xref: /linux/drivers/hid/hid-ntrig.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 inline int ntrig_get_mode(struct hid_device *hdev)
114 {
115 	struct hid_report *report = hdev->report_enum[HID_FEATURE_REPORT].
116 				    report_id_hash[0x0d];
117 
118 	if (!report)
119 		return -EINVAL;
120 
121 	usbhid_submit_report(hdev, report, USB_DIR_IN);
122 	usbhid_wait_io(hdev);
123 	return (int)report->field[0]->value[0];
124 }
125 
126 static inline void ntrig_set_mode(struct hid_device *hdev, const int mode)
127 {
128 	struct hid_report *report;
129 	__u8 mode_commands[4] = { 0xe, 0xf, 0x1b, 0x10 };
130 
131 	if (mode < 0 || mode > 3)
132 		return;
133 
134 	report = hdev->report_enum[HID_FEATURE_REPORT].
135 		 report_id_hash[mode_commands[mode]];
136 
137 	if (!report)
138 		return;
139 
140 	usbhid_submit_report(hdev, report, USB_DIR_IN);
141 }
142 
143 static void ntrig_report_version(struct hid_device *hdev)
144 {
145 	int ret;
146 	char buf[20];
147 	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
148 	unsigned char *data = kmalloc(8, GFP_KERNEL);
149 
150 	if (!data)
151 		goto err_free;
152 
153 	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
154 			      USB_REQ_CLEAR_FEATURE,
155 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
156 			      USB_DIR_IN,
157 			      0x30c, 1, data, 8,
158 			      USB_CTRL_SET_TIMEOUT);
159 
160 	if (ret == 8) {
161 		ret = ntrig_version_string(&data[2], buf);
162 
163 		hid_info(hdev, "Firmware version: %s (%02x%02x %02x%02x)\n",
164 			 buf, data[2], data[3], data[4], data[5]);
165 	}
166 
167 err_free:
168 	kfree(data);
169 }
170 
171 static ssize_t show_phys_width(struct device *dev,
172 			       struct device_attribute *attr,
173 			       char *buf)
174 {
175 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
176 	struct ntrig_data *nd = hid_get_drvdata(hdev);
177 
178 	return sprintf(buf, "%d\n", nd->sensor_physical_width);
179 }
180 
181 static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);
182 
183 static ssize_t show_phys_height(struct device *dev,
184 				struct device_attribute *attr,
185 				char *buf)
186 {
187 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
188 	struct ntrig_data *nd = hid_get_drvdata(hdev);
189 
190 	return sprintf(buf, "%d\n", nd->sensor_physical_height);
191 }
192 
193 static DEVICE_ATTR(sensor_physical_height, S_IRUGO, show_phys_height, NULL);
194 
195 static ssize_t show_log_width(struct device *dev,
196 			      struct device_attribute *attr,
197 			      char *buf)
198 {
199 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
200 	struct ntrig_data *nd = hid_get_drvdata(hdev);
201 
202 	return sprintf(buf, "%d\n", nd->sensor_logical_width);
203 }
204 
205 static DEVICE_ATTR(sensor_logical_width, S_IRUGO, show_log_width, NULL);
206 
207 static ssize_t show_log_height(struct device *dev,
208 			       struct device_attribute *attr,
209 			       char *buf)
210 {
211 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
212 	struct ntrig_data *nd = hid_get_drvdata(hdev);
213 
214 	return sprintf(buf, "%d\n", nd->sensor_logical_height);
215 }
216 
217 static DEVICE_ATTR(sensor_logical_height, S_IRUGO, show_log_height, NULL);
218 
219 static ssize_t show_min_width(struct device *dev,
220 			      struct device_attribute *attr,
221 			      char *buf)
222 {
223 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
224 	struct ntrig_data *nd = hid_get_drvdata(hdev);
225 
226 	return sprintf(buf, "%d\n", nd->min_width *
227 				    nd->sensor_physical_width /
228 				    nd->sensor_logical_width);
229 }
230 
231 static ssize_t set_min_width(struct device *dev,
232 			     struct device_attribute *attr,
233 			     const char *buf, size_t count)
234 {
235 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
236 	struct ntrig_data *nd = hid_get_drvdata(hdev);
237 
238 	unsigned long val;
239 
240 	if (strict_strtoul(buf, 0, &val))
241 		return -EINVAL;
242 
243 	if (val > nd->sensor_physical_width)
244 		return -EINVAL;
245 
246 	nd->min_width = val * nd->sensor_logical_width /
247 			      nd->sensor_physical_width;
248 
249 	return count;
250 }
251 
252 static DEVICE_ATTR(min_width, S_IWUSR | S_IRUGO, show_min_width, set_min_width);
253 
254 static ssize_t show_min_height(struct device *dev,
255 			       struct device_attribute *attr,
256 			       char *buf)
257 {
258 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
259 	struct ntrig_data *nd = hid_get_drvdata(hdev);
260 
261 	return sprintf(buf, "%d\n", nd->min_height *
262 				    nd->sensor_physical_height /
263 				    nd->sensor_logical_height);
