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kern_pmf.c revision 1.10.2.3
      1 /* kern_pmf.c,v 1.10.2.2 2008/01/09 01:56:06 matt 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  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *        This product includes software developed by Jared D. McNeill.
     18  * 4. Neither the name of The NetBSD Foundation nor the names of its
     19  *    contributors may be used to endorse or promote products derived
     20  *    from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     32  * POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "kern_pmf.c,v 1.10.2.2 2008/01/09 01:56:06 matt Exp");
     37 
     38 #include <sys/types.h>
     39 #include <sys/param.h>
     40 #include <sys/malloc.h>
     41 #include <sys/buf.h>
     42 #include <sys/callout.h>
     43 #include <sys/kernel.h>
     44 #include <sys/device.h>
     45 #include <sys/pmf.h>
     46 #include <sys/queue.h>
     47 #include <sys/syscallargs.h> /* for sys_sync */
     48 #include <sys/workqueue.h>
     49 #include <prop/proplib.h>
     50 #include <sys/condvar.h>
     51 #include <sys/mutex.h>
     52 #include <sys/proc.h>
     53 #include <sys/reboot.h>	/* for RB_NOSYNC */
     54 #include <sys/sched.h>
     55 
     56 /* XXX ugly special case, but for now the only client */
     57 #include "wsdisplay.h"
     58 #if NWSDISPLAY > 0
     59 #include <dev/wscons/wsdisplayvar.h>
     60 #endif
     61 
     62 #ifdef PMF_DEBUG
     63 int pmf_debug_event;
     64 int pmf_debug_idle;
     65 int pmf_debug_transition;
     66 
     67 #define	PMF_EVENT_PRINTF(x)		if (pmf_debug_event) printf x
     68 #define	PMF_IDLE_PRINTF(x)		if (pmf_debug_idle) printf x
     69 #define	PMF_TRANSITION_PRINTF(x)	if (pmf_debug_transition) printf x
     70 #define	PMF_TRANSITION_PRINTF2(y,x)	if (pmf_debug_transition>y) printf x
     71 #else
     72 #define	PMF_EVENT_PRINTF(x)		do { } while (0)
     73 #define	PMF_IDLE_PRINTF(x)		do { } while (0)
     74 #define	PMF_TRANSITION_PRINTF(x)	do { } while (0)
     75 #define	PMF_TRANSITION_PRINTF2(y,x)	do { } while (0)
     76 #endif
     77 
     78 /* #define PMF_DEBUG */
     79 
     80 MALLOC_DEFINE(M_PMF, "pmf", "device pmf messaging memory");
     81 
     82 static prop_dictionary_t pmf_platform = NULL;
     83 static struct workqueue *pmf_event_workqueue;
     84 
     85 typedef struct pmf_event_handler {
     86 	TAILQ_ENTRY(pmf_event_handler) pmf_link;
     87 	pmf_generic_event_t pmf_event;
     88 	void (*pmf_handler)(device_t);
     89 	device_t pmf_device;
     90 	bool pmf_global;
     91 } pmf_event_handler_t;
     92 
     93 static TAILQ_HEAD(, pmf_event_handler) pmf_all_events =
     94     TAILQ_HEAD_INITIALIZER(pmf_all_events);
     95 
     96 typedef struct pmf_event_workitem {
     97 	struct work		pew_work;
     98 	pmf_generic_event_t	pew_event;
     99 	device_t		pew_device;
    100 } pmf_event_workitem_t;
    101 
    102 struct shutdown_state {
    103 	bool initialized;
    104 	deviter_t di;
    105 };
    106 
    107 static device_t shutdown_first(struct shutdown_state *);
    108 static device_t shutdown_next(struct shutdown_state *);
    109 
    110 static bool pmf_device_resume_locked(device_t PMF_FN_PROTO);
    111 static bool pmf_device_suspend_locked(device_t PMF_FN_PROTO);
    112 
    113 static void
    114 pmf_event_worker(struct work *wk, void *dummy)
    115 {
    116 	pmf_event_workitem_t *pew;
    117 	pmf_event_handler_t *event;
    118 
    119 	pew = (void *)wk;
