xref: /freebsd/sys/dev/usb/input/wmt.c (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /*-
2  * Copyright (c) 2014-2017 Vladimir Kondratyev <wulf@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * MS Windows 7/8/10 compatible USB HID Multi-touch Device driver.
32  * https://msdn.microsoft.com/en-us/library/windows/hardware/jj151569(v=vs.85).aspx
33  * https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
34  */
35 
36 #include <sys/param.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/stddef.h>
45 #include <sys/sysctl.h>
46 #include <sys/systm.h>
47 
48 #include "usbdevs.h"
49 #include <dev/usb/usb.h>
50 #include <dev/usb/usbdi.h>
51 #include <dev/usb/usbdi_util.h>
52 #include <dev/usb/usbhid.h>
53 
54 #include <dev/usb/quirk/usb_quirk.h>
55 
56 #include <dev/evdev/evdev.h>
57 #include <dev/evdev/input.h>
58 
59 #define	USB_DEBUG_VAR wmt_debug
60 #include <dev/usb/usb_debug.h>
61 
62 #ifdef USB_DEBUG
63 static int wmt_debug = 0;
64 
65 static SYSCTL_NODE(_hw_usb, OID_AUTO, wmt, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
66     "USB MSWindows 7/8/10 compatible Multi-touch Device");
67 SYSCTL_INT(_hw_usb_wmt, OID_AUTO, debug, CTLFLAG_RWTUN,
68     &wmt_debug, 1, "Debug level");
69 #endif
70 
71 #define	WMT_BSIZE	1024	/* bytes, buffer size */
72 
73 enum {
74 	WMT_INTR_DT,
75 	WMT_N_TRANSFER,
76 };
77 
78 enum {
79 	WMT_TIP_SWITCH,
80 #define	WMT_SLOT	WMT_TIP_SWITCH
81 	WMT_WIDTH,
82 #define	WMT_MAJOR	WMT_WIDTH
83 	WMT_HEIGHT,
84 #define WMT_MINOR	WMT_HEIGHT
85 	WMT_ORIENTATION,
86 	WMT_X,
87 	WMT_Y,
88 	WMT_CONTACTID,
89 	WMT_PRESSURE,
90 	WMT_IN_RANGE,
91 	WMT_CONFIDENCE,
92 	WMT_TOOL_X,
93 	WMT_TOOL_Y,
94 	WMT_N_USAGES,
95 };
96 
97 #define	WMT_NO_CODE	(ABS_MAX + 10)
98 #define	WMT_NO_USAGE	-1
99 
100 struct wmt_hid_map_item {
101 	char		name[5];
102 	int32_t 	usage;		/* HID usage */
103 	uint32_t	code;		/* Evdev event code */
104 	bool		required;	/* Required for MT Digitizers */
105 };
106 
107 static const struct wmt_hid_map_item wmt_hid_map[WMT_N_USAGES] = {
108 
109 	[WMT_TIP_SWITCH] = {	/* WMT_SLOT */
110 		.name = "TIP",
111 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_SWITCH),
112 		.code = ABS_MT_SLOT,
113 		.required = true,
114 	},
115 	[WMT_WIDTH] = {		/* WMT_MAJOR */
116 		.name = "WDTH",
117 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_WIDTH),
118 		.code = ABS_MT_TOUCH_MAJOR,
119 		.required = false,
120 	},
121 	[WMT_HEIGHT] = {	/* WMT_MINOR */
122 		.name = "HGHT",
123 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_HEIGHT),
124 		.code = ABS_MT_TOUCH_MINOR,
125 		.required = false,
126 	},
127 	[WMT_ORIENTATION] = {
128 		.name = "ORIE",
129 		.usage = WMT_NO_USAGE,
130 		.code = ABS_MT_ORIENTATION,
131 		.required = false,
132 	},
133 	[WMT_X] = {
134 		.name = "X",
135 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X),
136 		.code = ABS_MT_POSITION_X,
137 		.required = true,
138 	},
139 	[WMT_Y] = {
140 		.name = "Y",
141 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y),
142 		.code = ABS_MT_POSITION_Y,
143 		.required = true,
144 	},
145 	[WMT_CONTACTID] = {
146 		.name = "C_ID",
147 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTID),
148 		.code = ABS_MT_TRACKING_ID,
