xref: /freebsd/sys/dev/hid/hidbus.c (revision d91f8db5f1822c43cd256f19aae1d059e4b25a26)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019-2020 Vladimir Kondratyev <wulf@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/ck.h>
34 #include <sys/epoch.h>
35 #include <sys/kdb.h>
36 #include <sys/kernel.h>
37 #include <sys/libkern.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/proc.h>
43 #include <sys/sbuf.h>
44 #include <sys/sx.h>
45 #include <sys/systm.h>
46 
47 #define	HID_DEBUG_VAR	hid_debug
48 #include <dev/hid/hid.h>
49 #include <dev/hid/hidbus.h>
50 #include <dev/hid/hidquirk.h>
51 
52 #include "hid_if.h"
53 
54 #define	INPUT_EPOCH	global_epoch_preempt
55 #define	HID_RSIZE_MAX	1024
56 
57 static hid_intr_t	hidbus_intr;
58 
59 static device_probe_t	hidbus_probe;
60 static device_attach_t	hidbus_attach;
61 static device_detach_t	hidbus_detach;
62 
63 struct hidbus_ivars {
64 	int32_t				usage;
65 	uint8_t				index;
66 	uint32_t			flags;
67 	uintptr_t			driver_info;    /* for internal use */
68 	struct mtx			*mtx;		/* child intr mtx */
69 	hid_intr_t			*intr_handler;	/* executed under mtx*/
70 	void				*intr_ctx;
71 	unsigned int			refcnt;		/* protected by mtx */
72 	struct epoch_context		epoch_ctx;
73 	CK_STAILQ_ENTRY(hidbus_ivars)	link;
74 };
75 
76 struct hidbus_softc {
77 	device_t			dev;
78 	struct sx			sx;
79 	struct mtx			mtx;
80 
81 	bool				nowrite;
82 
83 	struct hid_rdesc_info		rdesc;
84 	bool				overloaded;
85 	int				nest;	/* Child attach nesting lvl */
86 	int				nauto;	/* Number of autochildren */
87 
88 	CK_STAILQ_HEAD(, hidbus_ivars)	tlcs;
89 };
90 
91 static int
92 hidbus_fill_rdesc_info(struct hid_rdesc_info *hri, const void *data,
93     hid_size_t len)
94 {
95 	int error = 0;
96 
97 	hri->data = __DECONST(void *, data);
98 	hri->len = len;
99 
100 	/*
101 	 * If report descriptor is not available yet, set maximal
102 	 * report sizes high enough to allow hidraw to work.
103 	 */
104 	hri->isize = len == 0 ? HID_RSIZE_MAX :
105 	    hid_report_size_max(data, len, hid_input, &hri->iid);
106 	hri->osize = len == 0 ? HID_RSIZE_MAX :
107 	    hid_report_size_max(data, len, hid_output, &hri->oid);
108 	hri->fsize = len == 0 ? HID_RSIZE_MAX :
109 	    hid_report_size_max(data, len, hid_feature, &hri->fid);
110 
111 	if (hri->isize > HID_RSIZE_MAX) {
112 		DPRINTF("input size is too large, %u bytes (truncating)\n",
113 		    hri->isize);
114 		hri->isize = HID_RSIZE_MAX;
115 		error = EOVERFLOW;
116 	}
117 	if (hri->osize > HID_RSIZE_MAX) {
118 		DPRINTF("output size is too large, %u bytes (truncating)\n",
119 		    hri->osize);
120 		hri->osize = HID_RSIZE_MAX;
121 		error = EOVERFLOW;
122 	}
123 	if (hri->fsize > HID_RSIZE_MAX) {
124 		DPRINTF("feature size is too large, %u bytes (truncating)\n",
125 		    hri->fsize);
126 		hri->fsize = HID_RSIZE_MAX;
127 		error = EOVERFLOW;
128 	}
129 
130 	return (error);
131 }
132 
133 int
134 hidbus_locate(const void *desc, hid_size_t size, int32_t u, enum hid_kind k,
135     uint8_t tlc_index, uint8_t index, struct hid_location *loc,
136     uint32_t *flags, uint8_t *id, struct hid_absinfo *ai)
137 {
138 	struct hid_data *d;
139 	struct hid_item h;
140 	int i;
141 
142 	d = hid_start_parse(desc, size, 1 << k);
143 	HIDBUS_FOREACH_ITEM(d, &h, tlc_index) {
144 		for (i = 0; i < h.nusages; i++) {
145 			if (h.kind == k && h.usages[i] == u) {
