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kern_pmf.c revision 1.21 
      1 /* $NetBSD: kern_pmf.c,v 1.21 2009/02/06 01:19:33 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 1.21 2009/02/06 01:19:33 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 
    302 	for (curdev = shutdown_first(&s); curdev != NULL;
    303 	     curdev = shutdown_next(&s)) {
    304 		aprint_debug(" attempting %s shutdown",
    305 		    device_xname(curdev));
    306 		if (!device_pmf_is_registered(curdev))
    307 			aprint_debug("(skipped)");
    308 #if 0 /* needed? */
    309 		else if (!device_pmf_class_shutdown(curdev, how))
    310 			aprint_debug("(failed)");
    311 #endif
    312 		else if (!device_pmf_driver_shutdown(curdev, how))
    313 			aprint_debug("(failed)");
    314 		else if (!device_pmf_bus_shutdown(curdev, how))
    315 			aprint_debug("(failed)");
    316 	}
    317 
    318 	aprint_debug(".\n");
    319 }
    320 
    321 bool
    322 pmf_set_platform(const char *key, const char *value)
    323 {
    324 	if (pmf_platform == NULL)
    325 		pmf_platform = prop_dictionary_create();
    326 	if (pmf_platform == NULL)
    327 		return false;
    328 
    329 	return prop_dictionary_set_cstring(pmf_platform, key, value);
    330 }
    331 
    332 const char *
    333 pmf_get_platform(const char *key)
    334 {
    335 	const char *value;
    336 
    337 	if (pmf_platform == NULL)
    338 		return NULL;
    339 
    340 	if (!prop_dictionary_get_cstring_nocopy(pmf_platform, key, &value))
    341 		return NULL;
    342 
    343 	return value;
    344 }
    345 
    346 bool
    347 pmf_device_register1(device_t dev,
    348     bool (*suspend)(device_t PMF_FN_PROTO),
    349     bool (*resume)(device_t PMF_FN_PROTO),
    350     bool (*shutdown)(device_t, int))
    351 {
    352 	if (!device_pmf_driver_register(dev, suspend, resume, shutdown))
    353 		return false;
    354 
    355 	if (!device_pmf_driver_child_register(dev)) {
    356 		device_pmf_driver_deregister(dev);
    357 		return false;
    358 	}
    359 
    360 	return true;
    361 }
    362 
    363 void
    364 pmf_device_deregister(device_t dev)
    365 {
    366 	device_pmf_class_deregister(dev);
    367 	device_pmf_bus_deregister(dev);
    368 	device_pmf_driver_deregister(dev);
    369 }
    370 
    371 bool
    372 pmf_device_suspend_self(device_t dev)
    373 {
    374 	return pmf_device_suspend(dev, PMF_F_SELF);
    375 }
    376 
    377 bool
    378 pmf_device_suspend(device_t dev PMF_FN_ARGS)
    379 {
    380 	bool rc;
    381 
    382 	PMF_TRANSITION_PRINTF(("%s: suspend enter\n", device_xname(dev)));
    383 	if (!device_pmf_is_registered(dev))
    384 		return false;
    385 
    386 	if (!device_pmf_lock(dev PMF_FN_CALL))
    387 		return false;
    388 
    389 	rc = pmf_device_suspend_locked(dev PMF_FN_CALL);
    390 
    391 	device_pmf_unlock(dev PMF_FN_CALL);
    392 
    393 	PMF_TRANSITION_PRINTF(("%s: suspend exit\n", device_xname(dev)));
    394 	return rc;
    395 }
    396 
    397 static bool
    398 pmf_device_suspend_locked(device_t dev PMF_FN_ARGS)
    399 {
    400 	PMF_TRANSITION_PRINTF2(1, ("%s: self suspend\n", device_xname(dev)));
    401 	device_pmf_self_suspend(dev, flags);
    402 	PMF_TRANSITION_PRINTF2(1, ("%s: class suspend\n", device_xname(dev)));
    403 	if (!device_pmf_class_suspend(dev PMF_FN_CALL))
    404 		return false;
    405 	PMF_TRANSITION_PRINTF2(1, ("%s: driver suspend\n", device_xname(dev)));
    406 	if (!device_pmf_driver_suspend(dev PMF_FN_CALL))
    407 		return false;
    408 	PMF_TRANSITION_PRINTF2(1, ("%s: bus suspend\n", device_xname(dev)));
    409 	if (!device_pmf_bus_suspend(dev PMF_FN_CALL))
    410 		return false;
    411 
    412 	return true;
    413 }
    414 
    415 bool
    416 pmf_device_resume_self(device_t dev)
    417 {
    418 	return pmf_device_resume(dev, PMF_F_SELF);
    419 }
    420 
    421 bool
    422 pmf_device_resume(device_t dev PMF_FN_ARGS)
