thermal, trip, cdev,
781 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
782 					 THERMAL_WEIGHT_DEFAULT);
783 			else
784 				result =
785 					thermal_zone_unbind_cooling_device
786 					(thermal, trip, cdev);
787 			if (result)
788 				goto failed;
789 		}
790 	}
791 
792 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
793 		if (!tz->trips.active[i].flags.valid)
794 			break;
795 		trip++;
796 		for (j = 0;
797 		    j < tz->trips.active[i].devices.count;
798 		    j++) {
799 			handle = tz->trips.active[i].devices.handles[j];
800 			status = acpi_bus_get_device(handle, &dev);
801 			if (ACPI_FAILURE(status) || dev != device)
802 				continue;
803 			if (bind)
804 				result = thermal_zone_bind_cooling_device
805 					(thermal, trip, cdev,
806 					 THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
807 					 THERMAL_WEIGHT_DEFAULT);
808 			else
809 				result = thermal_zone_unbind_cooling_device
810 					(thermal, trip, cdev);
811 			if (result)
812 				goto failed;
813 		}
814 	}
815 
816 	for (i = 0; i < tz->devices.count; i++) {
817 		handle = tz->devices.handles[i];
818 		status = acpi_bus_get_device(handle, &dev);
819 		if (ACPI_SUCCESS(status) && (dev == device)) {
820 			if (bind)
821 				result = thermal_zone_bind_cooling_device
822 						(thermal, THERMAL_TRIPS_NONE,
823 						 cdev, THERMAL_NO_LIMIT,
824 						 THERMAL_NO_LIMIT,
825 						 THERMAL_WEIGHT_DEFAULT);
826 			else
827 				result = thermal_zone_unbind_cooling_device
828 						(thermal, THERMAL_TRIPS_NONE,
829 						 cdev);
830 			if (result)
831 				goto failed;
832 		}
833 	}
834 
835 failed:
836 	return result;
837 }
838 
839 static int
840 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
841 					struct thermal_cooling_device *cdev)
842 {
843 	return acpi_thermal_cooling_device_cb(thermal, cdev, true);
844 }
845 
846 static int
847 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
848 					struct thermal_cooling_device *cdev)
849 {
850 	return acpi_thermal_cooling_device_cb(thermal, cdev, false);
851 }
852 
853 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
854 	.bind = acpi_thermal_bind_cooling_device,
855 	.unbind	= acpi_thermal_unbind_cooling_device,
856 	.get_temp = thermal_get_temp,
857 	.get_mode = thermal_get_mode,
858 	.set_mode = thermal_set_mode,
859 	.get_trip_type = thermal_get_trip_type,
860 	.get_trip_temp = thermal_get_trip_temp,
861 	.get_crit_temp = thermal_get_crit_temp,
862 	.get_trend = thermal_get_trend,
863 	.notify = thermal_notify,
864 };
865 
866 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
867 {
868 	int trips = 0;
869 	int result;
870 	acpi_status status;
871 	int i;
872 
873 	if (tz->trips.critical.flags.valid)
874 		trips++;
875 
876 	if (tz->trips.hot.flags.valid)
877 		trips++;
878 
879 	if (tz->trips.passive.flags.valid)
880 		trips++;
881 
882 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
883 			tz->trips.active[i].flags.valid; i++, trips++);
884 
885 	if (tz->trips.passive.flags.valid)
886 		tz->thermal_zone =
887 			thermal_zone_device_register("acpitz", trips, 0, tz,
888 						&acpi_thermal_zone_ops, NULL,
889 						     tz->trips.passive.tsp*100,
890 						     tz->polling_frequency*100);
891 	else
892 		tz->thermal_zone =
893 			thermal_zone_device_register("acpitz", trips, 0, tz,
894 						&acpi_thermal_zone_ops, NULL,
895 						0, tz->polling_frequency*100);
896 	if (IS_ERR(tz->thermal_zone))
897 		return -ENODEV;
898 
899 	result = sysfs_create_link(&tz->device->dev.kobj,
900 				   &tz->thermal_zone->device.kobj, "thermal_zone");
901 	if (result)
902 		return result;
903 
904 	result = sysfs_create_link(&tz->thermal_zone->device.kobj,
905 				   &tz->device->dev.kobj, "device");
906 	if (result)
907 		return result;
908 
909 	status =  acpi_bus_attach_private_data(tz->device->handle,
910 					       tz->thermal_zone);
911 	if (ACPI_FAILURE(status))
912 		return -ENODEV;
913 
914 	tz->tz_enabled = 1;
915 
916 	dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
917 		 tz->thermal_zone->id);
918 	return 0;
919 }
920 
921 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
922 {
923 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
924 	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
925 	thermal_zone_device_unregister(tz->thermal_zone);
926 	tz->thermal_zone = NULL;
927 	acpi_bus_detach_private_data(tz->device->handle);
928 }
929 
930 
931 /* --------------------------------------------------------------------------
932                                  Driver Interface
933    -------------------------------------------------------------------------- */
934 
935 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
936 {
937 	struct acpi_thermal *tz = acpi_driver_data(device);
938 
939 
940 	if (!tz)
941 		return;
942 
943 	switch (event) {
944 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
945 		acpi_thermal_check(tz);
946 		break;
947 	case ACPI_THERMAL_NOTIFY_THRESHOLDS:
948 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
949 		acpi_thermal_check(tz);
950 		acpi_bus_generate_netlink_event(device->pnp.device_class,
951 						  dev_name(&device->dev), event, 0);
952 		break;
953 	case ACPI_THERMAL_NOTIFY_DEVICES:
954 		acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
955 		acpi_thermal_check(tz);
956 		acpi_bus_generate_netlink_event(device->pnp.device_class,
957 						  dev_name(&device->dev), event, 0);
958 		break;
959 	default:
960 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
961 				  "Unsupported event [0x%x]\n", event));
962 		break;
963 	}
964 }
965 
966 /*
967  * On some platforms, the AML code has dependency about
968  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
969  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
970  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
971  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
972  *    if _TMP has never been evaluated.