149 		.required = true,
150 	},
151 	[WMT_PRESSURE] = {
152 		.name = "PRES",
153 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_PRESSURE),
154 		.code = ABS_MT_PRESSURE,
155 		.required = false,
156 	},
157 	[WMT_IN_RANGE] = {
158 		.name = "RANG",
159 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_IN_RANGE),
160 		.code = ABS_MT_DISTANCE,
161 		.required = false,
162 	},
163 	[WMT_CONFIDENCE] = {
164 		.name = "CONF",
165 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_CONFIDENCE),
166 		.code = WMT_NO_CODE,
167 		.required = false,
168 	},
169 	[WMT_TOOL_X] = {	/* Shares HID usage with WMT_X */
170 		.name = "TL_X",
171 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X),
172 		.code = ABS_MT_TOOL_X,
173 		.required = false,
174 	},
175 	[WMT_TOOL_Y] = {	/* Shares HID usage with WMT_Y */
176 		.name = "TL_Y",
177 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y),
178 		.code = ABS_MT_TOOL_Y,
179 		.required = false,
180 	},
181 };
182 
183 struct wmt_absinfo {
184 	int32_t			min;
185 	int32_t			max;
186 	int32_t			res;
187 };
188 
189 struct wmt_softc
190 {
191 	device_t		dev;
192 	struct mtx		mtx;
193 	struct wmt_absinfo	ai[WMT_N_USAGES];
194 	struct hid_location	locs[MAX_MT_SLOTS][WMT_N_USAGES];
195 	struct hid_location	nconts_loc;
196 
197 	struct usb_xfer		*xfer[WMT_N_TRANSFER];
198 	struct evdev_dev	*evdev;
199 
200 	uint32_t		slot_data[WMT_N_USAGES];
201 	uint32_t		caps;
202 	uint32_t		isize;
203 	uint32_t		nconts_max;
204 	uint32_t		report_len;
205 	uint8_t			report_id;
206 
207 	struct hid_location	cont_max_loc;
208 	uint32_t		cont_max_rlen;
209 	uint8_t			cont_max_rid;
210 	uint32_t		thqa_cert_rlen;
211 	uint8_t			thqa_cert_rid;
212 
213 	uint8_t			buf[WMT_BSIZE] __aligned(4);
214 };
215 
216 #define	USAGE_SUPPORTED(caps, usage)	((caps) & (1 << (usage)))
217 #define	WMT_FOREACH_USAGE(caps, usage)			\
218 	for ((usage) = 0; (usage) < WMT_N_USAGES; ++(usage))	\
219 		if (USAGE_SUPPORTED((caps), (usage)))
220 
221 static bool wmt_hid_parse(struct wmt_softc *, const void *, uint16_t);
222 static void wmt_cont_max_parse(struct wmt_softc *, const void *, uint16_t);
223 
224 static usb_callback_t	wmt_intr_callback;
225 
226 static device_probe_t	wmt_probe;
227 static device_attach_t	wmt_attach;
228 static device_detach_t	wmt_detach;
229 
230 #if __FreeBSD_version >= 1200077
231 static evdev_open_t	wmt_ev_open;
232 static evdev_close_t	wmt_ev_close;
233 #else
234 static evdev_open_t	wmt_ev_open_11;
235 static evdev_close_t	wmt_ev_close_11;
236 #endif
237 
238 static const struct evdev_methods wmt_evdev_methods = {
239 #if __FreeBSD_version >= 1200077
240 	.ev_open = &wmt_ev_open,
241 	.ev_close = &wmt_ev_close,
242 #else
243 	.ev_open = &wmt_ev_open_11,
244 	.ev_close = &wmt_ev_close_11,
245 #endif
246 };
247 
248 static const struct usb_config wmt_config[WMT_N_TRANSFER] = {
249 
250 	[WMT_INTR_DT] = {
251 		.type = UE_INTERRUPT,
252 		.endpoint = UE_ADDR_ANY,
253 		.direction = UE_DIR_IN,
254 		.flags = { .pipe_bof = 1, .short_xfer_ok = 1 },
255 		.bufsize = WMT_BSIZE,
256 		.callback = &wmt_intr_callback,
257 	},
258 };
259 
260 static int
261 wmt_probe(device_t dev)
262 {
263 	struct usb_attach_arg *uaa = device_get_ivars(dev);
