xref: /openbmc/linux/drivers/hid/hid-ntrig.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  *  HID driver for N-Trig touchscreens
3  *
4  *  Copyright (c) 2008-2010 Rafi Rubin
5  *  Copyright (c) 2009-2010 Stephane Chatty
6  *
7  */
8 
9 /*
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 2 of the License, or (at your option)
13  * any later version.
14  */
15 
16 #include <linux/device.h>
17 #include <linux/hid.h>
18 #include <linux/usb.h>
19 #include "usbhid/usbhid.h"
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 
23 #include "hid-ids.h"
24 
25 #define NTRIG_DUPLICATE_USAGES	0x001
26 
27 static unsigned int min_width;
28 module_param(min_width, uint, 0644);
29 MODULE_PARM_DESC(min_width, "Minimum touch contact width to accept.");
30 
31 static unsigned int min_height;
32 module_param(min_height, uint, 0644);
33 MODULE_PARM_DESC(min_height, "Minimum touch contact height to accept.");
34 
35 static unsigned int activate_slack = 1;
36 module_param(activate_slack, uint, 0644);
37 MODULE_PARM_DESC(activate_slack, "Number of touch frames to ignore at "
38 		 "the start of touch input.");
39 
40 static unsigned int deactivate_slack = 4;
41 module_param(deactivate_slack, uint, 0644);
42 MODULE_PARM_DESC(deactivate_slack, "Number of empty frames to ignore before "
43 		 "deactivating touch.");
44 
45 static unsigned int activation_width = 64;
46 module_param(activation_width, uint, 0644);
47 MODULE_PARM_DESC(activation_width, "Width threshold to immediately start "
48 		 "processing touch events.");
49 
50 static unsigned int activation_height = 32;
51 module_param(activation_height, uint, 0644);
52 MODULE_PARM_DESC(activation_height, "Height threshold to immediately start "
53 		 "processing touch events.");
54 
55 struct ntrig_data {
56 	/* Incoming raw values for a single contact */
57 	__u16 x, y, w, h;
58 	__u16 id;
59 
60 	bool tipswitch;
61 	bool confidence;
62 	bool first_contact_touch;
63 
64 	bool reading_mt;
65 
66 	__u8 mt_footer[4];
67 	__u8 mt_foot_count;
68 
69 	/* The current activation state. */
70 	__s8 act_state;
71 
72 	/* Empty frames to ignore before recognizing the end of activity */
73 	__s8 deactivate_slack;
74 
75 	/* Frames to ignore before acknowledging the start of activity */
76 	__s8 activate_slack;
77 
78 	/* Minimum size contact to accept */
79 	__u16 min_width;
80 	__u16 min_height;
81 
82 	/* Threshold to override activation slack */
83 	__u16 activation_width;
84 	__u16 activation_height;
85 
86 	__u16 sensor_logical_width;
87 	__u16 sensor_logical_height;
88 	__u16 sensor_physical_width;
89 	__u16 sensor_physical_height;
90 };
91 
92 
93 /*
94  * This function converts the 4 byte raw firmware code into
95  * a string containing 5 comma separated numbers.
