xref: /freebsd/sys/dev/hid/hmt.c (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2014-2020 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 /*
32  * MS Windows 7/8/10 compatible HID Multi-touch Device driver.
33  * https://msdn.microsoft.com/en-us/library/windows/hardware/jj151569(v=vs.85).aspx
34  * http://download.microsoft.com/download/7/d/d/7dd44bb7-2a7a-4505-ac1c-7227d3d96d5b/hid-over-i2c-protocol-spec-v1-0.docx
35  * https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
36  */
37 
38 #include "opt_hid.h"
39 
40 #include <sys/param.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/module.h>
46 #include <sys/mutex.h>
47 #include <sys/sysctl.h>
48 #include <sys/systm.h>
49 
50 #include <dev/evdev/evdev.h>
51 #include <dev/evdev/input.h>
52 
53 #define	HID_DEBUG_VAR	hmt_debug
54 #include <dev/hid/hid.h>
55 #include <dev/hid/hidbus.h>
56 #include <dev/hid/hidquirk.h>
57 
58 #include <dev/hid/hconf.h>
59 
60 static SYSCTL_NODE(_hw_hid, OID_AUTO, hmt, CTLFLAG_RW, 0,
61     "MSWindows 7/8/10 compatible HID Multi-touch Device");
62 #ifdef HID_DEBUG
63 static int hmt_debug = 0;
64 SYSCTL_INT(_hw_hid_hmt, OID_AUTO, debug, CTLFLAG_RWTUN,
65     &hmt_debug, 1, "Debug level");
66 #endif
67 static bool hmt_timestamps = 0;
68 SYSCTL_BOOL(_hw_hid_hmt, OID_AUTO, timestamps, CTLFLAG_RDTUN,
69     &hmt_timestamps, 1, "Enable hardware timestamp reporting");
70 
71 #define	HMT_BTN_MAX	8	/* Number of buttons supported */
72 
73 enum hmt_type {
74 	HMT_TYPE_UNKNOWN = 0,	/* HID report descriptor is not probed */
75 	HMT_TYPE_UNSUPPORTED,	/* Repdescr does not belong to MT device */
76 	HMT_TYPE_TOUCHPAD,
77 	HMT_TYPE_TOUCHSCREEN,
78 };
79 
80 enum {
81 	HMT_TIP_SWITCH =	ABS_MT_INDEX(ABS_MT_TOOL_TYPE),
82 	HMT_WIDTH =		ABS_MT_INDEX(ABS_MT_TOUCH_MAJOR),
83 	HMT_HEIGHT =		ABS_MT_INDEX(ABS_MT_TOUCH_MINOR),
84 	HMT_ORIENTATION = 	ABS_MT_INDEX(ABS_MT_ORIENTATION),
85 	HMT_X =			ABS_MT_INDEX(ABS_MT_POSITION_X),
86 	HMT_Y =			ABS_MT_INDEX(ABS_MT_POSITION_Y),
87 	HMT_CONTACTID = 	ABS_MT_INDEX(ABS_MT_TRACKING_ID),
88 	HMT_PRESSURE =		ABS_MT_INDEX(ABS_MT_PRESSURE),
89 	HMT_IN_RANGE = 		ABS_MT_INDEX(ABS_MT_DISTANCE),
90 	HMT_CONFIDENCE = 	ABS_MT_INDEX(ABS_MT_BLOB_ID),
91 	HMT_TOOL_X =		ABS_MT_INDEX(ABS_MT_TOOL_X),
92 	HMT_TOOL_Y = 		ABS_MT_INDEX(ABS_MT_TOOL_Y),
93 };
94 
95 #define	HMT_N_USAGES	MT_CNT
96 #define	HMT_NO_USAGE	-1
97 
98 struct hmt_hid_map_item {
99 	char		name[5];
100 	int32_t 	usage;		/* HID usage */
101 	bool		reported;	/* Item value is passed to evdev */
102 	bool		required;	/* Required for MT Digitizers */
103 };
104 
105 static const struct hmt_hid_map_item hmt_hid_map[HMT_N_USAGES] = {
106 	[HMT_TIP_SWITCH] = {
107 		.name = "TIP",
108 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_SWITCH),
109 		.reported = false,
110 		.required = true,
111 	},
112 	[HMT_WIDTH] = {
113 		.name = "WDTH",
114 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_WIDTH),
115 		.reported = true,
116 		.required = false,
117 	},
118 	[HMT_HEIGHT] = {
119 		.name = "HGHT",
120 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_HEIGHT),
121 		.reported = true,
122 		.required = false,
123 	},
124 	[HMT_ORIENTATION] = {
125 		.name = "ORIE",
126 		.usage = HMT_NO_USAGE,
127 		.reported = true,
128 		.required = false,
129 	},
130 	[HMT_X] = {
131 		.name = "X",
132 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X),
133 		.reported = true,
134 		.required = true,
135 	},
136 	[HMT_Y] = {
137 		.name = "Y",
138 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y),
139 		.reported = true,
140 		.required = true,
141 	},
142 	[HMT_CONTACTID] = {
143 		.name = "C_ID",
144 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTID),
145 		.reported = true,
146 		.required = true,
147 	},
