xref: /freebsd-13-stable/sys/dev/hid/hidbus.c (revision 3bc80996974a61a4223eae4c1ccd47b6ee32a48a)
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 #include <sys/param.h>
30 #include <sys/bus.h>
31 #include <sys/ck.h>
32 #include <sys/epoch.h>
33 #include <sys/kdb.h>
34 #include <sys/kernel.h>
35 #include <sys/libkern.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/proc.h>
41 #include <sys/systm.h>
42 #include <sys/sx.h>
43 
44 #define	HID_DEBUG_VAR	hid_debug
45 #include <dev/hid/hid.h>
46 #include <dev/hid/hidbus.h>
47 #include <dev/hid/hidquirk.h>
48 
49 #include "hid_if.h"
50 
51 #define	INPUT_EPOCH	global_epoch_preempt
52 #define	HID_RSIZE_MAX	1024
53 
54 static hid_intr_t	hidbus_intr;
55 
56 static device_probe_t	hidbus_probe;
57 static device_attach_t	hidbus_attach;
58 static device_detach_t	hidbus_detach;
59 
60 struct hidbus_ivars {
61 	int32_t				usage;
62 	uint8_t				index;
63 	uint32_t			flags;
64 	uintptr_t			driver_info;    /* for internal use */
65 	struct mtx			*mtx;		/* child intr mtx */
66 	hid_intr_t			*intr_handler;	/* executed under mtx*/
67 	void				*intr_ctx;
68 	unsigned int			refcnt;		/* protected by mtx */
69 	struct epoch_context		epoch_ctx;
70 	CK_STAILQ_ENTRY(hidbus_ivars)	link;
71 };
72 
73 struct hidbus_softc {
74 	device_t			dev;
75 	struct sx			sx;
76 	struct mtx			mtx;
77 
78 	bool				nowrite;
79 
80 	struct hid_rdesc_info		rdesc;
81 	bool				overloaded;
82 	int				nest;	/* Child attach nesting lvl */
83 	int				nauto;	/* Number of autochildren */
84 
85 	CK_STAILQ_HEAD(, hidbus_ivars)	tlcs;
86 };
87 
88 static int
hidbus_fill_rdesc_info(struct hid_rdesc_info * hri,const void * data,hid_size_t len)89 hidbus_fill_rdesc_info(struct hid_rdesc_info *hri, const void *data,
90     hid_size_t len)
91 {
92 	int error = 0;
93 
94 	hri->data = __DECONST(void *, data);
95 	hri->len = len;
96 
97 	/*
98 	 * If report descriptor is not available yet, set maximal
99 	 * report sizes high enough to allow hidraw to work.
100 	 */
101 	hri->isize = len == 0 ? HID_RSIZE_MAX :
102 	    hid_report_size_max(data, len, hid_input, &hri->iid);
103 	hri->osize = len == 0 ? HID_RSIZE_MAX :
104 	    hid_report_size_max(data, len, hid_output, &hri->oid);
105 	hri->fsize = len == 0 ? HID_RSIZE_MAX :
106 	    hid_report_size_max(data, len, hid_feature, &hri->fid);
107 
108 	if (hri->isize > HID_RSIZE_MAX) {
109 		DPRINTF("input size is too large, %u bytes (truncating)\n",
110 		    hri->isize);
111 		hri->isize = HID_RSIZE_MAX;
112 		error = EOVERFLOW;
113 	}
114 	if (hri->osize > HID_RSIZE_MAX) {
115 		DPRINTF("output size is too large, %u bytes (truncating)\n",
116 		    hri->osize);
117 		hri->osize = HID_RSIZE_MAX;
118 		error = EOVERFLOW;
119 	}
120 	if (hri->fsize > HID_RSIZE_MAX) {
121 		DPRINTF("feature size is too large, %u bytes (truncating)\n",
122 		    hri->fsize);
123 		hri->fsize = HID_RSIZE_MAX;
124 		error = EOVERFLOW;
125 	}
126 
127 	return (error);
128 }
129 
130 int
hidbus_locate(const void * desc,hid_size_t size,int32_t u,enum hid_kind k,uint8_t tlc_index,uint8_t index,struct hid_location * loc,uint32_t * flags,uint8_t * id,struct hid_absinfo * ai)131 hidbus_locate(const void *desc, hid_size_t size, int32_t u, enum hid_kind k,
132     uint8_t tlc_index, uint8_t index, struct hid_location *loc,
133     uint32_t *flags, uint8_t *id, struct hid_absinfo *ai)
134 {
135 	struct hid_data *d;
136 	struct hid_item h;
137 	int i;
138 
139 	d = hid_start_parse(desc, size, 1 << k);
140 	HIDBUS_FOREACH_ITEM(d, &h, tlc_index) {
141 		for (i = 0; i < h.nusages; i++) {
142 			if (h.kind == k && h.usages[i] == u) {
143 				if (index--)