96  */
97 static int ntrig_version_string(unsigned char *raw, char *buf)
98 {
99 	__u8 a =  (raw[1] & 0x0e) >> 1;
100 	__u8 b =  (raw[0] & 0x3c) >> 2;
101 	__u8 c = ((raw[0] & 0x03) << 3) | ((raw[3] & 0xe0) >> 5);
102 	__u8 d = ((raw[3] & 0x07) << 3) | ((raw[2] & 0xe0) >> 5);
103 	__u8 e =   raw[2] & 0x07;
104 
105 	/*
106 	 * As yet unmapped bits:
107 	 * 0b11000000 0b11110001 0b00011000 0b00011000
108 	 */
109 
110 	return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
111 }
112 
113 static void ntrig_report_version(struct hid_device *hdev)
114 {
115 	int ret;
116 	char buf[20];
117 	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
118 	unsigned char *data = kmalloc(8, GFP_KERNEL);
119 
120 	if (!data)
121 		goto err_free;
122 
123 	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
124 			      USB_REQ_CLEAR_FEATURE,
125 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
126 			      USB_DIR_IN,
127 			      0x30c, 1, data, 8,
128 			      USB_CTRL_SET_TIMEOUT);
129 
130 	if (ret == 8) {
131 		ret = ntrig_version_string(&data[2], buf);
132 
133 		hid_info(hdev, "Firmware version: %s (%02x%02x %02x%02x)\n",
134 			 buf, data[2], data[3], data[4], data[5]);
135 	}
136 
137 err_free:
138 	kfree(data);
139 }
140 
141 static ssize_t show_phys_width(struct device *dev,
142 			       struct device_attribute *attr,
143 			       char *buf)
144 {
145 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
146 	struct ntrig_data *nd = hid_get_drvdata(hdev);
147 
148 	return sprintf(buf, "%d\n", nd->sensor_physical_width);
149 }
150 
151 static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);
152 
153 static ssize_t show_phys_height(struct device *dev,
154 				struct device_attribute *attr,
155 				char *buf)
156 {
157 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
158 	struct ntrig_data *nd = hid_get_drvdata(hdev);
159 
160 	return sprintf(buf, "%d\n", nd->sensor_physical_height);
161 }
162 
163 static DEVICE_ATTR(sensor_physical_height, S_IRUGO, show_phys_height, NULL);
164 
165 static ssize_t show_log_width(struct device *dev,
166 			      struct device_attribute *attr,
167 			      char *buf)
168 {
169 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
170 	struct ntrig_data *nd = hid_get_drvdata(hdev);
171 
172 	return sprintf(buf, "%d\n", nd->sensor_logical_width);
173 }
174 
175 static DEVICE_ATTR(sensor_logical_width, S_IRUGO, show_log_width, NULL);
176 
177 static ssize_t show_log_height(struct device *dev,
178 			       struct device_attribute *attr,
179 			       char *buf)
180 {
181 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
182 	struct ntrig_data *nd = hid_get_drvdata(hdev);
183 
184 	return sprintf(buf, "%d\n", nd->sensor_logical_height);
185 }
186 
187 static DEVICE_ATTR(sensor_logical_height, S_IRUGO, show_log_height, NULL);
188 
189 static ssize_t show_min_width(struct device *dev,
190 			      struct device_attribute *attr,
191 			      char *buf)
192 {
193 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
194 	struct ntrig_data *nd = hid_get_drvdata(hdev);
195 
196 	return sprintf(buf, "%d\n", nd->min_width *
197 				    nd->sensor_physical_width /
198 				    nd->sensor_logical_width);
199 }
200 
201 static ssize_t set_min_width(struct device *dev,
202 			     struct device_attribute *attr,
203 			     const char *buf, size_t count)
204 {
205 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
206 	struct ntrig_data *nd = hid_get_drvdata(hdev);
207 
208 	unsigned long val;
209 
210 	if (strict_strtoul(buf, 0, &val))
211 		return -EINVAL;
212 
213 	if (val > nd->sensor_physical_width)
214 		return -EINVAL;
215 
216 	nd->min_width = val * nd->sensor_logical_width /
217 			      nd->sensor_physical_width;
218 
219 	return count;
220 }
221 
222 static DEVICE_ATTR(min_width, S_IWUSR | S_IRUGO, show_min_width, set_min_width);
223 
224 static ssize_t show_min_height(struct device *dev,
225 			       struct device_attribute *attr,
226 			       char *buf)
227 {
228 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
229 	struct ntrig_data *nd = hid_get_drvdata(hdev);
230 
231 	return sprintf(buf, "%d\n", nd->min_height *
232 				    nd->sensor_physical_height /
233 				    nd->sensor_logical_height);
234 }
235 
236 static ssize_t set_min_height(struct device *dev,
237 			      struct device_attribute *attr,
238 			      const char *buf, size_t count)
239 {
