xref: /openbmc/linux/drivers/hid/hid-ntrig.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  HID driver for N-Trig touchscreens
4  *
5  *  Copyright (c) 2008-2010 Rafi Rubin
6  *  Copyright (c) 2009-2010 Stephane Chatty
7  */
8 
9 /*
10  */
11 
12 #include <linux/device.h>
13 #include <linux/hid.h>
14 #include <linux/usb.h>
15 #include "usbhid/usbhid.h"
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 
19 #include "hid-ids.h"
20 
21 #define NTRIG_DUPLICATE_USAGES	0x001
22 
23 static unsigned int min_width;
24 module_param(min_width, uint, 0644);
25 MODULE_PARM_DESC(min_width, "Minimum touch contact width to accept.");
26 
27 static unsigned int min_height;
28 module_param(min_height, uint, 0644);
29 MODULE_PARM_DESC(min_height, "Minimum touch contact height to accept.");
30 
31 static unsigned int activate_slack = 1;
32 module_param(activate_slack, uint, 0644);
33 MODULE_PARM_DESC(activate_slack, "Number of touch frames to ignore at "
34 		 "the start of touch input.");
35 
36 static unsigned int deactivate_slack = 4;
37 module_param(deactivate_slack, uint, 0644);
38 MODULE_PARM_DESC(deactivate_slack, "Number of empty frames to ignore before "
39 		 "deactivating touch.");
40 
41 static unsigned int activation_width = 64;
42 module_param(activation_width, uint, 0644);
43 MODULE_PARM_DESC(activation_width, "Width threshold to immediately start "
44 		 "processing touch events.");
45 
46 static unsigned int activation_height = 32;
47 module_param(activation_height, uint, 0644);
48 MODULE_PARM_DESC(activation_height, "Height threshold to immediately start "
49 		 "processing touch events.");
50 
51 struct ntrig_data {
52 	/* Incoming raw values for a single contact */
53 	__u16 x, y, w, h;
54 	__u16 id;
55 
56 	bool tipswitch;
57 	bool confidence;
58 	bool first_contact_touch;
59 
60 	bool reading_mt;
61 
62 	__u8 mt_footer[4];
63 	__u8 mt_foot_count;
64 
65 	/* The current activation state. */
66 	__s8 act_state;
67 
68 	/* Empty frames to ignore before recognizing the end of activity */
69 	__s8 deactivate_slack;
70 
71 	/* Frames to ignore before acknowledging the start of activity */
72 	__s8 activate_slack;
73 
74 	/* Minimum size contact to accept */
75 	__u16 min_width;
76 	__u16 min_height;
77 
78 	/* Threshold to override activation slack */
79 	__u16 activation_width;
80 	__u16 activation_height;
81 
82 	__u16 sensor_logical_width;
83 	__u16 sensor_logical_height;
84 	__u16 sensor_physical_width;
85 	__u16 sensor_physical_height;
86 };
87 
88 
89 /*
90  * This function converts the 4 byte raw firmware code into
91  * a string containing 5 comma separated numbers.
92  */
93 static int ntrig_version_string(unsigned char *raw, char *buf)
94 {
95 	__u8 a =  (raw[1] & 0x0e) >> 1;
96 	__u8 b =  (raw[0] & 0x3c) >> 2;
97 	__u8 c = ((raw[0] & 0x03) << 3) | ((raw[3] & 0xe0) >> 5);
98 	__u8 d = ((raw[3] & 0x07) << 3) | ((raw[2] & 0xe0) >> 5);
99 	__u8 e =   raw[2] & 0x07;
100 
101 	/*
102 	 * As yet unmapped bits:
103 	 * 0b11000000 0b11110001 0b00011000 0b00011000
104 	 */
105 
106 	return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
107 }
108 
109 static inline int ntrig_get_mode(struct hid_device *hdev)
110 {
111 	struct hid_report *report = hdev->report_enum[HID_FEATURE_REPORT].
112 				    report_id_hash[0x0d];
113 
114 	if (!report || report->maxfield < 1 ||
115 	    report->field[0]->report_count < 1)
116 		return -EINVAL;
117 
118 	hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
119 	hid_hw_wait(hdev);
120 	return (int)report->field[0]->value[0];
121 }
122 
123 static inline void ntrig_set_mode(struct hid_device *hdev, const int mode)
124 {
125 	struct hid_report *report;
126 	__u8 mode_commands[4] = { 0xe, 0xf, 0x1b, 0x10 };
127 
128 	if (mode < 0 || mode > 3)
129 		return;
130 
131 	report = hdev->report_enum[HID_FEATURE_REPORT].