144 					break;
145 				if (loc != NULL)
146 					*loc = h.loc;
147 				if (flags != NULL)
148 					*flags = h.flags;
149 				if (id != NULL)
150 					*id = h.report_ID;
151 				if (ai != NULL && (h.flags&HIO_RELATIVE) == 0)
152 					*ai = (struct hid_absinfo) {
153 					    .max = h.logical_maximum,
154 					    .min = h.logical_minimum,
155 					    .res = hid_item_resolution(&h),
156 					};
157 				hid_end_parse(d);
158 				return (1);
159 			}
160 		}
161 	}
162 	if (loc != NULL)
163 		loc->size = 0;
164 	if (flags != NULL)
165 		*flags = 0;
166 	if (id != NULL)
167 		*id = 0;
168 	hid_end_parse(d);
169 	return (0);
170 }
171 
172 bool
hidbus_is_collection(const void * desc,hid_size_t size,int32_t usage,uint8_t tlc_index)173 hidbus_is_collection(const void *desc, hid_size_t size, int32_t usage,
174     uint8_t tlc_index)
175 {
176 	struct hid_data *d;
177 	struct hid_item h;
178 	bool ret = false;
179 
180 	d = hid_start_parse(desc, size, 0);
181 	HIDBUS_FOREACH_ITEM(d, &h, tlc_index) {
182 		if (h.kind == hid_collection && h.usage == usage) {
183 			ret = true;
184 			break;
185 		}
186 	}
187 	hid_end_parse(d);
188 	return (ret);
189 }
190 
191 static device_t
hidbus_add_child(device_t dev,u_int order,const char * name,int unit)192 hidbus_add_child(device_t dev, u_int order, const char *name, int unit)
193 {
194 	struct hidbus_softc *sc = device_get_softc(dev);
195 	struct hidbus_ivars *tlc;
196 	device_t child;
197 
198 	child = device_add_child_ordered(dev, order, name, unit);
199 	if (child == NULL)
200 			return (child);
201 
202 	tlc = malloc(sizeof(struct hidbus_ivars), M_DEVBUF, M_WAITOK | M_ZERO);
203 	tlc->mtx = &sc->mtx;
204 	device_set_ivars(child, tlc);
205 	sx_xlock(&sc->sx);
206 	CK_STAILQ_INSERT_TAIL(&sc->tlcs, tlc, link);
207 	sx_unlock(&sc->sx);
208 
209 	return (child);
210 }
211 
212 static int
hidbus_enumerate_children(device_t dev,const void * data,hid_size_t len)213 hidbus_enumerate_children(device_t dev, const void* data, hid_size_t len)
214 {
215 	struct hidbus_softc *sc = device_get_softc(dev);
216 	struct hid_data *hd;
217 	struct hid_item hi;
218 	device_t child;
219 	uint8_t index = 0;
220 
221 	if (data == NULL || len == 0)
222 		return (ENXIO);
223 
224 	/* Add a child for each top level collection */
225 	hd = hid_start_parse(data, len, 1 << hid_input);
226 	while (hid_get_item(hd, &hi)) {
227 		if (hi.kind != hid_collection || hi.collevel != 1)
228 			continue;
229 		child = BUS_ADD_CHILD(dev, 0, NULL, -1);
230 		if (child == NULL) {
231 			device_printf(dev, "Could not add HID device\n");
232 			continue;
233 		}
234 		hidbus_set_index(child, index);
235 		hidbus_set_usage(child, hi.usage);
236 		hidbus_set_flags(child, HIDBUS_FLAG_AUTOCHILD);
237 		index++;
238 		DPRINTF("Add child TLC: 0x%04x:0x%04x\n",
239 		    HID_GET_USAGE_PAGE(hi.usage), HID_GET_USAGE(hi.usage));
240 	}
241 	hid_end_parse(hd);
242 
243 	if (index == 0)
244 		return (ENXIO);
245 
246 	sc->nauto = index;
247 
248 	return (0);
249 }
250 
251 static int
hidbus_attach_children(device_t dev)252 hidbus_attach_children(device_t dev)
253 {
254 	struct hidbus_softc *sc = device_get_softc(dev);
255 	int error;
256 
257 	HID_INTR_SETUP(device_get_parent(dev), hidbus_intr, sc, &sc->rdesc);
258 
259 	error = hidbus_enumerate_children(dev, sc->rdesc.data, sc->rdesc.len);
260 	if (error != 0)
261 		DPRINTF("failed to enumerate children: error %d\n", error);
262 
263 	/*
264 	 * hidbus_attach_children() can recurse through device_identify->
265 	 * hid_set_report_descr() call sequence. Do not perform children
266 	 * attach twice in that case.