264 	void *d_ptr;
265 	uint16_t d_len;
266 	int err;
267 
268 	if (uaa->usb_mode != USB_MODE_HOST)
269 		return (ENXIO);
270 
271 	if (uaa->info.bInterfaceClass != UICLASS_HID)
272 		return (ENXIO);
273 
274 	if (usb_test_quirk(uaa, UQ_WMT_IGNORE))
275 		return (ENXIO);
276 
277 	err = usbd_req_get_hid_desc(uaa->device, NULL,
278 	    &d_ptr, &d_len, M_TEMP, uaa->info.bIfaceIndex);
279 	if (err)
280 		return (ENXIO);
281 
282 	if (wmt_hid_parse(NULL, d_ptr, d_len))
283 		err = BUS_PROBE_DEFAULT;
284 	else
285 		err = ENXIO;
286 
287 	free(d_ptr, M_TEMP);
288 	return (err);
289 }
290 
291 static int
292 wmt_attach(device_t dev)
293 {
294 	struct usb_attach_arg *uaa = device_get_ivars(dev);
295 	struct wmt_softc *sc = device_get_softc(dev);
296 	void *d_ptr;
297 	uint16_t d_len;
298 	size_t i;
299 	int err;
300 	bool hid_ok;
301 
302 	device_set_usb_desc(dev);
303 	sc->dev = dev;
304 
305 	/* Get HID descriptor */
306 	err = usbd_req_get_hid_desc(uaa->device, NULL,
307 	    &d_ptr, &d_len, M_TEMP, uaa->info.bIfaceIndex);
308 	if (err) {
309 		DPRINTF("usbd_req_get_hid_desc error=%s\n", usbd_errstr(err));
310 		return (ENXIO);
311 	}
312 
313 	hid_ok = wmt_hid_parse(sc, d_ptr, d_len);
314 	free(d_ptr, M_TEMP);
315 	if (!hid_ok) {
316 		DPRINTF("multi-touch HID descriptor not found\n");
317 		return (ENXIO);
318 	}
319 
320 	/* Check HID report length */
321 	if (sc->isize <= 0 || sc->isize > WMT_BSIZE) {
322 		DPRINTF("Input size invalid or too large: %d\n", sc->isize);
323 		return (ENXIO);
324 	}
325 
326 	/* Fetch and parse "Contact count maximum" feature report */
327 	if (sc->cont_max_rlen > 0 && sc->cont_max_rlen <= WMT_BSIZE) {
328 		err = usbd_req_get_report(uaa->device, NULL, sc->buf,
329 		    sc->cont_max_rlen, uaa->info.bIfaceIndex,
330 		    UHID_FEATURE_REPORT, sc->cont_max_rid);
331 		if (err == USB_ERR_NORMAL_COMPLETION)
332 			wmt_cont_max_parse(sc, sc->buf, sc->cont_max_rlen);
333 		else
334 			DPRINTF("usbd_req_get_report error=(%s)\n",
335 			    usbd_errstr(err));
336 	} else
337 		DPRINTF("Feature report %hhu size invalid or too large: %u\n",
338 		    sc->cont_max_rid, sc->cont_max_rlen);
339 
340 	/* Fetch THQA certificate to enable some devices like WaveShare */
341 	if (sc->thqa_cert_rlen > 0 && sc->thqa_cert_rlen <= WMT_BSIZE &&
342 	    sc->thqa_cert_rid != sc->cont_max_rid)
343 		(void)usbd_req_get_report(uaa->device, NULL, sc->buf,
344 		    sc->thqa_cert_rlen, uaa->info.bIfaceIndex,
345 		    UHID_FEATURE_REPORT, sc->thqa_cert_rid);
346 
347 	mtx_init(&sc->mtx, "wmt lock", NULL, MTX_DEF);
348 
349 	err = usbd_transfer_setup(uaa->device, &uaa->info.bIfaceIndex,
350 	    sc->xfer, wmt_config, WMT_N_TRANSFER, sc, &sc->mtx);
351 	if (err != USB_ERR_NORMAL_COMPLETION) {
352 		DPRINTF("usbd_transfer_setup error=%s\n", usbd_errstr(err));
353 		goto detach;
354 	}
355 
356 	sc->evdev = evdev_alloc();
357 	evdev_set_name(sc->evdev, device_get_desc(dev));
358 	evdev_set_phys(sc->evdev, device_get_nameunit(dev));
359 	evdev_set_id(sc->evdev, BUS_USB, uaa->info.idVendor,
360 	    uaa->info.idProduct, 0);
361 	evdev_set_serial(sc->evdev, usb_get_serial(uaa->device));
362 	evdev_set_methods(sc->evdev, sc, &wmt_evdev_methods);