    120 	KASSERT(wk == &pew->pew_work);
    121 	KASSERT(pew != NULL);
    122 
    123 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
    124 		if (event->pmf_event != pew->pew_event)
    125 			continue;
    126 		if (event->pmf_device == pew->pew_device || event->pmf_global)
    127 			(*event->pmf_handler)(event->pmf_device);
    128 	}
    129 
    130 	free(pew, M_TEMP);
    131 
    132 	return;
    133 }
    134 
    135 static bool
    136 pmf_check_system_drivers(void)
    137 {
    138 	device_t curdev;
    139 	bool unsupported_devs;
    140 	deviter_t di;
    141 
    142 	unsupported_devs = false;
    143 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    144 	     curdev = deviter_next(&di)) {
    145 		if (device_pmf_is_registered(curdev))
    146 			continue;
    147 		if (!unsupported_devs)
    148 			printf("Devices without power management support:");
    149 		printf(" %s", device_xname(curdev));
    150 		unsupported_devs = true;
    151 	}
    152 	deviter_release(&di);
    153 	if (unsupported_devs) {
    154 		printf("\n");
    155 		return false;
    156 	}
    157 	return true;
    158 }
    159 
    160 bool
    161 pmf_system_bus_resume(PMF_FN_ARGS1)
    162 {
    163 	bool rv;
    164 	device_t curdev;
    165 	deviter_t di;
    166 
    167 	aprint_debug("Powering devices:");
    168 	/* D0 handlers are run in order */
    169 	rv = true;
    170 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
    171 	     curdev = deviter_next(&di)) {
    172 		if (!device_pmf_is_registered(curdev))
    173 			continue;
    174 		if (device_is_active(curdev) ||
    175 		    !device_is_enabled(curdev))
    176 			continue;
    177 
    178 		aprint_debug(" %s", device_xname(curdev));
    179 
    180 		if (!device_pmf_bus_resume(curdev PMF_FN_CALL)) {
    181 			rv = false;
    182 			aprint_debug("(failed)");
    183 		}
    184 	}
    185 	deviter_release(&di);
    186 	aprint_debug("\n");
    187 
    188 	return rv;
    189 }
    190 
    191 bool
    192 pmf_system_resume(PMF_FN_ARGS1)
    193 {
    194 	bool rv;
    195 	device_t curdev, parent;
    196 	deviter_t di;
    197 
    198 	if (!pmf_check_system_drivers())
    199 		return false;
    200 
    201 	aprint_debug("Resuming devices:");
    202 	/* D0 handlers are run in order */
    203 	rv = true;
    204 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
    205 	     curdev = deviter_next(&di)) {
    206 		if (device_is_active(curdev) ||
    207 		    !device_is_enabled(curdev))
    208 			continue;
    209 		parent = device_parent(curdev);
    210 		if (parent != NULL &&
    211 		    !device_is_active(parent))
    212 			continue;
    213 
    214 		aprint_debug(" %s", device_xname(curdev));
    215 
    216 		if (!pmf_device_resume(curdev PMF_FN_CALL)) {
    217 			rv = false;
    218 			aprint_debug("(failed)");
    219 		}
    220 	}
    221 	deviter_release(&di);
    222 	aprint_debug(".\n");
    223 
    224 	KERNEL_UNLOCK_ONE(0);
    225 #if NWSDISPLAY > 0
    226 	if (rv)
    227 		wsdisplay_handlex(1);
    228 #endif
    229 	return rv;
    230 }
    231 
    232 bool
    233 pmf_system_suspend(PMF_FN_ARGS1)
    234 {
    235 	device_t curdev;
    236 	deviter_t di;
    237 
    238 	if (!pmf_check_system_drivers())
    239 		return false;
    240 #if NWSDISPLAY > 0
    241 	if (wsdisplay_handlex(0))
    242 		return false;
    243 #endif
    244 	KERNEL_LOCK(1, 0);
    245 
    246 	/*
    247 	 * Flush buffers only if the shutdown didn't do so
    248 	 * already and if there was no panic.
