xref: /openbsd-src/sys/dev/hid/hidmt.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /* $OpenBSD: hidmt.c,v 1.11 2020/02/10 14:35:08 patrick Exp $ */
2 /*
3  * HID multitouch driver for devices conforming to Windows Precision Touchpad
4  * standard
5  *
6  * https://msdn.microsoft.com/en-us/library/windows/hardware/dn467314%28v=vs.85%29.aspx
7  * https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchscreen-packet-reporting-modes
8  *
9  * Copyright (c) 2016 joshua stein <jcs@openbsd.org>
10  *
11  * Permission to use, copy, modify, and distribute this software for any
12  * purpose with or without fee is hereby granted, provided that the above
13  * copyright notice and this permission notice appear in all copies.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
18  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
21  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22  */
23 
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/kernel.h>
27 #include <sys/device.h>
28 #include <sys/ioctl.h>
29 #include <sys/malloc.h>
30 
31 #include <dev/wscons/wsconsio.h>
32 #include <dev/wscons/wsmousevar.h>
33 
34 #include <dev/hid/hid.h>
35 #include <dev/hid/hidmtvar.h>
36 
37 /* #define HIDMT_DEBUG */
38 
39 #ifdef HIDMT_DEBUG
40 #define DPRINTF(x) printf x
41 #else
42 #define DPRINTF(x)
43 #endif
44 
45 #define HID_UNIT_CM	0x11
46 #define HID_UNIT_INCH	0x13
47 
48 /*
49  * Calculate the horizontal or vertical resolution, in device units per
50  * millimeter.
51  *
52  * With the length unit specified by the descriptor (centimeter or inch),
53  * the result is:
54  *     (logical_maximum - logical_minimum) / ((physical_maximum -
55  *         physical_minimum) * 10^unit_exponent)
56  *
57  * The descriptors should encode the unit exponent as a signed half-byte.
58  * However, this function accepts the values from -8 to -1 in both the
59  * 4-bit format and the usual encoding.  Other values beyond the 4-bit
60  * range are treated as undefined.  Possibly a misinterpretation of
61  * section 6.2.2.7 of the HID specification (v1.11) has been turned into
62  * a standard here, see (from www.usb.org)
63  *     HUTRR39: "HID Sensor Usage Tables", sect. 3.9, 3.10, 4.2.1
64  * for an official exegesis and
65  *     https://patchwork.kernel.org/patch/3033191
66  * for details and a different view.
67  */
68 int
69 hidmt_get_resolution(struct hid_item *h)
70 {
71 	int log_extent, phy_extent, exponent;
72 
73 	if (h->unit != HID_UNIT_CM && h->unit != HID_UNIT_INCH)
74 		return (0);
75 
76 	log_extent = h->logical_maximum - h->logical_minimum;
77 	phy_extent = h->physical_maximum - h->physical_minimum;
78 	if (log_extent <= 0 || phy_extent <= 0)
79 		return (0);
80 
81 	exponent = h->unit_exponent;
82 	if (exponent < -8 || exponent > 15)		/* See above. */
83 		return (0);
84 	if (exponent > 7)
85 		exponent -= 16;
86 
87 	for (; exponent < 0 && log_extent <= INT_MAX / 10; exponent++)
88 		log_extent *= 10;
89 	for (; exponent > 0 && phy_extent <= INT_MAX / 10; exponent--)
90 		phy_extent *= 10;
91 	if (exponent != 0)
92 		return (0);
93 
94 	if (h->unit == HID_UNIT_INCH) {			/* Map inches to mm. */
95 		if ((phy_extent > INT_MAX / 127)
96 		    || (log_extent > INT_MAX / 5))
97 			return (0);
98 		log_extent *= 5;