363 	evdev_set_flag(sc->evdev, EVDEV_FLAG_MT_STCOMPAT);
364 	evdev_support_prop(sc->evdev, INPUT_PROP_DIRECT);
365 	evdev_support_event(sc->evdev, EV_SYN);
366 	evdev_support_event(sc->evdev, EV_ABS);
367 	WMT_FOREACH_USAGE(sc->caps, i) {
368 		if (wmt_hid_map[i].code != WMT_NO_CODE)
369 			evdev_support_abs(sc->evdev, wmt_hid_map[i].code, 0,
370 			    sc->ai[i].min, sc->ai[i].max, 0, 0, sc->ai[i].res);
371 	}
372 
373 	err = evdev_register_mtx(sc->evdev, &sc->mtx);
374 	if (err)
375 		goto detach;
376 
377 	return (0);
378 
379 detach:
380 	wmt_detach(dev);
381 	return (ENXIO);
382 }
383 
384 static int
385 wmt_detach(device_t dev)
386 {
387 	struct wmt_softc *sc = device_get_softc(dev);
388 
389 	evdev_free(sc->evdev);
390 	usbd_transfer_unsetup(sc->xfer, WMT_N_TRANSFER);
391 	mtx_destroy(&sc->mtx);
392 	return (0);
393 }
394 
395 static void
396 wmt_process_report(struct wmt_softc *sc, uint8_t *buf, int len)
397 {
398 	size_t usage;
399 	uint32_t *slot_data = sc->slot_data;
400 	uint32_t cont;
401 	uint32_t nconts;
402 	uint32_t width;
403 	uint32_t height;
404 	int32_t slot;
405 
406 	nconts = hid_get_data_unsigned(buf, len, &sc->nconts_loc);
407 
408 #ifdef USB_DEBUG
409 	DPRINTFN(6, "nconts = %u   ", (unsigned)nconts);
410 	if (wmt_debug >= 6) {
411 		WMT_FOREACH_USAGE(sc->caps, usage) {
412 			if (wmt_hid_map[usage].usage != WMT_NO_USAGE)
413 				printf(" %-4s", wmt_hid_map[usage].name);
414 		}
415 		printf("\n");
416 	}
417 #endif
418 
419 	if (nconts > sc->nconts_max) {
420 		DPRINTF("Contact count overflow %u\n", (unsigned)nconts);
421 		nconts = sc->nconts_max;
422 	}
423 
424 	/* Use protocol Type B for reporting events */
425 	for (cont = 0; cont < nconts; cont++) {
426 
427 		bzero(slot_data, sizeof(sc->slot_data));
428 		WMT_FOREACH_USAGE(sc->caps, usage) {
429 			if (sc->locs[cont][usage].size > 0)
430 				slot_data[usage] = hid_get_data_unsigned(
431 				    buf, len, &sc->locs[cont][usage]);
432 		}
433 
434 		slot = evdev_get_mt_slot_by_tracking_id(sc->evdev,
435 		    slot_data[WMT_CONTACTID]);
436 
437 #ifdef USB_DEBUG
438 		DPRINTFN(6, "cont%01x: data = ", cont);
439 		if (wmt_debug >= 6) {
440 			WMT_FOREACH_USAGE(sc->caps, usage) {
441 				if (wmt_hid_map[usage].usage != WMT_NO_USAGE)
442 					printf("%04x ", slot_data[usage]);
443 			}
444 			printf("slot = %d\n", (int)slot);
445 		}
446 #endif
447 
448 		if (slot == -1) {
449 			DPRINTF("Slot overflow for contact_id %u\n",
450 			    (unsigned)slot_data[WMT_CONTACTID]);
451 			continue;
452 		}
453 
454 		if (slot_data[WMT_TIP_SWITCH] != 0 &&
455 		    !(USAGE_SUPPORTED(sc->caps, WMT_CONFIDENCE) &&
456 		      slot_data[WMT_CONFIDENCE] == 0)) {
457 			/* This finger is in proximity of the sensor */
458 			slot_data[WMT_SLOT] = slot;
459 			slot_data[WMT_IN_RANGE] = !slot_data[WMT_IN_RANGE];
460 			/* Divided by two to match visual scale of touch */
461 			width = slot_data[WMT_WIDTH] >> 1;
462 			height = slot_data[WMT_HEIGHT] >> 1;
463 			slot_data[WMT_ORIENTATION] = width > height;
464 			slot_data[WMT_MAJOR] = MAX(width, height);
465 			slot_data[WMT_MINOR] = MIN(width, height);
466 
467 			WMT_FOREACH_USAGE(sc->caps, usage)
468 				if (wmt_hid_map[usage].code != WMT_NO_CODE)
