Home | History | Annotate | Line # | Download | only in kern
kern_pmf.c revision 1.24 
      1 /* $NetBSD: kern_pmf.c,v 1.24 2009/04/07 18:16:28 dyoung Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 Jared D. McNeill <jmcneill (at) invisible.ca>
      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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: kern_pmf.c,v 1.24 2009/04/07 18:16:28 dyoung Exp $");
     31 
     32 #include <sys/types.h>
     33 #include <sys/param.h>
     34 #include <sys/malloc.h>
     35 #include <sys/buf.h>
     36 #include <sys/callout.h>
     37 #include <sys/kernel.h>
     38 #include <sys/device.h>
     39 #include <sys/pmf.h>
     40 #include <sys/queue.h>
     41 #include <sys/sched.h>
     42 #include <sys/syscallargs.h> /* for sys_sync */
     43 #include <sys/workqueue.h>
     44 #include <prop/proplib.h>
     45 #include <sys/condvar.h>
     46 #include <sys/mutex.h>
     47 #include <sys/proc.h>
     48 #include <sys/reboot.h>	/* for RB_NOSYNC */
     49 #include <sys/sched.h>
     50 
     51 /* XXX ugly special case, but for now the only client */
     52 #include "wsdisplay.h"
     53 #if NWSDISPLAY > 0
     54 #include <dev/wscons/wsdisplayvar.h>
     55 #endif
     56 
     57 #ifdef PMF_DEBUG
     58 int pmf_debug_event;
     59 int pmf_debug_idle;
     60 int pmf_debug_transition;
     61 
     62 #define	PMF_EVENT_PRINTF(x)		if (pmf_debug_event) printf x
     63 #define	PMF_IDLE_PRINTF(x)		if (pmf_debug_idle) printf x
     64 #define	PMF_TRANSITION_PRINTF(x)	if (pmf_debug_transition) printf x
     65 #define	PMF_TRANSITION_PRINTF2(y,x)	if (pmf_debug_transition>y) printf x
     66 #else
     67 #define	PMF_EVENT_PRINTF(x)		do { } while (0)
     68 #define	PMF_IDLE_PRINTF(x)		do { } while (0)
     69 #define	PMF_TRANSITION_PRINTF(x)	do { } while (0)
     70 #define	PMF_TRANSITION_PRINTF2(y,x)	do { } while (0)
     71 #endif
     72 
     73 /* #define PMF_DEBUG */
     74 
     75 MALLOC_DEFINE(M_PMF, "pmf", "device pmf messaging memory");
     76 
     77 static prop_dictionary_t pmf_platform = NULL;
     78 static struct workqueue *pmf_event_workqueue;
     79 
     80 typedef struct pmf_event_handler {
     81 	TAILQ_ENTRY(pmf_event_handler) pmf_link;
     82 	pmf_generic_event_t pmf_event;
     83 	void (*pmf_handler)(device_t);
     84 	device_t pmf_device;
     85 	bool pmf_global;
     86 } pmf_event_handler_t;
     87 
     88 static TAILQ_HEAD(, pmf_event_handler) pmf_all_events =
     89     TAILQ_HEAD_INITIALIZER(pmf_all_events);
     90 
     91 typedef struct pmf_event_workitem {
     92 	struct work		pew_work;
     93 	pmf_generic_event_t	pew_event;
     94 	device_t		pew_device;
     95 } pmf_event_workitem_t;
     96 
     97 struct shutdown_state {
     98 	bool initialized;
     99 	deviter_t di;
    100 };
    101 
    102 static device_t shutdown_first(struct shutdown_state *);
    103 static device_t shutdown_next(struct shutdown_state *);
    104 
    105 static bool pmf_device_resume_locked(device_t PMF_FN_PROTO);
    106 static bool pmf_device_suspend_locked(device_t PMF_FN_PROTO);
    107 
    108 static void
    109 pmf_event_worker(struct work *wk, void *dummy)
    110 {
    111 	pmf_event_workitem_t *pew;
    112 	pmf_event_handler_t *event;
    113 
    114 	pew = (void *)wk;
    115 	KASSERT(wk == &pew->pew_work);
    116 	KASSERT(pew != NULL);
    117 
    118 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