146 				if (index--)
147 					break;
148 				if (loc != NULL)
149 					*loc = h.loc;
150 				if (flags != NULL)
151 					*flags = h.flags;
152 				if (id != NULL)
153 					*id = h.report_ID;
154 				if (ai != NULL && (h.flags&HIO_RELATIVE) == 0)
155 					*ai = (struct hid_absinfo) {
156 					    .max = h.logical_maximum,
157 					    .min = h.logical_minimum,
158 					    .res = hid_item_resolution(&h),
159 					};
160 				hid_end_parse(d);
161 				return (1);
162 			}
163 		}
164 	}
165 	if (loc != NULL)
166 		loc->size = 0;
167 	if (flags != NULL)
168 		*flags = 0;
169 	if (id != NULL)
170 		*id = 0;
171 	hid_end_parse(d);
172 	return (0);
173 }
174 
175 bool
176 hidbus_is_collection(const void *desc, hid_size_t size, int32_t usage,
177     uint8_t tlc_index)
178 {
179 	struct hid_data *d;
180 	struct hid_item h;
181 	bool ret = false;
182 
183 	d = hid_start_parse(desc, size, 0);
184 	HIDBUS_FOREACH_ITEM(d, &h, tlc_index) {
185 		if (h.kind == hid_collection && h.usage == usage) {
186 			ret = true;
187 			break;
188 		}
189 	}
190 	hid_end_parse(d);
191 	return (ret);
192 }
193 
194 static device_t
195 hidbus_add_child(device_t dev, u_int order, const char *name, int unit)
196 {
197 	struct hidbus_softc *sc = device_get_softc(dev);
198 	struct hidbus_ivars *tlc;
199 	device_t child;
200 
201 	child = device_add_child_ordered(dev, order, name, unit);
202 	if (child == NULL)
203 			return (child);
204 
205 	tlc = malloc(sizeof(struct hidbus_ivars), M_DEVBUF, M_WAITOK | M_ZERO);
206 	tlc->mtx = &sc->mtx;
207 	device_set_ivars(child, tlc);
208 	sx_xlock(&sc->sx);
209 	CK_STAILQ_INSERT_TAIL(&sc->tlcs, tlc, link);
210 	sx_unlock(&sc->sx);
211 
212 	return (child);
213 }
214 
215 static int
216 hidbus_enumerate_children(device_t dev, const void* data, hid_size_t len)
217 {
218 	struct hidbus_softc *sc = device_get_softc(dev);
219 	struct hid_data *hd;
220 	struct hid_item hi;
221 	device_t child;
222 	uint8_t index = 0;
223 
224 	if (data == NULL || len == 0)
225 		return (ENXIO);
226 
227 	/* Add a child for each top level collection */
228 	hd = hid_start_parse(data, len, 1 << hid_input);
229 	while (hid_get_item(hd, &hi)) {
230 		if (hi.kind != hid_collection || hi.collevel != 1)
231 			continue;
232 		child = BUS_ADD_CHILD(dev, 0, NULL, -1);
233 		if (child == NULL) {
234 			device_printf(dev, "Could not add HID device\n");
235 			continue;
236 		}
237 		hidbus_set_index(child, index);
238 		hidbus_set_usage(child, hi.usage);
239 		hidbus_set_flags(child, HIDBUS_FLAG_AUTOCHILD);
240 		index++;
241 		DPRINTF("Add child TLC: 0x%04x:0x%04x\n",
242 		    HID_GET_USAGE_PAGE(hi.usage), HID_GET_USAGE(hi.usage));
243 	}
244 	hid_end_parse(hd);
245 
246 	if (index == 0)
247 		return (ENXIO);
248 
249 	sc->nauto = index;
250 
251 	return (0);
252 }
253 
254 static int
255 hidbus_attach_children(device_t dev)
256 {
257 	struct hidbus_softc *sc = device_get_softc(dev);
258 	int error;
259 
260 	HID_INTR_SETUP(device_get_parent(dev), hidbus_intr, sc, &sc->rdesc);
261 
262 	error = hidbus_enumerate_children(dev, sc->rdesc.data, sc->rdesc.len);
263 	if (error != 0)
264 		DPRINTF("failed to enumerate children: error %d\n", error);
265 
266 	/*
267 	 * hidbus_attach_children() can recurse through device_identify->
268 	 * hid_set_report_descr() call sequence. Do not perform children
269 	 * attach twice in that case.