267 	 */
268 	sc->nest++;
269 	bus_generic_probe(dev);
270 	sc->nest--;
271 	if (sc->nest != 0)
272 		return (0);
273 
274 	if (hid_is_keyboard(sc->rdesc.data, sc->rdesc.len) != 0)
275 		error = bus_generic_attach(dev);
276 	else
277 		error = bus_delayed_attach_children(dev);
278 	if (error != 0)
279 		device_printf(dev, "failed to attach child: error %d\n", error);
280 
281 	return (error);
282 }
283 
284 static int
hidbus_detach_children(device_t dev)285 hidbus_detach_children(device_t dev)
286 {
287 	device_t *children, bus;
288 	bool is_bus;
289 	int i, error;
290 
291 	error = 0;
292 
293 	is_bus = device_get_devclass(dev) == hidbus_devclass;
294 	bus = is_bus ? dev : device_get_parent(dev);
295 
296 	KASSERT(device_get_devclass(bus) == hidbus_devclass,
297 	    ("Device is not hidbus or it's child"));
298 
299 	if (is_bus) {
300 		/* If hidbus is passed, delete all children. */
301 		bus_generic_detach(bus);
302 		device_delete_children(bus);
303 	} else {
304 		/*
305 		 * If hidbus child is passed, delete all hidbus children
306 		 * except caller. Deleting the caller may result in deadlock.
307 		 */
308 		error = device_get_children(bus, &children, &i);
309 		if (error != 0)
310 			return (error);
311 		while (i-- > 0) {
312 			if (children[i] == dev)
313 				continue;
314 			DPRINTF("Delete child. index=%d (%s)\n",
315 			    hidbus_get_index(children[i]),
316 			    device_get_nameunit(children[i]));
317 			error = device_delete_child(bus, children[i]);
318 			if (error) {
319 				DPRINTF("Failed deleting %s\n",
320 				    device_get_nameunit(children[i]));
321 				break;
322 			}
323 		}
324 		free(children, M_TEMP);
325 	}
326 
327 	HID_INTR_UNSETUP(device_get_parent(bus));
328 
329 	return (error);
330 }
331 
332 static int
hidbus_probe(device_t dev)333 hidbus_probe(device_t dev)
334 {
335 
336 	device_set_desc(dev, "HID bus");
337 
338 	/* Allow other subclasses to override this driver. */
339 	return (BUS_PROBE_GENERIC);
340 }
341 
342 static int
hidbus_attach(device_t dev)343 hidbus_attach(device_t dev)
344 {
345 	struct hidbus_softc *sc = device_get_softc(dev);
346 	struct hid_device_info *devinfo = device_get_ivars(dev);
347 	void *d_ptr = NULL;
348 	hid_size_t d_len;
349 	int error;
350 
351 	sc->dev = dev;
352 	CK_STAILQ_INIT(&sc->tlcs);
353 	mtx_init(&sc->mtx, "hidbus ivar lock", NULL, MTX_DEF);
354 	sx_init(&sc->sx, "hidbus ivar list lock");
355 
356 	/*
357 	 * Ignore error. It is possible for non-HID device e.g. XBox360 gamepad
358 	 * to emulate HID through overloading of report descriptor.