973  *
974  * As this dependency is totally transparent to OS, evaluate
975  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
976  * _TMP, before they are actually used.
977  */
978 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
979 {
980 	acpi_handle handle = tz->device->handle;
981 	unsigned long long value;
982 	int i;
983 
984 	acpi_evaluate_integer(handle, "_CRT", NULL, &value);
985 	acpi_evaluate_integer(handle, "_HOT", NULL, &value);
986 	acpi_evaluate_integer(handle, "_PSV", NULL, &value);
987 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
988 		char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
989 		acpi_status status;
990 
991 		status = acpi_evaluate_integer(handle, name, NULL, &value);
992 		if (status == AE_NOT_FOUND)
993 			break;
994 	}
995 	acpi_evaluate_integer(handle, "_TMP", NULL, &value);
996 }
997 
998 static int acpi_thermal_get_info(struct acpi_thermal *tz)
999 {
1000 	int result = 0;
1001 
1002 
1003 	if (!tz)
1004 		return -EINVAL;
1005 
1006 	acpi_thermal_aml_dependency_fix(tz);
1007 
1008 	/* Get trip points [_CRT, _PSV, etc.] (required) */
1009 	result = acpi_thermal_get_trip_points(tz);
1010 	if (result)
1011 		return result;
1012 
1013 	/* Get temperature [_TMP] (required) */
1014 	result = acpi_thermal_get_temperature(tz);
1015 	if (result)
1016 		return result;
1017 
1018 	/* Set the cooling mode [_SCP] to active cooling (default) */
1019 	result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1020 	if (!result)
1021 		tz->flags.cooling_mode = 1;
1022 
1023 	/* Get default polling frequency [_TZP] (optional) */
1024 	if (tzp)
1025 		tz->polling_frequency = tzp;
1026 	else
1027 		acpi_thermal_get_polling_frequency(tz);
1028 
1029 	return 0;
1030 }
1031 
1032 /*
1033  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1034  * handles temperature values with a single decimal place. As a consequence,
1035  * some implementations use an offset of 273.1 and others use an offset of
1036  * 273.2. Try to find out which one is being used, to present the most
1037  * accurate and visually appealing number.
1038  *
1039  * The heuristic below should work for all ACPI thermal zones which have a
1040  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1041  */
1042 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1043 {
1044 	if (tz->trips.critical.flags.valid &&
1045 	    (tz->trips.critical.temperature % 5) == 1)
1046 		tz->kelvin_offset = 2731;
1047 	else
1048 		tz->kelvin_offset = 2732;
1049 }
1050 
1051 static void acpi_thermal_check_fn(struct work_struct *work)
1052 {
1053 	struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
1054 					       thermal_check_work);
1055 	acpi_thermal_check(tz);
1056 }
1057 
1058 static int acpi_thermal_add(struct acpi_device *device)
1059 {
1060 	int result = 0;
1061 	struct acpi_thermal *tz = NULL;
1062 
1063 
1064 	if (!device)
1065 		return -EINVAL;
1066 
1067 	tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1068 	if (!tz)
1069 		return -ENOMEM;
1070 
1071 	tz->device = device;
1072 	strcpy(tz->name, device->pnp.bus_id);
1073 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1074 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1075 	device->driver_data = tz;
1076 
1077 	result = acpi_thermal_get_info(tz);
1078 	if (result)
1079 		goto free_memory;
1080 
1081 	acpi_thermal_guess_offset(tz);
1082 
1083 	result = acpi_thermal_register_thermal_zone(tz);
1084 	if (result)
1085 		goto free_memory;
1086 
1087 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
1088 
1089 	pr_info(PREFIX "%s [%s] (%ld C)\n", acpi_device_name(device),
1090 		acpi_device_bid(device), DECI_KELVIN_TO_CELSIUS(tz->temperature));
1091 	goto end;
1092 
1093 free_memory:
1094 	kfree(tz);
1095 end:
1096 	return result;
1097 }
1098 
1099 static int acpi_thermal_remove(struct acpi_device *device)
1100 {
1101 	struct acpi_thermal *tz = NULL;
1102 
1103 	if (!device || !acpi_driver_data(device))
1104 		return -EINVAL;
1105 
1106 	flush_workqueue(acpi_thermal_pm_queue);
1107 	tz = acpi_driver_data(device);
1108 
1109 	acpi_thermal_unregister_thermal_zone(tz);
1110 	kfree(tz);
1111 	return 0;
1112 }
1113 
1114 #ifdef CONFIG_PM_SLEEP
1115 static int acpi_thermal_suspend(struct device *dev)
