xref: /netbsd-src/sys/dev/sysmon/sysmon_envsys_events.c (revision 267197ec1eebfcb9810ea27a89625b6ddf68e3e7)
1 /* $NetBSD: sysmon_envsys_events.c,v 1.48 2008/02/02 02:02:38 xtraeme Exp $ */
2 
3 /*-
4  * Copyright (c) 2007 Juan Romero Pardines.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /*
29  * sysmon_envsys(9) events framework.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: sysmon_envsys_events.c,v 1.48 2008/02/02 02:02:38 xtraeme Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/types.h>
37 #include <sys/conf.h>
38 #include <sys/errno.h>
39 #include <sys/kernel.h>
40 #include <sys/systm.h>
41 #include <sys/proc.h>
42 #include <sys/mutex.h>
43 #include <sys/kmem.h>
44 #include <sys/callout.h>
45 
46 /* #define ENVSYS_DEBUG */
47 #include <dev/sysmon/sysmonvar.h>
48 #include <dev/sysmon/sysmon_envsysvar.h>
49 
50 struct sme_sensor_event {
51 	int		state;
52 	int		event;
53 };
54 
55 static const struct sme_sensor_event sme_sensor_event[] = {
56 	{ ENVSYS_SVALID, 	PENVSYS_EVENT_NORMAL },
57 	{ ENVSYS_SCRITICAL, 	PENVSYS_EVENT_CRITICAL },
58 	{ ENVSYS_SCRITOVER, 	PENVSYS_EVENT_CRITOVER },
59 	{ ENVSYS_SCRITUNDER, 	PENVSYS_EVENT_CRITUNDER },
60 	{ ENVSYS_SWARNOVER, 	PENVSYS_EVENT_WARNOVER },
61 	{ ENVSYS_SWARNUNDER,	PENVSYS_EVENT_WARNUNDER },
62 	{ -1, 			-1 }
63 };
64 
65 kmutex_t sme_mtx, sme_events_mtx, sme_callout_mtx;
66 kcondvar_t sme_cv;
67 static bool sysmon_low_power = false;
68 
69 #define SME_EVTIMO	(SME_EVENTS_DEFTIMEOUT * hz)
70 
71 static bool sme_event_check_low_power(void);
72 static bool sme_battery_check(void);
73 static bool sme_battery_critical(envsys_data_t *);
74 static bool sme_acadapter_check(void);
75 
76 /*
77  * sme_event_register:
78  *
79  * 	+ Registers a new sysmon envsys event or updates any event
80  * 	  already in the queue.
81  */
82 int
83 sme_event_register(prop_dictionary_t sdict, envsys_data_t *edata,
84 		   struct sysmon_envsys *sme, const char *objkey,
85 		   int32_t critval, int crittype, int powertype)
86 {
87 	sme_event_t *see = NULL;
88 	prop_object_t obj;
89 	bool critvalup = false;
90 	int error = 0;
91 
92 	KASSERT(sdict != NULL || edata != NULL || sme != NULL);
93 	KASSERT(mutex_owned(&sme_mtx));
94 
95 	/*
96 	 * check if the event is already on the list and return
97 	 * EEXIST if value provided hasn't been changed.
98 	 */
99 	LIST_FOREACH(see, &sme->sme_events_list, see_list) {
100 		if (strcmp(edata->desc, see->see_pes.pes_sensname) == 0)
101 			if (crittype == see->see_type) {
102 				if (see->see_critval == critval) {
103 					DPRINTF(("%s: dev=%s sensor=%s type=%d "
104 				    	    "(already exists)\n", __func__,
105 				    	    see->see_pes.pes_dvname,
106 				    	    see->see_pes.pes_sensname,
107 					    see->see_type));
108 					return EEXIST;
109 				}
110 				critvalup = true;
111 				break;
112 			}
113 	}
114 
115 	/*
116 	 * Critical condition operation requested by userland.
117 	 */
118 	if (objkey && critval && critvalup) {
119 		obj = prop_dictionary_get(sdict, objkey);
120 		if (obj && prop_object_type(obj) == PROP_TYPE_NUMBER) {
121 			/*
122 			 * object is already in dictionary and value
123 			 * provided is not the same than we have
124 			 * currently,  update the critical value.