99 		phy_extent *= 127;
100 	} else {					/* Map cm to mm. */
101 		if (phy_extent > INT_MAX / 10)
102 			return (0);
103 		phy_extent *= 10;
104 	}
105 
106 	return (log_extent / phy_extent);
107 }
108 
109 int
110 hidmt_setup(struct device *self, struct hidmt *mt, void *desc, int dlen)
111 {
112 	struct hid_location cap;
113 	int32_t d;
114 	uint8_t *rep;
115 	int capsize;
116 
117 	struct hid_data *hd;
118 	struct hid_item h;
119 
120 	mt->sc_device = self;
121 	mt->sc_rep_input_size = hid_report_size(desc, dlen, hid_input,
122 	    mt->sc_rep_input);
123 
124 	mt->sc_minx = mt->sc_miny = mt->sc_maxx = mt->sc_maxy = 0;
125 
126 	capsize = hid_report_size(desc, dlen, hid_feature, mt->sc_rep_cap);
127 	rep = malloc(capsize, M_DEVBUF, M_NOWAIT | M_ZERO);
128 
129 	if (mt->hidev_report_type_conv == NULL)
130 		panic("no report type conversion function");
131 
132 	if (mt->hidev_get_report(mt->sc_device,
133 	    mt->hidev_report_type_conv(hid_feature), mt->sc_rep_cap,
134 	    rep, capsize)) {
135 		printf("\n%s: failed getting capability report\n",
136 		    self->dv_xname);
137 		return 1;
138 	}
139 
140 	/* find maximum number of contacts being reported per input report */
141 	if (!hid_locate(desc, dlen, HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACT_MAX),
142 	    mt->sc_rep_cap, hid_feature, &cap, NULL)) {
143 		printf("\n%s: can't find maximum contacts\n", self->dv_xname);
144 		return 1;
145 	}
146 
147 	d = hid_get_udata(rep, capsize, &cap);
148 	if (d > HIDMT_MAX_CONTACTS) {
149 		printf("\n%s: contacts %d > max %d\n", self->dv_xname, d,
150 		    HIDMT_MAX_CONTACTS);
151 		return 1;
152 	}
153 	else
154 		mt->sc_num_contacts = d;
155 
156 	/* find whether this is a clickpad or not */
157 	if (!hid_locate(desc, dlen, HID_USAGE2(HUP_DIGITIZERS, HUD_BUTTON_TYPE),
158 	    mt->sc_rep_cap, hid_feature, &cap, NULL)) {
159 		printf("\n%s: can't find button type\n", self->dv_xname);
160 		return 1;
161 	}
162 
163 	d = hid_get_udata(rep, capsize, &cap);
164 	mt->sc_clickpad = (d == 0);
165 
166 	/*
167 	 * Walk HID descriptor and store usages we care about to know what to
168 	 * pluck out of input reports.
169 	 */
170 
171 	SIMPLEQ_INIT(&mt->sc_inputs);
172 
173 	hd = hid_start_parse(desc, dlen, hid_input);
174 	while (hid_get_item(hd, &h)) {
175 		struct hidmt_data *input;
176 
177 		if (h.report_ID != mt->sc_rep_input)
178 			continue;
179 		if (h.kind != hid_input)
180 			continue;
181 
182 		switch (h.usage) {
183 		/* contact level usages */
184 		case HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X):
185 			if (h.logical_maximum - h.logical_minimum) {
186 				mt->sc_minx = h.logical_minimum;
187 				mt->sc_maxx = h.logical_maximum;
188 				mt->sc_resx = hidmt_get_resolution(&h);
189 			}
190 			break;
191 		case HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y):
192 			if (h.logical_maximum - h.logical_minimum) {
193 				mt->sc_miny = h.logical_minimum;
194 				mt->sc_maxy = h.logical_maximum;
195 				mt->sc_resy = hidmt_get_resolution(&h);
196 			}
197 			break;
198 		case HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_SWITCH):
199 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONFIDENCE):
200 		case HID_USAGE2(HUP_DIGITIZERS, HUD_WIDTH):
201 		case HID_USAGE2(HUP_DIGITIZERS, HUD_HEIGHT):