    423 {
    424 	bool rc;
    425 
    426 	PMF_TRANSITION_PRINTF(("%s: resume enter\n", device_xname(dev)));
    427 	if (!device_pmf_is_registered(dev))
    428 		return false;
    429 
    430 	if (!device_pmf_lock(dev PMF_FN_CALL))
    431 		return false;
    432 
    433 	rc = pmf_device_resume_locked(dev PMF_FN_CALL);
    434 
    435 	device_pmf_unlock(dev PMF_FN_CALL);
    436 
    437 	PMF_TRANSITION_PRINTF(("%s: resume exit\n", device_xname(dev)));
    438 	return rc;
    439 }
    440 
    441 static bool
    442 pmf_device_resume_locked(device_t dev PMF_FN_ARGS)
    443 {
    444 	PMF_TRANSITION_PRINTF2(1, ("%s: bus resume\n", device_xname(dev)));
    445 	if (!device_pmf_bus_resume(dev PMF_FN_CALL))
    446 		return false;
    447 	PMF_TRANSITION_PRINTF2(1, ("%s: driver resume\n", device_xname(dev)));
    448 	if (!device_pmf_driver_resume(dev PMF_FN_CALL))
    449 		return false;
    450 	PMF_TRANSITION_PRINTF2(1, ("%s: class resume\n", device_xname(dev)));
    451 	if (!device_pmf_class_resume(dev PMF_FN_CALL))
    452 		return false;
    453 	PMF_TRANSITION_PRINTF2(1, ("%s: self resume\n", device_xname(dev)));
    454 	device_pmf_self_resume(dev, flags);
    455 
    456 	return true;
    457 }
    458 
    459 bool
    460 pmf_device_recursive_suspend(device_t dv PMF_FN_ARGS)
    461 {
    462 	bool rv = true;
    463 	device_t curdev;
    464 	deviter_t di;
    465 
    466 	if (!device_is_active(dv))
    467 		return true;
    468 
    469 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    470 	     curdev = deviter_next(&di)) {
    471 		if (device_parent(curdev) != dv)
    472 			continue;
    473 		if (!pmf_device_recursive_suspend(curdev PMF_FN_CALL)) {
    474 			rv = false;
    475 			break;
    476 		}
    477 	}
    478 	deviter_release(&di);
    479 
    480 	return rv && pmf_device_suspend(dv PMF_FN_CALL);
    481 }
    482 
    483 bool
    484 pmf_device_recursive_resume(device_t dv PMF_FN_ARGS)
    485 {
    486 	device_t parent;
    487 
    488 	if (device_is_active(dv))
    489 		return true;
    490 
    491 	parent = device_parent(dv);
    492 	if (parent != NULL) {
    493 		if (!pmf_device_recursive_resume(parent PMF_FN_CALL))
    494 			return false;
    495 	}
    496 
    497 	return pmf_device_resume(dv PMF_FN_CALL);
    498 }
    499 
    500 bool
    501 pmf_device_resume_descendants(device_t dv PMF_FN_ARGS)
    502 {
    503 	bool rv = true;
    504 	device_t curdev;
    505 	deviter_t di;
    506 
    507 	for (curdev = deviter_first(&di, 0); curdev != NULL;
    508 	     curdev = deviter_next(&di)) {
    509 		if (device_parent(curdev) != dv)
    510 			continue;
    511 		if (!pmf_device_resume_subtree(curdev PMF_FN_CALL)) {
    512 			rv = false;
    513 			break;
    514 		}
    515 	}
    516 	deviter_release(&di);
    517 	return rv;
    518 }
    519 
    520 bool
    521 pmf_device_resume_subtree(device_t dv PMF_FN_ARGS)
    522 {
    523 	if (!pmf_device_recursive_resume(dv PMF_FN_CALL))
    524 		return false;
    525 
    526 	return pmf_device_resume_descendants(dv PMF_FN_CALL);
    527 }
    528 
    529 #include <net/if.h>
    530 
    531 static bool
    532 pmf_class_network_suspend(device_t dev PMF_FN_ARGS)
    533 {
    534 	struct ifnet *ifp = device_pmf_class_private(dev);
    535 	int s;
    536 
    537 	s = splnet();
    538 	(*ifp->if_stop)(ifp, 0);
    539 	splx(s);
    540 
    541 	return true;
    542 }
    543 
    544 static bool
    545 pmf_class_network_resume(device_t dev PMF_FN_ARGS)
    546 {
    547 	struct ifnet *ifp = device_pmf_class_private(dev);
    548 	int s;
    549 
    550 	if ((flags & PMF_F_SELF) != 0)
    551 		return true;
    552 
    553 	s = splnet();
    554 	if (ifp->if_flags & IFF_UP) {
    555 		ifp->if_flags &= ~IFF_RUNNING;
    556 		if ((*ifp->if_init)(ifp) != 0)
    557 			aprint_normal_ifnet(ifp, "resume failed\n");
    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