270 	 */
271 	sc->nest++;
272 	bus_generic_probe(dev);
273 	sc->nest--;
274 	if (sc->nest != 0)
275 		return (0);
276 
277 	if (hid_is_keyboard(sc->rdesc.data, sc->rdesc.len) != 0)
278 		error = bus_generic_attach(dev);
279 	else
280 		error = bus_delayed_attach_children(dev);
281 	if (error != 0)
282 		device_printf(dev, "failed to attach child: error %d\n", error);
283 
284 	return (error);
285 }
286 
287 static int
288 hidbus_detach_children(device_t dev)
289 {
290 	device_t *children, bus;
291 	bool is_bus;
292 	int i, error;
293 
294 	error = 0;
295 
296 	is_bus = device_get_devclass(dev) == devclass_find("hidbus");
297 	bus = is_bus ? dev : device_get_parent(dev);
298 
299 	KASSERT(device_get_devclass(bus) == devclass_find("hidbus"),
300 	    ("Device is not hidbus or it's child"));
301 
302 	if (is_bus) {
303 		/* If hidbus is passed, delete all children. */
304 		bus_generic_detach(bus);
305 		device_delete_children(bus);
306 	} else {
307 		/*
308 		 * If hidbus child is passed, delete all hidbus children
309 		 * except caller. Deleting the caller may result in deadlock.
310 		 */
311 		error = device_get_children(bus, &children, &i);
312 		if (error != 0)
313 			return (error);
314 		while (i-- > 0) {
315 			if (children[i] == dev)
316 				continue;
317 			DPRINTF("Delete child. index=%d (%s)\n",
318 			    hidbus_get_index(children[i]),
319 			    device_get_nameunit(children[i]));
320 			error = device_delete_child(bus, children[i]);
321 			if (error) {
322 				DPRINTF("Failed deleting %s\n",
323 				    device_get_nameunit(children[i]));
324 				break;
325 			}
326 		}
327 		free(children, M_TEMP);
328 	}
329 
330 	HID_INTR_UNSETUP(device_get_parent(bus));
331 
332 	return (error);
333 }
334 
335 static int
336 hidbus_probe(device_t dev)
337 {
338 
339 	device_set_desc(dev, "HID bus");
340 
341 	/* Allow other subclasses to override this driver. */
342 	return (BUS_PROBE_GENERIC);
343 }
344 
345 static int
346 hidbus_attach(device_t dev)
347 {
348 	struct hidbus_softc *sc = device_get_softc(dev);
349 	struct hid_device_info *devinfo = device_get_ivars(dev);
350 	void *d_ptr = NULL;
351 	hid_size_t d_len;
352 	int error;
353 
354 	sc->dev = dev;
355 	CK_STAILQ_INIT(&sc->tlcs);
356 	mtx_init(&sc->mtx, "hidbus ivar lock", NULL, MTX_DEF);
357 	sx_init(&sc->sx, "hidbus ivar list lock");
358 
359 	/*
360 	 * Ignore error. It is possible for non-HID device e.g. XBox360 gamepad
361 	 * to emulate HID through overloading of report descriptor.