469 					evdev_push_abs(sc->evdev,
470 					    wmt_hid_map[usage].code,
471 					    slot_data[usage]);
472 		} else {
473 			evdev_push_abs(sc->evdev, ABS_MT_SLOT, slot);
474 			evdev_push_abs(sc->evdev, ABS_MT_TRACKING_ID, -1);
475 		}
476 	}
477 	evdev_sync(sc->evdev);
478 }
479 
480 static void
481 wmt_intr_callback(struct usb_xfer *xfer, usb_error_t error)
482 {
483 	struct wmt_softc *sc = usbd_xfer_softc(xfer);
484 	struct usb_page_cache *pc;
485 	uint8_t *buf = sc->buf;
486 	int len;
487 
488 	usbd_xfer_status(xfer, &len, NULL, NULL, NULL);
489 
490 	switch (USB_GET_STATE(xfer)) {
491 	case USB_ST_TRANSFERRED:
492 		pc = usbd_xfer_get_frame(xfer, 0);
493 
494 		DPRINTFN(6, "sc=%p actlen=%d\n", sc, len);
495 
496 		if (len >= (int)sc->report_len ||
497 		    (len > 0 && sc->report_id != 0)) {
498 			/* Limit report length to the maximum */
499 			if (len > (int)sc->report_len)
500 				len = sc->report_len;
501 
502 			usbd_copy_out(pc, 0, buf, len);
503 
504 			/* Ignore irrelevant reports */
505 			if (sc->report_id && *buf != sc->report_id)
506 				goto tr_ignore;
507 
508 			/* Make sure we don't process old data */
509 			if (len < sc->report_len)
510 				bzero(buf + len, sc->report_len - len);
511 
512 			/* Strip leading "report ID" byte */
513 			if (sc->report_id) {
514 				len--;
515 				buf++;
516 			}
517 
518 			wmt_process_report(sc, buf, len);
519 		} else {
520 tr_ignore:
521 			DPRINTF("Ignored transfer, %d bytes\n", len);
522 		}
523 
524 	case USB_ST_SETUP:
525 tr_setup:
526 		usbd_xfer_set_frame_len(xfer, 0, sc->isize);
527 		usbd_transfer_submit(xfer);
528 		break;
529 	default:
530 		if (error != USB_ERR_CANCELLED) {
531 			/* Try clear stall first */
532 			usbd_xfer_set_stall(xfer);
533 			goto tr_setup;
534 		}
535 		break;
536 	}
537 }
538 
539 static void
540 wmt_ev_close_11(struct evdev_dev *evdev, void *ev_softc)
541 {
542 	struct wmt_softc *sc = ev_softc;
543 
544 	mtx_assert(&sc->mtx, MA_OWNED);
545 	usbd_transfer_stop(sc->xfer[WMT_INTR_DT]);
546 }
547 
548 static int
549 wmt_ev_open_11(struct evdev_dev *evdev, void *ev_softc)
550 {
551 	struct wmt_softc *sc = ev_softc;
552 
553 	mtx_assert(&sc->mtx, MA_OWNED);
554 	usbd_transfer_start(sc->xfer[WMT_INTR_DT]);
555 
556 	return (0);
557 }
558 
559 #if __FreeBSD_version >= 1200077
560 static int
561 wmt_ev_close(struct evdev_dev *evdev)
562 {
563 	struct wmt_softc *sc = evdev_get_softc(evdev);
564 
565 	wmt_ev_close_11(evdev, sc);
566 
567 	return (0);
568 }
569 
570 static int
571 wmt_ev_open(struct evdev_dev *evdev)
572 {
573 	struct wmt_softc *sc = evdev_get_softc(evdev);
574 
575 	return (wmt_ev_open_11(evdev, sc));
576 
577 }
578 #endif
579 
580 /* port of userland hid_report_size() from usbhid(3) to kernel */
581 static int
582 wmt_hid_report_size(const void *buf, uint16_t len, enum hid_kind k, uint8_t id)
583 {
584 	struct hid_data *d;
585 	struct hid_item h;
586 	uint32_t temp;
587 	uint32_t hpos;
588 	uint32_t lpos;
589 	int report_id = 0;
590 
591 	hpos = 0;
592 	lpos = 0xFFFFFFFF;
593 
594 	for (d = hid_start_parse(buf, len, 1 << k); hid_get_item(d, &h);) {
595 		if (h.kind == k && h.report_ID == id) {
596 			/* compute minimum */