240 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
241 	struct ntrig_data *nd = hid_get_drvdata(hdev);
242 
243 	unsigned long val;
244 
245 	if (strict_strtoul(buf, 0, &val))
246 		return -EINVAL;
247 
248 	if (val > nd->sensor_physical_height)
249 		return -EINVAL;
250 
251 	nd->min_height = val * nd->sensor_logical_height /
252 			       nd->sensor_physical_height;
253 
254 	return count;
255 }
256 
257 static DEVICE_ATTR(min_height, S_IWUSR | S_IRUGO, show_min_height,
258 		   set_min_height);
259 
260 static ssize_t show_activate_slack(struct device *dev,
261 				   struct device_attribute *attr,
262 				   char *buf)
263 {
264 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
265 	struct ntrig_data *nd = hid_get_drvdata(hdev);
266 
267 	return sprintf(buf, "%d\n", nd->activate_slack);
268 }
269 
270 static ssize_t set_activate_slack(struct device *dev,
271 				  struct device_attribute *attr,
272 				  const char *buf, size_t count)
273 {
274 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
275 	struct ntrig_data *nd = hid_get_drvdata(hdev);
276 
277 	unsigned long val;
278 
279 	if (strict_strtoul(buf, 0, &val))
280 		return -EINVAL;
281 
282 	if (val > 0x7f)
283 		return -EINVAL;
284 
285 	nd->activate_slack = val;
286 
287 	return count;
288 }
289 
290 static DEVICE_ATTR(activate_slack, S_IWUSR | S_IRUGO, show_activate_slack,
291 		   set_activate_slack);
292 
293 static ssize_t show_activation_width(struct device *dev,
294 				     struct device_attribute *attr,
295 				     char *buf)
296 {
297 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
298 	struct ntrig_data *nd = hid_get_drvdata(hdev);
299 
300 	return sprintf(buf, "%d\n", nd->activation_width *
301 				    nd->sensor_physical_width /
302 				    nd->sensor_logical_width);
303 }
304 
305 static ssize_t set_activation_width(struct device *dev,
306 				    struct device_attribute *attr,
307 				    const char *buf, size_t count)
308 {
309 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
310 	struct ntrig_data *nd = hid_get_drvdata(hdev);
311 
312 	unsigned long val;
313 
314 	if (strict_strtoul(buf, 0, &val))
315 		return -EINVAL;
316 
317 	if (val > nd->sensor_physical_width)
318 		return -EINVAL;
319 
320 	nd->activation_width = val * nd->sensor_logical_width /
321 				     nd->sensor_physical_width;
322 
323 	return count;
324 }
325 
326 static DEVICE_ATTR(activation_width, S_IWUSR | S_IRUGO, show_activation_width,
327 		   set_activation_width);
328 
329 static ssize_t show_activation_height(struct device *dev,
330 				      struct device_attribute *attr,
331 				      char *buf)
332 {
333 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
334 	struct ntrig_data *nd = hid_get_drvdata(hdev);
335 
336 	return sprintf(buf, "%d\n", nd->activation_height *
337 				    nd->sensor_physical_height /
338 				    nd->sensor_logical_height);
339 }
340 
341 static ssize_t set_activation_height(struct device *dev,
342 				     struct device_attribute *attr,
343 				     const char *buf, size_t count)
344 {
345 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
346 	struct ntrig_data *nd = hid_get_drvdata(hdev);
347 
348 	unsigned long val;
349 
350 	if (strict_strtoul(buf, 0, &val))
351 		return -EINVAL;
352 
353 	if (val > nd->sensor_physical_height)
354 		return -EINVAL;
355 
356 	nd->activation_height = val * nd->sensor_logical_height /
357 				      nd->sensor_physical_height;
358 
359 	return count;
360 }
361 
362 static DEVICE_ATTR(activation_height, S_IWUSR | S_IRUGO,
363 		   show_activation_height, set_activation_height);
364 
365 static ssize_t show_deactivate_slack(struct device *dev,
366 				     struct device_attribute *attr,
367 				     char *buf)
368 {
369 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
370 	struct ntrig_data *nd = hid_get_drvdata(hdev);
371 
372 	return sprintf(buf, "%d\n", -nd->deactivate_slack);
373 }
374 
375 static ssize_t set_deactivate_slack(struct device *dev,
376 				    struct device_attribute *attr,
377 				    const char *buf, size_t count)
378 {
379 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
380 	struct ntrig_data *nd = hid_get_drvdata(hdev);
381 
382 	unsigned long val;
383 
384 	if (strict_strtoul(buf, 0, &val))
385 		return -EINVAL;
386 
387 	/*
388 	 * No more than 8 terminal frames have been observed so far
389 	 * and higher slack is highly likely to leave the single
390 	 * touch emulation stuck down.