359 	 */
360 	d_len = devinfo->rdescsize;
361 	if (d_len != 0) {
362 		d_ptr = malloc(d_len, M_DEVBUF, M_ZERO | M_WAITOK);
363 		error = hid_get_rdesc(dev, d_ptr, d_len);
364 		if (error != 0) {
365 			free(d_ptr, M_DEVBUF);
366 			d_len = 0;
367 			d_ptr = NULL;
368 		}
369 	}
370 
371 	hidbus_fill_rdesc_info(&sc->rdesc, d_ptr, d_len);
372 
373 	sc->nowrite = hid_test_quirk(devinfo, HQ_NOWRITE);
374 
375 	error = hidbus_attach_children(dev);
376 	if (error != 0) {
377 		hidbus_detach(dev);
378 		return (ENXIO);
379 	}
380 
381 	return (0);
382 }
383 
384 static int
hidbus_detach(device_t dev)385 hidbus_detach(device_t dev)
386 {
387 	struct hidbus_softc *sc = device_get_softc(dev);
388 
389 	hidbus_detach_children(dev);
390 	sx_destroy(&sc->sx);
391 	mtx_destroy(&sc->mtx);
392 	free(sc->rdesc.data, M_DEVBUF);
393 
394 	return (0);
395 }
396 
397 static void
hidbus_child_detached(device_t bus,device_t child)398 hidbus_child_detached(device_t bus, device_t child)
399 {
400 	struct hidbus_softc *sc = device_get_softc(bus);
401 	struct hidbus_ivars *tlc = device_get_ivars(child);
402 
403 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
404 	tlc->mtx = &sc->mtx;
405 	tlc->intr_handler = NULL;
406 	tlc->flags &= ~HIDBUS_FLAG_CAN_POLL;
407 }
408 
409 /*
410  * Epoch callback indicating tlc is safe to destroy
411  */
412 static void
hidbus_ivar_dtor(epoch_context_t ctx)413 hidbus_ivar_dtor(epoch_context_t ctx)
414 {
415 	struct hidbus_ivars *tlc;
416 
417 	tlc = __containerof(ctx, struct hidbus_ivars, epoch_ctx);
418 	free(tlc, M_DEVBUF);
419 }
420 
421 static void
hidbus_child_deleted(device_t bus,device_t child)422 hidbus_child_deleted(device_t bus, device_t child)
423 {
424 	struct hidbus_softc *sc = device_get_softc(bus);
425 	struct hidbus_ivars *tlc = device_get_ivars(child);
426 
427 	sx_xlock(&sc->sx);
428 	KASSERT(tlc->refcnt == 0, ("Child device is running"));
429 	CK_STAILQ_REMOVE(&sc->tlcs, tlc, hidbus_ivars, link);
430 	sx_unlock(&sc->sx);
431 	epoch_call(INPUT_EPOCH, hidbus_ivar_dtor, &tlc->epoch_ctx);
432 }
433 
434 static int
hidbus_read_ivar(device_t bus,device_t child,int which,uintptr_t * result)435 hidbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
436 {
437 	struct hidbus_softc *sc = device_get_softc(bus);
438 	struct hidbus_ivars *tlc = device_get_ivars(child);
439 
440 	switch (which) {
441 	case HIDBUS_IVAR_INDEX:
442 		*result = tlc->index;
443 		break;
444 	case HIDBUS_IVAR_USAGE:
445 		*result = tlc->usage;
446 		break;
447 	case HIDBUS_IVAR_FLAGS:
448 		*result = tlc->flags;
449 		break;
450 	case HIDBUS_IVAR_DRIVER_INFO:
451 		*result = tlc->driver_info;
452 		break;
453 	case HIDBUS_IVAR_LOCK:
454 		*result = (uintptr_t)(tlc->mtx == &sc->mtx ? NULL : tlc->mtx);
455 		break;
456 	default:
457 		return (EINVAL);
458 	}
459 	return (0);
460 }
461 
462 static int
hidbus_write_ivar(device_t bus,device_t child,int which,uintptr_t value)463 hidbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
464 {
465 	struct hidbus_softc *sc = device_get_softc(bus);
466 	struct hidbus_ivars *tlc = device_get_ivars(child);
467 
468 	switch (which) {
469 	case HIDBUS_IVAR_INDEX:
470 		tlc->index = value;
471 		break;
472 	case HIDBUS_IVAR_USAGE:
473 		tlc->usage = value;
474 		break;
475 	case HIDBUS_IVAR_FLAGS:
476 		tlc->flags = value;
477 		if ((value & HIDBUS_FLAG_CAN_POLL) != 0)
478 			HID_INTR_SETUP(
479 			    device_get_parent(bus), NULL, NULL, NULL);
480 		break;
481 	case HIDBUS_IVAR_DRIVER_INFO:
482 		tlc->driver_info = value;
483 		break;
484 	case HIDBUS_IVAR_LOCK:
485 		tlc->mtx = (struct mtx *)value == NULL ?
