xref: /freebsd/sys/dev/hid/hidbus.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/systm.h>
44 #include <sys/sx.h>
45 
46 #define	HID_DEBUG_VAR	hid_debug
47 #include <dev/hid/hid.h>
48 #include <dev/hid/hidbus.h>
49 #include <dev/hid/hidquirk.h>
50 
51 #include "hid_if.h"
52 
53 #define	INPUT_EPOCH	global_epoch_preempt
54 #define	HID_RSIZE_MAX	1024
55 
56 static hid_intr_t	hidbus_intr;
57 
58 static device_probe_t	hidbus_probe;
59 static device_attach_t	hidbus_attach;
60 static device_detach_t	hidbus_detach;
61 
62 struct hidbus_ivars {
63 	int32_t				usage;
64 	uint8_t				index;
65 	uint32_t			flags;
66 	uintptr_t			driver_info;    /* for internal use */
67 	struct mtx			*mtx;		/* child intr mtx */
68 	hid_intr_t			*intr_handler;	/* executed under mtx*/
69 	void				*intr_ctx;
70 	unsigned int			refcnt;		/* protected by mtx */
71 	struct epoch_context		epoch_ctx;
72 	CK_STAILQ_ENTRY(hidbus_ivars)	link;
73 };
74 
75 struct hidbus_softc {
76 	device_t			dev;
77 	struct sx			sx;
78 	struct mtx			mtx;
79 
80 	bool				nowrite;
81 
82 	struct hid_rdesc_info		rdesc;
83 	bool				overloaded;
84 	int				nest;	/* Child attach nesting lvl */
85 	int				nauto;	/* Number of autochildren */
86 
87 	CK_STAILQ_HEAD(, hidbus_ivars)	tlcs;
88 };
89 
90 static int
91 hidbus_fill_rdesc_info(struct hid_rdesc_info *hri, const void *data,
92     hid_size_t len)
93 {
94 	int error = 0;
95 
96 	hri->data = __DECONST(void *, data);
97 	hri->len = len;
98 
99 	/*
100 	 * If report descriptor is not available yet, set maximal
101 	 * report sizes high enough to allow hidraw to work.
102 	 */
103 	hri->isize = len == 0 ? HID_RSIZE_MAX :
104 	    hid_report_size_max(data, len, hid_input, &hri->iid);
105 	hri->osize = len == 0 ? HID_RSIZE_MAX :
106 	    hid_report_size_max(data, len, hid_output, &hri->oid);
107 	hri->fsize = len == 0 ? HID_RSIZE_MAX :
108 	    hid_report_size_max(data, len, hid_feature, &hri->fid);
109 
110 	if (hri->isize > HID_RSIZE_MAX) {
111 		DPRINTF("input size is too large, %u bytes (truncating)\n",
112 		    hri->isize);
113 		hri->isize = HID_RSIZE_MAX;
114 		error = EOVERFLOW;
115 	}
116 	if (hri->osize > HID_RSIZE_MAX) {
117 		DPRINTF("output size is too large, %u bytes (truncating)\n",
118 		    hri->osize);
119 		hri->osize = HID_RSIZE_MAX;
120 		error = EOVERFLOW;
121 	}
122 	if (hri->fsize > HID_RSIZE_MAX) {
123 		DPRINTF("feature size is too large, %u bytes (truncating)\n",
124 		    hri->fsize);
125 		hri->fsize = HID_RSIZE_MAX;
126 		error = EOVERFLOW;
127 	}
128 
129 	return (error);
130 }
131 
132 int
133 hidbus_locate(const void *desc, hid_size_t size, int32_t u, enum hid_kind k,
134     uint8_t tlc_index, uint8_t index, struct hid_location *loc,
135     uint32_t *flags, uint8_t *id, struct hid_absinfo *ai)
136 {
137 	struct hid_data *d;
138 	struct hid_item h;
139 	int i;
140 
141 	d = hid_start_parse(desc, size, 1 << k);
142 	HIDBUS_FOREACH_ITEM(d, &h, tlc_index) {
143 		for (i = 0; i < h.nusages; i++) {