    119 		if (event->pmf_event != pew->pew_event)
    120 			continue;
    121 		if (event->pmf_device == pew->pew_device || event->pmf_global)
    122 			(*event->pmf_handler)(event->pmf_device);
    123 	}
    124 
    125 	free(pew, M_TEMP);
    126 }
    127 
    128 static bool
    129 pmf_check_system_drivers(void)
    130 {
    131 	device_t curdev;
    132 	bool unsupported_devs;
    133 	deviter_t di;
    134 
    135 	unsupported_devs = false;
    136 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    137 	     curdev = deviter_next(&di)) {
    138 		if (device_pmf_is_registered(curdev))
    139 			continue;
    140 		if (!unsupported_devs)
    141 			printf("Devices without power management support:");
    142 		printf(" %s", device_xname(curdev));
    143 		unsupported_devs = true;
    144 	}
    145 	deviter_release(&di);
    146 	if (unsupported_devs) {
    147 		printf("\n");
    148 		return false;
    149 	}
    150 	return true;
    151 }
    152 
    153 bool
    154 pmf_system_bus_resume(PMF_FN_ARGS1)
    155 {
    156 	bool rv;
    157 	device_t curdev;
    158 	deviter_t di;
    159 
    160 	aprint_debug("Powering devices:");
    161 	/* D0 handlers are run in order */
    162 	rv = true;
    163 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
    164 	     curdev = deviter_next(&di)) {
    165 		if (!device_pmf_is_registered(curdev))
    166 			continue;
    167 		if (device_is_active(curdev) ||
    168 		    !device_is_enabled(curdev))
    169 			continue;
    170 
    171 		aprint_debug(" %s", device_xname(curdev));
    172 
    173 		if (!device_pmf_bus_resume(curdev PMF_FN_CALL)) {
    174 			rv = false;
    175 			aprint_debug("(failed)");
    176 		}
    177 	}
    178 	deviter_release(&di);
    179 	aprint_debug("\n");
    180 
    181 	return rv;
    182 }
    183 
    184 bool
    185 pmf_system_resume(PMF_FN_ARGS1)
    186 {
    187 	bool rv;
    188 	device_t curdev, parent;
    189 	deviter_t di;
    190 
    191 	if (!pmf_check_system_drivers())
    192 		return false;
    193 
    194 	aprint_debug("Resuming devices:");
    195 	/* D0 handlers are run in order */
    196 	rv = true;
    197 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
    198 	     curdev = deviter_next(&di)) {
    199 		if (device_is_active(curdev) ||
    200 		    !device_is_enabled(curdev))
    201 			continue;
    202 		parent = device_parent(curdev);
    203 		if (parent != NULL &&
    204 		    !device_is_active(parent))
    205 			continue;
    206 
    207 		aprint_debug(" %s", device_xname(curdev));
    208 
    209 		if (!pmf_device_resume(curdev PMF_FN_CALL)) {
    210 			rv = false;
    211 			aprint_debug("(failed)");
    212 		}
    213 	}
    214 	deviter_release(&di);
    215 	aprint_debug(".\n");
    216 
    217 	KERNEL_UNLOCK_ONE(0);
    218 #if NWSDISPLAY > 0
    219 	if (rv)
    220 		wsdisplay_handlex(1);
    221 #endif
    222 	return rv;
    223 }
    224 
    225 bool
    226 pmf_system_suspend(PMF_FN_ARGS1)
    227 {
    228 	device_t curdev;
    229 	deviter_t di;
    230 
    231 	if (!pmf_check_system_drivers())
    232 		return false;
    233 #if NWSDISPLAY > 0
    234 	if (wsdisplay_handlex(0))
    235 		return false;
    236 #endif
    237 	KERNEL_LOCK(1, 0);
    238 
    239 	/*
    240 	 * Flush buffers only if the shutdown didn't do so
    241 	 * already and if there was no panic.