391 	 */
392 	if (val > 7)
393 		return -EINVAL;
394 
395 	nd->deactivate_slack = -val;
396 
397 	return count;
398 }
399 
400 static DEVICE_ATTR(deactivate_slack, S_IWUSR | S_IRUGO, show_deactivate_slack,
401 		   set_deactivate_slack);
402 
403 static struct attribute *sysfs_attrs[] = {
404 	&dev_attr_sensor_physical_width.attr,
405 	&dev_attr_sensor_physical_height.attr,
406 	&dev_attr_sensor_logical_width.attr,
407 	&dev_attr_sensor_logical_height.attr,
408 	&dev_attr_min_height.attr,
409 	&dev_attr_min_width.attr,
410 	&dev_attr_activate_slack.attr,
411 	&dev_attr_activation_width.attr,
412 	&dev_attr_activation_height.attr,
413 	&dev_attr_deactivate_slack.attr,
414 	NULL
415 };
416 
417 static struct attribute_group ntrig_attribute_group = {
418 	.attrs = sysfs_attrs
419 };
420 
421 /*
422  * this driver is aimed at two firmware versions in circulation:
423  *  - dual pen/finger single touch
424  *  - finger multitouch, pen not working
425  */
426 
427 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
428 			       struct hid_field *field, struct hid_usage *usage,
429 			       unsigned long **bit, int *max)
430 {
431 	struct ntrig_data *nd = hid_get_drvdata(hdev);
432 
433 	/* No special mappings needed for the pen and single touch */
434 	if (field->physical)
435 		return 0;
436 
437 	switch (usage->hid & HID_USAGE_PAGE) {
438 	case HID_UP_GENDESK:
439 		switch (usage->hid) {
440 		case HID_GD_X:
441 			hid_map_usage(hi, usage, bit, max,
442 					EV_ABS, ABS_MT_POSITION_X);
443 			input_set_abs_params(hi->input, ABS_X,
444 					field->logical_minimum,
445 					field->logical_maximum, 0, 0);
446 
447 			if (!nd->sensor_logical_width) {
448 				nd->sensor_logical_width =
449 					field->logical_maximum -
450 					field->logical_minimum;
451 				nd->sensor_physical_width =
452 					field->physical_maximum -
453 					field->physical_minimum;
454 				nd->activation_width = activation_width *
455 					nd->sensor_logical_width /
456 					nd->sensor_physical_width;
457 				nd->min_width = min_width *
458 					nd->sensor_logical_width /
459 					nd->sensor_physical_width;
460 			}
461 			return 1;
462 		case HID_GD_Y:
463 			hid_map_usage(hi, usage, bit, max,
464 					EV_ABS, ABS_MT_POSITION_Y);
465 			input_set_abs_params(hi->input, ABS_Y,
466 					field->logical_minimum,
467 					field->logical_maximum, 0, 0);
468 
469 			if (!nd->sensor_logical_height) {
470 				nd->sensor_logical_height =
471 					field->logical_maximum -
472 					field->logical_minimum;
473 				nd->sensor_physical_height =
474 					field->physical_maximum -
475 					field->physical_minimum;
476 				nd->activation_height = activation_height *
477 					nd->sensor_logical_height /
478 					nd->sensor_physical_height;
479 				nd->min_height = min_height *
480 					nd->sensor_logical_height /
481 					nd->sensor_physical_height;
482 			}
483 			return 1;
484 		}
485 		return 0;
486 
487 	case HID_UP_DIGITIZER:
488 		switch (usage->hid) {
489 		/* we do not want to map these for now */
490 		case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
491 		case HID_DG_INPUTMODE:
492 		case HID_DG_DEVICEINDEX:
493 		case HID_DG_CONTACTMAX:
494 			return -1;
495 
496 		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
497 		case HID_DG_WIDTH:
498 			hid_map_usage(hi, usage, bit, max,
499 				      EV_ABS, ABS_MT_TOUCH_MAJOR);
500 			return 1;
501 		case HID_DG_HEIGHT:
502 			hid_map_usage(hi, usage, bit, max,