144 			if (h.kind == k && h.usages[i] == u) {
145 				if (index--)
146 					break;
147 				if (loc != NULL)
148 					*loc = h.loc;
149 				if (flags != NULL)
150 					*flags = h.flags;
151 				if (id != NULL)
152 					*id = h.report_ID;
153 				if (ai != NULL && (h.flags&HIO_RELATIVE) == 0)
154 					*ai = (struct hid_absinfo) {
155 					    .max = h.logical_maximum,
156 					    .min = h.logical_minimum,
157 					    .res = hid_item_resolution(&h),
158 					};
159 				hid_end_parse(d);
160 				return (1);
161 			}
162 		}
163 	}
164 	if (loc != NULL)
165 		loc->size = 0;
166 	if (flags != NULL)
167 		*flags = 0;
168 	if (id != NULL)
169 		*id = 0;
170 	hid_end_parse(d);
171 	return (0);
172 }
173 
174 static device_t
175 hidbus_add_child(device_t dev, u_int order, const char *name, int unit)
176 {
177 	struct hidbus_softc *sc = device_get_softc(dev);
178 	struct hidbus_ivars *tlc;
179 	device_t child;
180 
181 	child = device_add_child_ordered(dev, order, name, unit);
182 	if (child == NULL)
183 			return (child);
184 
185 	tlc = malloc(sizeof(struct hidbus_ivars), M_DEVBUF, M_WAITOK | M_ZERO);
186 	tlc->mtx = &sc->mtx;
187 	device_set_ivars(child, tlc);
188 	sx_xlock(&sc->sx);
189 	CK_STAILQ_INSERT_TAIL(&sc->tlcs, tlc, link);
190 	sx_unlock(&sc->sx);
191 
192 	return (child);
193 }
194 
195 static int
196 hidbus_enumerate_children(device_t dev, const void* data, hid_size_t len)
197 {
198 	struct hidbus_softc *sc = device_get_softc(dev);
199 	struct hid_data *hd;
200 	struct hid_item hi;
201 	device_t child;
202 	uint8_t index = 0;
203 
204 	if (data == NULL || len == 0)
205 		return (ENXIO);
206 
207 	/* Add a child for each top level collection */
208 	hd = hid_start_parse(data, len, 1 << hid_input);
209 	while (hid_get_item(hd, &hi)) {
210 		if (hi.kind != hid_collection || hi.collevel != 1)
211 			continue;
212 		child = BUS_ADD_CHILD(dev, 0, NULL, -1);
213 		if (child == NULL) {
214 			device_printf(dev, "Could not add HID device\n");
215 			continue;
216 		}
217 		hidbus_set_index(child, index);
218 		hidbus_set_usage(child, hi.usage);
219 		hidbus_set_flags(child, HIDBUS_FLAG_AUTOCHILD);
220 		index++;
221 		DPRINTF("Add child TLC: 0x%04x:0x%04x\n",
222 		    HID_GET_USAGE_PAGE(hi.usage), HID_GET_USAGE(hi.usage));
223 	}
224 	hid_end_parse(hd);
225 
226 	if (index == 0)
227 		return (ENXIO);
228 
229 	sc->nauto = index;
230 
231 	return (0);
232 }
233 
234 static int
235 hidbus_attach_children(device_t dev)
236 {
237 	struct hidbus_softc *sc = device_get_softc(dev);
238 	int error;
239 
240 	HID_INTR_SETUP(device_get_parent(dev), hidbus_intr, sc, &sc->rdesc);
241 
242 	error = hidbus_enumerate_children(dev, sc->rdesc.data, sc->rdesc.len);
243 	if (error != 0)
244 		DPRINTF("failed to enumerate children: error %d\n", error);
245 
246 	/*
247 	 * hidbus_attach_children() can recurse through device_identify->
248 	 * hid_set_report_descr() call sequence. Do not perform children
249 	 * attach twice in that case.