486 		    &sc->mtx : (struct mtx *)value;
487 		break;
488 	default:
489 		return (EINVAL);
490 	}
491 	return (0);
492 }
493 
494 /* Location hint for devctl(8) */
495 static int
hidbus_child_location_str(device_t bus,device_t child,char * buf,size_t buflen)496 hidbus_child_location_str(device_t bus, device_t child, char *buf,
497     size_t buflen)
498 {
499 	struct hidbus_ivars *tlc = device_get_ivars(child);
500 
501 	snprintf(buf, buflen, "index=%hhu", tlc->index);
502         return (0);
503 }
504 
505 /* PnP information for devctl(8) */
506 static int
hidbus_child_pnpinfo_str(device_t bus,device_t child,char * buf,size_t buflen)507 hidbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
508     size_t buflen)
509 {
510 	struct hidbus_ivars *tlc = device_get_ivars(child);
511 	struct hid_device_info *devinfo = device_get_ivars(bus);
512 
513 	snprintf(buf, buflen, "page=0x%04x usage=0x%04x bus=0x%02hx "
514 	    "vendor=0x%04hx product=0x%04hx version=0x%04hx%s%s",
515 	    HID_GET_USAGE_PAGE(tlc->usage), HID_GET_USAGE(tlc->usage),
516 	    devinfo->idBus, devinfo->idVendor, devinfo->idProduct,
517 	    devinfo->idVersion, devinfo->idPnP[0] == '\0' ? "" : " _HID=",
518 	    devinfo->idPnP[0] == '\0' ? "" : devinfo->idPnP);
519 	return (0);
520 }
521 
522 void
hidbus_set_desc(device_t child,const char * suffix)523 hidbus_set_desc(device_t child, const char *suffix)
524 {
525 	device_t bus = device_get_parent(child);
526 	struct hidbus_softc *sc = device_get_softc(bus);
527 	struct hid_device_info *devinfo = device_get_ivars(bus);
528 	struct hidbus_ivars *tlc = device_get_ivars(child);
529 	char buf[80];
530 
531 	/* Do not add NULL suffix or if device name already contains it. */
532 	if (suffix != NULL && strcasestr(devinfo->name, suffix) == NULL &&
533 	    (sc->nauto > 1 || (tlc->flags & HIDBUS_FLAG_AUTOCHILD) == 0)) {
534 		snprintf(buf, sizeof(buf), "%s %s", devinfo->name, suffix);
535 		device_set_desc_copy(child, buf);
536 	} else
537 		device_set_desc(child, devinfo->name);
538 }
539 
540 device_t
hidbus_find_child(device_t bus,int32_t usage)541 hidbus_find_child(device_t bus, int32_t usage)
542 {
543 	device_t *children, child;
544 	int ccount, i;
545 
546 	GIANT_REQUIRED;
547 
548 	/* Get a list of all hidbus children */
549 	if (device_get_children(bus, &children, &ccount) != 0)
550 		return (NULL);
551 
552 	/* Scan through to find required TLC */
553 	for (i = 0, child = NULL; i < ccount; i++) {
554 		if (hidbus_get_usage(children[i]) == usage) {
555 			child = children[i];
556 			break;
557 		}
558 	}
559 	free(children, M_TEMP);
560 
561 	return (child);
562 }
563 
564 void
hidbus_intr(void * context,void * buf,hid_size_t len)565 hidbus_intr(void *context, void *buf, hid_size_t len)
566 {
567 	struct hidbus_softc *sc = context;
568 	struct hidbus_ivars *tlc;
569 	struct epoch_tracker et;
570 
571 	/*
572 	 * Broadcast input report to all subscribers.
573 	 * TODO: Add check for input report ID.
574 	 *
575 	 * Relock mutex on every TLC item as we can't hold any locks over whole
576 	 * TLC list here due to LOR with open()/close() handlers.