503 				      EV_ABS, ABS_MT_TOUCH_MINOR);
504 			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
505 					     0, 1, 0, 0);
506 			return 1;
507 		}
508 		return 0;
509 
510 	case 0xff000000:
511 		/* we do not want to map these: no input-oriented meaning */
512 		return -1;
513 	}
514 
515 	return 0;
516 }
517 
518 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
519 			      struct hid_field *field, struct hid_usage *usage,
520 			      unsigned long **bit, int *max)
521 {
522 	/* No special mappings needed for the pen and single touch */
523 	if (field->physical)
524 		return 0;
525 
526 	if (usage->type == EV_KEY || usage->type == EV_REL
527 			|| usage->type == EV_ABS)
528 		clear_bit(usage->code, *bit);
529 
530 	return 0;
531 }
532 
533 /*
534  * this function is called upon all reports
535  * so that we can filter contact point information,
536  * decide whether we are in multi or single touch mode
537  * and call input_mt_sync after each point if necessary
538  */
539 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
540 			struct hid_usage *usage, __s32 value)
541 {
542 	struct input_dev *input = field->hidinput->input;
543 	struct ntrig_data *nd = hid_get_drvdata(hid);
544 
545 	/* No special handling needed for the pen */
546 	if (field->application == HID_DG_PEN)
547 		return 0;
548 
549         if (hid->claimed & HID_CLAIMED_INPUT) {
550 		switch (usage->hid) {
551 		case 0xff000001:
552 			/* Tag indicating the start of a multitouch group */
553 			nd->reading_mt = 1;
554 			nd->first_contact_touch = 0;
555 			break;
556 		case HID_DG_TIPSWITCH:
557 			nd->tipswitch = value;
558 			/* Prevent emission of touch until validated */
559 			return 1;
560 		case HID_DG_CONFIDENCE:
561 			nd->confidence = value;
562 			break;
563 		case HID_GD_X:
564 			nd->x = value;
565 			/* Clear the contact footer */
566 			nd->mt_foot_count = 0;
567 			break;
568 		case HID_GD_Y:
569 			nd->y = value;
570 			break;
571 		case HID_DG_CONTACTID:
572 			nd->id = value;
573 			break;
574 		case HID_DG_WIDTH:
575 			nd->w = value;
576 			break;
577 		case HID_DG_HEIGHT:
578 			nd->h = value;
579 			/*
580 			 * when in single touch mode, this is the last
581 			 * report received in a finger event. We want
582 			 * to emit a normal (X, Y) position
583 			 */
584 			if (!nd->reading_mt) {
585 				/*
586 				 * TipSwitch indicates the presence of a
587 				 * finger in single touch mode.
588 				 */
589 				input_report_key(input, BTN_TOUCH,
590 						 nd->tipswitch);
591 				input_report_key(input, BTN_TOOL_DOUBLETAP,
592 						 nd->tipswitch);
593 				input_event(input, EV_ABS, ABS_X, nd->x);
594 				input_event(input, EV_ABS, ABS_Y, nd->y);
595 			}
596 			break;
597 		case 0xff000002:
598 			/*
599 			 * we receive this when the device is in multitouch
600 			 * mode. The first of the three values tagged with
601 			 * this usage tells if the contact point is real
602 			 * or a placeholder
603 			 */
604 
605 			/* Shouldn't get more than 4 footer packets, so skip */
606 			if (nd->mt_foot_count >= 4)
607 				break;
608 
609 			nd->mt_footer[nd->mt_foot_count++] = value;
610 
611 			/* if the footer isn't complete break */
612 			if (nd->mt_foot_count != 4)
613 				break;
614 
615 			/* Pen activity signal. */
616 			if (nd->mt_footer[2]) {
617 				/*
618 				 * When the pen deactivates touch, we see a
619 				 * bogus frame with ContactCount > 0.