202 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTID):
203 
204 		/* report level usages */
205 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTCOUNT):
206 		case HID_USAGE2(HUP_BUTTON, 0x01):
207 		case HID_USAGE2(HUP_BUTTON, 0x02):
208 		case HID_USAGE2(HUP_BUTTON, 0x03):
209 			break;
210 		default:
211 			continue;
212 		}
213 
214 		input = malloc(sizeof(*input), M_DEVBUF, M_NOWAIT | M_ZERO);
215 		memcpy(&input->loc, &h.loc, sizeof(struct hid_location));
216 		input->usage = h.usage;
217 
218 		SIMPLEQ_INSERT_TAIL(&mt->sc_inputs, input, entry);
219 	}
220 	hid_end_parse(hd);
221 
222 	if (mt->sc_maxx <= 0 || mt->sc_maxy <= 0) {
223 		printf("\n%s: invalid max X/Y %d/%d\n", self->dv_xname,
224 		    mt->sc_maxx, mt->sc_maxy);
225 		return 1;
226 	}
227 
228 	if (hidmt_set_input_mode(mt, HIDMT_INPUT_MODE_MT_TOUCHPAD)) {
229 		printf("\n%s: switch to multitouch mode failed\n",
230 		    self->dv_xname);
231 		return 1;
232 	}
233 
234 	return 0;
235 }
236 
237 void
238 hidmt_configure(struct hidmt *mt)
239 {
240 	struct wsmousehw *hw;
241 
242 	if (mt->sc_wsmousedev == NULL)
243 		return;
244 
245 	hw = wsmouse_get_hw(mt->sc_wsmousedev);
246 	hw->type = WSMOUSE_TYPE_TOUCHPAD;
247 	hw->hw_type = (mt->sc_clickpad
248 	    ? WSMOUSEHW_CLICKPAD : WSMOUSEHW_TOUCHPAD);
249 	hw->x_min = mt->sc_minx;
250 	hw->x_max = mt->sc_maxx;
251 	hw->y_min = mt->sc_miny;
252 	hw->y_max = mt->sc_maxy;
253 	hw->h_res = mt->sc_resx;
254 	hw->v_res = mt->sc_resy;
255 	hw->mt_slots = HIDMT_MAX_CONTACTS;
256 
257 	wsmouse_configure(mt->sc_wsmousedev, NULL, 0);
258 }
259 
260 void
261 hidmt_attach(struct hidmt *mt, const struct wsmouse_accessops *ops)
262 {
263 	struct wsmousedev_attach_args a;
264 
265 	printf(": %spad, %d contact%s\n",
266 	    (mt->sc_clickpad ? "click" : "touch"), mt->sc_num_contacts,
267 	    (mt->sc_num_contacts == 1 ? "" : "s"));
268 
269 	a.accessops = ops;
270 	a.accesscookie = mt->sc_device;
271 	mt->sc_wsmousedev = config_found(mt->sc_device, &a, wsmousedevprint);
272 	hidmt_configure(mt);
273 }
274 
275 int
276 hidmt_detach(struct hidmt *mt, int flags)
277 {
278 	int rv = 0;
279 
280 	if (mt->sc_wsmousedev != NULL)
281 		rv = config_detach(mt->sc_wsmousedev, flags);
282 
283 	return (rv);
284 }
285 
286 int
287 hidmt_set_input_mode(struct hidmt *mt, uint16_t mode)
288 {
289 	if (mt->hidev_report_type_conv == NULL)
290 		panic("no report type conversion function");
291 
292 	return mt->hidev_set_report(mt->sc_device,
293 	    mt->hidev_report_type_conv(hid_feature),
294 	    mt->sc_rep_config, &mode, sizeof(mode));
295 }
296 
297 void
298 hidmt_input(struct hidmt *mt, uint8_t *data, u_int len)
299 {
300 	struct hidmt_data *hi;
301 	struct hidmt_contact hc;
302 	int32_t d, firstu = 0;
303 	int contactcount = 0, seencontacts = 0, tips = 0, buttons = 0, i, s, z;
304 
305 	if (len != mt->sc_rep_input_size) {
306 		DPRINTF(("%s: %s: length %d not %d, ignoring\n",
307 		    mt->sc_device->dv_xname, __func__, len,
308 		    mt->sc_rep_input_size));
309 		return;
310 	}
311 
312 	/*
313 	 * "In Parallel mode, devices report all contact information in a
314 	 * single packet. Each physical contact is represented by a logical
315 	 * collection that is embedded in the top-level collection."