132 		 report_id_hash[mode_commands[mode]];
133 
134 	if (!report)
135 		return;
136 
137 	hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
138 }
139 
140 static void ntrig_report_version(struct hid_device *hdev)
141 {
142 	int ret;
143 	char buf[20];
144 	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
145 	unsigned char *data = kmalloc(8, GFP_KERNEL);
146 
147 	if (!data)
148 		goto err_free;
149 
150 	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
151 			      USB_REQ_CLEAR_FEATURE,
152 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
153 			      USB_DIR_IN,
154 			      0x30c, 1, data, 8,
155 			      USB_CTRL_SET_TIMEOUT);
156 
157 	if (ret == 8) {
158 		ret = ntrig_version_string(&data[2], buf);
159 
160 		hid_info(hdev, "Firmware version: %s (%02x%02x %02x%02x)\n",
161 			 buf, data[2], data[3], data[4], data[5]);
162 	}
163 
164 err_free:
165 	kfree(data);
166 }
167 
168 static ssize_t show_phys_width(struct device *dev,
169 			       struct device_attribute *attr,
170 			       char *buf)
171 {
172 	struct hid_device *hdev = to_hid_device(dev);
173 	struct ntrig_data *nd = hid_get_drvdata(hdev);
174 
175 	return sprintf(buf, "%d\n", nd->sensor_physical_width);
176 }
177 
178 static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);
179 
180 static ssize_t show_phys_height(struct device *dev,
181 				struct device_attribute *attr,
182 				char *buf)
183 {
184 	struct hid_device *hdev = to_hid_device(dev);
185 	struct ntrig_data *nd = hid_get_drvdata(hdev);
186 
187 	return sprintf(buf, "%d\n", nd->sensor_physical_height);
188 }
189 
190 static DEVICE_ATTR(sensor_physical_height, S_IRUGO, show_phys_height, NULL);
191 
192 static ssize_t show_log_width(struct device *dev,
193 			      struct device_attribute *attr,
194 			      char *buf)
195 {
196 	struct hid_device *hdev = to_hid_device(dev);
197 	struct ntrig_data *nd = hid_get_drvdata(hdev);
198 
199 	return sprintf(buf, "%d\n", nd->sensor_logical_width);
200 }
201 
202 static DEVICE_ATTR(sensor_logical_width, S_IRUGO, show_log_width, NULL);
203 
204 static ssize_t show_log_height(struct device *dev,
205 			       struct device_attribute *attr,
206 			       char *buf)
207 {
208 	struct hid_device *hdev = to_hid_device(dev);
209 	struct ntrig_data *nd = hid_get_drvdata(hdev);
210 
211 	return sprintf(buf, "%d\n", nd->sensor_logical_height);
212 }
213 
214 static DEVICE_ATTR(sensor_logical_height, S_IRUGO, show_log_height, NULL);
215 
216 static ssize_t show_min_width(struct device *dev,
217 			      struct device_attribute *attr,
218 			      char *buf)
219 {
220 	struct hid_device *hdev = to_hid_device(dev);
221 	struct ntrig_data *nd = hid_get_drvdata(hdev);
222 
223 	return sprintf(buf, "%d\n", nd->min_width *
224 				    nd->sensor_physical_width /
225 				    nd->sensor_logical_width);
226 }
227 
228 static ssize_t set_min_width(struct device *dev,
229 			     struct device_attribute *attr,
230 			     const char *buf, size_t count)
231 {
232 	struct hid_device *hdev = to_hid_device(dev);
233 	struct ntrig_data *nd = hid_get_drvdata(hdev);
234 
235 	unsigned long val;
236 
237 	if (kstrtoul(buf, 0, &val))
238 		return -EINVAL;
239 
240 	if (val > nd->sensor_physical_width)
241 		return -EINVAL;
242 
243 	nd->min_width = val * nd->sensor_logical_width /
244 			      nd->sensor_physical_width;
245 
246 	return count;
247 }
248 
249 static DEVICE_ATTR(min_width, S_IWUSR | S_IRUGO, show_min_width, set_min_width);
250 