620 				 * We can
621 				 * save a bit of work by ensuring act_state < 0
622 				 * even if deactivation slack is turned off.
623 				 */
624 				nd->act_state = deactivate_slack - 1;
625 				nd->confidence = 0;
626 				break;
627 			}
628 
629 			/*
630 			 * The first footer value indicates the presence of a
631 			 * finger.
632 			 */
633 			if (nd->mt_footer[0]) {
634 				/*
635 				 * We do not want to process contacts under
636 				 * the size threshold, but do not want to
637 				 * ignore them for activation state
638 				 */
639 				if (nd->w < nd->min_width ||
640 				    nd->h < nd->min_height)
641 					nd->confidence = 0;
642 			} else
643 				break;
644 
645 			if (nd->act_state > 0) {
646 				/*
647 				 * Contact meets the activation size threshold
648 				 */
649 				if (nd->w >= nd->activation_width &&
650 				    nd->h >= nd->activation_height) {
651 					if (nd->id)
652 						/*
653 						 * first contact, activate now
654 						 */
655 						nd->act_state = 0;
656 					else {
657 						/*
658 						 * avoid corrupting this frame
659 						 * but ensure next frame will
660 						 * be active
661 						 */
662 						nd->act_state = 1;
663 						break;
664 					}
665 				} else
666 					/*
667 					 * Defer adjusting the activation state
668 					 * until the end of the frame.
669 					 */
670 					break;
671 			}
672 
673 			/* Discarding this contact */
674 			if (!nd->confidence)
675 				break;
676 
677 			/* emit a normal (X, Y) for the first point only */
678 			if (nd->id == 0) {
679 				/*
680 				 * TipSwitch is superfluous in multitouch
681 				 * mode.  The footer events tell us
682 				 * if there is a finger on the screen or
683 				 * not.
684 				 */
685 				nd->first_contact_touch = nd->confidence;
686 				input_event(input, EV_ABS, ABS_X, nd->x);
687 				input_event(input, EV_ABS, ABS_Y, nd->y);
688 			}
689 
690 			/* Emit MT events */
691 			input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
692 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
693 
694 			/*
695 			 * Translate from height and width to size
696 			 * and orientation.
697 			 */
698 			if (nd->w > nd->h) {
699 				input_event(input, EV_ABS,
700 						ABS_MT_ORIENTATION, 1);
701 				input_event(input, EV_ABS,
702 						ABS_MT_TOUCH_MAJOR, nd->w);
703 				input_event(input, EV_ABS,
704 						ABS_MT_TOUCH_MINOR, nd->h);
705 			} else {
706 				input_event(input, EV_ABS,
707 						ABS_MT_ORIENTATION, 0);
708 				input_event(input, EV_ABS,
709 						ABS_MT_TOUCH_MAJOR, nd->h);
710 				input_event(input, EV_ABS,
711 						ABS_MT_TOUCH_MINOR, nd->w);
712 			}
713 			input_mt_sync(field->hidinput->input);
714 			break;
715 
716 		case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
717 			if (!nd->reading_mt) /* Just to be sure */
718 				break;
719 
720 			nd->reading_mt = 0;
721 
722 
723 			/*
724 			 * Activation state machine logic:
725 			 *
726 			 * Fundamental states:
727 			 *	state >  0: Inactive
728 			 *	state <= 0: Active
729 			 *	state <  -deactivate_slack:
730 			 *		 Pen termination of touch
731 			 *
732 			 * Specific values of interest
733 			 *	state == activate_slack
734 			 *		 no valid input since the last reset
735 			 *
736 			 *	state == 0
737 			 *		 general operational state
738 			 *
739 			 *	state == -deactivate_slack
740 			 *		 read sufficient empty frames to accept
741 			 *		 the end of input and reset
742 			 */
743 
744 			if (nd->act_state > 0) { /* Currently inactive */
745 				if (value)
746 					/*
747 					 * Consider each live contact as
748 					 * evidence of intentional activity.