125 			 */
126 			see->see_critval = critval;
127 			DPRINTF(("%s: (%s) sensor=%s type=%d "
128 			    "(critval updated)\n", __func__, sme->sme_name,
129 			    edata->desc, see->see_type));
130 			error = sme_sensor_upint32(sdict, objkey, critval);
131 			return error;
132 		}
133 	}
134 
135 	/*
136 	 * The event is not in on the list or in a dictionary, create a new
137 	 * sme event, assign required members and update the object in
138 	 * the dictionary.
139 	 */
140 	see = kmem_zalloc(sizeof(*see), KM_NOSLEEP);
141 	if (see == NULL)
142 		return ENOMEM;
143 
144 	see->see_edata = edata;
145 	see->see_critval = critval;
146 	see->see_type = crittype;
147 	see->see_sme = sme;
148 	(void)strlcpy(see->see_pes.pes_dvname, sme->sme_name,
149 	    sizeof(see->see_pes.pes_dvname));
150 	see->see_pes.pes_type = powertype;
151 	(void)strlcpy(see->see_pes.pes_sensname, edata->desc,
152 	    sizeof(see->see_pes.pes_sensname));
153 
154 	LIST_INSERT_HEAD(&sme->sme_events_list, see, see_list);
155 	if (objkey && critval) {
156 		error = sme_sensor_upint32(sdict, objkey, critval);
157 		if (error)
158 			goto out;
159 	}
160 	DPRINTF(("%s: (%s) registering sensor=%s snum=%d type=%d "
161 	    "critval=%" PRIu32 "\n", __func__,
162 	    see->see_sme->sme_name, see->see_pes.pes_sensname,
163 	    see->see_edata->sensor, see->see_type, see->see_critval));
164 	/*
165 	 * Initialize the events framework if it wasn't initialized before.
166 	 */
167 	mutex_enter(&sme_events_mtx);
168 	if ((sme->sme_flags & SME_CALLOUT_INITIALIZED) == 0)
169 		error = sme_events_init(sme);
170 	mutex_exit(&sme_events_mtx);
171 out:
172 	if (error)
173 		kmem_free(see, sizeof(*see));
174 	return error;
175 }
176 
177 /*
178  * sme_event_unregister_all:
179  *
180  * 	+ Unregisters all sysmon envsys events associated with a
181  * 	  sysmon envsys device.
182  */
183 void
184 sme_event_unregister_all(struct sysmon_envsys *sme)
185 {
186 	sme_event_t *see;
187 	int evcounter = 0;
188 
189 	KASSERT(mutex_owned(&sme_mtx));
190 	KASSERT(sme != NULL);
191 
192 	LIST_FOREACH(see, &sme->sme_events_list, see_list) {
193 		if (strcmp(see->see_pes.pes_dvname, sme->sme_name) == 0)
194 			evcounter++;
195 	}
196 
197 	DPRINTF(("%s: total events %d (%s)\n", __func__,
198 	    evcounter, sme->sme_name));
199 
200 	while ((see = LIST_FIRST(&sme->sme_events_list))) {
201 		if (evcounter == 0)
202 			break;
203 
204 		if (strcmp(see->see_pes.pes_dvname, sme->sme_name) == 0) {
205 			DPRINTF(("%s: event %s %d removed (%s)\n", __func__,
206 			    see->see_pes.pes_sensname, see->see_type,
207 			    sme->sme_name));
208 
209 			while (see->see_flags & SME_EVENT_WORKING)
210 				cv_wait(&sme_cv, &sme_mtx);
211 
212 			LIST_REMOVE(see, see_list);
213 			kmem_free(see, sizeof(*see));
214 			evcounter--;
215 		}
216 	}
217 
218 	if (LIST_EMPTY(&sme->sme_events_list)) {
219 		mutex_enter(&sme_events_mtx);
220 		if (sme->sme_flags & SME_CALLOUT_INITIALIZED)
221 			sme_events_destroy(sme);
222 		mutex_exit(&sme_events_mtx);
223 	}
224 }
225 
226 /*
227  * sme_event_unregister:
228  *
229  * 	+ Unregisters an event from the specified sysmon envsys device.