250 	 */
251 	sc->nest++;
252 	bus_generic_probe(dev);
253 	sc->nest--;
254 	if (sc->nest != 0)
255 		return (0);
256 
257 	if (hid_is_keyboard(sc->rdesc.data, sc->rdesc.len) != 0)
258 		error = bus_generic_attach(dev);
259 	else
260 		error = bus_delayed_attach_children(dev);
261 	if (error != 0)
262 		device_printf(dev, "failed to attach child: error %d\n", error);
263 
264 	return (error);
265 }
266 
267 static int
268 hidbus_detach_children(device_t dev)
269 {
270 	device_t *children, bus;
271 	bool is_bus;
272 	int i, error;
273 
274 	error = 0;
275 
276 	is_bus = device_get_devclass(dev) == hidbus_devclass;
277 	bus = is_bus ? dev : device_get_parent(dev);
278 
279 	KASSERT(device_get_devclass(bus) == hidbus_devclass,
280 	    ("Device is not hidbus or it's child"));
281 
282 	if (is_bus) {
283 		/* If hidbus is passed, delete all children. */
284 		bus_generic_detach(bus);
285 		device_delete_children(bus);
286 	} else {
287 		/*
288 		 * If hidbus child is passed, delete all hidbus children
289 		 * except caller. Deleting the caller may result in deadlock.
290 		 */
291 		error = device_get_children(bus, &children, &i);
292 		if (error != 0)
293 			return (error);
294 		while (i-- > 0) {
295 			if (children[i] == dev)
296 				continue;
297 			DPRINTF("Delete child. index=%d (%s)\n",
298 			    hidbus_get_index(children[i]),
299 			    device_get_nameunit(children[i]));
300 			error = device_delete_child(bus, children[i]);
301 			if (error) {
302 				DPRINTF("Failed deleting %s\n",
303 				    device_get_nameunit(children[i]));
304 				break;
305 			}
306 		}
307 		free(children, M_TEMP);
308 	}
309 
310 	HID_INTR_UNSETUP(device_get_parent(bus));
311 
312 	return (error);
313 }
314 
315 static int
316 hidbus_probe(device_t dev)
317 {
318 
319 	device_set_desc(dev, "HID bus");
320 
321 	/* Allow other subclasses to override this driver. */
322 	return (BUS_PROBE_GENERIC);
323 }
324 
325 static int
326 hidbus_attach(device_t dev)
327 {
328 	struct hidbus_softc *sc = device_get_softc(dev);
329 	struct hid_device_info *devinfo = device_get_ivars(dev);
330 	void *d_ptr = NULL;
331 	hid_size_t d_len;
332 	int error;
333 
334 	sc->dev = dev;
335 	CK_STAILQ_INIT(&sc->tlcs);
336 	mtx_init(&sc->mtx, "hidbus ivar lock", NULL, MTX_DEF);
337 	sx_init(&sc->sx, "hidbus ivar list lock");
338 
339 	/*
340 	 * Ignore error. It is possible for non-HID device e.g. XBox360 gamepad
341 	 * to emulate HID through overloading of report descriptor.