577 	 */
578 	if (!HID_IN_POLLING_MODE())
579 		epoch_enter_preempt(INPUT_EPOCH, &et);
580 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
581 		if (tlc->refcnt == 0 || tlc->intr_handler == NULL)
582 			continue;
583 		if (HID_IN_POLLING_MODE()) {
584 			if ((tlc->flags & HIDBUS_FLAG_CAN_POLL) != 0)
585 				tlc->intr_handler(tlc->intr_ctx, buf, len);
586 		} else {
587 			mtx_lock(tlc->mtx);
588 			tlc->intr_handler(tlc->intr_ctx, buf, len);
589 			mtx_unlock(tlc->mtx);
590 		}
591 	}
592 	if (!HID_IN_POLLING_MODE())
593 		epoch_exit_preempt(INPUT_EPOCH, &et);
594 }
595 
596 void
hidbus_set_intr(device_t child,hid_intr_t * handler,void * context)597 hidbus_set_intr(device_t child, hid_intr_t *handler, void *context)
598 {
599 	struct hidbus_ivars *tlc = device_get_ivars(child);
600 
601 	tlc->intr_handler = handler;
602 	tlc->intr_ctx = context;
603 }
604 
605 int
hidbus_intr_start(device_t child)606 hidbus_intr_start(device_t child)
607 {
608 	device_t bus = device_get_parent(child);
609 	struct hidbus_softc *sc = device_get_softc(bus);
610 	struct hidbus_ivars *ivar = device_get_ivars(child);
611 	struct hidbus_ivars *tlc;
612 	bool refcnted = false;
613 	int error;
614 
615 	if (sx_xlock_sig(&sc->sx) != 0)
616 		return (EINTR);
617 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
618 		refcnted |= (tlc->refcnt != 0);
619 		if (tlc == ivar) {
620 			mtx_lock(tlc->mtx);
621 			++tlc->refcnt;
622 			mtx_unlock(tlc->mtx);
623 		}
624 	}
625 	error = refcnted ? 0 : HID_INTR_START(device_get_parent(bus));
626 	sx_unlock(&sc->sx);
627 
628 	return (error);
629 }
630 
631 int
hidbus_intr_stop(device_t child)632 hidbus_intr_stop(device_t child)
633 {
634 	device_t bus = device_get_parent(child);
635 	struct hidbus_softc *sc = device_get_softc(bus);
636 	struct hidbus_ivars *ivar = device_get_ivars(child);
637 	struct hidbus_ivars *tlc;
638 	bool refcnted = false;
639 	int error;
640 
641 	if (sx_xlock_sig(&sc->sx) != 0)
642 		return (EINTR);
643 	CK_STAILQ_FOREACH(tlc, &sc->tlcs, link) {
644 		if (tlc == ivar) {
645 			mtx_lock(tlc->mtx);
646 			MPASS(tlc->refcnt != 0);
647 			--tlc->refcnt;
648 			mtx_unlock(tlc->mtx);
649 		}
650 		refcnted |= (tlc->refcnt != 0);
651 	}
652 	error = refcnted ? 0 : HID_INTR_STOP(device_get_parent(bus));
653 	sx_unlock(&sc->sx);
654 
655 	return (error);
656 }
657 
658 void
hidbus_intr_poll(device_t child)659 hidbus_intr_poll(device_t child)
660 {
661 	device_t bus = device_get_parent(child);
662 
663 	HID_INTR_POLL(device_get_parent(bus));
664 }
665 
666 struct hid_rdesc_info *
hidbus_get_rdesc_info(device_t child)667 hidbus_get_rdesc_info(device_t child)
668 {
669 	device_t bus = device_get_parent(child);
670 	struct hidbus_softc *sc = device_get_softc(bus);
671 
672 	return (&sc->rdesc);
673 }
674 
675 /*
676  * HID interface.
677  *
678  * Hidbus as well as any hidbus child can be passed as first arg.
679  */
680 
681 /* Read cached report descriptor */
682 int
hid_get_report_descr(device_t dev,void ** data,hid_size_t * len)683 hid_get_report_descr(device_t dev, void **data, hid_size_t *len)
684 {
685 	device_t bus;
686 	struct hidbus_softc *sc;
687 
688 	bus = device_get_devclass(dev) == hidbus_devclass ?
689 	    dev : device_get_parent(dev);
690 	sc = device_get_softc(bus);
691 
692 	/*
693 	 * Do not send request to a transport backend.
694 	 * Use cached report descriptor instead of it.
695 	 */
696 	if (sc->rdesc.data == NULL || sc->rdesc.len == 0)
697 		return (ENXIO);
698 
699 	if (data != NULL)
700 		*data = sc->rdesc.data;
701 	if (len != NULL)
702 		*len = sc->rdesc.len;
703 
704 	return (0);
705 }
706 
707 /*
708  * Replace cached report descriptor with top level driver provided one.