    249 	 */
    250 	if (doing_shutdown == 0 && panicstr == NULL) {
    251 		printf("Flushing disk caches: ");
    252 		sys_sync(NULL, NULL, NULL);
    253 		if (buf_syncwait() != 0)
    254 			printf("giving up\n");
    255 		else
    256 			printf("done\n");
    257 	}
    258 
    259 	aprint_debug("Suspending devices:");
    260 
    261 	for (curdev = deviter_first(&di, DEVITER_F_LEAVES_FIRST);
    262 	     curdev != NULL;
    263 	     curdev = deviter_next(&di)) {
    264 		if (!device_is_active(curdev))
    265 			continue;
    266 
    267 		aprint_debug(" %s", device_xname(curdev));
    268 
    269 		/* XXX joerg check return value and abort suspend */
    270 		if (!pmf_device_suspend(curdev PMF_FN_CALL))
    271 			aprint_debug("(failed)");
    272 	}
    273 	deviter_release(&di);
    274 
    275 	aprint_debug(".\n");
    276 
    277 	return true;
    278 }
    279 
    280 static device_t
    281 shutdown_first(struct shutdown_state *s)
    282 {
    283 	if (!s->initialized) {
    284 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
    285 		s->initialized = true;
    286 	}
    287 	return shutdown_next(s);
    288 }
    289 
    290 static device_t
    291 shutdown_next(struct shutdown_state *s)
    292 {
    293 	device_t dv;
    294 
    295 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
    296 		;
    297 
    298 	return dv;
    299 }
    300 
    301 void
    302 pmf_system_shutdown(int how)
    303 {
    304 	static struct shutdown_state s;
    305 	device_t curdev;
    306 
    307 	aprint_debug("Shutting down devices:");
    308 
    309 	for (curdev = shutdown_first(&s); curdev != NULL;
    310 	     curdev = shutdown_next(&s)) {
    311 		aprint_debug(" attempting %s shutdown",
    312 		    device_xname(curdev));
    313 		if (!device_pmf_is_registered(curdev))
    314 			aprint_debug("(skipped)");
    315 #if 0 /* needed? */
    316 		else if (!device_pmf_class_shutdown(curdev, how))
    317 			aprint_debug("(failed)");
    318 #endif
    319 		else if (!device_pmf_driver_shutdown(curdev, how))
    320 			aprint_debug("(failed)");
    321 		else if (!device_pmf_bus_shutdown(curdev, how))
    322 			aprint_debug("(failed)");
    323 	}
    324 
    325 	aprint_debug(".\n");
    326 }
    327 
    328 bool
    329 pmf_set_platform(const char *key, const char *value)
    330 {
    331 	if (pmf_platform == NULL)
    332 		pmf_platform = prop_dictionary_create();
    333 	if (pmf_platform == NULL)
    334 		return false;
    335 
    336 	return prop_dictionary_set_cstring(pmf_platform, key, value);
    337 }
    338 
    339 const char *
    340 pmf_get_platform(const char *key)
    341 {
    342 	const char *value;
    343 
    344 	if (pmf_platform == NULL)
    345 		return NULL;
    346 
    347 	if (!prop_dictionary_get_cstring_nocopy(pmf_platform, key, &value))
    348 		return NULL;
    349 
    350 	return value;
    351 }
    352 
    353 bool
    354 pmf_device_register1(device_t dev,
    355     bool (*suspend)(device_t PMF_FN_PROTO),
    356     bool (*resume)(device_t PMF_FN_PROTO),
    357     bool (*shutdown)(device_t, int))
    358 {
    359 	if (!device_pmf_driver_register(dev, suspend, resume, shutdown))
    360 		return false;
    361 
    362 	if (!device_pmf_driver_child_register(dev)) {
    363 		device_pmf_driver_deregister(dev);
    364 		return false;
    365 	}
    366 
    367 	return true;
    368 }
    369 
    370 void