362 	 */
363 	d_len = devinfo->rdescsize;
364 	if (d_len != 0) {
365 		d_ptr = malloc(d_len, M_DEVBUF, M_ZERO | M_WAITOK);
366 		error = hid_get_rdesc(dev, d_ptr, d_len);
367 		if (error != 0) {
368 			free(d_ptr, M_DEVBUF);
369 			d_len = 0;
370 			d_ptr = NULL;
371 		}
372 	}
373 
374 	hidbus_fill_rdesc_info(&sc->rdesc, d_ptr, d_len);
375 
376 	sc->nowrite = hid_test_quirk(devinfo, HQ_NOWRITE);
377 
378 	error = hidbus_attach_children(dev);
379 	if (error != 0) {
380 		hidbus_detach(dev);
381 		return (ENXIO);
382 	}
383 
384 	return (0);
385 }
386 
387 static int
388 hidbus_detach(device_t dev)
389 {
390 	struct hidbus_softc *sc = device_get_softc(dev);
391 
392 	hidbus_detach_children(dev);
393 	sx_destroy(&sc->sx);
394 	mtx_destroy(&sc->mtx);
395 	free(sc->rdesc.data, M_DEVBUF);
396 
397 	return (0);
398 }
399 
400 static void
401 hidbus_child_detached(device_t bus, device_t child)
402 {
403 	struct hidbus_softc *sc = device_get_softc(bus);
404 	struct hidbus_ivars *tlc = device_get_ivars(child);
405 
406 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
407 	tlc->mtx = &sc->mtx;
408 	tlc->intr_handler = NULL;
409 	tlc->flags &= ~HIDBUS_FLAG_CAN_POLL;
410 }
411 
412 /*
413  * Epoch callback indicating tlc is safe to destroy
414  */
415 static void
416 hidbus_ivar_dtor(epoch_context_t ctx)
417 {
418 	struct hidbus_ivars *tlc;
419 
420 	tlc = __containerof(ctx, struct hidbus_ivars, epoch_ctx);
421 	free(tlc, M_DEVBUF);
422 }
423 
424 static void
425 hidbus_child_deleted(device_t bus, device_t child)
426 {
427 	struct hidbus_softc *sc = device_get_softc(bus);
428 	struct hidbus_ivars *tlc = device_get_ivars(child);
429 
430 	sx_xlock(&sc->sx);
431 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
432 	CK_STAILQ_REMOVE(&sc->tlcs, tlc, hidbus_ivars, link);
433 	sx_unlock(&sc->sx);
434 	epoch_call(INPUT_EPOCH, hidbus_ivar_dtor, &tlc->epoch_ctx);
435 }
436 
437 static int
438 hidbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
439 {
440 	struct hidbus_softc *sc = device_get_softc(bus);
441 	struct hidbus_ivars *tlc = device_get_ivars(child);
442 
443 	switch (which) {
444 	case HIDBUS_IVAR_INDEX:
445 		*result = tlc->index;
446 		break;
447 	case HIDBUS_IVAR_USAGE:
448 		*result = tlc->usage;
449 		break;
450 	case HIDBUS_IVAR_FLAGS:
451 		*result = tlc->flags;
452 		break;
453 	case HIDBUS_IVAR_DRIVER_INFO:
454 		*result = tlc->driver_info;
455 		break;
456 	case HIDBUS_IVAR_LOCK:
457 		*result = (uintptr_t)(tlc->mtx == &sc->mtx ? NULL : tlc->mtx);
458 		break;
459 	default:
460 		return (EINVAL);
461 	}
462 	return (0);
463 }
464 
465 static int
466 hidbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
467 {
468 	struct hidbus_softc *sc = device_get_softc(bus);
469 	struct hidbus_ivars *tlc = device_get_ivars(child);
470 
471 	switch (which) {
472 	case HIDBUS_IVAR_INDEX:
473 		tlc->index = value;
474 		break;
475 	case HIDBUS_IVAR_USAGE:
476 		tlc->usage = value;
477 		break;
478 	case HIDBUS_IVAR_FLAGS:
479 		tlc->flags = value;
480 		if ((value & HIDBUS_FLAG_CAN_POLL) != 0)
481 			HID_INTR_SETUP(
482 			    device_get_parent(bus), NULL, NULL, NULL);
483 		break;
484 	case HIDBUS_IVAR_DRIVER_INFO:
485 		tlc->driver_info = value;
486 		break;
487 	case HIDBUS_IVAR_LOCK:
488 		tlc->mtx = (struct mtx *)value == NULL ?