316 	 *
317 	 * Since additional contacts that were not present will still be in the
318 	 * report with contactid=0 but contactids are zero-based, find
319 	 * contactcount first.
320 	 */
321 	SIMPLEQ_FOREACH(hi, &mt->sc_inputs, entry) {
322 		if (hi->usage == HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTCOUNT))
323 			contactcount = hid_get_udata(data, len, &hi->loc);
324 	}
325 
326 	if (contactcount)
327 		mt->sc_cur_contactcount = contactcount;
328 	else {
329 		/*
330 		* "In Hybrid mode, the number of contacts that can be reported
331 		* in one report is less than the maximum number of contacts
332 		* that the device supports. For example, a device that supports
333 		* a maximum of 4 concurrent physical contacts, can set up its
334 		* top-level collection to deliver a maximum of two contacts in
335 		* one report. If four contact points are present, the device
336 		* can break these up into two serial reports that deliver two
337 		* contacts each.
338 		*
339 		* "When a device delivers data in this manner, the Contact
340 		* Count usage value in the first report should reflect the
341 		* total number of contacts that are being delivered in the
342 		* hybrid reports. The other serial reports should have a
343 		* contact count of zero (0)."
344 		*/
345 		contactcount = mt->sc_cur_contactcount;
346 	}
347 
348 	if (!contactcount) {
349 		DPRINTF(("%s: %s: no contactcount in report\n",
350 		    mt->sc_device->dv_xname, __func__));
351 		return;
352 	}
353 
354 	/*
355 	 * Walk through each input we know about and fetch its data from the
356 	 * report, storing it in a temporary contact.  Once we see our first
357 	 * usage again, we'll know we saw all usages being presented for that
358 	 * contact.
359 	 */
360 	bzero(&hc, sizeof(struct hidmt_contact));
361 	SIMPLEQ_FOREACH(hi, &mt->sc_inputs, entry) {
362 		d = hid_get_udata(data, len, &hi->loc);
363 
364 		if (firstu && hi->usage == firstu) {
365 			if (seencontacts < contactcount) {
366 				hc.seen = 1;
367 				i = wsmouse_id_to_slot(
368 				    mt->sc_wsmousedev, hc.contactid);
369 				if (i >= 0)
370 					memcpy(&mt->sc_contacts[i], &hc,
371 					    sizeof(struct hidmt_contact));
372 				seencontacts++;
373 			}
374 
375 			bzero(&hc, sizeof(struct hidmt_contact));
376 		}
377 		else if (!firstu)
378 			firstu = hi->usage;
379 
380 		switch (hi->usage) {
381 		case HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X):
382 			hc.x = d;
383 			break;
384 		case HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y):
385 			if (mt->sc_flags & HIDMT_REVY)
386 				hc.y = mt->sc_maxy - d;
387 			else
388 				hc.y = d;
389 			break;
390 		case HID_USAGE2(HUP_DIGITIZERS, HUD_TIP_SWITCH):
391 			hc.tip = d;
392 			if (d)
393 				tips++;
394 			break;
395 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONFIDENCE):
396 			hc.confidence = d;
397 			break;
398 		case HID_USAGE2(HUP_DIGITIZERS, HUD_WIDTH):
399 			hc.width = d;
400 			break;
401 		case HID_USAGE2(HUP_DIGITIZERS, HUD_HEIGHT):
402 			hc.height = d;
403 			break;
404 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTID):
405 			hc.contactid = d;
406 			break;
407 
408 		/* these will only appear once per report */