264 }
265 
266 static ssize_t set_min_height(struct device *dev,
267 			      struct device_attribute *attr,
268 			      const char *buf, size_t count)
269 {
270 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
271 	struct ntrig_data *nd = hid_get_drvdata(hdev);
272 
273 	unsigned long val;
274 
275 	if (strict_strtoul(buf, 0, &val))
276 		return -EINVAL;
277 
278 	if (val > nd->sensor_physical_height)
279 		return -EINVAL;
280 
281 	nd->min_height = val * nd->sensor_logical_height /
282 			       nd->sensor_physical_height;
283 
284 	return count;
285 }
286 
287 static DEVICE_ATTR(min_height, S_IWUSR | S_IRUGO, show_min_height,
288 		   set_min_height);
289 
290 static ssize_t show_activate_slack(struct device *dev,
291 				   struct device_attribute *attr,
292 				   char *buf)
293 {
294 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
295 	struct ntrig_data *nd = hid_get_drvdata(hdev);
296 
297 	return sprintf(buf, "%d\n", nd->activate_slack);
298 }
299 
300 static ssize_t set_activate_slack(struct device *dev,
301 				  struct device_attribute *attr,
302 				  const char *buf, size_t count)
303 {
304 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
305 	struct ntrig_data *nd = hid_get_drvdata(hdev);
306 
307 	unsigned long val;
308 
309 	if (strict_strtoul(buf, 0, &val))
310 		return -EINVAL;
311 
312 	if (val > 0x7f)
313 		return -EINVAL;
314 
315 	nd->activate_slack = val;
316 
317 	return count;
318 }
319 
320 static DEVICE_ATTR(activate_slack, S_IWUSR | S_IRUGO, show_activate_slack,
321 		   set_activate_slack);
322 
323 static ssize_t show_activation_width(struct device *dev,
324 				     struct device_attribute *attr,
325 				     char *buf)
326 {
327 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
328 	struct ntrig_data *nd = hid_get_drvdata(hdev);
329 
330 	return sprintf(buf, "%d\n", nd->activation_width *
331 				    nd->sensor_physical_width /
332 				    nd->sensor_logical_width);
333 }
334 
335 static ssize_t set_activation_width(struct device *dev,
336 				    struct device_attribute *attr,
337 				    const char *buf, size_t count)
338 {
339 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
340 	struct ntrig_data *nd = hid_get_drvdata(hdev);
341 
342 	unsigned long val;
343 
344 	if (strict_strtoul(buf, 0, &val))
345 		return -EINVAL;
346 
347 	if (val > nd->sensor_physical_width)
348 		return -EINVAL;
349 
350 	nd->activation_width = val * nd->sensor_logical_width /
351 				     nd->sensor_physical_width;
352 
353 	return count;
354 }
355 
356 static DEVICE_ATTR(activation_width, S_IWUSR | S_IRUGO, show_activation_width,
357 		   set_activation_width);
358 
359 static ssize_t show_activation_height(struct device *dev,
360 				      struct device_attribute *attr,
361 				      char *buf)
362 {
363 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
364 	struct ntrig_data *nd = hid_get_drvdata(hdev);
365 
366 	return sprintf(buf, "%d\n", nd->activation_height *
367 				    nd->sensor_physical_height /
368 				    nd->sensor_logical_height);
369 }
370 
371 static ssize_t set_activation_height(struct device *dev,
372 				     struct device_attribute *attr,
373 				     const char *buf, size_t count)
374 {
375 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
376 	struct ntrig_data *nd = hid_get_drvdata(hdev);
377 
378 	unsigned long val;
379 
380 	if (strict_strtoul(buf, 0, &val))
381 		return -EINVAL;
382 
383 	if (val > nd->sensor_physical_height)
384 		return -EINVAL;
385 
386 	nd->activation_height = val * nd->sensor_logical_height /
387 				      nd->sensor_physical_height;
388 
389 	return count;
390 }
391 
392 static DEVICE_ATTR(activation_height, S_IWUSR | S_IRUGO,
393 		   show_activation_height, set_activation_height);
394 
395 static ssize_t show_deactivate_slack(struct device *dev,
396 				     struct device_attribute *attr,
397 				     char *buf)
398 {
399 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
400 	struct ntrig_data *nd = hid_get_drvdata(hdev);
401 
402 	return sprintf(buf, "%d\n", -nd->deactivate_slack);
403 }
404 
405 static ssize_t set_deactivate_slack(struct device *dev,
406 				    struct device_attribute *attr,
407 				    const char *buf, size_t count)
408 {
409 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
410 	struct ntrig_data *nd = hid_get_drvdata(hdev);
411 
412 	unsigned long val;
413 
414 	if (strict_strtoul(buf, 0, &val))
415 		return -EINVAL;
416 
417 	/*
418 	 * No more than 8 terminal frames have been observed so far
419 	 * and higher slack is highly likely to leave the single
420 	 * touch emulation stuck down.