230  */
231 int
232 sme_event_unregister(struct sysmon_envsys *sme, const char *sensor, int type)
233 {
234 	sme_event_t *see;
235 	bool found = false;
236 
237 	KASSERT(mutex_owned(&sme_mtx));
238 	KASSERT(sensor != NULL);
239 
240 	LIST_FOREACH(see, &sme->sme_events_list, see_list) {
241 		if (strcmp(see->see_pes.pes_sensname, sensor) == 0) {
242 			if (see->see_type == type) {
243 				found = true;
244 				break;
245 			}
246 		}
247 	}
248 
249 	if (!found)
250 		return EINVAL;
251 
252 	while (see->see_flags & SME_EVENT_WORKING)
253 		cv_wait(&sme_cv, &sme_mtx);
254 
255 	DPRINTF(("%s: removing dev=%s sensor=%s type=%d\n",
256 	    __func__, see->see_pes.pes_dvname, sensor, type));
257 	LIST_REMOVE(see, see_list);
258 	/*
259 	 * So the events list is empty, we'll do the following:
260 	 *
261 	 * 	- stop and destroy the callout.
262 	 * 	- destroy the workqueue.
263 	 */
264 	if (LIST_EMPTY(&sme->sme_events_list)) {
265 		mutex_enter(&sme_events_mtx);
266 		sme_events_destroy(sme);
267 		mutex_exit(&sme_events_mtx);
268 	}
269 
270 	kmem_free(see, sizeof(*see));
271 	return 0;
272 }
273 
274 /*
275  * sme_event_drvadd:
276  *
277  * 	+ Registers a new event for a device that had enabled any of
278  * 	  the monitoring flags in the driver.
279  */
280 void
281 sme_event_drvadd(void *arg)
282 {
283 	sme_event_drv_t *sed_t = arg;
284 	int error = 0;
285 
286 	KASSERT(sed_t != NULL);
287 
288 #define SEE_REGEVENT(a, b, c)						\
289 do {									\
290 	if (sed_t->sed_edata->flags & (a)) {				\
291 		char str[ENVSYS_DESCLEN] = "monitoring-state-";		\
292 									\
293 		sysmon_envsys_acquire(sed_t->sed_sme);			\
294 		error = sme_event_register(sed_t->sed_sdict,		\
295 				      sed_t->sed_edata,			\
296 				      sed_t->sed_sme,			\
297 				      NULL,				\
298 				      0,				\
299 				      (b),				\
300 				      sed_t->sed_powertype);		\
301 		if (error && error != EEXIST)				\
302 			printf("%s: failed to add event! "		\
303 			    "error=%d sensor=%s event=%s\n",		\
304 			    __func__, error,				\
305 			    sed_t->sed_edata->desc, (c));		\
306 		else {							\
307 			(void)strlcat(str, (c), sizeof(str));		\
308 			prop_dictionary_set_bool(sed_t->sed_sdict,	\
309 						 str,			\
310 						 true);			\
311 		}							\
312 		sysmon_envsys_release(sed_t->sed_sme);			\
313 	}								\
314 } while (/* CONSTCOND */ 0)
315 
316 	mutex_enter(&sme_mtx);
317 	SEE_REGEVENT(ENVSYS_FMONCRITICAL,
318 		     PENVSYS_EVENT_CRITICAL,
319 		     "critical");
320 
321 	SEE_REGEVENT(ENVSYS_FMONCRITUNDER,
322 		     PENVSYS_EVENT_CRITUNDER,
323 		     "critunder");
324 
325 	SEE_REGEVENT(ENVSYS_FMONCRITOVER,
326 		     PENVSYS_EVENT_CRITOVER,
327 		     "critover");
328 
329 	SEE_REGEVENT(ENVSYS_FMONWARNUNDER,
330 		     PENVSYS_EVENT_WARNUNDER,
331 		     "warnunder");
332 
333 	SEE_REGEVENT(ENVSYS_FMONWARNOVER,
334 		     PENVSYS_EVENT_WARNOVER,
335 		     "warnover");
336 
337 	SEE_REGEVENT(ENVSYS_FMONSTCHANGED,
338 		     PENVSYS_EVENT_STATE_CHANGED,
339 		     "state-changed");
340 	mutex_exit(&sme_mtx);
341 
342 	/*
343 	 * we are done, free memory now.
344 	 */
345 	kmem_free(sed_t, sizeof(*sed_t));
346 }
347 
348 /*
349  * sme_events_init:
350  *
351  * 	+ Initialize the events framework for this device.