148 	[HMT_PRESSURE] = {
149 		.name = "PRES",
150 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_PRESSURE),
151 		.reported = true,
152 		.required = false,
153 	},
154 	[HMT_IN_RANGE] = {
155 		.name = "RANG",
156 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_IN_RANGE),
157 		.reported = true,
158 		.required = false,
159 	},
160 	[HMT_CONFIDENCE] = {
161 		.name = "CONF",
162 		.usage = HID_USAGE2(HUP_DIGITIZERS, HUD_CONFIDENCE),
163 		.reported = false,
164 		.required = false,
165 	},
166 	[HMT_TOOL_X] = { /* Shares HID usage with POS_X */
167 		.name = "TL_X",
168 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X),
169 		.reported = true,
170 		.required = false,
171 	},
172 	[HMT_TOOL_Y] = { /* Shares HID usage with POS_Y */
173 		.name = "TL_Y",
174 		.usage = HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y),
175 		.reported = true,
176 		.required = false,
177 	},
178 };
179 
180 struct hmt_softc {
181 	device_t		dev;
182 	enum hmt_type		type;
183 
184 	int32_t			cont_count_max;
185 	struct hid_absinfo	ai[HMT_N_USAGES];
186 	struct hid_location	locs[MAX_MT_SLOTS][HMT_N_USAGES];
187 	struct hid_location	cont_count_loc;
188 	struct hid_location	btn_loc[HMT_BTN_MAX];
189 	struct hid_location	int_btn_loc;
190 	struct hid_location	scan_time_loc;
191 	int32_t			scan_time_max;
192 	int32_t			scan_time;
193 	int32_t			timestamp;
194 	bool			touch;
195 	bool			prev_touch;
196 
197 	struct evdev_dev	*evdev;
198 
199 	union evdev_mt_slot	slot_data;
200 	uint8_t			caps[howmany(HMT_N_USAGES, 8)];
201 	uint8_t			buttons[howmany(HMT_BTN_MAX, 8)];
202 	uint32_t		nconts_per_report;
203 	uint32_t		nconts_todo;
204 	uint8_t			report_id;
205 	uint32_t		max_button;
206 	bool			has_int_button;
207 	bool			has_cont_count;
208 	bool			has_scan_time;
209 	bool			is_clickpad;
210 	bool			do_timestamps;
211 #ifdef IICHID_SAMPLING
212 	bool			iichid_sampling;
213 #endif
214 
215 	struct hid_location	cont_max_loc;
216 	uint32_t		cont_max_rlen;
217 	uint8_t			cont_max_rid;
218 	struct hid_location	btn_type_loc;
219 	uint32_t		btn_type_rlen;
220 	uint8_t			btn_type_rid;
221 	uint32_t		thqa_cert_rlen;
222 	uint8_t			thqa_cert_rid;
223 };
224 
225 #define	HMT_FOREACH_USAGE(caps, usage)			\
226 	for ((usage) = 0; (usage) < HMT_N_USAGES; ++(usage))	\
227 		if (isset((caps), (usage)))
228 
229 static enum hmt_type hmt_hid_parse(struct hmt_softc *, const void *,
230     hid_size_t, uint32_t, uint8_t);
231 static int hmt_set_input_mode(struct hmt_softc *, enum hconf_input_mode);
232 
233 static hid_intr_t	hmt_intr;
234 
235 static device_probe_t	hmt_probe;
236 static device_attach_t	hmt_attach;
237 static device_detach_t	hmt_detach;
238 
239 static evdev_open_t	hmt_ev_open;
240 static evdev_close_t	hmt_ev_close;
241 
242 static const struct evdev_methods hmt_evdev_methods = {
243 	.ev_open = &hmt_ev_open,
244 	.ev_close = &hmt_ev_close,
245 };
246 
247 static const struct hid_device_id hmt_devs[] = {
248 	{ HID_TLC(HUP_DIGITIZERS, HUD_TOUCHSCREEN) },
249 	{ HID_TLC(HUP_DIGITIZERS, HUD_TOUCHPAD) },
250 };
251 
252 static int
253 hmt_ev_close(struct evdev_dev *evdev)
254 {
255 	return (hidbus_intr_stop(evdev_get_softc(evdev)));
256 }
257 
258 static int
259 hmt_ev_open(struct evdev_dev *evdev)
260 {
261 	return (hidbus_intr_start(evdev_get_softc(evdev)));
262 }
263 
264 static int
265 hmt_probe(device_t dev)
266 {
267 	struct hmt_softc *sc = device_get_softc(dev);
268 	void *d_ptr;
269 	hid_size_t d_len;
270 	int err;
271 
272 	err = HIDBUS_LOOKUP_DRIVER_INFO(dev, hmt_devs);
273 	if (err != 0)
274 		return (err);
275 
276 	err = hid_get_report_descr(dev, &d_ptr, &d_len);
277 	if (err != 0) {
278 		device_printf(dev, "could not retrieve report descriptor from "
279 		     "device: %d\n", err);