421 	 */
422 	if (val > 7)
423 		return -EINVAL;
424 
425 	nd->deactivate_slack = -val;
426 
427 	return count;
428 }
429 
430 static DEVICE_ATTR(deactivate_slack, S_IWUSR | S_IRUGO, show_deactivate_slack,
431 		   set_deactivate_slack);
432 
433 static struct attribute *sysfs_attrs[] = {
434 	&dev_attr_sensor_physical_width.attr,
435 	&dev_attr_sensor_physical_height.attr,
436 	&dev_attr_sensor_logical_width.attr,
437 	&dev_attr_sensor_logical_height.attr,
438 	&dev_attr_min_height.attr,
439 	&dev_attr_min_width.attr,
440 	&dev_attr_activate_slack.attr,
441 	&dev_attr_activation_width.attr,
442 	&dev_attr_activation_height.attr,
443 	&dev_attr_deactivate_slack.attr,
444 	NULL
445 };
446 
447 static struct attribute_group ntrig_attribute_group = {
448 	.attrs = sysfs_attrs
449 };
450 
451 /*
452  * this driver is aimed at two firmware versions in circulation:
453  *  - dual pen/finger single touch
454  *  - finger multitouch, pen not working
455  */
456 
457 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
458 			       struct hid_field *field, struct hid_usage *usage,
459 			       unsigned long **bit, int *max)
460 {
461 	struct ntrig_data *nd = hid_get_drvdata(hdev);
462 
463 	/* No special mappings needed for the pen and single touch */
464 	if (field->physical)
465 		return 0;
466 
467 	switch (usage->hid & HID_USAGE_PAGE) {
468 	case HID_UP_GENDESK:
469 		switch (usage->hid) {
470 		case HID_GD_X:
471 			hid_map_usage(hi, usage, bit, max,
472 					EV_ABS, ABS_MT_POSITION_X);
473 			input_set_abs_params(hi->input, ABS_X,
474 					field->logical_minimum,
475 					field->logical_maximum, 0, 0);
476 
477 			if (!nd->sensor_logical_width) {
478 				nd->sensor_logical_width =
479 					field->logical_maximum -
480 					field->logical_minimum;
481 				nd->sensor_physical_width =
482 					field->physical_maximum -
483 					field->physical_minimum;
484 				nd->activation_width = activation_width *
485 					nd->sensor_logical_width /
486 					nd->sensor_physical_width;
487 				nd->min_width = min_width *
488 					nd->sensor_logical_width /
489 					nd->sensor_physical_width;
490 			}
491 			return 1;
492 		case HID_GD_Y:
493 			hid_map_usage(hi, usage, bit, max,
494 					EV_ABS, ABS_MT_POSITION_Y);
495 			input_set_abs_params(hi->input, ABS_Y,
496 					field->logical_minimum,
497 					field->logical_maximum, 0, 0);
498 
499 			if (!nd->sensor_logical_height) {
500 				nd->sensor_logical_height =
501 					field->logical_maximum -
502 					field->logical_minimum;
503 				nd->sensor_physical_height =
504 					field->physical_maximum -
505 					field->physical_minimum;
506 				nd->activation_height = activation_height *
507 					nd->sensor_logical_height /
508 					nd->sensor_physical_height;
509 				nd->min_height = min_height *
510 					nd->sensor_logical_height /
511 					nd->sensor_physical_height;
512 			}
513 			return 1;
514 		}
515 		return 0;
516 
517 	case HID_UP_DIGITIZER:
518 		switch (usage->hid) {
519 		/* we do not want to map these for now */
520 		case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