597 			if (lpos > h.loc.pos)
598 				lpos = h.loc.pos;
599 			/* compute end position */
600 			temp = h.loc.pos + (h.loc.size * h.loc.count);
601 			/* compute maximum */
602 			if (hpos < temp)
603 				hpos = temp;
604 			if (h.report_ID != 0)
605 				report_id = 1;
606 		}
607 	}
608 	hid_end_parse(d);
609 
610 	/* safety check - can happen in case of currupt descriptors */
611 	if (lpos > hpos)
612 		temp = 0;
613 	else
614 		temp = hpos - lpos;
615 
616 	/* return length in bytes rounded up */
617 	return ((temp + 7) / 8 + report_id);
618 }
619 
620 static bool
621 wmt_hid_parse(struct wmt_softc *sc, const void *d_ptr, uint16_t d_len)
622 {
623 	struct hid_item hi;
624 	struct hid_data *hd;
625 	size_t i;
626 	size_t cont = 0;
627 	uint32_t caps = 0;
628 	int32_t cont_count_max = 0;
629 	uint8_t report_id = 0;
630 	uint8_t cont_max_rid = 0;
631 	uint8_t thqa_cert_rid = 0;
632 	bool touch_coll = false;
633 	bool finger_coll = false;
634 	bool cont_count_found = false;
635 	bool scan_time_found = false;
636 
637 #define WMT_HI_ABSOLUTE(hi)	\
638 	(((hi).flags & (HIO_CONST|HIO_VARIABLE|HIO_RELATIVE)) == HIO_VARIABLE)
639 #define	HUMS_THQA_CERT	0xC5
640 
641 	/* Parse features for maximum contact count */
642 	hd = hid_start_parse(d_ptr, d_len, 1 << hid_feature);
643 	while (hid_get_item(hd, &hi)) {
644 		switch (hi.kind) {
645 		case hid_collection:
646 			if (hi.collevel == 1 && hi.usage ==
647 			    HID_USAGE2(HUP_DIGITIZERS, HUD_TOUCHSCREEN))
648 				touch_coll = true;
649 			break;
650 		case hid_endcollection:
651 			if (hi.collevel == 0 && touch_coll)
652 				touch_coll = false;
653 			break;
654 		case hid_feature:
655 			if (hi.collevel == 1 && touch_coll && hi.usage ==
656 			      HID_USAGE2(HUP_MICROSOFT, HUMS_THQA_CERT)) {
657 				thqa_cert_rid = hi.report_ID;
658 				break;
659 			}
660 			if (hi.collevel == 1 && touch_coll && hi.usage ==
661 			    HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACT_MAX)) {
662 				cont_count_max = hi.logical_maximum;
663 				cont_max_rid = hi.report_ID;
664 				if (sc != NULL)
665 					sc->cont_max_loc = hi.loc;
666 			}
667 			break;
668 		default:
669 			break;
670 		}
671 	}
672 	hid_end_parse(hd);
673 
674 	/* Maximum contact count is required usage */
675 	if (cont_max_rid == 0)
676 		return (false);
677 
678 	touch_coll = false;
679 
680 	/* Parse input for other parameters */
681 	hd = hid_start_parse(d_ptr, d_len, 1 << hid_input);
682 	while (hid_get_item(hd, &hi)) {
683 		switch (hi.kind) {
684 		case hid_collection:
685 			if (hi.collevel == 1 && hi.usage ==
686 			    HID_USAGE2(HUP_DIGITIZERS, HUD_TOUCHSCREEN))
687 				touch_coll = true;
688 			else if (touch_coll && hi.collevel == 2 &&
689 			    (report_id == 0 || report_id == hi.report_ID) &&
690 			    hi.usage == HID_USAGE2(HUP_DIGITIZERS, HUD_FINGER))
691 				finger_coll = true;
692 			break;
693 		case hid_endcollection:
694 			if (hi.collevel == 1 && finger_coll) {
695 				finger_coll = false;
696 				cont++;
697 			} else if (hi.collevel == 0 && touch_coll)
698 				touch_coll = false;
699 			break;
700 		case hid_input:
701 			/*
702 			 * Ensure that all usages are located within the same
703 			 * report and proper collection.