280 		return (ENXIO);
281 	}
282 
283 	/* Check if report descriptor belongs to a HID multitouch device */
284 	if (sc->type == HMT_TYPE_UNKNOWN)
285 		sc->type = hmt_hid_parse(sc, d_ptr, d_len,
286 		    hidbus_get_usage(dev), hidbus_get_index(dev));
287 	if (sc->type == HMT_TYPE_UNSUPPORTED)
288 		return (ENXIO);
289 
290 	hidbus_set_desc(dev,
291 	    sc->type == HMT_TYPE_TOUCHPAD ? "TouchPad" : "TouchScreen");
292 
293 	return (BUS_PROBE_DEFAULT);
294 }
295 
296 static int
297 hmt_attach(device_t dev)
298 {
299 	struct hmt_softc *sc = device_get_softc(dev);
300 	const struct hid_device_info *hw = hid_get_device_info(dev);
301 	void *d_ptr;
302 	uint8_t *fbuf = NULL;
303 	hid_size_t d_len, fsize, rsize;
304 	uint32_t cont_count_max;
305 	int nbuttons, btn;
306 	size_t i;
307 	int err;
308 
309 	err = hid_get_report_descr(dev, &d_ptr, &d_len);
310 	if (err != 0) {
311 		device_printf(dev, "could not retrieve report descriptor from "
312 		    "device: %d\n", err);
313 		return (ENXIO);
314 	}
315 
316 	sc->dev = dev;
317 
318 	fsize = hid_report_size_max(d_ptr, d_len, hid_feature, NULL);
319 	if (fsize != 0)
320 		fbuf = malloc(fsize, M_TEMP, M_WAITOK | M_ZERO);
321 
322 	/* Fetch and parse "Contact count maximum" feature report */
323 	if (sc->cont_max_rlen > 1) {
324 		err = hid_get_report(dev, fbuf, sc->cont_max_rlen, &rsize,
325 		    HID_FEATURE_REPORT, sc->cont_max_rid);
326 		if (err == 0 && (rsize - 1) * 8 >=
327 		    sc->cont_max_loc.pos + sc->cont_max_loc.size) {
328 			cont_count_max = hid_get_udata(fbuf + 1,
329 			    sc->cont_max_rlen - 1, &sc->cont_max_loc);
330 			/*
331 			 * Feature report is a primary source of
332 			 * 'Contact Count Maximum'
333 			 */
334 			if (cont_count_max > 0)
335 				sc->cont_count_max = cont_count_max;
336 		} else
337 			DPRINTF("hid_get_report error=%d\n", err);
338 	}
339 	if (sc->cont_count_max == 0)
340 		sc->cont_count_max = sc->type == HMT_TYPE_TOUCHSCREEN ? 10 : 5;
341 
342 	/* Fetch and parse "Button type" feature report */
343 	if (sc->btn_type_rlen > 1 && sc->btn_type_rid != sc->cont_max_rid) {
344 		bzero(fbuf, fsize);
345 		err = hid_get_report(dev, fbuf, sc->btn_type_rlen, &rsize,
346 		    HID_FEATURE_REPORT, sc->btn_type_rid);
347 		if (err != 0)
348 			DPRINTF("hid_get_report error=%d\n", err);
349 	}
350 	if (sc->btn_type_rlen > 1 && err == 0 && (rsize - 1) * 8 >=
351 	    sc->btn_type_loc.pos + sc->btn_type_loc.size)
352 		sc->is_clickpad = hid_get_udata(fbuf + 1, sc->btn_type_rlen - 1,
353 		    &sc->btn_type_loc) == 0;
354 	else
355 		sc->is_clickpad = sc->max_button == 0 && sc->has_int_button;
356 
357 	/* Fetch THQA certificate to enable some devices like WaveShare */
358 	if (sc->thqa_cert_rlen > 1 && sc->thqa_cert_rid != sc->cont_max_rid)
359 		(void)hid_get_report(dev, fbuf, sc->thqa_cert_rlen, NULL,
360 		    HID_FEATURE_REPORT, sc->thqa_cert_rid);
361 
362 	free(fbuf, M_TEMP);
363 
364 	/* Switch touchpad in to absolute multitouch mode */
365 	if (sc->type == HMT_TYPE_TOUCHPAD) {
366 		err = hmt_set_input_mode(sc, HCONF_INPUT_MODE_MT_TOUCHPAD);
367 		if (err != 0)
368 			DPRINTF("Failed to set input mode: %d\n", err);
369 	}
370 
371 	/* Cap contact count maximum to MAX_MT_SLOTS */
372 	if (sc->cont_count_max > MAX_MT_SLOTS) {
373 		DPRINTF("Hardware reported %d contacts while only %d is "
374 		    "supported\n", sc->cont_count_max, MAX_MT_SLOTS);
375 		sc->cont_count_max = MAX_MT_SLOTS;
376 	}
377 
378 	if (sc->has_scan_time &&
379 	    (hid_test_quirk(hw, HQ_MT_TIMESTAMP) || hmt_timestamps))
380 		sc->do_timestamps = true;
381 #ifdef IICHID_SAMPLING
382 	if (hid_test_quirk(hw, HQ_IICHID_SAMPLING))
383 		sc->iichid_sampling = true;
384 #endif
385 
386 	hidbus_set_intr(dev, hmt_intr, sc);
387 