709  *
710  * It deletes all hidbus children except caller and enumerates them again after
711  * new descriptor has been registered. Currently it can not be called from
712  * autoenumerated (by report's TLC) child device context as it results in child
713  * duplication. To overcome this limitation hid_set_report_descr() should be
714  * called from device_identify driver's handler with hidbus itself passed as
715  * 'device_t dev' parameter.
716  */
717 int
hid_set_report_descr(device_t dev,const void * data,hid_size_t len)718 hid_set_report_descr(device_t dev, const void *data, hid_size_t len)
719 {
720 	struct hid_rdesc_info rdesc;
721 	device_t bus;
722 	struct hidbus_softc *sc;
723 	bool is_bus;
724 	int error;
725 
726 	GIANT_REQUIRED;
727 
728 	is_bus = device_get_devclass(dev) == hidbus_devclass;
729 	bus = is_bus ? dev : device_get_parent(dev);
730 	sc = device_get_softc(bus);
731 
732 	/*
733 	 * Do not overload already overloaded report descriptor in
734 	 * device_identify handler. It causes infinite recursion loop.
735 	 */
736 	if (is_bus && sc->overloaded)
737 		return(0);
738 
739 	DPRINTFN(5, "len=%d\n", len);
740 	DPRINTFN(5, "data = %*D\n", len, data, " ");
741 
742 	error = hidbus_fill_rdesc_info(&rdesc, data, len);
743 	if (error != 0)
744 		return (error);
745 
746 	error = hidbus_detach_children(dev);
747 	if (error != 0)
748 		return(error);
749 
750 	/* Make private copy to handle a case of dynamicaly allocated data. */
751 	rdesc.data = malloc(len, M_DEVBUF, M_ZERO | M_WAITOK);
752 	bcopy(data, rdesc.data, len);
753 	sc->overloaded = true;
754 	free(sc->rdesc.data, M_DEVBUF);
755 	bcopy(&rdesc, &sc->rdesc, sizeof(struct hid_rdesc_info));
756 
757 	error = hidbus_attach_children(bus);
758 
759 	return (error);
760 }
761 
762 static int
hidbus_write(device_t dev,const void * data,hid_size_t len)763 hidbus_write(device_t dev, const void *data, hid_size_t len)
764 {
765 	struct hidbus_softc *sc;
766 	uint8_t id;
767 
768 	sc = device_get_softc(dev);
769 	/*
770 	 * Output interrupt endpoint is often optional. If HID device
771 	 * does not provide it, send reports via control pipe.
772 	 */
773 	if (sc->nowrite) {
774 		/* try to extract the ID byte */
775 		id = (sc->rdesc.oid & (len > 0)) ? *(const uint8_t*)data : 0;
776 		return (hid_set_report(dev, data, len, HID_OUTPUT_REPORT, id));
777 	}
778 
779 	return (hid_write(dev, data, len));
780 }
781 
782 /*------------------------------------------------------------------------*
783  *	hidbus_lookup_id
784  *
785  * This functions takes an array of "struct hid_device_id" and tries
786  * to match the entries with the information in "struct hid_device_info".
787  *
788  * Return values:
789  * NULL: No match found.
790  * Else: Pointer to matching entry.