342 	 */
343 	d_len = devinfo->rdescsize;
344 	if (d_len != 0) {
345 		d_ptr = malloc(d_len, M_DEVBUF, M_ZERO | M_WAITOK);
346 		error = hid_get_rdesc(dev, d_ptr, d_len);
347 		if (error != 0) {
348 			free(d_ptr, M_DEVBUF);
349 			d_len = 0;
350 			d_ptr = NULL;
351 		}
352 	}
353 
354 	hidbus_fill_rdesc_info(&sc->rdesc, d_ptr, d_len);
355 
356 	sc->nowrite = hid_test_quirk(devinfo, HQ_NOWRITE);
357 
358 	error = hidbus_attach_children(dev);
359 	if (error != 0) {
360 		hidbus_detach(dev);
361 		return (ENXIO);
362 	}
363 
364 	return (0);
365 }
366 
367 static int
368 hidbus_detach(device_t dev)
369 {
370 	struct hidbus_softc *sc = device_get_softc(dev);
371 
372 	hidbus_detach_children(dev);
373 	sx_destroy(&sc->sx);
374 	mtx_destroy(&sc->mtx);
375 	free(sc->rdesc.data, M_DEVBUF);
376 
377 	return (0);
378 }
379 
380 static void
381 hidbus_child_detached(device_t bus, device_t child)
382 {
383 	struct hidbus_softc *sc = device_get_softc(bus);
384 	struct hidbus_ivars *tlc = device_get_ivars(child);
385 
386 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
387 	tlc->mtx = &sc->mtx;
388 	tlc->intr_handler = NULL;
389 	tlc->flags &= ~HIDBUS_FLAG_CAN_POLL;
390 }
391 
392 /*
393  * Epoch callback indicating tlc is safe to destroy
394  */
395 static void
396 hidbus_ivar_dtor(epoch_context_t ctx)
397 {
398 	struct hidbus_ivars *tlc;
399 
400 	tlc = __containerof(ctx, struct hidbus_ivars, epoch_ctx);
401 	free(tlc, M_DEVBUF);
402 }
403 
404 static void
405 hidbus_child_deleted(device_t bus, device_t child)
406 {
407 	struct hidbus_softc *sc = device_get_softc(bus);
408 	struct hidbus_ivars *tlc = device_get_ivars(child);
409 
410 	sx_xlock(&sc->sx);
411 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
412 	CK_STAILQ_REMOVE(&sc->tlcs, tlc, hidbus_ivars, link);
413 	sx_unlock(&sc->sx);
414 	epoch_call(INPUT_EPOCH, hidbus_ivar_dtor, &tlc->epoch_ctx);
415 }
416 
417 static int
418 hidbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
419 {
420 	struct hidbus_softc *sc = device_get_softc(bus);
421 	struct hidbus_ivars *tlc = device_get_ivars(child);
422 
423 	switch (which) {
424 	case HIDBUS_IVAR_INDEX:
425 		*result = tlc->index;
426 		break;
427 	case HIDBUS_IVAR_USAGE:
428 		*result = tlc->usage;
429 		break;
430 	case HIDBUS_IVAR_FLAGS:
431 		*result = tlc->flags;
432 		break;
433 	case HIDBUS_IVAR_DRIVER_INFO:
434 		*result = tlc->driver_info;
435 		break;
436 	case HIDBUS_IVAR_LOCK:
437 		*result = (uintptr_t)(tlc->mtx == &sc->mtx ? NULL : tlc->mtx);
438 		break;
439 	default:
440 		return (EINVAL);
441 	}
442 	return (0);
443 }
444 
445 static int
446 hidbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
447 {
448 	struct hidbus_softc *sc = device_get_softc(bus);
449 	struct hidbus_ivars *tlc = device_get_ivars(child);
450 
451 	switch (which) {
452 	case HIDBUS_IVAR_INDEX:
453 		tlc->index = value;
454 		break;
455 	case HIDBUS_IVAR_USAGE:
456 		tlc->usage = value;
457 		break;
458 	case HIDBUS_IVAR_FLAGS:
459 		tlc->flags = value;
460 		break;
461 	case HIDBUS_IVAR_DRIVER_INFO:
462 		tlc->driver_info = value;
463 		break;
464 	case HIDBUS_IVAR_LOCK:
465 		tlc->mtx = (struct mtx *)value == NULL ?