    242 	 */
    243 	if (doing_shutdown == 0 && panicstr == NULL) {
    244 		printf("Flushing disk caches: ");
    245 		sys_sync(NULL, NULL, NULL);
    246 		if (buf_syncwait() != 0)
    247 			printf("giving up\n");
    248 		else
    249 			printf("done\n");
    250 	}
    251 
    252 	aprint_debug("Suspending devices:");
    253 
    254 	for (curdev = deviter_first(&di, DEVITER_F_LEAVES_FIRST);
    255 	     curdev != NULL;
    256 	     curdev = deviter_next(&di)) {
    257 		if (!device_is_active(curdev))
    258 			continue;
    259 
    260 		aprint_debug(" %s", device_xname(curdev));
    261 
    262 		/* XXX joerg check return value and abort suspend */
    263 		if (!pmf_device_suspend(curdev PMF_FN_CALL))
    264 			aprint_debug("(failed)");
    265 	}
    266 	deviter_release(&di);
    267 
    268 	aprint_debug(".\n");
    269 
    270 	return true;
    271 }
    272 
    273 static device_t
    274 shutdown_first(struct shutdown_state *s)
    275 {
    276 	if (!s->initialized) {
    277 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
    278 		s->initialized = true;
    279 	}
    280 	return shutdown_next(s);
    281 }
    282 
    283 static device_t
    284 shutdown_next(struct shutdown_state *s)
    285 {
    286 	device_t dv;
    287 
    288 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
    289 		;
    290 
    291 	return dv;
    292 }
    293 
    294 void
    295 pmf_system_shutdown(int how)
    296 {
    297 	static struct shutdown_state s;
    298 	device_t curdev;
    299 
    300 	aprint_debug("Shutting down devices:");
    301 	suspendsched();
    302 
    303 	for (curdev = shutdown_first(&s); curdev != NULL;
    304 	     curdev = shutdown_next(&s)) {
    305 		aprint_debug(" attempting %s shutdown", device_xname(curdev));
    306 		if ((boothowto & RB_NOSYNC) == 0 &&
    307 		    config_detach(curdev, DETACH_SHUTDOWN) == 0)
    308 			aprint_debug("(detached)");
    309 		else if (!device_pmf_is_registered(curdev))
    310 			aprint_debug("(skipped)");
    311 #if 0 /* needed? */
    312 		else if (!device_pmf_class_shutdown(curdev, how))
    313 			aprint_debug("(failed)");
    314 #endif
    315 		else if (!device_pmf_driver_shutdown(curdev, how))
    316 			aprint_debug("(failed)");
    317 		else if (!device_pmf_bus_shutdown(curdev, how))
    318 			aprint_debug("(failed)");
    319 	}
    320 
    321 	aprint_debug(".\n");
    322 }
    323 
    324 bool
    325 pmf_set_platform(const char *key, const char *value)
    326 {
    327 	if (pmf_platform == NULL)
    328 		pmf_platform = prop_dictionary_create();
    329 	if (pmf_platform == NULL)
    330 		return false;
    331 
    332 	return prop_dictionary_set_cstring(pmf_platform, key, value);
    333 }
    334 
    335 const char *
    336 pmf_get_platform(const char *key)
    337 {
    338 	const char *value;
    339 
    340 	if (pmf_platform == NULL)
    341 		return NULL;
    342 
    343 	if (!prop_dictionary_get_cstring_nocopy(pmf_platform, key, &value))
    344 		return NULL;
    345 
    346 	return value;
    347 }
    348 
    349 bool
    350 pmf_device_register1(device_t dev,
    351     bool (*suspend)(device_t PMF_FN_PROTO),
    352     bool (*resume)(device_t PMF_FN_PROTO),
    353     bool (*shutdown)(device_t, int))
    354 {
    355 	if (!device_pmf_driver_register(dev, suspend, resume, shutdown))
    356 		return false;
    357 
    358 	if (!device_pmf_driver_child_register(dev)) {
    359 		device_pmf_driver_deregister(dev);
    360 		return false;
    361 	}