704 			 */
705 			if (WMT_HI_ABSOLUTE(hi) && touch_coll &&
706 			    (report_id == 0 || report_id == hi.report_ID))
707 				report_id = hi.report_ID;
708 			else
709 				break;
710 
711 			if (hi.collevel == 1 && hi.usage ==
712 			    HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTCOUNT)) {
713 				cont_count_found = true;
714 				if (sc != NULL)
715 					sc->nconts_loc = hi.loc;
716 				break;
717 			}
718 			/* Scan time is required but clobbered by evdev */
719 			if (hi.collevel == 1 && hi.usage ==
720 			    HID_USAGE2(HUP_DIGITIZERS, HUD_SCAN_TIME)) {
721 				scan_time_found = true;
722 				break;
723 			}
724 
725 			if (!finger_coll || hi.collevel != 2)
726 				break;
727 			if (sc == NULL && cont > 0)
728 				break;
729 			if (cont >= MAX_MT_SLOTS) {
730 				DPRINTF("Finger %zu ignored\n", cont);
731 				break;
732 			}
733 
734 			for (i = 0; i < WMT_N_USAGES; i++) {
735 				if (hi.usage == wmt_hid_map[i].usage) {
736 					if (sc == NULL) {
737 						if (USAGE_SUPPORTED(caps, i))
738 							continue;
739 						caps |= 1 << i;
740 						break;
741 					}
742 					/*
743 					 * HUG_X usage is an array mapped to
744 					 * both ABS_MT_POSITION and ABS_MT_TOOL
745 					 * events. So don`t stop search if we
746 					 * already have HUG_X mapping done.
747 					 */
748 					if (sc->locs[cont][i].size)
749 						continue;
750 					sc->locs[cont][i] = hi.loc;
751 					/*
752 					 * Hid parser returns valid logical and
753 					 * physical sizes for first finger only
754 					 * at least on ElanTS 0x04f3:0x0012.
755 					 */
756 					if (cont > 0)
757 						break;
758 					caps |= 1 << i;
759 					sc->ai[i] = (struct wmt_absinfo) {
760 					    .max = hi.logical_maximum,
761 					    .min = hi.logical_minimum,
762 					    .res = hid_item_resolution(&hi),
763 					};
764 					break;
765 				}
766 			}
767 			break;
768 		default:
769 			break;
770 		}
771 	}
772 	hid_end_parse(hd);
773 
774 	/* Check for required HID Usages */
775 	if (!cont_count_found || !scan_time_found || cont == 0)
776 		return (false);
777 	for (i = 0; i < WMT_N_USAGES; i++) {
778 		if (wmt_hid_map[i].required && !USAGE_SUPPORTED(caps, i))
779 			return (false);
780 	}
781 
782 	/* Stop probing here */
783 	if (sc == NULL)
784 		return (true);
785 
786 	/*
787 	 * According to specifications 'Contact Count Maximum' should be read
788 	 * from Feature Report rather than from HID descriptor. Set sane
789 	 * default value now to handle the case of 'Get Report' request failure
790 	 */
791 	if (cont_count_max < 1)
792 		cont_count_max = cont;
793 
794 	/* Cap contact count maximum to MAX_MT_SLOTS */
795 	if (cont_count_max > MAX_MT_SLOTS)
796 		cont_count_max = MAX_MT_SLOTS;
797 
798 	/* Set number of MT protocol type B slots */
799 	sc->ai[WMT_SLOT] = (struct wmt_absinfo) {
800 		.min = 0,
801 		.max = cont_count_max - 1,
802 		.res = 0,
803 	};
804 
805 	/* Report touch orientation if both width and height are supported */