352  */
353 int
354 sme_events_init(struct sysmon_envsys *sme)
355 {
356 	int error;
357 	uint64_t timo;
358 
359 	KASSERT(sme != NULL);
360 	KASSERT(mutex_owned(&sme_events_mtx));
361 
362 	if (sme->sme_events_timeout)
363 		timo = sme->sme_events_timeout * hz;
364 	else
365 		timo = SME_EVTIMO;
366 
367 	error = workqueue_create(&sme->sme_wq, sme->sme_name,
368 	    sme_events_worker, sme, PRI_NONE, IPL_SOFTCLOCK, WQ_MPSAFE);
369 	if (error)
370 		goto out;
371 
372 	callout_setfunc(&sme->sme_callout, sme_events_check, sme);
373 	callout_schedule(&sme->sme_callout, timo);
374 	sme->sme_flags |= SME_CALLOUT_INITIALIZED;
375 	DPRINTF(("%s: events framework initialized for '%s'\n",
376 	    __func__, sme->sme_name));
377 
378 out:
379 	return error;
380 }
381 
382 /*
383  * sme_events_destroy:
384  *
385  * 	+ Destroys the events framework for this device: the callout
386  * 	  is stopped and its workqueue is destroyed because the queue
387  * 	  is empty.
388  */
389 void
390 sme_events_destroy(struct sysmon_envsys *sme)
391 {
392 	KASSERT(mutex_owned(&sme_events_mtx));
393 
394 	callout_stop(&sme->sme_callout);
395 	sme->sme_flags &= ~SME_CALLOUT_INITIALIZED;
396 	DPRINTF(("%s: events framework destroyed for '%s'\n",
397 	    __func__, sme->sme_name));
398 	workqueue_destroy(sme->sme_wq);
399 }
400 
401 /*
402  * sme_events_check:
403  *
404  * 	+ Runs the work on the passed sysmon envsys device for all
405  * 	  registered events.
406  */
407 void
408 sme_events_check(void *arg)
409 {
410 	struct sysmon_envsys *sme = arg;
411 	sme_event_t *see;
412 	uint64_t timo;
413 
414 	KASSERT(sme != NULL);
415 
416 	mutex_enter(&sme_callout_mtx);
417 
418 	LIST_FOREACH(see, &sme->sme_events_list, see_list)
419 		workqueue_enqueue(sme->sme_wq, &see->see_wk, NULL);
420 
421 	/*
422 	 * Now that the events list was checked, reset the refresh value.
423 	 */
424 	LIST_FOREACH(see, &sme->sme_events_list, see_list)
425 		see->see_flags &= ~SME_EVENT_REFRESHED;
426 
427 	if (sme->sme_events_timeout)
428 		timo = sme->sme_events_timeout * hz;
429 	else
430 		timo = SME_EVTIMO;
431 
432 	if (!sysmon_low_power)
433 		callout_schedule(&sme->sme_callout, timo);
434 
435 	mutex_exit(&sme_callout_mtx);
436 }
437 
438 /*
439  * sme_events_worker:
440  *
441  * 	+ workqueue thread that checks if there's a critical condition
442  * 	  and sends an event if the condition was triggered.
443  */
444 void
445 sme_events_worker(struct work *wk, void *arg)
446 {
447 	const struct sme_description_table *sdt = NULL;
448 	const struct sme_sensor_event *sse = sme_sensor_event;
449 	sme_event_t *see = (void *)wk;
450 	struct sysmon_envsys *sme;
451 	int i, state, error;
452 
453 	KASSERT(wk == &see->see_wk);
454 	KASSERT(see != NULL);
455 
456 	state = error = 0;
457 
458 	mutex_enter(&sme_mtx);
459 	see->see_flags |= SME_EVENT_WORKING;
460 	sme = see->see_sme;
461 
462 	/*
463 	 * refresh the sensor that was marked with a critical event
464 	 * only if it wasn't refreshed before or if the driver doesn't
465 	 * use its own method for refreshing.