    362 
    363 	return true;
    364 }
    365 
    366 void
    367 pmf_device_deregister(device_t dev)
    368 {
    369 	device_pmf_class_deregister(dev);
    370 	device_pmf_bus_deregister(dev);
    371 	device_pmf_driver_deregister(dev);
    372 }
    373 
    374 bool
    375 pmf_device_suspend_self(device_t dev)
    376 {
    377 	return pmf_device_suspend(dev, PMF_F_SELF);
    378 }
    379 
    380 bool
    381 pmf_device_suspend(device_t dev PMF_FN_ARGS)
    382 {
    383 	bool rc;
    384 
    385 	PMF_TRANSITION_PRINTF(("%s: suspend enter\n", device_xname(dev)));
    386 	if (!device_pmf_is_registered(dev))
    387 		return false;
    388 
    389 	if (!device_pmf_lock(dev PMF_FN_CALL))
    390 		return false;
    391 
    392 	rc = pmf_device_suspend_locked(dev PMF_FN_CALL);
    393 
    394 	device_pmf_unlock(dev PMF_FN_CALL);
    395 
    396 	PMF_TRANSITION_PRINTF(("%s: suspend exit\n", device_xname(dev)));
    397 	return rc;
    398 }
    399 
    400 static bool
    401 pmf_device_suspend_locked(device_t dev PMF_FN_ARGS)
    402 {
    403 	PMF_TRANSITION_PRINTF2(1, ("%s: self suspend\n", device_xname(dev)));
    404 	device_pmf_self_suspend(dev, flags);
    405 	PMF_TRANSITION_PRINTF2(1, ("%s: class suspend\n", device_xname(dev)));
    406 	if (!device_pmf_class_suspend(dev PMF_FN_CALL))
    407 		return false;
    408 	PMF_TRANSITION_PRINTF2(1, ("%s: driver suspend\n", device_xname(dev)));
    409 	if (!device_pmf_driver_suspend(dev PMF_FN_CALL))
    410 		return false;
    411 	PMF_TRANSITION_PRINTF2(1, ("%s: bus suspend\n", device_xname(dev)));
    412 	if (!device_pmf_bus_suspend(dev PMF_FN_CALL))
    413 		return false;
    414 
    415 	return true;
    416 }
    417 
    418 bool
    419 pmf_device_resume_self(device_t dev)
    420 {
    421 	return pmf_device_resume(dev, PMF_F_SELF);
    422 }
    423 
    424 bool
    425 pmf_device_resume(device_t dev PMF_FN_ARGS)
    426 {
    427 	bool rc;
    428 
    429 	PMF_TRANSITION_PRINTF(("%s: resume enter\n", device_xname(dev)));
    430 	if (!device_pmf_is_registered(dev))
    431 		return false;
    432 
    433 	if (!device_pmf_lock(dev PMF_FN_CALL))
    434 		return false;
    435 
    436 	rc = pmf_device_resume_locked(dev PMF_FN_CALL);
    437 
    438 	device_pmf_unlock(dev PMF_FN_CALL);
    439 
    440 	PMF_TRANSITION_PRINTF(("%s: resume exit\n", device_xname(dev)));
    441 	return rc;
    442 }
    443 
    444 static bool
    445 pmf_device_resume_locked(device_t dev PMF_FN_ARGS)
    446 {
    447 	PMF_TRANSITION_PRINTF2(1, ("%s: bus resume\n", device_xname(dev)));
    448 	if (!device_pmf_bus_resume(dev PMF_FN_CALL))
    449 		return false;
    450 	PMF_TRANSITION_PRINTF2(1, ("%s: driver resume\n", device_xname(dev)));
    451 	if (!device_pmf_driver_resume(dev PMF_FN_CALL))
    452 		return false;
    453 	PMF_TRANSITION_PRINTF2(1, ("%s: class resume\n", device_xname(dev)));
    454 	if (!device_pmf_class_resume(dev PMF_FN_CALL))
    455 		return false;
    456 	PMF_TRANSITION_PRINTF2(1, ("%s: self resume\n", device_xname(dev)));
    457 	device_pmf_self_resume(dev, flags);
    458 
    459 	return true;
    460 }
    461 
    462 bool
    463 pmf_device_recursive_suspend(device_t dv PMF_FN_ARGS)
    464 {
    465 	bool rv = true;
    466 	device_t curdev;
    467 	deviter_t di;
    468 
    469 	if (!device_is_active(dv))
    470 		return true;
    471 
    472 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    473 	     curdev = deviter_next(&di)) {
    474 		if (device_parent(curdev) != dv)