    371 pmf_device_deregister(device_t dev)
    372 {
    373 	device_pmf_class_deregister(dev);
    374 	device_pmf_bus_deregister(dev);
    375 	device_pmf_driver_deregister(dev);
    376 }
    377 
    378 bool
    379 pmf_device_suspend_self(device_t dev)
    380 {
    381 	return pmf_device_suspend(dev, PMF_F_SELF);
    382 }
    383 
    384 bool
    385 pmf_device_suspend(device_t dev PMF_FN_ARGS)
    386 {
    387 	bool rc;
    388 
    389 	PMF_TRANSITION_PRINTF(("%s: suspend enter\n", device_xname(dev)));
    390 	if (!device_pmf_is_registered(dev))
    391 		return false;
    392 
    393 	if (!device_pmf_lock(dev PMF_FN_CALL))
    394 		return false;
    395 
    396 	rc = pmf_device_suspend_locked(dev PMF_FN_CALL);
    397 
    398 	device_pmf_unlock(dev PMF_FN_CALL);
    399 
    400 	PMF_TRANSITION_PRINTF(("%s: suspend exit\n", device_xname(dev)));
    401 	return rc;
    402 }
    403 
    404 static bool
    405 pmf_device_suspend_locked(device_t dev PMF_FN_ARGS)
    406 {
    407 	PMF_TRANSITION_PRINTF2(1, ("%s: self suspend\n", device_xname(dev)));
    408 	device_pmf_self_suspend(dev, flags);
    409 	PMF_TRANSITION_PRINTF2(1, ("%s: class suspend\n", device_xname(dev)));
    410 	if (!device_pmf_class_suspend(dev PMF_FN_CALL))
    411 		return false;
    412 	PMF_TRANSITION_PRINTF2(1, ("%s: driver suspend\n", device_xname(dev)));
    413 	if (!device_pmf_driver_suspend(dev PMF_FN_CALL))
    414 		return false;
    415 	PMF_TRANSITION_PRINTF2(1, ("%s: bus suspend\n", device_xname(dev)));
    416 	if (!device_pmf_bus_suspend(dev PMF_FN_CALL))
    417 		return false;
    418 
    419 	return true;
    420 }
    421 
    422 bool
    423 pmf_device_resume_self(device_t dev)
    424 {
    425 	return pmf_device_resume(dev, PMF_F_SELF);
    426 }
    427 
    428 bool
    429 pmf_device_resume(device_t dev PMF_FN_ARGS)
    430 {
    431 	bool rc;
    432 
    433 	PMF_TRANSITION_PRINTF(("%s: resume enter\n", device_xname(dev)));
    434 	if (!device_pmf_is_registered(dev))
    435 		return false;
    436 
    437 	if (!device_pmf_lock(dev PMF_FN_CALL))
    438 		return false;
    439 
    440 	rc = pmf_device_resume_locked(dev PMF_FN_CALL);
    441 
    442 	device_pmf_unlock(dev PMF_FN_CALL);
    443 
    444 	PMF_TRANSITION_PRINTF(("%s: resume exit\n", device_xname(dev)));
    445 	return rc;
    446 }
    447 
    448 static bool
    449 pmf_device_resume_locked(device_t dev PMF_FN_ARGS)
    450 {
    451 	PMF_TRANSITION_PRINTF2(1, ("%s: bus resume\n", device_xname(dev)));
    452 	if (!device_pmf_bus_resume(dev PMF_FN_CALL))
    453 		return false;
    454 	PMF_TRANSITION_PRINTF2(1, ("%s: driver resume\n", device_xname(dev)));
    455 	if (!device_pmf_driver_resume(dev PMF_FN_CALL))
    456 		return false;
    457 	PMF_TRANSITION_PRINTF2(1, ("%s: class resume\n", device_xname(dev)));
    458 	if (!device_pmf_class_resume(dev PMF_FN_CALL))
    459 		return false;
    460 	PMF_TRANSITION_PRINTF2(1, ("%s: self resume\n", device_xname(dev)));
    461 	device_pmf_self_resume(dev, flags);
    462 
    463 	return true;
    464 }
    465 
    466 bool
    467 pmf_device_recursive_suspend(device_t dv PMF_FN_ARGS)
    468 {
    469 	bool rv = true;
    470 	device_t curdev;
    471 	deviter_t di;
    472 
    473 	if (!device_is_active(dv))
    474 		return true;
    475 
    476 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    477 	     curdev = deviter_next(&di)) {