466 		    &sc->mtx : (struct mtx *)value;
467 		break;
468 	default:
469 		return (EINVAL);
470 	}
471 	return (0);
472 }
473 
474 /* Location hint for devctl(8) */
475 static int
476 hidbus_child_location_str(device_t bus, device_t child, char *buf,
477     size_t buflen)
478 {
479 	struct hidbus_ivars *tlc = device_get_ivars(child);
480 
481 	snprintf(buf, buflen, "index=%hhu", tlc->index);
482         return (0);
483 }
484 
485 /* PnP information for devctl(8) */
486 static int
487 hidbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
488     size_t buflen)
489 {
490 	struct hidbus_ivars *tlc = device_get_ivars(child);
491 	struct hid_device_info *devinfo = device_get_ivars(bus);
492 
493 	snprintf(buf, buflen, "page=0x%04x usage=0x%04x bus=0x%02hx "
494 	    "vendor=0x%04hx product=0x%04hx version=0x%04hx%s%s",
495 	    HID_GET_USAGE_PAGE(tlc->usage), HID_GET_USAGE(tlc->usage),
496 	    devinfo->idBus, devinfo->idVendor, devinfo->idProduct,
497 	    devinfo->idVersion, devinfo->idPnP[0] == '\0' ? "" : " _HID=",
498 	    devinfo->idPnP[0] == '\0' ? "" : devinfo->idPnP);
499 	return (0);
500 }
501 
502 void
503 hidbus_set_desc(device_t child, const char *suffix)
504 {
505 	device_t bus = device_get_parent(child);
506 	struct hidbus_softc *sc = device_get_softc(bus);
507 	struct hid_device_info *devinfo = device_get_ivars(bus);
508 	struct hidbus_ivars *tlc = device_get_ivars(child);
509 	char buf[80];
510 
511 	/* Do not add NULL suffix or if device name already contains it. */
512 	if (suffix != NULL && strcasestr(devinfo->name, suffix) == NULL &&
513 	    (sc->nauto > 1 || (tlc->flags & HIDBUS_FLAG_AUTOCHILD) == 0)) {
514 		snprintf(buf, sizeof(buf), "%s %s", devinfo->name, suffix);
515 		device_set_desc_copy(child, buf);
516 	} else
517 		device_set_desc(child, devinfo->name);
518 }
519 
520 device_t
521 hidbus_find_child(device_t bus, int32_t usage)
522 {
523 	device_t *children, child;
524 	int ccount, i;
525 
526 	GIANT_REQUIRED;
527 
528 	/* Get a list of all hidbus children */
529 	if (device_get_children(bus, &children, &ccount) != 0)
530 		return (NULL);
531 
532 	/* Scan through to find required TLC */
533 	for (i = 0, child = NULL; i < ccount; i++) {
534 		if (hidbus_get_usage(children[i]) == usage) {
535 			child = children[i];
536 			break;
537 		}
538 	}
539 	free(children, M_TEMP);
540 
541 	return (child);
542 }
543 
544 void
545 hidbus_intr(void *context, void *buf, hid_size_t len)
546 {
547 	struct hidbus_softc *sc = context;
548 	struct hidbus_ivars *tlc;
549 	struct epoch_tracker et;
550 
551 	/*
552 	 * Broadcast input report to all subscribers.
553 	 * TODO: Add check for input report ID.
554 	 *
555 	 * Relock mutex on every TLC item as we can't hold any locks over whole
556 	 * TLC list here due to LOR with open()/close() handlers.