388 	sc->evdev = evdev_alloc();
389 	evdev_set_name(sc->evdev, device_get_desc(dev));
390 	evdev_set_phys(sc->evdev, device_get_nameunit(dev));
391 	evdev_set_id(sc->evdev, hw->idBus, hw->idVendor, hw->idProduct,
392 	    hw->idVersion);
393 	evdev_set_serial(sc->evdev, hw->serial);
394 	evdev_set_methods(sc->evdev, dev, &hmt_evdev_methods);
395 	evdev_set_flag(sc->evdev, EVDEV_FLAG_MT_STCOMPAT);
396 	evdev_set_flag(sc->evdev, EVDEV_FLAG_EXT_EPOCH); /* hidbus child */
397 	switch (sc->type) {
398 	case HMT_TYPE_TOUCHSCREEN:
399 		evdev_support_prop(sc->evdev, INPUT_PROP_DIRECT);
400 		break;
401 	case HMT_TYPE_TOUCHPAD:
402 		evdev_support_prop(sc->evdev, INPUT_PROP_POINTER);
403 		if (sc->is_clickpad)
404 			evdev_support_prop(sc->evdev, INPUT_PROP_BUTTONPAD);
405 		break;
406 	default:
407 		KASSERT(0, ("hmt_attach: unsupported touch device type"));
408 	}
409 	evdev_support_event(sc->evdev, EV_SYN);
410 	evdev_support_event(sc->evdev, EV_ABS);
411 	if (sc->do_timestamps) {
412 		evdev_support_event(sc->evdev, EV_MSC);
413 		evdev_support_msc(sc->evdev, MSC_TIMESTAMP);
414 	}
415 #ifdef IICHID_SAMPLING
416 	if (sc->iichid_sampling)
417 		evdev_set_flag(sc->evdev, EVDEV_FLAG_MT_AUTOREL);
418 #endif
419 	nbuttons = 0;
420 	if (sc->max_button != 0 || sc->has_int_button) {
421 		evdev_support_event(sc->evdev, EV_KEY);
422 		if (sc->has_int_button)
423 			evdev_support_key(sc->evdev, BTN_LEFT);
424 		for (btn = 0; btn < sc->max_button; ++btn) {
425 			if (isset(sc->buttons, btn)) {
426 				evdev_support_key(sc->evdev, BTN_MOUSE + btn);
427 				nbuttons++;
428 			}
429 		}
430 	}
431 	evdev_support_abs(sc->evdev,
432 	    ABS_MT_SLOT, 0, sc->cont_count_max - 1, 0, 0, 0);
433 	HMT_FOREACH_USAGE(sc->caps, i) {
434 		if (hmt_hid_map[i].reported)
435 			evdev_support_abs(sc->evdev, ABS_MT_FIRST + i,
436 			    sc->ai[i].min, sc->ai[i].max, 0, 0, sc->ai[i].res);
437 	}
438 
439 	err = evdev_register(sc->evdev);
440 	if (err) {
441 		hmt_detach(dev);
442 		return (ENXIO);
443 	}
444 
445 	/* Announce information about the touch device */
446 	device_printf(sc->dev, "%s %s with %d external button%s%s\n",
447 	    sc->cont_count_max > 1 ? "Multitouch" : "Singletouch",
448 	    sc->type == HMT_TYPE_TOUCHSCREEN ? "touchscreen" : "touchpad",
449 	    nbuttons, nbuttons != 1 ? "s" : "",
450 	    sc->is_clickpad ? ", click-pad" : "");
451 	device_printf(sc->dev,
452 	    "%d contact%s with [%s%s%s%s%s] properties. Report range [%d:%d] - [%d:%d]\n",
453 	    (int)sc->cont_count_max, sc->cont_count_max != 1 ? "s" : "",
454 	    isset(sc->caps, HMT_IN_RANGE) ? "R" : "",
455 	    isset(sc->caps, HMT_CONFIDENCE) ? "C" : "",
456 	    isset(sc->caps, HMT_WIDTH) ? "W" : "",
457 	    isset(sc->caps, HMT_HEIGHT) ? "H" : "",
458 	    isset(sc->caps, HMT_PRESSURE) ? "P" : "",
459 	    (int)sc->ai[HMT_X].min, (int)sc->ai[HMT_Y].min,
460 	    (int)sc->ai[HMT_X].max, (int)sc->ai[HMT_Y].max);
461 
462 	return (0);
463 }
464 
465 static int
466 hmt_detach(device_t dev)
467 {
468 	struct hmt_softc *sc = device_get_softc(dev);
469 
470 	evdev_free(sc->evdev);
471 
472 	return (0);
473 }
474 
475 static void
476 hmt_intr(void *context, void *buf, hid_size_t len)
477 {
478 	struct hmt_softc *sc = context;
479 	size_t usage;
480 	union evdev_mt_slot *slot_data;
481 	uint32_t cont, btn;
482 	uint32_t cont_count;
483 	uint32_t width;
484 	uint32_t height;
485 	uint32_t int_btn = 0;
486 	uint32_t left_btn = 0;
487 	int slot;
488 	uint32_t scan_time;
489 	int32_t delta;
490 	uint8_t id;
491 
492 #ifdef IICHID_SAMPLING
493 	/*
494 	 * Special packet of zero length is generated by iichid driver running
495 	 * in polling mode at the start of inactivity period to workaround
496 	 * "stuck touch" problem caused by miss of finger release events.