806 	if (USAGE_SUPPORTED(caps, WMT_WIDTH) &&
807 	    USAGE_SUPPORTED(caps, WMT_HEIGHT)) {
808 		caps |= (1 << WMT_ORIENTATION);
809 		sc->ai[WMT_ORIENTATION].max = 1;
810 	}
811 
812 	sc->isize = hid_report_size(d_ptr, d_len, hid_input, NULL);
813 	sc->report_len = wmt_hid_report_size(d_ptr, d_len, hid_input,
814 	    report_id);
815 	sc->cont_max_rlen = wmt_hid_report_size(d_ptr, d_len, hid_feature,
816 	    cont_max_rid);
817 	if (thqa_cert_rid > 0)
818 		sc->thqa_cert_rlen = wmt_hid_report_size(d_ptr, d_len,
819 		    hid_feature, thqa_cert_rid);
820 
821 	sc->report_id = report_id;
822 	sc->caps = caps;
823 	sc->nconts_max = cont;
824 	sc->cont_max_rid = cont_max_rid;
825 	sc->thqa_cert_rid = thqa_cert_rid;
826 
827 	/* Announce information about the touch device */
828 	device_printf(sc->dev,
829 	    "%d contacts and [%s%s%s%s%s]. Report range [%d:%d] - [%d:%d]\n",
830 	    (int)cont_count_max,
831 	    USAGE_SUPPORTED(sc->caps, WMT_IN_RANGE) ? "R" : "",
832 	    USAGE_SUPPORTED(sc->caps, WMT_CONFIDENCE) ? "C" : "",
833 	    USAGE_SUPPORTED(sc->caps, WMT_WIDTH) ? "W" : "",
834 	    USAGE_SUPPORTED(sc->caps, WMT_HEIGHT) ? "H" : "",
835 	    USAGE_SUPPORTED(sc->caps, WMT_PRESSURE) ? "P" : "",
836 	    (int)sc->ai[WMT_X].min, (int)sc->ai[WMT_Y].min,
837 	    (int)sc->ai[WMT_X].max, (int)sc->ai[WMT_Y].max);
838 	return (true);
839 }
840 
841 static void
842 wmt_cont_max_parse(struct wmt_softc *sc, const void *r_ptr, uint16_t r_len)
843 {
844 	uint32_t cont_count_max;
845 
846 	cont_count_max = hid_get_data_unsigned((const uint8_t *)r_ptr + 1,
847 	    r_len - 1, &sc->cont_max_loc);
848 	if (cont_count_max > MAX_MT_SLOTS) {
849 		DPRINTF("Hardware reported %d contacts while only %d is "
850 		    "supported\n", (int)cont_count_max, MAX_MT_SLOTS);
851 		cont_count_max = MAX_MT_SLOTS;
852 	}
853 	/* Feature report is a primary source of 'Contact Count Maximum' */
854 	if (cont_count_max > 0 &&
855 	    cont_count_max != sc->ai[WMT_SLOT].max + 1) {
856 		sc->ai[WMT_SLOT].max = cont_count_max - 1;
857 		device_printf(sc->dev, "%d feature report contacts",
858 		    cont_count_max);
859 	}
860 }
861 
862 static const STRUCT_USB_HOST_ID wmt_devs[] = {
863 	/* generic HID class w/o boot interface */
864 	{USB_IFACE_CLASS(UICLASS_HID),
865 	 USB_IFACE_SUBCLASS(0),},
866 };
867 
868 static devclass_t wmt_devclass;
869 
870 static device_method_t wmt_methods[] = {
871 	DEVMETHOD(device_probe, wmt_probe),
872 	DEVMETHOD(device_attach, wmt_attach),
873 	DEVMETHOD(device_detach, wmt_detach),
874 
875 	DEVMETHOD_END
876 };
877 
878 static driver_t wmt_driver = {
879 	.name = "wmt",
880 	.methods = wmt_methods,
881 	.size = sizeof(struct wmt_softc),
882 };
883 
884 DRIVER_MODULE(wmt, uhub, wmt_driver, wmt_devclass, NULL, 0);
885 MODULE_DEPEND(wmt, usb, 1, 1, 1);
886 MODULE_DEPEND(wmt, evdev, 1, 1, 1);
887 MODULE_VERSION(wmt, 1);
888 USB_PNP_HOST_INFO(wmt_devs);
889