557 	 */
558 	if (!HID_IN_POLLING_MODE())
559 		epoch_enter_preempt(INPUT_EPOCH, &et);
560 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
561 		if (tlc->refcnt == 0 || tlc->intr_handler == NULL)
562 			continue;
563 		if (HID_IN_POLLING_MODE()) {
564 			if ((tlc->flags & HIDBUS_FLAG_CAN_POLL) != 0)
565 				tlc->intr_handler(tlc->intr_ctx, buf, len);
566 		} else {
567 			mtx_lock(tlc->mtx);
568 			tlc->intr_handler(tlc->intr_ctx, buf, len);
569 			mtx_unlock(tlc->mtx);
570 		}
571 	}
572 	if (!HID_IN_POLLING_MODE())
573 		epoch_exit_preempt(INPUT_EPOCH, &et);
574 }
575 
576 void
577 hidbus_set_intr(device_t child, hid_intr_t *handler, void *context)
578 {
579 	struct hidbus_ivars *tlc = device_get_ivars(child);
580 
581 	tlc->intr_handler = handler;
582 	tlc->intr_ctx = context;
583 }
584 
585 int
586 hidbus_intr_start(device_t child)
587 {
588 	device_t bus = device_get_parent(child);
589 	struct hidbus_softc *sc = device_get_softc(bus);
590 	struct hidbus_ivars *ivar = device_get_ivars(child);
591 	struct hidbus_ivars *tlc;
592 	int refcnt = 0;
593 	int error;
594 
595 	if (sx_xlock_sig(&sc->sx) != 0)
596 		return (EINTR);
597 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
598 		refcnt += tlc->refcnt;
599 		if (tlc == ivar) {
600 			mtx_lock(tlc->mtx);
601 			++tlc->refcnt;
602 			mtx_unlock(tlc->mtx);
603 		}
604 	}
605 	error = refcnt != 0 ? 0 : HID_INTR_START(device_get_parent(bus));
606 	sx_unlock(&sc->sx);
607 
608 	return (error);
609 }
610 
611 int
612 hidbus_intr_stop(device_t child)
613 {
614 	device_t bus = device_get_parent(child);
615 	struct hidbus_softc *sc = device_get_softc(bus);
616 	struct hidbus_ivars *ivar = device_get_ivars(child);
617 	struct hidbus_ivars *tlc;
618 	bool refcnt = 0;
619 	int error;
620 
621 	if (sx_xlock_sig(&sc->sx) != 0)
622 		return (EINTR);
623 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
624 		if (tlc == ivar) {
625 			mtx_lock(tlc->mtx);
626 			MPASS(tlc->refcnt != 0);
627 			--tlc->refcnt;
628 			mtx_unlock(tlc->mtx);
629 		}
630 		refcnt += tlc->refcnt;
631 	}
632 	error = refcnt != 0 ? 0 : HID_INTR_STOP(device_get_parent(bus));
633 	sx_unlock(&sc->sx);
634 
635 	return (error);
636 }
637 
638 void
639 hidbus_intr_poll(device_t child)
640 {
641 	device_t bus = device_get_parent(child);
642 
643 	HID_INTR_POLL(device_get_parent(bus));
644 }
645 
646 struct hid_rdesc_info *
647 hidbus_get_rdesc_info(device_t child)
648 {
649 	device_t bus = device_get_parent(child);
650 	struct hidbus_softc *sc = device_get_softc(bus);
651 
652 	return (&sc->rdesc);
653 }
654 
655 /*
656  * HID interface.
657  *
658  * Hidbus as well as any hidbus child can be passed as first arg.
659  */
660 
661 /* Read cached report descriptor */
662 int
663 hid_get_report_descr(device_t dev, void **data, hid_size_t *len)
664 {
665 	device_t bus;
666 	struct hidbus_softc *sc;
667 
668 	bus = device_get_devclass(dev) == hidbus_devclass ?
669 	    dev : device_get_parent(dev);
670 	sc = device_get_softc(bus);
671 
672 	/*
673 	 * Do not send request to a transport backend.
674 	 * Use cached report descriptor instead of it.
675 	 */
676 	if (sc->rdesc.data == NULL || sc->rdesc.len == 0)
677 		return (ENXIO);
678 
679 	if (data != NULL)
680 		*data = sc->rdesc.data;
681 	if (len != NULL)
682 		*len = sc->rdesc.len;
683 
684 	return (0);
685 }
686 
687 /*
688  * Replace cached report descriptor with top level driver provided one.
689  *
690  * It deletes all hidbus children except caller and enumerates them again after
691  * new descriptor has been registered. Currently it can not be called from
692  * autoenumerated (by report's TLC) child device context as it results in child
693  * duplication. To overcome this limitation hid_set_report_descr() should be
694  * called from device_identify driver's handler with hidbus itself passed as
695  * 'device_t dev' parameter.