497 	 * This snippet is to be removed after GPIO interrupt support is added.
498 	 */
499 	if (sc->iichid_sampling && len == 0) {
500 		sc->prev_touch = false;
501 		sc->timestamp = 0;
502 		/* EVDEV_FLAG_MT_AUTOREL releases all touches for us */
503 		evdev_sync(sc->evdev);
504 		return;
505 	}
506 #endif
507 
508 	/* Ignore irrelevant reports */
509 	id = sc->report_id != 0 ? *(uint8_t *)buf : 0;
510 	if (sc->report_id != id) {
511 		DPRINTF("Skip report with unexpected ID: %hhu\n", id);
512 		return;
513 	}
514 
515 	/* Strip leading "report ID" byte */
516 	if (sc->report_id != 0) {
517 		len--;
518 		buf = (uint8_t *)buf + 1;
519 	}
520 
521 	/*
522 	 * "In Serial mode, each packet contains information that describes a
523 	 * single physical contact point. Multiple contacts are streamed
524 	 * serially. In this mode, devices report all contact information in a
525 	 * series of packets. The device sends a separate packet for each
526 	 * concurrent contact."
527 	 *
528 	 * "In Parallel mode, devices report all contact information in a
529 	 * single packet. Each physical contact is represented by a logical
530 	 * collection that is embedded in the top-level collection."
531 	 *
532 	 * Since additional contacts that were not present will still be in the
533 	 * report with contactid=0 but contactids are zero-based, find
534 	 * contactcount first.
535 	 */
536 	if (sc->has_cont_count)
537 		cont_count = hid_get_udata(buf, len, &sc->cont_count_loc);
538 	else
539 		cont_count = 1;
540 	/*
541 	 * "In Hybrid mode, the number of contacts that can be reported in one
542 	 * report is less than the maximum number of contacts that the device
543 	 * supports. For example, a device that supports a maximum of
544 	 * 4 concurrent physical contacts, can set up its top-level collection
545 	 * to deliver a maximum of two contacts in one report. If four contact
546 	 * points are present, the device can break these up into two serial
547 	 * reports that deliver two contacts each.
548 	 *
549 	 * "When a device delivers data in this manner, the Contact Count usage
550 	 * value in the first report should reflect the total number of
551 	 * contacts that are being delivered in the hybrid reports. The other
552 	 * serial reports should have a contact count of zero (0)."