409 		case HID_USAGE2(HUP_DIGITIZERS, HUD_CONTACTCOUNT):
410 			if (d)
411 				contactcount = d;
412 			break;
413 		case HID_USAGE2(HUP_BUTTON, 0x01):
414 		case HID_USAGE2(HUP_BUTTON, 0x02):
415 			if (d != 0)
416 				buttons |= 1;
417 			break;
418 		case HID_USAGE2(HUP_BUTTON, 0x03):
419 			if (d != 0)
420 				buttons |= 1 << 2;
421 			break;
422 		}
423 	}
424 	if (seencontacts < contactcount) {
425 		hc.seen = 1;
426 		i = wsmouse_id_to_slot(mt->sc_wsmousedev, hc.contactid);
427 		if (i >= 0)
428 			memcpy(&mt->sc_contacts[i], &hc,
429 			    sizeof(struct hidmt_contact));
430 		seencontacts++;
431 	}
432 
433 	s = spltty();
434 	if (mt->sc_buttons != buttons) {
435 		wsmouse_buttons(mt->sc_wsmousedev, buttons);
436 		mt->sc_buttons = buttons;
437 	}
438 	for (i = 0; i < HIDMT_MAX_CONTACTS; i++) {
439 		if (!mt->sc_contacts[i].seen)
440 			continue;
441 
442 		mt->sc_contacts[i].seen = 0;
443 
444 		DPRINTF(("%s: %s: contact %d of %d: id %d, x %d, y %d, "
445 		    "touch %d, confidence %d, width %d, height %d "
446 		    "(button 0x%x)\n",
447 		    mt->sc_device->dv_xname, __func__,
448 		    i + 1, contactcount,
449 		    mt->sc_contacts[i].contactid,
450 		    mt->sc_contacts[i].x,
451 		    mt->sc_contacts[i].y,
452 		    mt->sc_contacts[i].tip,
453 		    mt->sc_contacts[i].confidence,
454 		    mt->sc_contacts[i].width,
455 		    mt->sc_contacts[i].height,
456 		    mt->sc_buttons));
457 
458 		if (mt->sc_contacts[i].tip && !mt->sc_contacts[i].confidence)
459 			continue;
460 
461 		/* Report width as pressure. */
462 		z = (mt->sc_contacts[i].tip
463 		    ? imax(mt->sc_contacts[i].width, 50) : 0);
464 
465 		wsmouse_mtstate(mt->sc_wsmousedev,
466 		    i, mt->sc_contacts[i].x, mt->sc_contacts[i].y, z);
467 	}
468 	wsmouse_input_sync(mt->sc_wsmousedev);
469 
470 	splx(s);
471 }
472 
473 int
474 hidmt_enable(struct hidmt *mt)
475 {
476 	if (mt->sc_enabled)
477 		return EBUSY;
478 
479 	mt->sc_enabled = 1;
480 
481 	return 0;
482 }
483 
484 int
485 hidmt_ioctl(struct hidmt *mt, u_long cmd, caddr_t data, int flag,
486     struct proc *p)
487 {
488 	struct wsmouse_calibcoords *wsmc = (struct wsmouse_calibcoords *)data;
489 	int wsmode;
490 
491 	switch (cmd) {
492 	case WSMOUSEIO_GTYPE: {
493 		struct wsmousehw *hw = wsmouse_get_hw(mt->sc_wsmousedev);
494 		*(u_int *)data = hw->type;
495 		break;
496 	}
497 
498 	case WSMOUSEIO_GCALIBCOORDS:
499 		wsmc->minx = mt->sc_minx;
500 		wsmc->maxx = mt->sc_maxx;
501 		wsmc->miny = mt->sc_miny;
502 		wsmc->maxy = mt->sc_maxy;
503 		wsmc->swapxy = 0;
504 		wsmc->resx = mt->sc_resx;
505 		wsmc->resy = mt->sc_resy;
506 		break;
507 
508 	case WSMOUSEIO_SETMODE:
509 		wsmode = *(u_int *)data;
510 		if (wsmode != WSMOUSE_COMPAT && wsmode != WSMOUSE_NATIVE) {
511 			printf("%s: invalid mode %d\n",
512 			    mt->sc_device->dv_xname, wsmode);
513 			return (EINVAL);
514 		}
515 
516 		DPRINTF(("%s: changing mode to %s\n", mt->sc_device->dv_xname,
517 		    (wsmode == WSMOUSE_COMPAT ? "compat" : "native")));
518 
519 		wsmouse_set_mode(mt->sc_wsmousedev, wsmode);
520 
521 		break;
522 
523 	default:
524 		return -1;
525 	}
526 
527 	return 0;
528 }
529 
530 void
531 hidmt_disable(struct hidmt *mt)
532 {
533 	mt->sc_enabled = 0;
534 }
535