    475 			continue;
    476 		if (!pmf_device_recursive_suspend(curdev PMF_FN_CALL)) {
    477 			rv = false;
    478 			break;
    479 		}
    480 	}
    481 	deviter_release(&di);
    482 
    483 	return rv && pmf_device_suspend(dv PMF_FN_CALL);
    484 }
    485 
    486 bool
    487 pmf_device_recursive_resume(device_t dv PMF_FN_ARGS)
    488 {
    489 	device_t parent;
    490 
    491 	if (device_is_active(dv))
    492 		return true;
    493 
    494 	parent = device_parent(dv);
    495 	if (parent != NULL) {
    496 		if (!pmf_device_recursive_resume(parent PMF_FN_CALL))
    497 			return false;
    498 	}
    499 
    500 	return pmf_device_resume(dv PMF_FN_CALL);
    501 }
    502 
    503 bool
    504 pmf_device_resume_descendants(device_t dv PMF_FN_ARGS)
    505 {
    506 	bool rv = true;
    507 	device_t curdev;
    508 	deviter_t di;
    509 
    510 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    511 	     curdev = deviter_next(&di)) {
    512 		if (device_parent(curdev) != dv)
    513 			continue;
    514 		if (!pmf_device_resume_subtree(curdev PMF_FN_CALL)) {
    515 			rv = false;
    516 			break;
    517 		}
    518 	}
    519 	deviter_release(&di);
    520 	return rv;
    521 }
    522 
    523 bool
    524 pmf_device_resume_subtree(device_t dv PMF_FN_ARGS)
    525 {
    526 	if (!pmf_device_recursive_resume(dv PMF_FN_CALL))
    527 		return false;
    528 
    529 	return pmf_device_resume_descendants(dv PMF_FN_CALL);
    530 }
    531 
    532 #include <net/if.h>
    533 
    534 static bool
    535 pmf_class_network_suspend(device_t dev PMF_FN_ARGS)
    536 {
    537 	struct ifnet *ifp = device_pmf_class_private(dev);
    538 	int s;
    539 
    540 	s = splnet();
    541 	(*ifp->if_stop)(ifp, 0);
    542 	splx(s);
    543 
    544 	return true;
    545 }
    546 
    547 static bool
    548 pmf_class_network_resume(device_t dev PMF_FN_ARGS)
    549 {
    550 	struct ifnet *ifp = device_pmf_class_private(dev);
    551 	int s;
    552 
    553 	if ((flags & PMF_F_SELF) != 0)
    554 		return true;
    555 
    556 	s = splnet();
    557 	if (ifp->if_flags & IFF_UP) {
    558 		ifp->if_flags &= ~IFF_RUNNING;
    559 		if ((*ifp->if_init)(ifp) != 0)
    560 			aprint_normal_ifnet(ifp, "resume failed\n");
    561 		(*ifp->if_start)(ifp);
    562 	}
    563 	splx(s);
    564 
    565 	return true;
    566 }
    567 
    568 void
    569 pmf_class_network_register(device_t dev, struct ifnet *ifp)
    570 {
    571 	device_pmf_class_register(dev, ifp, pmf_class_network_suspend,
    572 	    pmf_class_network_resume, NULL);
    573 }
    574 
    575 bool
    576 pmf_event_inject(device_t dv, pmf_generic_event_t ev)
    577 {
    578 	pmf_event_workitem_t *pew;
    579 
    580 	pew = malloc(sizeof(pmf_event_workitem_t), M_TEMP, M_NOWAIT);
    581 	if (pew == NULL) {
    582 		PMF_EVENT_PRINTF(("%s: PMF event %d dropped (no memory)\n",
    583 		    dv ? device_xname(dv) : "<anonymous>", ev));
    584 		return false;
    585 	}
    586 
    587 	pew->pew_event = ev;
    588 	pew->pew_device = dv;
    589 
    590 	workqueue_enqueue(pmf_event_workqueue, (void *)pew, NULL);
    591 	PMF_EVENT_PRINTF(("%s: PMF event %d injected\n",
    592 	    dv ? device_xname(dv) : "<anonymous>", ev));
    593 
    594 	return true;
    595 }
    596 
    597 bool
    598 pmf_event_register(device_t dv, pmf_generic_event_t ev,
    599     void (*handler)(device_t), bool global)
    600 {
    601 	pmf_event_handler_t *event;
    602 
    603 	event = malloc(sizeof(*event), M_DEVBUF, M_WAITOK);