489 		    &sc->mtx : (struct mtx *)value;
490 		break;
491 	default:
492 		return (EINVAL);
493 	}
494 	return (0);
495 }
496 
497 /* Location hint for devctl(8) */
498 static int
499 hidbus_child_location(device_t bus, device_t child, struct sbuf *sb)
500 {
501 	struct hidbus_ivars *tlc = device_get_ivars(child);
502 
503 	sbuf_printf(sb, "index=%hhu", tlc->index);
504         return (0);
505 }
506 
507 /* PnP information for devctl(8) */
508 static int
509 hidbus_child_pnpinfo(device_t bus, device_t child, struct sbuf *sb)
510 {
511 	struct hidbus_ivars *tlc = device_get_ivars(child);
512 	struct hid_device_info *devinfo = device_get_ivars(bus);
513 
514 	sbuf_printf(sb, "page=0x%04x usage=0x%04x bus=0x%02hx "
515 	    "vendor=0x%04hx product=0x%04hx version=0x%04hx%s%s",
516 	    HID_GET_USAGE_PAGE(tlc->usage), HID_GET_USAGE(tlc->usage),
517 	    devinfo->idBus, devinfo->idVendor, devinfo->idProduct,
518 	    devinfo->idVersion, devinfo->idPnP[0] == '\0' ? "" : " _HID=",
519 	    devinfo->idPnP[0] == '\0' ? "" : devinfo->idPnP);
520 	return (0);
521 }
522 
523 void
524 hidbus_set_desc(device_t child, const char *suffix)
525 {
526 	device_t bus = device_get_parent(child);
527 	struct hidbus_softc *sc = device_get_softc(bus);
528 	struct hid_device_info *devinfo = device_get_ivars(bus);
529 	struct hidbus_ivars *tlc = device_get_ivars(child);
530 	char buf[80];
531 
532 	/* Do not add NULL suffix or if device name already contains it. */
533 	if (suffix != NULL && strcasestr(devinfo->name, suffix) == NULL &&
534 	    (sc->nauto > 1 || (tlc->flags & HIDBUS_FLAG_AUTOCHILD) == 0)) {
535 		snprintf(buf, sizeof(buf), "%s %s", devinfo->name, suffix);
536 		device_set_desc_copy(child, buf);
537 	} else
538 		device_set_desc(child, devinfo->name);
539 }
540 
541 device_t
542 hidbus_find_child(device_t bus, int32_t usage)
543 {
544 	device_t *children, child;
545 	int ccount, i;
546 
547 	bus_topo_assert();
548 
549 	/* Get a list of all hidbus children */
550 	if (device_get_children(bus, &children, &ccount) != 0)
551 		return (NULL);
552 
553 	/* Scan through to find required TLC */
554 	for (i = 0, child = NULL; i < ccount; i++) {
555 		if (hidbus_get_usage(children[i]) == usage) {
556 			child = children[i];
557 			break;
558 		}
559 	}
560 	free(children, M_TEMP);
561 
562 	return (child);
563 }
564 
565 void
566 hidbus_intr(void *context, void *buf, hid_size_t len)
567 {
568 	struct hidbus_softc *sc = context;
569 	struct hidbus_ivars *tlc;
570 	struct epoch_tracker et;
571 
572 	/*
573 	 * Broadcast input report to all subscribers.
574 	 * TODO: Add check for input report ID.
575 	 *
576 	 * Relock mutex on every TLC item as we can't hold any locks over whole
577 	 * TLC list here due to LOR with open()/close() handlers.