553 	 */
554 	if (cont_count != 0)
555 		sc->nconts_todo = cont_count;
556 
557 #ifdef HID_DEBUG
558 	DPRINTFN(6, "cont_count:%2u", (unsigned)cont_count);
559 	if (hmt_debug >= 6) {
560 		HMT_FOREACH_USAGE(sc->caps, usage) {
561 			if (hmt_hid_map[usage].usage != HMT_NO_USAGE)
562 				printf(" %-4s", hmt_hid_map[usage].name);
563 		}
564 		printf("\n");
565 	}
566 #endif
567 
568 	/* Find the number of contacts reported in current report */
569 	cont_count = MIN(sc->nconts_todo, sc->nconts_per_report);
570 
571 	/* Use protocol Type B for reporting events */
572 	for (cont = 0; cont < cont_count; cont++) {
573 		slot_data = &sc->slot_data;
574 		bzero(slot_data, sizeof(sc->slot_data));
575 		HMT_FOREACH_USAGE(sc->caps, usage) {
576 			if (sc->locs[cont][usage].size > 0)
577 				slot_data->val[usage] = hid_get_udata(
578 				    buf, len, &sc->locs[cont][usage]);
579 		}
580 
581 		slot = evdev_mt_id_to_slot(sc->evdev, slot_data->id);
582 
583 #ifdef HID_DEBUG
584 		DPRINTFN(6, "cont%01x: data = ", cont);
585 		if (hmt_debug >= 6) {
586 			HMT_FOREACH_USAGE(sc->caps, usage) {
587 				if (hmt_hid_map[usage].usage != HMT_NO_USAGE)
588 					printf("%04x ", slot_data->val[usage]);
589 			}
590 			printf("slot = %d\n", slot);
591 		}
592 #endif
593 
594 		if (slot == -1) {
595 			DPRINTF("Slot overflow for contact_id %u\n",
596 			    (unsigned)slot_data->id);
597 			continue;
598 		}
599 
600 		if (slot_data->val[HMT_TIP_SWITCH] != 0 &&
601 		    !(isset(sc->caps, HMT_CONFIDENCE) &&
602 		      slot_data->val[HMT_CONFIDENCE] == 0)) {
603 			/* This finger is in proximity of the sensor */
604 			sc->touch = true;
605 			slot_data->dist = !slot_data->val[HMT_IN_RANGE];
606 			/* Divided by two to match visual scale of touch */
607 			width = slot_data->val[HMT_WIDTH] >> 1;
608 			height = slot_data->val[HMT_HEIGHT] >> 1;
609 			slot_data->ori = width > height;
610 			slot_data->maj = MAX(width, height);
611 			slot_data->min = MIN(width, height);
612 		} else
613 			slot_data = NULL;
614 
615 		evdev_mt_push_slot(sc->evdev, slot, slot_data);
616 	}
617 
618 	sc->nconts_todo -= cont_count;
619 	if (sc->do_timestamps && sc->nconts_todo == 0) {
620 		/* HUD_SCAN_TIME is measured in 100us, convert to us. */
621 		scan_time = hid_get_udata(buf, len, &sc->scan_time_loc);
622 		if (sc->prev_touch) {
623 			delta = scan_time - sc->scan_time;
624 			if (delta < 0)
625 				delta += sc->scan_time_max;
626 		} else
627 			delta = 0;
628 		sc->scan_time = scan_time;
629 		sc->timestamp += delta * 100;
630 		evdev_push_msc(sc->evdev, MSC_TIMESTAMP, sc->timestamp);
631 		sc->prev_touch = sc->touch;
632 		sc->touch = false;
633 		if (!sc->prev_touch)
634 			sc->timestamp = 0;
635 	}
636 	if (sc->nconts_todo == 0) {
637 		/* Report both the click and external left btns as BTN_LEFT */
638 		if (sc->has_int_button)
639 			int_btn = hid_get_data(buf, len, &sc->int_btn_loc);
640 		if (isset(sc->buttons, 0))
641 			left_btn = hid_get_data(buf, len, &sc->btn_loc[0]);
642 		if (sc->has_int_button || isset(sc->buttons, 0))
643 			evdev_push_key(sc->evdev, BTN_LEFT,
644 			    (int_btn != 0) | (left_btn != 0));
645 		for (btn = 1; btn < sc->max_button; ++btn) {
646 			if (isset(sc->buttons, btn))
647 				evdev_push_key(sc->evdev, BTN_MOUSE + btn,
648 				    hid_get_data(buf,
649 						 len,
650 						 &sc->btn_loc[btn]) != 0);
651 		}
652 		evdev_sync(sc->evdev);
653 	}
654 }
655 
656 static enum hmt_type
657 hmt_hid_parse(struct hmt_softc *sc, const void *d_ptr, hid_size_t d_len,
658     uint32_t tlc_usage, uint8_t tlc_index)
659 {
660 	struct hid_absinfo ai;
661 	struct hid_item hi;
662 	struct hid_data *hd;
663 	uint32_t flags;
664 	size_t i;
665 	size_t cont = 0;
666 	enum hmt_type type;
667 	uint32_t left_btn, btn;
668 	int32_t cont_count_max = 0;
669 	uint8_t report_id = 0;
670 	bool finger_coll = false;
671 	bool cont_count_found = false;
672 	bool scan_time_found = false;
673 	bool has_int_button = false;
674 
675 #define HMT_HI_ABSOLUTE(hi)	((hi).nusages != 0 &&	\
676 	((hi).flags & (HIO_VARIABLE | HIO_RELATIVE)) == HIO_VARIABLE)
677 #define	HUMS_THQA_CERT	0xC5
678 
679 	/*
680 	 * Get left button usage taking in account MS Precision Touchpad specs.
681 	 * For Windows PTP report descriptor assigns buttons in following way:
682 	 * Button 1 - Indicates Button State for touchpad button integrated
683 	 *            with digitizer.
684 	 * Button 2 - Indicates Button State for external button for primary
685 	 *            (default left) clicking.
686 	 * Button 3 - Indicates Button State for external button for secondary
687 	 *            (default right) clicking.
688 	 * If a device only supports external buttons, it must still use
689 	 * Button 2 and Button 3 to reference the external buttons.