749 					 */
750 					nd->act_state = (nd->act_state > value)
751 							? nd->act_state - value
752 							: 0;
753 				else
754 					/*
755 					 * Empty frame before we hit the
756 					 * activity threshold, reset.
757 					 */
758 					nd->act_state = nd->activate_slack;
759 
760 				/*
761 				 * Entered this block inactive and no
762 				 * coordinates sent this frame, so hold off
763 				 * on button state.
764 				 */
765 				break;
766 			} else { /* Currently active */
767 				if (value && nd->act_state >=
768 					     nd->deactivate_slack)
769 					/*
770 					 * Live point: clear accumulated
771 					 * deactivation count.
772 					 */
773 					nd->act_state = 0;
774 				else if (nd->act_state <= nd->deactivate_slack)
775 					/*
776 					 * We've consumed the deactivation
777 					 * slack, time to deactivate and reset.
778 					 */
779 					nd->act_state =
780 						nd->activate_slack;
781 				else { /* Move towards deactivation */
782 					nd->act_state--;
783 					break;
784 				}
785 			}
786 
787 			if (nd->first_contact_touch && nd->act_state <= 0) {
788 				/*
789 				 * Check to see if we're ready to start
790 				 * emitting touch events.
791 				 *
792 				 * Note: activation slack will decrease over
793 				 * the course of the frame, and it will be
794 				 * inconsistent from the start to the end of
795 				 * the frame.  However if the frame starts
796 				 * with slack, first_contact_touch will still
797 				 * be 0 and we will not get to this point.
798 				 */
799 				input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
800 				input_report_key(input, BTN_TOUCH, 1);
801 			} else {
802 				input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
803 				input_report_key(input, BTN_TOUCH, 0);
804 			}
805 			break;
806 
807 		default:
808 			/* fall-back to the generic hidinput handling */
809 			return 0;
810 		}
811 	}
812 
813 	/* we have handled the hidinput part, now remains hiddev */
814 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
815 		hid->hiddev_hid_event(hid, field, usage, value);
816 
817 	return 1;
818 }
819 
820 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
821 {
822 	int ret;
823 	struct ntrig_data *nd;
824 	struct hid_input *hidinput;
825 	struct input_dev *input;
826 	struct hid_report *report;
827 
828 	if (id->driver_data)
829 		hdev->quirks |= HID_QUIRK_MULTI_INPUT;
830 
831 	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
832 	if (!nd) {
833 		hid_err(hdev, "cannot allocate N-Trig data\n");
834 		return -ENOMEM;
835 	}
836 
837 	nd->reading_mt = 0;
838 	nd->min_width = 0;
839 	nd->min_height = 0;
840 	nd->activate_slack = activate_slack;
841 	nd->act_state = activate_slack;
842 	nd->deactivate_slack = -deactivate_slack;
843 	nd->sensor_logical_width = 0;
844 	nd->sensor_logical_height = 0;
845 	nd->sensor_physical_width = 0;
846 	nd->sensor_physical_height = 0;
847 
848 	hid_set_drvdata(hdev, nd);
849 
850 	ret = hid_parse(hdev);
851 	if (ret) {
852 		hid_err(hdev, "parse failed\n");
853 		goto err_free;
854 	}
855 
856 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
857 	if (ret) {
858 		hid_err(hdev, "hw start failed\n");
859 		goto err_free;
860 	}
861 
862 
863 	list_for_each_entry(hidinput, &hdev->inputs, list) {
864 		if (hidinput->report->maxfield < 1)
865 			continue;
866 
867 		input = hidinput->input;
868 		switch (hidinput->report->field[0]->application) {
869 		case HID_DG_PEN:
870 			input->name = "N-Trig Pen";
871 			break;
872 		case HID_DG_TOUCHSCREEN:
873 			/* These keys are redundant for fingers, clear them
874 			 * to prevent incorrect identification */
875 			__clear_bit(BTN_TOOL_PEN, input->keybit);
876 			__clear_bit(BTN_TOOL_FINGER, input->keybit);
877 			__clear_bit(BTN_0, input->keybit);
878 			__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
879 			/*
880 			 * The physical touchscreen (single touch)
881 			 * input has a value for physical, whereas
882 			 * the multitouch only has logical input
883 			 * fields.