578 	 */
579 	if (!HID_IN_POLLING_MODE())
580 		epoch_enter_preempt(INPUT_EPOCH, &et);
581 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
582 		if (tlc->refcnt == 0 || tlc->intr_handler == NULL)
583 			continue;
584 		if (HID_IN_POLLING_MODE()) {
585 			if ((tlc->flags & HIDBUS_FLAG_CAN_POLL) != 0)
586 				tlc->intr_handler(tlc->intr_ctx, buf, len);
587 		} else {
588 			mtx_lock(tlc->mtx);
589 			tlc->intr_handler(tlc->intr_ctx, buf, len);
590 			mtx_unlock(tlc->mtx);
591 		}
592 	}
593 	if (!HID_IN_POLLING_MODE())
594 		epoch_exit_preempt(INPUT_EPOCH, &et);
595 }
596 
597 void
598 hidbus_set_intr(device_t child, hid_intr_t *handler, void *context)
599 {
600 	struct hidbus_ivars *tlc = device_get_ivars(child);
601 
602 	tlc->intr_handler = handler;
603 	tlc->intr_ctx = context;
604 }
605 
606 int
607 hidbus_intr_start(device_t child)
608 {
609 	device_t bus = device_get_parent(child);
610 	struct hidbus_softc *sc = device_get_softc(bus);
611 	struct hidbus_ivars *ivar = device_get_ivars(child);
612 	struct hidbus_ivars *tlc;
613 	bool refcnted = false;
614 	int error;
615 
616 	if (sx_xlock_sig(&sc->sx) != 0)
617 		return (EINTR);
618 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
619 		refcnted |= (tlc->refcnt != 0);
620 		if (tlc == ivar) {
621 			mtx_lock(tlc->mtx);
622 			++tlc->refcnt;
623 			mtx_unlock(tlc->mtx);
624 		}
625 	}
626 	error = refcnted ? 0 : HID_INTR_START(device_get_parent(bus));
627 	sx_unlock(&sc->sx);
628 
629 	return (error);
630 }
631 
632 int
633 hidbus_intr_stop(device_t child)
634 {
635 	device_t bus = device_get_parent(child);
636 	struct hidbus_softc *sc = device_get_softc(bus);
637 	struct hidbus_ivars *ivar = device_get_ivars(child);
638 	struct hidbus_ivars *tlc;
639 	bool refcnted = false;
640 	int error;
641 
642 	if (sx_xlock_sig(&sc->sx) != 0)
643 		return (EINTR);
644 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
645 		if (tlc == ivar) {
646 			mtx_lock(tlc->mtx);
647 			MPASS(tlc->refcnt != 0);
648 			--tlc->refcnt;
649 			mtx_unlock(tlc->mtx);
650 		}
651 		refcnted |= (tlc->refcnt != 0);
652 	}
653 	error = refcnted ? 0 : HID_INTR_STOP(device_get_parent(bus));
654 	sx_unlock(&sc->sx);
655 
656 	return (error);
657 }
658 
659 void
660 hidbus_intr_poll(device_t child)
661 {
662 	device_t bus = device_get_parent(child);
663 
664 	HID_INTR_POLL(device_get_parent(bus));
665 }
666 
667 struct hid_rdesc_info *
668 hidbus_get_rdesc_info(device_t child)
669 {
670 	device_t bus = device_get_parent(child);
671 	struct hidbus_softc *sc = device_get_softc(bus);
672 
673 	return (&sc->rdesc);
674 }
675 
676 /*
677  * HID interface.
678  *
679  * Hidbus as well as any hidbus child can be passed as first arg.
680  */
681 
682 /* Read cached report descriptor */
683 int
684 hid_get_report_descr(device_t dev, void **data, hid_size_t *len)
685 {
686 	device_t bus;
687 	struct hidbus_softc *sc;
688 
689 	bus = device_get_devclass(dev) == devclass_find("hidbus") ?
690 	    dev : device_get_parent(dev);
691 	sc = device_get_softc(bus);
692 
693 	/*
694 	 * Do not send request to a transport backend.
695 	 * Use cached report descriptor instead of it.
696 	 */
697 	if (sc->rdesc.data == NULL || sc->rdesc.len == 0)
698 		return (ENXIO);
699 
700 	if (data != NULL)
701 		*data = sc->rdesc.data;
702 	if (len != NULL)
703 		*len = sc->rdesc.len;
704 
705 	return (0);
706 }
707 
708 /*
709  * Replace cached report descriptor with top level driver provided one.
710  *
711  * It deletes all hidbus children except caller and enumerates them again after
712  * new descriptor has been registered. Currently it can not be called from
713  * autoenumerated (by report's TLC) child device context as it results in child
714  * duplication. To overcome this limitation hid_set_report_descr() should be
715  * called from device_identify driver's handler with hidbus itself passed as
716  * 'device_t dev' parameter.