521 		case HID_DG_INPUTMODE:
522 		case HID_DG_DEVICEINDEX:
523 		case HID_DG_CONTACTMAX:
524 			return -1;
525 
526 		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
527 		case HID_DG_WIDTH:
528 			hid_map_usage(hi, usage, bit, max,
529 				      EV_ABS, ABS_MT_TOUCH_MAJOR);
530 			return 1;
531 		case HID_DG_HEIGHT:
532 			hid_map_usage(hi, usage, bit, max,
533 				      EV_ABS, ABS_MT_TOUCH_MINOR);
534 			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
535 					     0, 1, 0, 0);
536 			return 1;
537 		}
538 		return 0;
539 
540 	case 0xff000000:
541 		/* we do not want to map these: no input-oriented meaning */
542 		return -1;
543 	}
544 
545 	return 0;
546 }
547 
548 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
549 			      struct hid_field *field, struct hid_usage *usage,
550 			      unsigned long **bit, int *max)
551 {
552 	/* No special mappings needed for the pen and single touch */
553 	if (field->physical)
554 		return 0;
555 
556 	if (usage->type == EV_KEY || usage->type == EV_REL
557 			|| usage->type == EV_ABS)
558 		clear_bit(usage->code, *bit);
559 
560 	return 0;
561 }
562 
563 /*
564  * this function is called upon all reports
565  * so that we can filter contact point information,
566  * decide whether we are in multi or single touch mode
567  * and call input_mt_sync after each point if necessary
568  */
569 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
570 			struct hid_usage *usage, __s32 value)
571 {
572 	struct ntrig_data *nd = hid_get_drvdata(hid);
573 	struct input_dev *input;
574 
575 	/* Skip processing if not a claimed input */
576 	if (!(hid->claimed & HID_CLAIMED_INPUT))
577 		goto not_claimed_input;
578 
579 	/* This function is being called before the structures are fully
580 	 * initialized */
581 	if(!(field->hidinput && field->hidinput->input))
582 		return -EINVAL;
583 
584 	input = field->hidinput->input;
585 
586 	/* No special handling needed for the pen */
587 	if (field->application == HID_DG_PEN)
588 		return 0;
589 
590 	switch (usage->hid) {
591 	case 0xff000001:
592 		/* Tag indicating the start of a multitouch group */
593 		nd->reading_mt = 1;
594 		nd->first_contact_touch = 0;
595 		break;
596 	case HID_DG_TIPSWITCH:
597 		nd->tipswitch = value;
598 		/* Prevent emission of touch until validated */
599 		return 1;
600 	case HID_DG_CONFIDENCE:
601 		nd->confidence = value;
602 		break;
603 	case HID_GD_X:
604 		nd->x = value;
605 		/* Clear the contact footer */
606 		nd->mt_foot_count = 0;
607 		break;
608 	case HID_GD_Y:
609 		nd->y = value;
610 		break;
611 	case HID_DG_CONTACTID:
612 		nd->id = value;
613 		break;
614 	case HID_DG_WIDTH:
615 		nd->w = value;
616 		break;
617 	case HID_DG_HEIGHT:
618 		nd->h = value;
619 		/*
620 		 * when in single touch mode, this is the last
621 		 * report received in a finger event. We want
622 		 * to emit a normal (X, Y) position
623 		 */
624 		if (!nd->reading_mt) {
625 			/*
626 			 * TipSwitch indicates the presence of a
627 			 * finger in single touch mode.