690 	 */
691 	switch (tlc_usage) {
692 	case HID_USAGE2(HUP_DIGITIZERS, HUD_TOUCHSCREEN):
693 		type = HMT_TYPE_TOUCHSCREEN;
694 		left_btn = 1;
695 		break;
696 	case HID_USAGE2(HUP_DIGITIZERS, HUD_TOUCHPAD):
697 		type = HMT_TYPE_TOUCHPAD;
698 		left_btn = 2;
699 		break;
700 	default:
701 		return (HMT_TYPE_UNSUPPORTED);
702 	}
703 
704 	/* Parse features for mandatory maximum contact count usage */
705 	if (!hidbus_locate(d_ptr, d_len,
706 	    HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACT_MAX), hid_feature,
707 	    tlc_index, 0, &sc->cont_max_loc, &flags, &sc->cont_max_rid, &ai) ||
708 	    (flags & (HIO_VARIABLE | HIO_RELATIVE)) != HIO_VARIABLE)
709 		return (HMT_TYPE_UNSUPPORTED);
710 
711 	cont_count_max = ai.max;
712 
713 	/* Parse features for button type usage */
714 	if (hidbus_locate(d_ptr, d_len,
715 	    HID_USAGE2(HUP_DIGITIZERS, HUD_BUTTON_TYPE), hid_feature,
716 	    tlc_index, 0, &sc->btn_type_loc, &flags, &sc->btn_type_rid, NULL)
717 	    && (flags & (HIO_VARIABLE | HIO_RELATIVE)) != HIO_VARIABLE)
718 		sc->btn_type_rid = 0;
719 
720 	/* Parse features for THQA certificate report ID */
721 	hidbus_locate(d_ptr, d_len, HID_USAGE2(HUP_MICROSOFT, HUMS_THQA_CERT),
722 	    hid_feature, tlc_index, 0, NULL, NULL, &sc->thqa_cert_rid, NULL);
723 
724 	/* Parse input for other parameters */
725 	hd = hid_start_parse(d_ptr, d_len, 1 << hid_input);
726 	HIDBUS_FOREACH_ITEM(hd, &hi, tlc_index) {
727 		switch (hi.kind) {
728 		case hid_collection:
729 			if (hi.collevel == 2 &&
730 			    hi.usage == HID_USAGE2(HUP_DIGITIZERS, HUD_FINGER))
731 				finger_coll = true;
732 			break;
733 		case hid_endcollection:
734 			if (hi.collevel == 1 && finger_coll) {
735 				finger_coll = false;
736 				cont++;
737 			}
738 			break;
739 		case hid_input:
740 			/*
741 			 * Ensure that all usages belong to the same report
742 			 */
743 			if (HMT_HI_ABSOLUTE(hi) &&
744 			    (report_id == 0 || report_id == hi.report_ID))
745 				report_id = hi.report_ID;
746 			else
747 				break;
748 
749 			if (hi.collevel == 1 && left_btn == 2 &&
750 			    hi.usage == HID_USAGE2(HUP_BUTTON, 1)) {
751 				has_int_button = true;
752 				sc->int_btn_loc = hi.loc;
753 				break;
754 			}
755 			if (hi.collevel == 1 &&
756 			    hi.usage >= HID_USAGE2(HUP_BUTTON, left_btn) &&
757 			    hi.usage <= HID_USAGE2(HUP_BUTTON, HMT_BTN_MAX)) {
758 				btn = (hi.usage & 0xFFFF) - left_btn;
759 				setbit(sc->buttons, btn);
760 				sc->btn_loc[btn] = hi.loc;
761 				if (btn >= sc->max_button)
762 					sc->max_button = btn + 1;
763 				break;
764 			}
765 			if (hi.collevel == 1 && hi.usage ==
766 			    HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTCOUNT)) {
767 				cont_count_found = true;
768 				sc->cont_count_loc = hi.loc;
769 				break;
770 			}
771 			if (hi.collevel == 1 && hi.usage ==
772 			    HID_USAGE2(HUP_DIGITIZERS, HUD_SCAN_TIME)) {
773 				scan_time_found = true;
774 				sc->scan_time_loc = hi.loc;
775 				sc->scan_time_max = hi.logical_maximum;
776 				break;
777 			}
778 
779 			if (!finger_coll || hi.collevel != 2)
780 				break;
781 			if (cont >= MAX_MT_SLOTS) {
782 				DPRINTF("Finger %zu ignored\n", cont);
783 				break;
784 			}
785 
786 			for (i = 0; i < HMT_N_USAGES; i++) {
787 				if (hi.usage == hmt_hid_map[i].usage) {
788 					/*
789 					 * HUG_X usage is an array mapped to
790 					 * both ABS_MT_POSITION and ABS_MT_TOOL
791 					 * events. So don`t stop search if we
792 					 * already have HUG_X mapping done.
793 					 */
794 					if (sc->locs[cont][i].size)
795 						continue;
796 					sc->locs[cont][i] = hi.loc;
797 					/*
798 					 * Hid parser returns valid logical and
799 					 * physical sizes for first finger only
800 					 * at least on ElanTS 0x04f3:0x0012.
