aboutsummaryrefslogtreecommitdiff
path: root/drivers/hid/hid-multitouch.c
blob: 07d3183fdde50ca4fd3a57807e727b73094b3e6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
/*
 *  HID driver for multitouch panels
 *
 *  Copyright (c) 2010-2011 Stephane Chatty <chatty@enac.fr>
 *  Copyright (c) 2010-2011 Benjamin Tissoires <benjamin.tissoires@gmail.com>
 *  Copyright (c) 2010-2011 Ecole Nationale de l'Aviation Civile, France
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/input/mt.h>
#include "usbhid/usbhid.h"


MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
MODULE_DESCRIPTION("HID multitouch panels");
MODULE_LICENSE("GPL");

#include "hid-ids.h"

/* quirks to control the device */
#define MT_QUIRK_NOT_SEEN_MEANS_UP	(1 << 0)
#define MT_QUIRK_SLOT_IS_CONTACTID	(1 << 1)
#define MT_QUIRK_CYPRESS		(1 << 2)
#define MT_QUIRK_SLOT_IS_CONTACTNUMBER	(1 << 3)
#define MT_QUIRK_VALID_IS_INRANGE	(1 << 4)
#define MT_QUIRK_VALID_IS_CONFIDENCE	(1 << 5)

struct mt_slot {
	__s32 x, y, p, w, h;
	__s32 contactid;	/* the device ContactID assigned to this slot */
	bool touch_state;	/* is the touch valid? */
	bool seen_in_this_frame;/* has this slot been updated */
};

struct mt_device {
	struct mt_slot curdata;	/* placeholder of incoming data */
	struct mt_class *mtclass;	/* our mt device class */
	unsigned last_field_index;	/* last field index of the report */
	unsigned last_slot_field;	/* the last field of a slot */
	__s8 inputmode;		/* InputMode HID feature, -1 if non-existent */
	__u8 num_received;	/* how many contacts we received */
	__u8 num_expected;	/* expected last contact index */
	bool curvalid;		/* is the current contact valid? */
	struct mt_slot slots[0];	/* first slot */
};

struct mt_class {
	__s32 name;	/* MT_CLS */
	__s32 quirks;
	__s32 sn_move;	/* Signal/noise ratio for move events */
	__s32 sn_pressure;	/* Signal/noise ratio for pressure events */
	__u8 maxcontacts;
};

/* classes of device behavior */
#define MT_CLS_DEFAULT	1
#define MT_CLS_DUAL1	2
#define MT_CLS_DUAL2	3
#define MT_CLS_CYPRESS	4

/*
 * these device-dependent functions determine what slot corresponds
 * to a valid contact that was just read.
 */

static int cypress_compute_slot(struct mt_device *td)
{
	if (td->curdata.contactid != 0 || td->num_received == 0)
		return td->curdata.contactid;
	else
		return -1;
}

static int find_slot_from_contactid(struct mt_device *td)
{
	int i;
	for (i = 0; i < td->mtclass->maxcontacts; ++i) {
		if (td->slots[i].contactid == td->curdata.contactid &&
			td->slots[i].touch_state)
			return i;
	}
	for (i = 0; i < td->mtclass->maxcontacts; ++i) {
		if (!td->slots[i].seen_in_this_frame &&
			!td->slots[i].touch_state)
			return i;
	}
	/* should not occurs. If this happens that means
	 * that the device sent more touches that it says
	 * in the report descriptor. It is ignored then. */
	return -1;
}

struct mt_class mt_classes[] = {
	{ .name = MT_CLS_DEFAULT,
		.quirks = MT_QUIRK_VALID_IS_INRANGE,
		.maxcontacts = 10 },
	{ .name = MT_CLS_DUAL1,
		.quirks = MT_QUIRK_VALID_IS_INRANGE |
			MT_QUIRK_SLOT_IS_CONTACTID,
		.maxcontacts = 2 },
	{ .name = MT_CLS_DUAL2,
		.quirks = MT_QUIRK_VALID_IS_INRANGE |
			MT_QUIRK_SLOT_IS_CONTACTNUMBER,
		.maxcontacts = 2 },
	{ .name = MT_CLS_CYPRESS,
		.quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
			MT_QUIRK_CYPRESS,
		.maxcontacts = 10 },