628 			 */
629 			input_report_key(input, BTN_TOUCH,
630 					 nd->tipswitch);
631 			input_report_key(input, BTN_TOOL_DOUBLETAP,
632 					 nd->tipswitch);
633 			input_event(input, EV_ABS, ABS_X, nd->x);
634 			input_event(input, EV_ABS, ABS_Y, nd->y);
635 		}
636 		break;
637 	case 0xff000002:
638 		/*
639 		 * we receive this when the device is in multitouch
640 		 * mode. The first of the three values tagged with
641 		 * this usage tells if the contact point is real
642 		 * or a placeholder
643 		 */
644 
645 		/* Shouldn't get more than 4 footer packets, so skip */
646 		if (nd->mt_foot_count >= 4)
647 			break;
648 
649 		nd->mt_footer[nd->mt_foot_count++] = value;
650 
651 		/* if the footer isn't complete break */
652 		if (nd->mt_foot_count != 4)
653 			break;
654 
655 		/* Pen activity signal. */
656 		if (nd->mt_footer[2]) {
657 			/*
658 			 * When the pen deactivates touch, we see a
659 			 * bogus frame with ContactCount > 0.
660 			 * We can
661 			 * save a bit of work by ensuring act_state < 0
662 			 * even if deactivation slack is turned off.
663 			 */
664 			nd->act_state = deactivate_slack - 1;
665 			nd->confidence = 0;
666 			break;
667 		}
668 
669 		/*
670 		 * The first footer value indicates the presence of a
671 		 * finger.
672 		 */
673 		if (nd->mt_footer[0]) {
674 			/*
675 			 * We do not want to process contacts under
676 			 * the size threshold, but do not want to
677 			 * ignore them for activation state
678 			 */
679 			if (nd->w < nd->min_width ||
680 			    nd->h < nd->min_height)
681 				nd->confidence = 0;
682 		} else
683 			break;
684 
685 		if (nd->act_state > 0) {
686 			/*
687 			 * Contact meets the activation size threshold
688 			 */
689 			if (nd->w >= nd->activation_width &&
690 			    nd->h >= nd->activation_height) {
691 				if (nd->id)
692 					/*
693 					 * first contact, activate now
694 					 */
695 					nd->act_state = 0;
696 				else {
697 					/*
698 					 * avoid corrupting this frame
699 					 * but ensure next frame will
700 					 * be active
701 					 */
702 					nd->act_state = 1;
703 					break;
704 				}
705 			} else
706 				/*
707 				 * Defer adjusting the activation state
708 				 * until the end of the frame.
709 				 */
710 				break;
711 		}
712 
713 		/* Discarding this contact */
714 		if (!nd->confidence)
715 			break;
716 
717 		/* emit a normal (X, Y) for the first point only */
718 		if (nd->id == 0) {
719 			/*
720 			 * TipSwitch is superfluous in multitouch
721 			 * mode.  The footer events tell us
722 			 * if there is a finger on the screen or
723 			 * not.
724 			 */
725 			nd->first_contact_touch = nd->confidence;
726 			input_event(input, EV_ABS, ABS_X, nd->x);
727 			input_event(input, EV_ABS, ABS_Y, nd->y);
728 		}
729 
730 		/* Emit MT events */
731 		input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
732 		input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
733 
734 		/*
735 		 * Translate from height and width to size
736 		 * and orientation.
737 		 */
738 		if (nd->w > nd->h) {
739 			input_event(input, EV_ABS,
740 					ABS_MT_ORIENTATION, 1);
741 			input_event(input, EV_ABS,
742 					ABS_MT_TOUCH_MAJOR, nd->w);
743 			input_event(input, EV_ABS,
744 					ABS_MT_TOUCH_MINOR, nd->h);
745 		} else {
746 			input_event(input, EV_ABS,
747 					ABS_MT_ORIENTATION, 0);
748 			input_event(input, EV_ABS,
749 					ABS_MT_TOUCH_MAJOR, nd->h);
750 			input_event(input, EV_ABS,
751 					ABS_MT_TOUCH_MINOR, nd->w);
752 		}
753 		input_mt_sync(field->hidinput->input);
754 		break;
755 
756 	case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
757 		if (!nd->reading_mt) /* Just to be sure */
758 			break;
759 
760 		nd->reading_mt = 0;
761 
762 
763 		/*
764 		 * Activation state machine logic:
765 		 *
766 		 * Fundamental states:
767 		 *	state >  0: Inactive
768 		 *	state <= 0: Active
769 		 *	state <  -deactivate_slack:
770 		 *		 Pen termination of touch
771 		 *
772 		 * Specific values of interest
773 		 *	state == activate_slack
774 		 *		 no valid input since the last reset
775 		 *
776 		 *	state == 0
777 		 *		 general operational state
778 		 *
779 		 *	state == -deactivate_slack
780 		 *		 read sufficient empty frames to accept
781 		 *		 the end of input and reset
782 		 */
783 
784 		if (nd->act_state > 0) { /* Currently inactive */
785 			if (value)
786 				/*
787 				 * Consider each live contact as
788 				 * evidence of intentional activity.