884 			 */
885 			input->name =
886 				(hidinput->report->field[0]
887 				 ->physical) ?
888 				"N-Trig Touchscreen" :
889 				"N-Trig MultiTouch";
890 			break;
891 		}
892 	}
893 
894 	/* This is needed for devices with more recent firmware versions */
895 	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
896 	if (report)
897 		usbhid_submit_report(hdev, report, USB_DIR_OUT);
898 
899 	ntrig_report_version(hdev);
900 
901 	ret = sysfs_create_group(&hdev->dev.kobj,
902 			&ntrig_attribute_group);
903 
904 	return 0;
905 err_free:
906 	kfree(nd);
907 	return ret;
908 }
909 
910 static void ntrig_remove(struct hid_device *hdev)
911 {
912 	sysfs_remove_group(&hdev->dev.kobj,
913 			   &ntrig_attribute_group);
914 	hid_hw_stop(hdev);
915 	kfree(hid_get_drvdata(hdev));
916 }
917 
918 static const struct hid_device_id ntrig_devices[] = {
919 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
920 		.driver_data = NTRIG_DUPLICATE_USAGES },
921 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_1),
922 		.driver_data = NTRIG_DUPLICATE_USAGES },
923 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_2),
924 		.driver_data = NTRIG_DUPLICATE_USAGES },
925 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_3),
926 		.driver_data = NTRIG_DUPLICATE_USAGES },
927 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_4),
928 		.driver_data = NTRIG_DUPLICATE_USAGES },
929 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_5),
930 		.driver_data = NTRIG_DUPLICATE_USAGES },
931 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_6),
932 		.driver_data = NTRIG_DUPLICATE_USAGES },
933 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_7),
934 		.driver_data = NTRIG_DUPLICATE_USAGES },
935 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_8),
936 		.driver_data = NTRIG_DUPLICATE_USAGES },
937 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_9),
938 		.driver_data = NTRIG_DUPLICATE_USAGES },
939 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_10),
940 		.driver_data = NTRIG_DUPLICATE_USAGES },
941 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_11),
942 		.driver_data = NTRIG_DUPLICATE_USAGES },
943 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_12),
944 		.driver_data = NTRIG_DUPLICATE_USAGES },
945 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_13),
946 		.driver_data = NTRIG_DUPLICATE_USAGES },
947 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_14),
948 		.driver_data = NTRIG_DUPLICATE_USAGES },
949 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_15),
950 		.driver_data = NTRIG_DUPLICATE_USAGES },
951 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_16),
952 		.driver_data = NTRIG_DUPLICATE_USAGES },
953 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_17),
954 		.driver_data = NTRIG_DUPLICATE_USAGES },
955 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_18),
956 		.driver_data = NTRIG_DUPLICATE_USAGES },
957 	{ }
958 };
959 MODULE_DEVICE_TABLE(hid, ntrig_devices);
960 
961 static const struct hid_usage_id ntrig_grabbed_usages[] = {
962 	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
963 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
964 };
965 
966 static struct hid_driver ntrig_driver = {
967 	.name = "ntrig",
968 	.id_table = ntrig_devices,
969 	.probe = ntrig_probe,
970 	.remove = ntrig_remove,
971 	.input_mapping = ntrig_input_mapping,
972 	.input_mapped = ntrig_input_mapped,
973 	.usage_table = ntrig_grabbed_usages,
974 	.event = ntrig_event,
975 };
976 
977 static int __init ntrig_init(void)
978 {
979 	return hid_register_driver(&ntrig_driver);
980 }
981 
982 static void __exit ntrig_exit(void)
983 {
984 	hid_unregister_driver(&ntrig_driver);
985 }
986 
987 module_init(ntrig_init);
988 module_exit(ntrig_exit);
989 MODULE_LICENSE("GPL");
990