1116 {
1117 	/* Make sure the previously queued thermal check work has been done */
1118 	flush_workqueue(acpi_thermal_pm_queue);
1119 	return 0;
1120 }
1121 
1122 static int acpi_thermal_resume(struct device *dev)
1123 {
1124 	struct acpi_thermal *tz;
1125 	int i, j, power_state, result;
1126 
1127 	if (!dev)
1128 		return -EINVAL;
1129 
1130 	tz = acpi_driver_data(to_acpi_device(dev));
1131 	if (!tz)
1132 		return -EINVAL;
1133 
1134 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1135 		if (!(&tz->trips.active[i]))
1136 			break;
1137 		if (!tz->trips.active[i].flags.valid)
1138 			break;
1139 		tz->trips.active[i].flags.enabled = 1;
1140 		for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1141 			result = acpi_bus_update_power(
1142 					tz->trips.active[i].devices.handles[j],
1143 					&power_state);
1144 			if (result || (power_state != ACPI_STATE_D0)) {
1145 				tz->trips.active[i].flags.enabled = 0;
1146 				break;
1147 			}
1148 		}
1149 		tz->state.active |= tz->trips.active[i].flags.enabled;
1150 	}
1151 
1152 	queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
1153 
1154 	return AE_OK;
1155 }
1156 #endif
1157 
1158 static int thermal_act(const struct dmi_system_id *d) {
1159 
1160 	if (act == 0) {
1161 		pr_notice(PREFIX "%s detected: "
1162 			  "disabling all active thermal trip points\n", d->ident);
1163 		act = -1;
1164 	}
1165 	return 0;
1166 }
1167 static int thermal_nocrt(const struct dmi_system_id *d) {
1168 
1169 	pr_notice(PREFIX "%s detected: "
1170 		  "disabling all critical thermal trip point actions.\n", d->ident);
1171 	nocrt = 1;
1172 	return 0;
1173 }
1174 static int thermal_tzp(const struct dmi_system_id *d) {
1175 
1176 	if (tzp == 0) {
1177 		pr_notice(PREFIX "%s detected: "
1178 			  "enabling thermal zone polling\n", d->ident);
1179 		tzp = 300;	/* 300 dS = 30 Seconds */
1180 	}
1181 	return 0;
1182 }
1183 static int thermal_psv(const struct dmi_system_id *d) {
1184 
1185 	if (psv == 0) {
1186 		pr_notice(PREFIX "%s detected: "
1187 			  "disabling all passive thermal trip points\n", d->ident);
1188 		psv = -1;
1189 	}
1190 	return 0;
1191 }
1192 
1193 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1194 	/*
1195 	 * Award BIOS on this AOpen makes thermal control almost worthless.
1196 	 * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1197 	 */
1198 	{
1199 	 .callback = thermal_act,
1200 	 .ident = "AOpen i915GMm-HFS",
1201 	 .matches = {
1202 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1203 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1204 		},
1205 	},
1206 	{
1207 	 .callback = thermal_psv,
1208 	 .ident = "AOpen i915GMm-HFS",
1209 	 .matches = {
1210 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1211 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1212 		},
1213 	},
1214 	{
1215 	 .callback = thermal_tzp,
1216 	 .ident = "AOpen i915GMm-HFS",
1217 	 .matches = {
1218 		DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1219 		DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1220 		},
1221 	},
1222 	{
1223 	 .callback = thermal_nocrt,
1224 	 .ident = "Gigabyte GA-7ZX",
1225 	 .matches = {
1226 		DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1227 		DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1228 		},
1229 	},
1230 	{}
1231 };
1232 
1233 static int __init acpi_thermal_init(void)
1234 {
1235 	int result = 0;
1236 
1237 	dmi_check_system(thermal_dmi_table);
1238 
1239 	if (off) {
1240 		pr_notice(PREFIX "thermal control disabled\n");
1241 		return -ENODEV;
1242 	}
1243 
1244 	acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1245 						WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1246 	if (!acpi_thermal_pm_queue)
1247 		return -ENODEV;
1248 
1249 	result = acpi_bus_register_driver(&acpi_thermal_driver);
1250 	if (result < 0) {
1251 		destroy_workqueue(acpi_thermal_pm_queue);
1252 		return -ENODEV;
1253 	}
1254 
1255 	return 0;
1256 }
1257 
1258 static void __exit acpi_thermal_exit(void)
1259 {
1260 	acpi_bus_unregister_driver(&acpi_thermal_driver);
1261 	destroy_workqueue(acpi_thermal_pm_queue);
1262 
1263 	return;
1264 }
1265 
1266 module_init(acpi_thermal_init);
1267 module_exit(acpi_thermal_exit);
1268