696  */
697 int
698 hid_set_report_descr(device_t dev, const void *data, hid_size_t len)
699 {
700 	struct hid_rdesc_info rdesc;
701 	device_t bus;
702 	struct hidbus_softc *sc;
703 	bool is_bus;
704 	int error;
705 
706 	GIANT_REQUIRED;
707 
708 	is_bus = device_get_devclass(dev) == hidbus_devclass;
709 	bus = is_bus ? dev : device_get_parent(dev);
710 	sc = device_get_softc(bus);
711 
712 	/*
713 	 * Do not overload already overloaded report descriptor in
714 	 * device_identify handler. It causes infinite recursion loop.
715 	 */
716 	if (is_bus && sc->overloaded)
717 		return(0);
718 
719 	DPRINTFN(5, "len=%d\n", len);
720 	DPRINTFN(5, "data = %*D\n", len, data, " ");
721 
722 	error = hidbus_fill_rdesc_info(&rdesc, data, len);
723 	if (error != 0)
724 		return (error);
725 
726 	error = hidbus_detach_children(dev);
727 	if (error != 0)
728 		return(error);
729 
730 	/* Make private copy to handle a case of dynamicaly allocated data. */
731 	rdesc.data = malloc(len, M_DEVBUF, M_ZERO | M_WAITOK);
732 	bcopy(data, rdesc.data, len);
733 	sc->overloaded = true;
734 	free(sc->rdesc.data, M_DEVBUF);
735 	bcopy(&rdesc, &sc->rdesc, sizeof(struct hid_rdesc_info));
736 
737 	error = hidbus_attach_children(bus);
738 
739 	return (error);
740 }
741 
742 static int
743 hidbus_write(device_t dev, const void *data, hid_size_t len)
744 {
745 	struct hidbus_softc *sc;
746 	uint8_t id;
747 
748 	sc = device_get_softc(dev);
749 	/*
750 	 * Output interrupt endpoint is often optional. If HID device
751 	 * does not provide it, send reports via control pipe.
752 	 */
753 	if (sc->nowrite) {
754 		/* try to extract the ID byte */
755 		id = (sc->rdesc.oid & (len > 0)) ? *(const uint8_t*)data : 0;
756 		return (hid_set_report(dev, data, len, HID_OUTPUT_REPORT, id));
757 	}
758 
759 	return (hid_write(dev, data, len));
760 }
761 
762 /*------------------------------------------------------------------------*
763  *	hidbus_lookup_id
764  *
765  * This functions takes an array of "struct hid_device_id" and tries
766  * to match the entries with the information in "struct hid_device_info".
767  *
768  * Return values:
769  * NULL: No match found.
770  * Else: Pointer to matching entry.
771  *------------------------------------------------------------------------*/
772 const struct hid_device_id *
773 hidbus_lookup_id(device_t dev, const struct hid_device_id *id, int nitems_id)
774 {
775 	const struct hid_device_id *id_end;
776 	const struct hid_device_info *info;
777 	int32_t usage;
778 	bool is_child;
779 
780 	if (id == NULL) {
781 		goto done;
782 	}
783 
784 	id_end = id + nitems_id;
785 	info = hid_get_device_info(dev);
786 	is_child = device_get_devclass(dev) != hidbus_devclass;
787 	if (is_child)
788 		usage = hidbus_get_usage(dev);
789 
790 	/*
791 	 * Keep on matching array entries until we find a match or
792 	 * until we reach the end of the matching array:
793 	 */
794 	for (; id != id_end; id++) {
795 
796 		if (is_child && (id->match_flag_page) &&
797 		    (id->page != HID_GET_USAGE_PAGE(usage))) {
798 			continue;
799 		}
800 		if (is_child && (id->match_flag_usage) &&
801 		    (id->usage != HID_GET_USAGE(usage))) {