801 					 */
802 					if (cont > 0)
803 						break;
804 					setbit(sc->caps, i);
805 					sc->ai[i] = (struct hid_absinfo) {
806 					    .max = hi.logical_maximum,
807 					    .min = hi.logical_minimum,
808 					    .res = hid_item_resolution(&hi),
809 					};
810 					break;
811 				}
812 			}
813 			break;
814 		default:
815 			break;
816 		}
817 	}
818 	hid_end_parse(hd);
819 
820 	/* Check for required HID Usages */
821 	if ((!cont_count_found && cont != 1) || cont == 0)
822 		return (HMT_TYPE_UNSUPPORTED);
823 	for (i = 0; i < HMT_N_USAGES; i++) {
824 		if (hmt_hid_map[i].required && isclr(sc->caps, i))
825 			return (HMT_TYPE_UNSUPPORTED);
826 	}
827 
828 	/* Touchpads must have at least one button */
829 	if (type == HMT_TYPE_TOUCHPAD && !sc->max_button && !has_int_button)
830 		return (HMT_TYPE_UNSUPPORTED);
831 
832 	/*
833 	 * According to specifications 'Contact Count Maximum' should be read
834 	 * from Feature Report rather than from HID descriptor. Set sane
835 	 * default value now to handle the case of 'Get Report' request failure
836 	 */
837 	if (cont_count_max < 1)
838 		cont_count_max = cont;
839 
840 	/* Report touch orientation if both width and height are supported */
841 	if (isset(sc->caps, HMT_WIDTH) && isset(sc->caps, HMT_HEIGHT)) {
842 		setbit(sc->caps, HMT_ORIENTATION);
843 		sc->ai[HMT_ORIENTATION].max = 1;
844 	}
845 
846 	sc->cont_max_rlen = hid_report_size(d_ptr, d_len, hid_feature,
847 	    sc->cont_max_rid);
848 	if (sc->btn_type_rid > 0)
849 		sc->btn_type_rlen = hid_report_size(d_ptr, d_len,
850 		    hid_feature, sc->btn_type_rid);
851 	if (sc->thqa_cert_rid > 0)
852 		sc->thqa_cert_rlen = hid_report_size(d_ptr, d_len,
853 		    hid_feature, sc->thqa_cert_rid);
854 
855 	sc->report_id = report_id;
856 	sc->cont_count_max = cont_count_max;
857 	sc->nconts_per_report = cont;
858 	sc->has_int_button = has_int_button;
859 	sc->has_cont_count = cont_count_found;
860 	sc->has_scan_time = scan_time_found;
861 
862 	return (type);
863 }
864 
865 static int
866 hmt_set_input_mode(struct hmt_softc *sc, enum hconf_input_mode mode)
867 {
868 	devclass_t hconf_devclass;
869 	device_t hconf;
870 	int  err;
871 
872 	bus_topo_assert();
873 
874 	/* Find touchpad's configuration TLC */
875 	hconf = hidbus_find_child(device_get_parent(sc->dev),
876 	    HID_USAGE2(HUP_DIGITIZERS, HUD_CONFIG));
877 	if (hconf == NULL)
878 		return (ENXIO);
879 
880 	/* Ensure that hconf driver is attached to configuration TLC */
881 	if (device_is_alive(hconf) == 0)
882 		device_probe_and_attach(hconf);
883 	if (device_is_attached(hconf) == 0)
884 		return (ENXIO);
885 	hconf_devclass = devclass_find("hconf");
886 	if (device_get_devclass(hconf) != hconf_devclass)
887 		return (ENXIO);
888 
889 	/* hconf_set_input_mode can drop the the topo lock while sleeping */
890 	device_busy(hconf);
891 	err = hconf_set_input_mode(hconf, mode);
892 	device_unbusy(hconf);
893 
894 	return (err);
895 }
896 
897 static devclass_t hmt_devclass;
898 
899 static device_method_t hmt_methods[] = {
900 	DEVMETHOD(device_probe,		hmt_probe),
901 	DEVMETHOD(device_attach,	hmt_attach),
902 	DEVMETHOD(device_detach,	hmt_detach),
903 
904 	DEVMETHOD_END
905 };
906 
907 static driver_t hmt_driver = {
908 	.name = "hmt",
909 	.methods = hmt_methods,
910 	.size = sizeof(struct hmt_softc),
911 };
912 
913 DRIVER_MODULE(hmt, hidbus, hmt_driver, hmt_devclass, NULL, 0);
914 MODULE_DEPEND(hmt, hidbus, 1, 1, 1);
915 MODULE_DEPEND(hmt, hid, 1, 1, 1);
916 MODULE_DEPEND(hmt, hconf, 1, 1, 1);
917 MODULE_DEPEND(hmt, evdev, 1, 1, 1);
918 MODULE_VERSION(hmt, 1);
919 HID_PNP_INFO(hmt_devs);
920