	{ }
};

static void mt_feature_mapping(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage)
{
	if (usage->hid == HID_DG_INPUTMODE) {
		struct mt_device *td = hid_get_drvdata(hdev);
		td->inputmode = field->report->id;
	}
}

static void set_abs(struct input_dev *input, unsigned int code,
		struct hid_field *field, int snratio)
{
	int fmin = field->logical_minimum;
	int fmax = field->logical_maximum;
	int fuzz = snratio ? (fmax - fmin) / snratio : 0;
	input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
}

static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{
	struct mt_device *td = hid_get_drvdata(hdev);
	struct mt_class *cls = td->mtclass;
	switch (usage->hid & HID_USAGE_PAGE) {

	case HID_UP_GENDESK:
		switch (usage->hid) {
		case HID_GD_X:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_POSITION_X);
			set_abs(hi->input, ABS_MT_POSITION_X, field,
				cls->sn_move);
			/* touchscreen emulation */
			set_abs(hi->input, ABS_X, field, cls->sn_move);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_GD_Y:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_POSITION_Y);
			set_abs(hi->input, ABS_MT_POSITION_Y, field,
				cls->sn_move);
			/* touchscreen emulation */
			set_abs(hi->input, ABS_Y, field, cls->sn_move);
			td->last_slot_field = usage->hid;
			return 1;
		}
		return 0;

	case HID_UP_DIGITIZER:
		switch (usage->hid) {
		case HID_DG_INRANGE:
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_CONFIDENCE:
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_TIPSWITCH:
			hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
			input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_CONTACTID:
			input_mt_init_slots(hi->input,
					td->mtclass->maxcontacts);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_WIDTH:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_TOUCH_MAJOR);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_HEIGHT:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_TOUCH_MINOR);
			field->logical_maximum = 1;
			field->logical_minimum = 0;
			set_abs(hi->input, ABS_MT_ORIENTATION, field, 0);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_TIPPRESSURE:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_PRESSURE);
			set_abs(hi->input, ABS_MT_PRESSURE, field,
				cls->sn_pressure);
			/* touchscreen emulation */
			set_abs(hi->input, ABS_PRESSURE, field,
				cls->sn_pressure);
			td->last_slot_field = usage->hid;
			return 1;
		case HID_DG_CONTACTCOUNT:
			td->last_field_index = field->report->maxfield - 1;
			return 1;
		case HID_DG_CONTACTMAX:
			/* we don't set td->last_slot_field as contactcount and
			 * contact max are global to the report */
			return -1;
		}
		/* let hid-input decide for the others */
		return 0;

	case 0xff000000:
		/* we do not want to map these: no input-oriented meaning */
		return -1;
	}

	return 0;
}

static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{
	if (usage->type == EV_KEY || usage->type == EV_ABS)
		set_bit(usage->type, hi->input->evbit);

	return -1;
}

static int mt_compute_slot(struct mt_device *td)
{
	__s32 quirks = td->mtclass->quirks;

	if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
		return td->curdata.contactid;

	if (quirks & MT_QUIRK_CYPRESS)
		return cypress_compute_slot(td);

	if (quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
		return td->num_received;

	return find_slot_from_contactid(td);
}

/*
 * this function is called when a whole contact has been processed,
 * so that it can assign it to a slot and store the data there
 */
static void mt_complete_slot(struct mt_device *td)
{
	td->curdata.seen_in_this_frame = true;
	if (td->curvalid) {
		int slotnum = mt_compute_slot(td);

		if (slotnum >= 0 && slotnum < td->mtclass->maxcontacts)
			td->slots[slotnum] = td->curdata;
	}
	td->num_received++;
}


/*
 * this function is called when a whole packet has been received and processed,
 * so that it can decide what to send to the input layer.
 */
static void mt_emit_event(struct mt_device *td, struct input_dev *input)
{
	int i;

	for (i = 0; i < td->mtclass->maxcontacts; ++i) {
		struct mt_slot *s = &(td->slots[i]);
		if ((td->mtclass->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
			!s->seen_in_this_frame) {
			s->touch_state = false;
		}

		input_mt_slot(input, i);
		input_mt_report_slot_state(input, MT_TOOL_FINGER,
			s->touch_state);
		if (s->touch_state) {
			input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
			input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
			input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
			input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
		}
		s->seen_in_this_frame = false;