802 			continue;
803 		}
804 		if ((id->match_flag_bus) &&
805 		    (id->idBus != info->idBus)) {
806 			continue;
807 		}
808 		if ((id->match_flag_vendor) &&
809 		    (id->idVendor != info->idVendor)) {
810 			continue;
811 		}
812 		if ((id->match_flag_product) &&
813 		    (id->idProduct != info->idProduct)) {
814 			continue;
815 		}
816 		if ((id->match_flag_ver_lo) &&
817 		    (id->idVersion_lo > info->idVersion)) {
818 			continue;
819 		}
820 		if ((id->match_flag_ver_hi) &&
821 		    (id->idVersion_hi < info->idVersion)) {
822 			continue;
823 		}
824 		if (id->match_flag_pnp &&
825 		    strncmp(id->idPnP, info->idPnP, HID_PNP_ID_SIZE) != 0) {
826 			continue;
827 		}
828 		/* We found a match! */
829 		return (id);
830 	}
831 
832 done:
833 	return (NULL);
834 }
835 
836 /*------------------------------------------------------------------------*
837  *	hidbus_lookup_driver_info - factored out code
838  *
839  * Return values:
840  *    0: Success
841  * Else: Failure
842  *------------------------------------------------------------------------*/
843 int
844 hidbus_lookup_driver_info(device_t child, const struct hid_device_id *id,
845     int nitems_id)
846 {
847 
848 	id = hidbus_lookup_id(child, id, nitems_id);
849 	if (id) {
850 		/* copy driver info */
851 		hidbus_set_driver_info(child, id->driver_info);
852 		return (0);
853 	}
854 	return (ENXIO);
855 }
856 
857 const struct hid_device_info *
858 hid_get_device_info(device_t dev)
859 {
860 	device_t bus;
861 
862 	bus = device_get_devclass(dev) == hidbus_devclass ?
863 	    dev : device_get_parent(dev);
864 
865 	return (device_get_ivars(bus));
866 }
867 
868 static device_method_t hidbus_methods[] = {
869 	/* device interface */
870 	DEVMETHOD(device_probe,		hidbus_probe),
871 	DEVMETHOD(device_attach,	hidbus_attach),
872 	DEVMETHOD(device_detach,	hidbus_detach),
873 	DEVMETHOD(device_suspend,	bus_generic_suspend),
874 	DEVMETHOD(device_resume,	bus_generic_resume),
875 
876 	/* bus interface */
877 	DEVMETHOD(bus_add_child,	hidbus_add_child),
878 	DEVMETHOD(bus_child_detached,	hidbus_child_detached),
879 	DEVMETHOD(bus_child_deleted,	hidbus_child_deleted),
880 	DEVMETHOD(bus_read_ivar,	hidbus_read_ivar),
881 	DEVMETHOD(bus_write_ivar,	hidbus_write_ivar),
882 	DEVMETHOD(bus_child_pnpinfo_str,hidbus_child_pnpinfo_str),
883 	DEVMETHOD(bus_child_location_str,hidbus_child_location_str),
884 
885 	/* hid interface */
886 	DEVMETHOD(hid_get_rdesc,	hid_get_rdesc),
887 	DEVMETHOD(hid_read,		hid_read),
888 	DEVMETHOD(hid_write,		hidbus_write),
889 	DEVMETHOD(hid_get_report,	hid_get_report),
890 	DEVMETHOD(hid_set_report,	hid_set_report),
891 	DEVMETHOD(hid_set_idle,		hid_set_idle),
892 	DEVMETHOD(hid_set_protocol,	hid_set_protocol),
893 
894 	DEVMETHOD_END
895 };
896 
897 devclass_t hidbus_devclass;
898 driver_t hidbus_driver = {
899 	"hidbus",
900 	hidbus_methods,
901 	sizeof(struct hidbus_softc),
902 };
903 
904 MODULE_DEPEND(hidbus, hid, 1, 1, 1);
905 MODULE_VERSION(hidbus, 1);
906 DRIVER_MODULE(hidbus, iichid, hidbus_driver, hidbus_devclass, 0, 0);
907 DRIVER_MODULE(hidbus, usbhid, hidbus_driver, hidbus_devclass, 0, 0);
908