    478 		if (device_parent(curdev) != dv)
    479 			continue;
    480 		if (!pmf_device_recursive_suspend(curdev PMF_FN_CALL)) {
    481 			rv = false;
    482 			break;
    483 		}
    484 	}
    485 	deviter_release(&di);
    486 
    487 	return rv && pmf_device_suspend(dv PMF_FN_CALL);
    488 }
    489 
    490 bool
    491 pmf_device_recursive_resume(device_t dv PMF_FN_ARGS)
    492 {
    493 	device_t parent;
    494 
    495 	if (device_is_active(dv))
    496 		return true;
    497 
    498 	parent = device_parent(dv);
    499 	if (parent != NULL) {
    500 		if (!pmf_device_recursive_resume(parent PMF_FN_CALL))
    501 			return false;
    502 	}
    503 
    504 	return pmf_device_resume(dv PMF_FN_CALL);
    505 }
    506 
    507 bool
    508 pmf_device_resume_subtree(device_t dv PMF_FN_ARGS)
    509 {
    510 	bool rv = true;
    511 	device_t curdev;
    512 	deviter_t di;
    513 
    514 	if (!pmf_device_recursive_resume(dv PMF_FN_CALL))
    515 		return false;
    516 
    517 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    518 	     curdev = deviter_next(&di)) {
    519 		if (device_parent(curdev) != dv)
    520 			continue;
    521 		if (!pmf_device_resume_subtree(curdev PMF_FN_CALL)) {
    522 			rv = false;
    523 			break;
    524 		}
    525 	}
    526 	deviter_release(&di);
    527 	return rv;
    528 }
    529 
    530 #include <net/if.h>
    531 
    532 static bool
    533 pmf_class_network_suspend(device_t dev PMF_FN_ARGS)
    534 {
    535 	struct ifnet *ifp = device_pmf_class_private(dev);
    536 	int s;
    537 
    538 	s = splnet();
    539 	(*ifp->if_stop)(ifp, 0);
    540 	splx(s);
    541 
    542 	return true;
    543 }
    544 
    545 static bool
    546 pmf_class_network_resume(device_t dev PMF_FN_ARGS)
    547 {
    548 	struct ifnet *ifp = device_pmf_class_private(dev);
    549 	int s;
    550 
    551 	if ((flags & PMF_F_SELF) != 0)
    552 		return true;
    553 
    554 	s = splnet();
    555 	if (ifp->if_flags & IFF_UP) {
    556 		ifp->if_flags &= ~IFF_RUNNING;
    557 		(*ifp->if_init)(ifp);
    558 		(*ifp->if_start)(ifp);
    559 	}
    560 	splx(s);
    561 
    562 	return true;
    563 }
    564 
    565 void
    566 pmf_class_network_register(device_t dev, struct ifnet *ifp)
    567 {
    568 	device_pmf_class_register(dev, ifp, pmf_class_network_suspend,
    569 	    pmf_class_network_resume, NULL);
    570 }
    571 
    572 bool
    573 pmf_event_inject(device_t dv, pmf_generic_event_t ev)
    574 {
    575 	pmf_event_workitem_t *pew;
    576 
    577 	pew = malloc(sizeof(pmf_event_workitem_t), M_TEMP, M_NOWAIT);
    578 	if (pew == NULL) {
    579 		PMF_EVENT_PRINTF(("%s: PMF event %d dropped (no memory)\n",
    580 		    dv ? device_xname(dv) : "<anonymous>", ev));
    581 		return false;
    582 	}
    583 
    584 	pew->pew_event = ev;
    585 	pew->pew_device = dv;
    586 
    587 	workqueue_enqueue(pmf_event_workqueue, (void *)pew, NULL);
    588 	PMF_EVENT_PRINTF(("%s: PMF event %d injected\n",
    589 	    dv ? device_xname(dv) : "<anonymous>", ev));
    590 
    591 	return true;
    592 }
    593 
    594 bool
    595 pmf_event_register(device_t dv, pmf_generic_event_t ev,
    596     void (*handler)(device_t), bool global)
    597 {
    598 	pmf_event_handler_t *event;
    599 
    600 	event = malloc(sizeof(*event), M_DEVBUF, M_WAITOK);
    601 	event->pmf_event = ev;
    602 	event->pmf_handler = handler;