	}

	input_mt_report_pointer_emulation(input, true);
	input_sync(input);
	td->num_received = 0;
}



static int mt_event(struct hid_device *hid, struct hid_field *field,
				struct hid_usage *usage, __s32 value)
{
	struct mt_device *td = hid_get_drvdata(hid);
	__s32 quirks = td->mtclass->quirks;

	if (hid->claimed & HID_CLAIMED_INPUT) {
		switch (usage->hid) {
		case HID_DG_INRANGE:
			if (quirks & MT_QUIRK_VALID_IS_INRANGE)
				td->curvalid = value;
			break;
		case HID_DG_TIPSWITCH:
			if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
				td->curvalid = value;
			td->curdata.touch_state = value;
			break;
		case HID_DG_CONFIDENCE:
			if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
				td->curvalid = value;
			break;
		case HID_DG_CONTACTID:
			td->curdata.contactid = value;
			break;
		case HID_DG_TIPPRESSURE:
			td->curdata.p = value;
			break;
		case HID_GD_X:
			td->curdata.x = value;
			break;
		case HID_GD_Y:
			td->curdata.y = value;
			break;
		case HID_DG_WIDTH:
			td->curdata.w = value;
			break;
		case HID_DG_HEIGHT:
			td->curdata.h = value;
			break;
		case HID_DG_CONTACTCOUNT:
			/*
			 * Includes multi-packet support where subsequent
			 * packets are sent with zero contactcount.
			 */
			if (value)
				td->num_expected = value;
			break;

		default:
			/* fallback to the generic hidinput handling */
			return 0;
		}

		if (usage->hid == td->last_slot_field)
			mt_complete_slot(td);

		if (field->index == td->last_field_index
			&& td->num_received >= td->num_expected)
			mt_emit_event(td, field->hidinput->input);

	}

	/* we have handled the hidinput part, now remains hiddev */
	if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
		hid->hiddev_hid_event(hid, field, usage, value);

	return 1;
}

static void mt_set_input_mode(struct hid_device *hdev)
{
	struct mt_device *td = hid_get_drvdata(hdev);
	struct hid_report *r;
	struct hid_report_enum *re;

	if (td->inputmode < 0)
		return;

	re = &(hdev->report_enum[HID_FEATURE_REPORT]);
	r = re->report_id_hash[td->inputmode];
	if (r) {
		r->field[0]->value[0] = 0x02;
		usbhid_submit_report(hdev, r, USB_DIR_OUT);
	}
}

static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
	int ret, i;
	struct mt_device *td;
	struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */

	for (i = 0; mt_classes[i].name ; i++) {
		if (id->driver_data == mt_classes[i].name) {
			mtclass = &(mt_classes[i]);
			break;
		}
	}

	/* This allows the driver to correctly support devices
	 * that emit events over several HID messages.
	 */
	hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;

	td = kzalloc(sizeof(struct mt_device) +
				mtclass->maxcontacts * sizeof(struct mt_slot),
				GFP_KERNEL);
	if (!td) {
		dev_err(&hdev->dev, "cannot allocate multitouch data\n");
		return -ENOMEM;
	}
	td->mtclass = mtclass;
	td->inputmode = -1;
	hid_set_drvdata(hdev, td);

	ret = hid_parse(hdev);
	if (ret != 0)
		goto fail;

	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
	if (ret)
		goto fail;

	mt_set_input_mode(hdev);

	return 0;

fail:
	kfree(td);
	return ret;
}

#ifdef CONFIG_PM
static int mt_reset_resume(struct hid_device *hdev)
{
	mt_set_input_mode(hdev);
	return 0;
}
#endif

static void mt_remove(struct hid_device *hdev)
{
	struct mt_device *td = hid_get_drvdata(hdev);
	hid_hw_stop(hdev);
	kfree(td);
	hid_set_drvdata(hdev, NULL);
}

static const struct hid_device_id mt_devices[] = {

	/* Cypress panel */
	{ .driver_data = MT_CLS_CYPRESS,
		HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS,
			USB_DEVICE_ID_CYPRESS_TRUETOUCH) },

	/* GeneralTouch panel */
	{ .driver_data = MT_CLS_DUAL2,
		HID_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
			USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },

	/* PixCir-based panels */
	{ .driver_data = MT_CLS_DUAL1,
		HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
			USB_DEVICE_ID_HANVON_MULTITOUCH) },
	{ .driver_data = MT_CLS_DUAL1,
		HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
			USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },

	{ }
};
MODULE_DEVICE_TABLE(hid, mt_devices);

static const struct hid_usage_id mt_grabbed_usages[] = {
	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
};

static struct hid_driver mt_driver = {
	.name = "hid-multitouch",
	.id_table = mt_devices,
	.probe = mt_probe,
	.remove = mt_remove,
	.input_mapping = mt_input_mapping,
	.input_mapped = mt_input_mapped,
	.feature_mapping = mt_feature_mapping,
	.usage_table = mt_grabbed_usages,
	.event = mt_event,
#ifdef CONFIG_PM
	.reset_resume = mt_reset_resume,
#endif
};

static int __init mt_init(void)
{
	return hid_register_driver(&mt_driver);
}

static void __exit mt_exit(void)
{
	hid_unregister_driver(&mt_driver);
}

module_init(mt_init);
module_exit(mt_exit);