791  *------------------------------------------------------------------------*/
792 const struct hid_device_id *
hidbus_lookup_id(device_t dev,const struct hid_device_id * id,int nitems_id)793 hidbus_lookup_id(device_t dev, const struct hid_device_id *id, int nitems_id)
794 {
795 	const struct hid_device_id *id_end;
796 	const struct hid_device_info *info;
797 	int32_t usage;
798 	bool is_child;
799 
800 	if (id == NULL) {
801 		goto done;
802 	}
803 
804 	id_end = id + nitems_id;
805 	info = hid_get_device_info(dev);
806 	is_child = device_get_devclass(dev) != hidbus_devclass;
807 	if (is_child)
808 		usage = hidbus_get_usage(dev);
809 
810 	/*
811 	 * Keep on matching array entries until we find a match or
812 	 * until we reach the end of the matching array:
813 	 */
814 	for (; id != id_end; id++) {
815 
816 		if (is_child && (id->match_flag_page) &&
817 		    (id->page != HID_GET_USAGE_PAGE(usage))) {
818 			continue;
819 		}
820 		if (is_child && (id->match_flag_usage) &&
821 		    (id->usage != HID_GET_USAGE(usage))) {
822 			continue;
823 		}
824 		if ((id->match_flag_bus) &&
825 		    (id->idBus != info->idBus)) {
826 			continue;
827 		}
828 		if ((id->match_flag_vendor) &&
829 		    (id->idVendor != info->idVendor)) {
830 			continue;
831 		}
832 		if ((id->match_flag_product) &&
833 		    (id->idProduct != info->idProduct)) {
834 			continue;
835 		}
836 		if ((id->match_flag_ver_lo) &&
837 		    (id->idVersion_lo > info->idVersion)) {
838 			continue;
839 		}
840 		if ((id->match_flag_ver_hi) &&
841 		    (id->idVersion_hi < info->idVersion)) {
842 			continue;
843 		}
844 		if (id->match_flag_pnp &&
845 		    strncmp(id->idPnP, info->idPnP, HID_PNP_ID_SIZE) != 0) {
846 			continue;
847 		}
848 		/* We found a match! */
849 		return (id);
850 	}
851 
852 done:
853 	return (NULL);
854 }
855 
856 /*------------------------------------------------------------------------*
857  *	hidbus_lookup_driver_info - factored out code
858  *
859  * Return values:
860  *    0: Success
861  * Else: Failure
862  *------------------------------------------------------------------------*/
863 int
hidbus_lookup_driver_info(device_t child,const struct hid_device_id * id,int nitems_id)864 hidbus_lookup_driver_info(device_t child, const struct hid_device_id *id,
865     int nitems_id)
866 {
867 
868 	id = hidbus_lookup_id(child, id, nitems_id);
869 	if (id) {
870 		/* copy driver info */
871 		hidbus_set_driver_info(child, id->driver_info);
872 		return (0);
873 	}
874 	return (ENXIO);
875 }
876 
877 const struct hid_device_info *
hid_get_device_info(device_t dev)878 hid_get_device_info(device_t dev)
879 {
880 	device_t bus;
881 
882 	bus = device_get_devclass(dev) == hidbus_devclass ?
883 	    dev : device_get_parent(dev);
884 
885 	return (device_get_ivars(bus));
886 }
887 
888 static device_method_t hidbus_methods[] = {
889 	/* device interface */
890 	DEVMETHOD(device_probe,		hidbus_probe),
891 	DEVMETHOD(device_attach,	hidbus_attach),
892 	DEVMETHOD(device_detach,	hidbus_detach),
893 	DEVMETHOD(device_suspend,	bus_generic_suspend),
894 	DEVMETHOD(device_resume,	bus_generic_resume),
895 
896 	/* bus interface */
897 	DEVMETHOD(bus_add_child,	hidbus_add_child),
898 	DEVMETHOD(bus_child_detached,	hidbus_child_detached),
899 	DEVMETHOD(bus_child_deleted,	hidbus_child_deleted),
900 	DEVMETHOD(bus_read_ivar,	hidbus_read_ivar),
901 	DEVMETHOD(bus_write_ivar,	hidbus_write_ivar),
902 	DEVMETHOD(bus_child_pnpinfo_str,hidbus_child_pnpinfo_str),
903 	DEVMETHOD(bus_child_location_str,hidbus_child_location_str),
904 
905 	/* hid interface */
906 	DEVMETHOD(hid_get_rdesc,	hid_get_rdesc),
907 	DEVMETHOD(hid_read,		hid_read),
908 	DEVMETHOD(hid_write,		hidbus_write),
909 	DEVMETHOD(hid_get_report,	hid_get_report),
910 	DEVMETHOD(hid_set_report,	hid_set_report),
911 	DEVMETHOD(hid_set_idle,		hid_set_idle),
912 	DEVMETHOD(hid_set_protocol,	hid_set_protocol),
913 	DEVMETHOD(hid_ioctl,		hid_ioctl),
914 
915 	DEVMETHOD_END
916 };
917 
918 devclass_t hidbus_devclass;
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, hidbus_devclass, 0, 0);
928 DRIVER_MODULE(hidbus, iichid, hidbus_driver, hidbus_devclass, 0, 0);
929 DRIVER_MODULE(hidbus, usbhid, hidbus_driver, hidbus_devclass, 0, 0);
930