    603 	event->pmf_device = dv;
    604 	event->pmf_global = global;
    605 	TAILQ_INSERT_TAIL(&pmf_all_events, event, pmf_link);
    606 
    607 	return true;
    608 }
    609 
    610 void
    611 pmf_event_deregister(device_t dv, pmf_generic_event_t ev,
    612     void (*handler)(device_t), bool global)
    613 {
    614 	pmf_event_handler_t *event;
    615 
    616 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
    617 		if (event->pmf_event != ev)
    618 			continue;
    619 		if (event->pmf_device != dv)
    620 			continue;
    621 		if (event->pmf_global != global)
    622 			continue;
    623 		if (event->pmf_handler != handler)
    624 			continue;
    625 		TAILQ_REMOVE(&pmf_all_events, event, pmf_link);
    626 		free(event, M_DEVBUF);
    627 		return;
    628 	}
    629 }
    630 
    631 struct display_class_softc {
    632 	TAILQ_ENTRY(display_class_softc) dc_link;
    633 	device_t dc_dev;
    634 };
    635 
    636 static TAILQ_HEAD(, display_class_softc) all_displays;
    637 static callout_t global_idle_counter;
    638 static int idle_timeout = 30;
    639 
    640 static void
    641 input_idle(void *dummy)
    642 {
    643 	PMF_IDLE_PRINTF(("Input idle handler called\n"));
    644 	pmf_event_inject(NULL, PMFE_DISPLAY_OFF);
    645 }
    646 
    647 static void
    648 input_activity_handler(device_t dv, devactive_t type)
    649 {
    650 	if (!TAILQ_EMPTY(&all_displays))
    651 		callout_schedule(&global_idle_counter, idle_timeout * hz);
    652 }
    653 
    654 static void
    655 pmf_class_input_deregister(device_t dv)
    656 {
    657 	device_active_deregister(dv, input_activity_handler);
    658 }
    659 
    660 bool
    661 pmf_class_input_register(device_t dv)
    662 {
    663 	if (!device_active_register(dv, input_activity_handler))
    664 		return false;
    665 
    666 	device_pmf_class_register(dv, NULL, NULL, NULL,
    667 	    pmf_class_input_deregister);
    668 
    669 	return true;
    670 }
    671 
    672 static void
    673 pmf_class_display_deregister(device_t dv)
    674 {
    675 	struct display_class_softc *sc = device_pmf_class_private(dv);
    676 	int s;
    677 
    678 	s = splsoftclock();
    679 	TAILQ_REMOVE(&all_displays, sc, dc_link);
    680 	if (TAILQ_EMPTY(&all_displays))
    681 		callout_stop(&global_idle_counter);
    682 	splx(s);
    683 
    684 	free(sc, M_DEVBUF);
    685 }
    686 
    687 bool
    688 pmf_class_display_register(device_t dv)
    689 {
    690 	struct display_class_softc *sc;
    691 	int s;
    692 
    693 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
    694 
    695 	s = splsoftclock();
    696 	if (TAILQ_EMPTY(&all_displays))
    697 		callout_schedule(&global_idle_counter, idle_timeout * hz);
    698 
    699 	TAILQ_INSERT_HEAD(&all_displays, sc, dc_link);
    700 	splx(s);
    701 
    702 	device_pmf_class_register(dv, sc, NULL, NULL,
    703 	    pmf_class_display_deregister);
    704 
    705 	return true;
    706 }
    707 
    708 void
    709 pmf_init(void)
    710 {
    711 	int err;
    712 
    713 	KASSERT(pmf_event_workqueue == NULL);
    714 	err = workqueue_create(&pmf_event_workqueue, "pmfevent",
    715 	    pmf_event_worker, NULL, PRI_NONE, IPL_VM, 0);
    716 	if (err)
    717 		panic("couldn't create pmfevent workqueue");
    718 
    719 	callout_init(&global_idle_counter, 0);
    720 	callout_setfunc(&global_idle_counter, input_idle, NULL);
    721 }
    722