466 	 */
467 	if ((sme->sme_flags & SME_DISABLE_REFRESH) == 0) {
468 		if ((see->see_flags & SME_EVENT_REFRESHED) == 0) {
469 			(*sme->sme_refresh)(sme, see->see_edata);
470 			see->see_flags |= SME_EVENT_REFRESHED;
471 		}
472 	}
473 
474 	DPRINTFOBJ(("%s: (%s) desc=%s sensor=%d units=%d value_cur=%d\n",
475 	    __func__, sme->sme_name, see->see_edata->desc,
476 	    see->see_edata->sensor,
477 	    see->see_edata->units, see->see_edata->value_cur));
478 
479 #define SME_SEND_NORMALEVENT()						\
480 do {									\
481 	see->see_evsent = false;					\
482 	sysmon_penvsys_event(&see->see_pes, PENVSYS_EVENT_NORMAL);	\
483 } while (/* CONSTCOND */ 0)
484 
485 #define SME_SEND_EVENT(type)						\
486 do {									\
487 	see->see_evsent = true;						\
488 	sysmon_penvsys_event(&see->see_pes, (type));			\
489 } while (/* CONSTCOND */ 0)
490 
491 
492 	switch (see->see_type) {
493 	/*
494 	 * if state is the same than the one that matches sse[i].state,
495 	 * send the event...
496 	 */
497 	case PENVSYS_EVENT_CRITICAL:
498 	case PENVSYS_EVENT_CRITUNDER:
499 	case PENVSYS_EVENT_CRITOVER:
500 	case PENVSYS_EVENT_WARNUNDER:
501 	case PENVSYS_EVENT_WARNOVER:
502 		for (i = 0; sse[i].state != -1; i++)
503 			if (sse[i].event == see->see_type)
504 				break;
505 
506 		if (see->see_evsent && see->see_edata->state == ENVSYS_SVALID)
507 			SME_SEND_NORMALEVENT();
508 
509 		if (!see->see_evsent && see->see_edata->state == sse[i].state)
510 			SME_SEND_EVENT(see->see_type);
511 
512 		break;
513 	/*
514 	 * if value_cur is lower than the limit, send the event...
515 	 */
516 	case PENVSYS_EVENT_BATT_USERCAP:
517 	case PENVSYS_EVENT_USER_CRITMIN:
518 		if (see->see_evsent &&
519 		    see->see_edata->value_cur > see->see_critval)
520 			SME_SEND_NORMALEVENT();
521 
522 		if (!see->see_evsent &&
523 		    see->see_edata->value_cur < see->see_critval)
524 			SME_SEND_EVENT(see->see_type);
525 
526 		break;
527 	/*
528 	 * if value_cur is higher than the limit, send the event...
529 	 */
530 	case PENVSYS_EVENT_USER_CRITMAX:
531 		if (see->see_evsent &&
532 		    see->see_edata->value_cur < see->see_critval)
533 			SME_SEND_NORMALEVENT();
534 
535 		if (!see->see_evsent &&
536 		    see->see_edata->value_cur > see->see_critval)
537 			SME_SEND_EVENT(see->see_type);
538 
539 		break;
540 	/*
541 	 * if value_cur is not normal (battery) or online (drive),
542 	 * send the event...
543 	 */
544 	case PENVSYS_EVENT_STATE_CHANGED:
545 		/*
546 		 * the state has not been changed, just ignore the event.
547 		 */
548 		if (see->see_edata->value_cur == see->see_evsent)
549 			break;
550 
551 		switch (see->see_edata->units) {
552 		case ENVSYS_DRIVE:
553 			sdt = sme_get_description_table(SME_DESC_DRIVE_STATES);
554 			state = ENVSYS_DRIVE_ONLINE;
555 			break;
556 		case ENVSYS_BATTERY_CAPACITY:
557 			sdt =
558 			    sme_get_description_table(SME_DESC_BATTERY_CAPACITY);
559 			state = ENVSYS_BATTERY_CAPACITY_NORMAL;
560 			break;
561 		default:
562 			panic("%s: invalid units for ENVSYS_FMONSTCHANGED",
563 			    __func__);
564 		}
565 
566 		for (i = 0; sdt[i].type != -1; i++)
567 			if (sdt[i].type == see->see_edata->value_cur)
568 				break;
569 
570 		/*
571 		 * copy current state description.
572 		 */
573 		(void)strlcpy(see->see_pes.pes_statedesc, sdt[i].desc,
574 		    sizeof(see->see_pes.pes_statedesc));
575 
576 		/*
577 		 * state is ok again... send a normal event.
578 		 */
579 		if (see->see_evsent && see->see_edata->value_cur == state)
580 			SME_SEND_NORMALEVENT();
581 
582 		/*
583 		 * state has been changed... send event.