789 				 */
790 				nd->act_state = (nd->act_state > value)
791 						? nd->act_state - value
792 						: 0;
793 			else
794 				/*
795 				 * Empty frame before we hit the
796 				 * activity threshold, reset.
797 				 */
798 				nd->act_state = nd->activate_slack;
799 
800 			/*
801 			 * Entered this block inactive and no
802 			 * coordinates sent this frame, so hold off
803 			 * on button state.
804 			 */
805 			break;
806 		} else { /* Currently active */
807 			if (value && nd->act_state >=
808 				     nd->deactivate_slack)
809 				/*
810 				 * Live point: clear accumulated
811 				 * deactivation count.
812 				 */
813 				nd->act_state = 0;
814 			else if (nd->act_state <= nd->deactivate_slack)
815 				/*
816 				 * We've consumed the deactivation
817 				 * slack, time to deactivate and reset.
818 				 */
819 				nd->act_state =
820 					nd->activate_slack;
821 			else { /* Move towards deactivation */
822 				nd->act_state--;
823 				break;
824 			}
825 		}
826 
827 		if (nd->first_contact_touch && nd->act_state <= 0) {
828 			/*
829 			 * Check to see if we're ready to start
830 			 * emitting touch events.
831 			 *
832 			 * Note: activation slack will decrease over
833 			 * the course of the frame, and it will be
834 			 * inconsistent from the start to the end of
835 			 * the frame.  However if the frame starts
836 			 * with slack, first_contact_touch will still
837 			 * be 0 and we will not get to this point.
838 			 */
839 			input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
840 			input_report_key(input, BTN_TOUCH, 1);
841 		} else {
842 			input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
843 			input_report_key(input, BTN_TOUCH, 0);
844 		}
845 		break;
846 
847 	default:
848 		/* fall-back to the generic hidinput handling */
849 		return 0;
850 	}
851 
852 not_claimed_input:
853 
854 	/* we have handled the hidinput part, now remains hiddev */
855 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
856 		hid->hiddev_hid_event(hid, field, usage, value);
857 
858 	return 1;
859 }
860 
861 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
862 {
863 	int ret;
864 	struct ntrig_data *nd;
865 	struct hid_input *hidinput;
866 	struct input_dev *input;
867 	struct hid_report *report;
868 
869 	if (id->driver_data)
870 		hdev->quirks |= HID_QUIRK_MULTI_INPUT
871 				| HID_QUIRK_NO_INIT_REPORTS;
872 
873 	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
874 	if (!nd) {
875 		hid_err(hdev, "cannot allocate N-Trig data\n");
876 		return -ENOMEM;
877 	}
878 
879 	nd->reading_mt = 0;
880 	nd->min_width = 0;
881 	nd->min_height = 0;
882 	nd->activate_slack = activate_slack;
883 	nd->act_state = activate_slack;
884 	nd->deactivate_slack = -deactivate_slack;
885 	nd->sensor_logical_width = 1;
886 	nd->sensor_logical_height = 1;
887 	nd->sensor_physical_width = 1;
888 	nd->sensor_physical_height = 1;
889 
890 	hid_set_drvdata(hdev, nd);
891 
892 	ret = hid_parse(hdev);
893 	if (ret) {
894 		hid_err(hdev, "parse failed\n");
895 		goto err_free;
896 	}
897 
898 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
899 	if (ret) {
900 		hid_err(hdev, "hw start failed\n");
901 		goto err_free;
902 	}
903 
904 
905 	list_for_each_entry(hidinput, &hdev->inputs, list) {
906 		if (hidinput->report->maxfield < 1)
907 			continue;
908 
909 		input = hidinput->input;
910 		switch (hidinput->report->field[0]->application) {
911 		case HID_DG_PEN:
912 			input->name = "N-Trig Pen";
913 			break;
914 		case HID_DG_TOUCHSCREEN:
915 			/* These keys are redundant for fingers, clear them
916 			 * to prevent incorrect identification */
917 			__clear_bit(BTN_TOOL_PEN, input->keybit);
918 			__clear_bit(BTN_TOOL_FINGER, input->keybit);
919 			__clear_bit(BTN_0, input->keybit);
920 			__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
921 			/*
922 			 * The physical touchscreen (single touch)
923 			 * input has a value for physical, whereas
924 			 * the multitouch only has logical input
925 			 * fields.