717  */
718 int
719 hid_set_report_descr(device_t dev, const void *data, hid_size_t len)
720 {
721 	struct hid_rdesc_info rdesc;
722 	device_t bus;
723 	struct hidbus_softc *sc;
724 	bool is_bus;
725 	int error;
726 
727 	bus_topo_assert();
728 
729 	is_bus = device_get_devclass(dev) == devclass_find("hidbus");
730 	bus = is_bus ? dev : device_get_parent(dev);
731 	sc = device_get_softc(bus);
732 
733 	/*
734 	 * Do not overload already overloaded report descriptor in
735 	 * device_identify handler. It causes infinite recursion loop.
736 	 */
737 	if (is_bus && sc->overloaded)
738 		return(0);
739 
740 	DPRINTFN(5, "len=%d\n", len);
741 	DPRINTFN(5, "data = %*D\n", len, data, " ");
742 
743 	error = hidbus_fill_rdesc_info(&rdesc, data, len);
744 	if (error != 0)
745 		return (error);
746 
747 	error = hidbus_detach_children(dev);
748 	if (error != 0)
749 		return(error);
750 
751 	/* Make private copy to handle a case of dynamicaly allocated data. */
752 	rdesc.data = malloc(len, M_DEVBUF, M_ZERO | M_WAITOK);
753 	bcopy(data, rdesc.data, len);
754 	sc->overloaded = true;
755 	free(sc->rdesc.data, M_DEVBUF);
756 	bcopy(&rdesc, &sc->rdesc, sizeof(struct hid_rdesc_info));
757 
758 	error = hidbus_attach_children(bus);
759 
760 	return (error);
761 }
762 
763 static int
764 hidbus_write(device_t dev, const void *data, hid_size_t len)
765 {
766 	struct hidbus_softc *sc;
767 	uint8_t id;
768 
769 	sc = device_get_softc(dev);
770 	/*
771 	 * Output interrupt endpoint is often optional. If HID device
772 	 * does not provide it, send reports via control pipe.
773 	 */
774 	if (sc->nowrite) {
775 		/* try to extract the ID byte */
776 		id = (sc->rdesc.oid & (len > 0)) ? *(const uint8_t*)data : 0;
777 		return (hid_set_report(dev, data, len, HID_OUTPUT_REPORT, id));
778 	}
779 
780 	return (hid_write(dev, data, len));
781 }
782 
783 /*------------------------------------------------------------------------*
784  *	hidbus_lookup_id
785  *
786  * This functions takes an array of "struct hid_device_id" and tries
787  * to match the entries with the information in "struct hid_device_info".
788  *
789  * Return values:
790  * NULL: No match found.
791  * Else: Pointer to matching entry.
792  *------------------------------------------------------------------------*/
793 const struct hid_device_id *
794 hidbus_lookup_id(device_t dev, const struct hid_device_id *id, int nitems_id)
795 {
796 	const struct hid_device_id *id_end;
797 	const struct hid_device_info *info;
798 	int32_t usage;
799 	bool is_child;
800 
801 	if (id == NULL) {
802 		goto done;
803 	}
804 
805 	id_end = id + nitems_id;
806 	info = hid_get_device_info(dev);
807 	is_child = device_get_devclass(dev) != devclass_find("hidbus");
808 	if (is_child)
809 		usage = hidbus_get_usage(dev);
810 
811 	/*
812 	 * Keep on matching array entries until we find a match or
813 	 * until we reach the end of the matching array:
814 	 */
815 	for (; id != id_end; id++) {
816 
817 		if (is_child && (id->match_flag_page) &&
818 		    (id->page != HID_GET_USAGE_PAGE(usage))) {
819 			continue;
820 		}
821 		if (is_child && (id->match_flag_usage) &&
822 		    (id->usage != HID_GET_USAGE(usage))) {