584 		 */
585 		if (see->see_evsent || see->see_edata->value_cur != state) {
586 			/*
587 			 * save current drive state.
588 			 */
589 			see->see_evsent = see->see_edata->value_cur;
590 			sysmon_penvsys_event(&see->see_pes, see->see_type);
591 		}
592 
593 		/*
594 		 * Check if the system is running in low power and send the
595 		 * event to powerd (if running) or shutdown the system
596 		 * otherwise.
597 		 */
598 		if (!sysmon_low_power && sme_event_check_low_power()) {
599 			struct penvsys_state pes;
600 
601 			/*
602 			 * Stop the callout and send the 'low-power' event.
603 			 */
604 			sysmon_low_power = true;
605 			callout_stop(&sme->sme_callout);
606 			pes.pes_type = PENVSYS_TYPE_BATTERY;
607 			sysmon_penvsys_event(&pes, PENVSYS_EVENT_LOW_POWER);
608 		}
609 		break;
610 	}
611 
612 	see->see_flags &= ~SME_EVENT_WORKING;
613 	cv_broadcast(&sme_cv);
614 	mutex_exit(&sme_mtx);
615 }
616 
617 /*
618  * Returns true if the system is in low power state: all AC adapters
619  * are OFF and all batteries are in LOW/CRITICAL state.
620  */
621 static bool
622 sme_event_check_low_power(void)
623 {
624 	KASSERT(mutex_owned(&sme_mtx));
625 
626 	if (!sme_acadapter_check())
627 		return false;
628 
629 	return sme_battery_check();
630 }
631 
632 static bool
633 sme_acadapter_check(void)
634 {
635 	struct sysmon_envsys *sme;
636 	envsys_data_t *edata;
637 	bool sensor = false;
638 
639 	KASSERT(mutex_owned(&sme_mtx));
640 
641 	LIST_FOREACH(sme, &sysmon_envsys_list, sme_list)
642 		if (sme->sme_class == SME_CLASS_ACADAPTER)
643 			break;
644 	/*
645 	 * No AC Adapter devices were found.
646 	 */
647 	if (!sme)
648 		return false;
649 	/*
650 	 * Check if there's an AC adapter device connected.
651 	 */
652 	TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
653 		if (edata->units == ENVSYS_INDICATOR) {
654 			sensor = true;
655 			if (edata->value_cur)
656 				return false;
657 		}
658 	}
659 	if (!sensor)
660 		return false;
661 
662 	return true;
663 }
664 
665 static bool
666 sme_battery_check(void)
667 {
668 	struct sysmon_envsys *sme;
669 	envsys_data_t *edata;
670 	bool battery, batterycap, batterycharge;
671 
672 	KASSERT(mutex_owned(&sme_mtx));
673 
674 	battery = batterycap = batterycharge = false;
675 
676 	/*
677 	 * Check for battery devices and its state.
678 	 */
679 	LIST_FOREACH(sme, &sysmon_envsys_list, sme_list) {
680 		if (sme->sme_class != SME_CLASS_BATTERY)
681 			continue;
682 
683 		/*
684 		 * We've found a battery device...
685 		 */
686 		battery = true;
687 		TAILQ_FOREACH(edata, &sme->sme_sensors_list, sensors_head) {
688 			if (edata->units == ENVSYS_BATTERY_CAPACITY) {
689 				batterycap = true;
690 				if (!sme_battery_critical(edata))
691 					return false;
692 			} else if (edata->units == ENVSYS_BATTERY_CHARGE) {
693 				batterycharge = true;
694 				if (edata->value_cur)
695 					return false;
696 			}
697 		}
698 	}
699 	if (!battery || !batterycap || !batterycharge)
700 		return false;
701 
702 	/*
703 	 * All batteries in low/critical capacity and discharging.
704 	 */
705 	return true;
706 }
707 
708 static bool
709 sme_battery_critical(envsys_data_t *edata)
710 {
711 	KASSERT(mutex_owned(&sme_mtx));
712 
713 	if (edata->value_cur == ENVSYS_BATTERY_CAPACITY_CRITICAL ||
714 	    edata->value_cur == ENVSYS_BATTERY_CAPACITY_LOW)
715 		return true;
716 
717 	return false;
718 }
719