    604 	event->pmf_event = ev;
    605 	event->pmf_handler = handler;
    606 	event->pmf_device = dv;
    607 	event->pmf_global = global;
    608 	TAILQ_INSERT_TAIL(&pmf_all_events, event, pmf_link);
    609 
    610 	return true;
    611 }
    612 
    613 void
    614 pmf_event_deregister(device_t dv, pmf_generic_event_t ev,
    615     void (*handler)(device_t), bool global)
    616 {
    617 	pmf_event_handler_t *event;
    618 
    619 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
    620 		if (event->pmf_event != ev)
    621 			continue;
    622 		if (event->pmf_device != dv)
    623 			continue;
    624 		if (event->pmf_global != global)
    625 			continue;
    626 		if (event->pmf_handler != handler)
    627 			continue;
    628 		TAILQ_REMOVE(&pmf_all_events, event, pmf_link);
    629 		free(event, M_DEVBUF);
    630 		return;
    631 	}
    632 }
    633 
    634 struct display_class_softc {
    635 	TAILQ_ENTRY(display_class_softc) dc_link;
    636 	device_t dc_dev;
    637 };
    638 
    639 static TAILQ_HEAD(, display_class_softc) all_displays;
    640 static callout_t global_idle_counter;
    641 static int idle_timeout = 30;
    642 
    643 static void
    644 input_idle(void *dummy)
    645 {
    646 	PMF_IDLE_PRINTF(("Input idle handler called\n"));
    647 	pmf_event_inject(NULL, PMFE_DISPLAY_OFF);
    648 }
    649 
    650 static void
    651 input_activity_handler(device_t dv, devactive_t type)
    652 {
    653 	if (!TAILQ_EMPTY(&all_displays))
    654 		callout_schedule(&global_idle_counter, idle_timeout * hz);
    655 }
    656 
    657 static void
    658 pmf_class_input_deregister(device_t dv)
    659 {
    660 	device_active_deregister(dv, input_activity_handler);
    661 }
    662 
    663 bool
    664 pmf_class_input_register(device_t dv)
    665 {
    666 	if (!device_active_register(dv, input_activity_handler))
    667 		return false;
    668 
    669 	device_pmf_class_register(dv, NULL, NULL, NULL,
    670 	    pmf_class_input_deregister);
    671 
    672 	return true;
    673 }
    674 
    675 static void
    676 pmf_class_display_deregister(device_t dv)
    677 {
    678 	struct display_class_softc *sc = device_pmf_class_private(dv);
    679 	int s;
    680 
    681 	s = splsoftclock();
    682 	TAILQ_REMOVE(&all_displays, sc, dc_link);
    683 	if (TAILQ_EMPTY(&all_displays))
    684 		callout_stop(&global_idle_counter);
    685 	splx(s);
    686 
    687 	free(sc, M_DEVBUF);
    688 }
    689 
    690 bool
    691 pmf_class_display_register(device_t dv)
    692 {
    693 	struct display_class_softc *sc;
    694 	int s;
    695 
    696 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
    697 
    698 	s = splsoftclock();
    699 	if (TAILQ_EMPTY(&all_displays))
    700 		callout_schedule(&global_idle_counter, idle_timeout * hz);
    701 
    702 	TAILQ_INSERT_HEAD(&all_displays, sc, dc_link);
    703 	splx(s);
    704 
    705 	device_pmf_class_register(dv, sc, NULL, NULL,
    706 	    pmf_class_display_deregister);
    707 
    708 	return true;
    709 }
    710 
    711 void
    712 pmf_init(void)
    713 {
    714 	int err;
    715 
    716 	KASSERT(pmf_event_workqueue == NULL);
    717 	err = workqueue_create(&pmf_event_workqueue, "pmfevent",
    718 	    pmf_event_worker, NULL, PRI_NONE, IPL_VM, 0);
    719 	if (err)
    720 		panic("couldn't create pmfevent workqueue");
    721 
    722 	callout_init(&global_idle_counter, 0);
    723 	callout_setfunc(&global_idle_counter, input_idle, NULL);
    724 }
    725