823 			continue;
824 		}
825 		if ((id->match_flag_bus) &&
826 		    (id->idBus != info->idBus)) {
827 			continue;
828 		}
829 		if ((id->match_flag_vendor) &&
830 		    (id->idVendor != info->idVendor)) {
831 			continue;
832 		}
833 		if ((id->match_flag_product) &&
834 		    (id->idProduct != info->idProduct)) {
835 			continue;
836 		}
837 		if ((id->match_flag_ver_lo) &&
838 		    (id->idVersion_lo > info->idVersion)) {
839 			continue;
840 		}
841 		if ((id->match_flag_ver_hi) &&
842 		    (id->idVersion_hi < info->idVersion)) {
843 			continue;
844 		}
845 		if (id->match_flag_pnp &&
846 		    strncmp(id->idPnP, info->idPnP, HID_PNP_ID_SIZE) != 0) {
847 			continue;
848 		}
849 		/* We found a match! */
850 		return (id);
851 	}
852 
853 done:
854 	return (NULL);
855 }
856 
857 /*------------------------------------------------------------------------*
858  *	hidbus_lookup_driver_info - factored out code
859  *
860  * Return values:
861  *    0: Success
862  * Else: Failure
863  *------------------------------------------------------------------------*/
864 int
865 hidbus_lookup_driver_info(device_t child, const struct hid_device_id *id,
866     int nitems_id)
867 {
868 
869 	id = hidbus_lookup_id(child, id, nitems_id);
870 	if (id) {
871 		/* copy driver info */
872 		hidbus_set_driver_info(child, id->driver_info);
873 		return (0);
874 	}
875 	return (ENXIO);
876 }
877 
878 const struct hid_device_info *
879 hid_get_device_info(device_t dev)
880 {
881 	device_t bus;
882 
883 	bus = device_get_devclass(dev) == devclass_find("hidbus") ?
884 	    dev : device_get_parent(dev);
885 
886 	return (device_get_ivars(bus));
887 }
888 
889 static device_method_t hidbus_methods[] = {
890 	/* device interface */
891 	DEVMETHOD(device_probe,		hidbus_probe),
892 	DEVMETHOD(device_attach,	hidbus_attach),
893 	DEVMETHOD(device_detach,	hidbus_detach),
894 	DEVMETHOD(device_suspend,	bus_generic_suspend),
895 	DEVMETHOD(device_resume,	bus_generic_resume),
896 
897 	/* bus interface */
898 	DEVMETHOD(bus_add_child,	hidbus_add_child),
899 	DEVMETHOD(bus_child_detached,	hidbus_child_detached),
900 	DEVMETHOD(bus_child_deleted,	hidbus_child_deleted),
901 	DEVMETHOD(bus_read_ivar,	hidbus_read_ivar),
902 	DEVMETHOD(bus_write_ivar,	hidbus_write_ivar),
903 	DEVMETHOD(bus_child_pnpinfo,	hidbus_child_pnpinfo),
904 	DEVMETHOD(bus_child_location,	hidbus_child_location),
905 
906 	/* hid interface */
907 	DEVMETHOD(hid_get_rdesc,	hid_get_rdesc),
908 	DEVMETHOD(hid_read,		hid_read),
909 	DEVMETHOD(hid_write,		hidbus_write),
910 	DEVMETHOD(hid_get_report,	hid_get_report),
911 	DEVMETHOD(hid_set_report,	hid_set_report),
912 	DEVMETHOD(hid_set_idle,		hid_set_idle),
913 	DEVMETHOD(hid_set_protocol,	hid_set_protocol),
914 	DEVMETHOD(hid_ioctl,		hid_ioctl),
915 
916 	DEVMETHOD_END
917 };
918 
919 driver_t hidbus_driver = {
920 	"hidbus",
921 	hidbus_methods,
922 	sizeof(struct hidbus_softc),
923 };
924 
925 MODULE_DEPEND(hidbus, hid, 1, 1, 1);
926 MODULE_VERSION(hidbus, 1);
927 DRIVER_MODULE(hidbus, hvhid, hidbus_driver, 0, 0);
928 DRIVER_MODULE(hidbus, iichid, hidbus_driver, 0, 0);
929 DRIVER_MODULE(hidbus, usbhid, hidbus_driver, 0, 0);
930