926 			 */
927 			input->name =
928 				(hidinput->report->field[0]
929 				 ->physical) ?
930 				"N-Trig Touchscreen" :
931 				"N-Trig MultiTouch";
932 			break;
933 		}
934 	}
935 
936 	/* This is needed for devices with more recent firmware versions */
937 	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
938 	if (report) {
939 		/* Let the device settle to ensure the wakeup message gets
940 		 * through */
941 		usbhid_wait_io(hdev);
942 		usbhid_submit_report(hdev, report, USB_DIR_IN);
943 
944 		/*
945 		 * Sanity check: if the current mode is invalid reset it to
946 		 * something reasonable.
947 		 */
948 		if (ntrig_get_mode(hdev) >= 4)
949 			ntrig_set_mode(hdev, 3);
950 	}
951 
952 	ntrig_report_version(hdev);
953 
954 	ret = sysfs_create_group(&hdev->dev.kobj,
955 			&ntrig_attribute_group);
956 
957 	return 0;
958 err_free:
959 	kfree(nd);
960 	return ret;
961 }
962 
963 static void ntrig_remove(struct hid_device *hdev)
964 {
965 	sysfs_remove_group(&hdev->dev.kobj,
966 			   &ntrig_attribute_group);
967 	hid_hw_stop(hdev);
968 	kfree(hid_get_drvdata(hdev));
969 }
970 
971 static const struct hid_device_id ntrig_devices[] = {
972 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
973 		.driver_data = NTRIG_DUPLICATE_USAGES },
974 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_1),
975 		.driver_data = NTRIG_DUPLICATE_USAGES },
976 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_2),
977 		.driver_data = NTRIG_DUPLICATE_USAGES },
978 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_3),
979 		.driver_data = NTRIG_DUPLICATE_USAGES },
980 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_4),
981 		.driver_data = NTRIG_DUPLICATE_USAGES },
982 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_5),
983 		.driver_data = NTRIG_DUPLICATE_USAGES },
984 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_6),
985 		.driver_data = NTRIG_DUPLICATE_USAGES },
986 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_7),
987 		.driver_data = NTRIG_DUPLICATE_USAGES },
988 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_8),
989 		.driver_data = NTRIG_DUPLICATE_USAGES },
990 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_9),
991 		.driver_data = NTRIG_DUPLICATE_USAGES },
992 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_10),
993 		.driver_data = NTRIG_DUPLICATE_USAGES },
994 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_11),
995 		.driver_data = NTRIG_DUPLICATE_USAGES },
996 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_12),
997 		.driver_data = NTRIG_DUPLICATE_USAGES },
998 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_13),
999 		.driver_data = NTRIG_DUPLICATE_USAGES },
1000 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_14),
1001 		.driver_data = NTRIG_DUPLICATE_USAGES },
1002 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_15),
1003 		.driver_data = NTRIG_DUPLICATE_USAGES },
1004 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_16),
1005 		.driver_data = NTRIG_DUPLICATE_USAGES },
1006 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_17),
1007 		.driver_data = NTRIG_DUPLICATE_USAGES },
1008 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_18),
1009 		.driver_data = NTRIG_DUPLICATE_USAGES },
1010 	{ }
1011 };
1012 MODULE_DEVICE_TABLE(hid, ntrig_devices);
1013 
1014 static const struct hid_usage_id ntrig_grabbed_usages[] = {
1015 	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
1016 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
1017 };
1018 
1019 static struct hid_driver ntrig_driver = {
1020 	.name = "ntrig",
1021 	.id_table = ntrig_devices,
1022 	.probe = ntrig_probe,
1023 	.remove = ntrig_remove,
1024 	.input_mapping = ntrig_input_mapping,
1025 	.input_mapped = ntrig_input_mapped,
1026 	.usage_table = ntrig_grabbed_usages,
1027 	.event = ntrig_event,
1028 };
1029 
1030 static int __init ntrig_init(void)
1031 {
1032 	return hid_register_driver(&ntrig_driver);
1033 }
1034 
1035 static void __exit ntrig_exit(void)
1036 {
1037 	hid_unregister_driver(&ntrig_driver);
1038 }
1039 
1040 module_init(ntrig_init);
1041 module_exit(ntrig_exit);
1042 MODULE_LICENSE("GPL");
1043