251 static ssize_t show_min_height(struct device *dev,
252 			       struct device_attribute *attr,
253 			       char *buf)
254 {
255 	struct hid_device *hdev = to_hid_device(dev);
256 	struct ntrig_data *nd = hid_get_drvdata(hdev);
257 
258 	return sprintf(buf, "%d\n", nd->min_height *
259 				    nd->sensor_physical_height /
260 				    nd->sensor_logical_height);
261 }
262 
263 static ssize_t set_min_height(struct device *dev,
264 			      struct device_attribute *attr,
265 			      const char *buf, size_t count)
266 {
267 	struct hid_device *hdev = to_hid_device(dev);
268 	struct ntrig_data *nd = hid_get_drvdata(hdev);
269 
270 	unsigned long val;
271 
272 	if (kstrtoul(buf, 0, &val))
273 		return -EINVAL;
274 
275 	if (val > nd->sensor_physical_height)
276 		return -EINVAL;
277 
278 	nd->min_height = val * nd->sensor_logical_height /
279 			       nd->sensor_physical_height;
280 
281 	return count;
282 }
283 
284 static DEVICE_ATTR(min_height, S_IWUSR | S_IRUGO, show_min_height,
285 		   set_min_height);
286 
287 static ssize_t show_activate_slack(struct device *dev,
288 				   struct device_attribute *attr,
289 				   char *buf)
290 {
291 	struct hid_device *hdev = to_hid_device(dev);
292 	struct ntrig_data *nd = hid_get_drvdata(hdev);
293 
294 	return sprintf(buf, "%d\n", nd->activate_slack);
295 }
296 
297 static ssize_t set_activate_slack(struct device *dev,
298 				  struct device_attribute *attr,
299 				  const char *buf, size_t count)
300 {
301 	struct hid_device *hdev = to_hid_device(dev);
302 	struct ntrig_data *nd = hid_get_drvdata(hdev);
303 
304 	unsigned long val;
305 
306 	if (kstrtoul(buf, 0, &val))
307 		return -EINVAL;
308 
309 	if (val > 0x7f)
310 		return -EINVAL;
311 
312 	nd->activate_slack = val;
313 
314 	return count;
315 }
316 
317 static DEVICE_ATTR(activate_slack, S_IWUSR | S_IRUGO, show_activate_slack,
318 		   set_activate_slack);
319 
320 static ssize_t show_activation_width(struct device *dev,
321 				     struct device_attribute *attr,
322 				     char *buf)
323 {
324 	struct hid_device *hdev = to_hid_device(dev);
325 	struct ntrig_data *nd = hid_get_drvdata(hdev);
326 
327 	return sprintf(buf, "%d\n", nd->activation_width *
328 				    nd->sensor_physical_width /
329 				    nd->sensor_logical_width);
330 }
331 
332 static ssize_t set_activation_width(struct device *dev,
333 				    struct device_attribute *attr,
334 				    const char *buf, size_t count)
335 {
336 	struct hid_device *hdev = to_hid_device(dev);
337 	struct ntrig_data *nd = hid_get_drvdata(hdev);
338 
339 	unsigned long val;
340 
341 	if (kstrtoul(buf, 0, &val))
342 		return -EINVAL;
343 
344 	if (val > nd->sensor_physical_width)
345 		return -EINVAL;
346 
347 	nd->activation_width = val * nd->sensor_logical_width /
348 				     nd->sensor_physical_width;
349 
350 	return count;
351 }
352 
353 static DEVICE_ATTR(activation_width, S_IWUSR | S_IRUGO, show_activation_width,
354 		   set_activation_width);
355 
356 static ssize_t show_activation_height(struct device *dev,
357 				      struct device_attribute *attr,
358 				      char *buf)
359 {
360 	struct hid_device *hdev = to_hid_device(dev);
361 	struct ntrig_data *nd = hid_get_drvdata(hdev);
362 
363 	return sprintf(buf, "%d\n", nd->activation_height *
364 				    nd->sensor_physical_height /
365 				    nd->sensor_logical_height);
366 }
367 
368 static ssize_t set_activation_height(struct device *dev,
369 				     struct device_attribute *attr,
370 				     const char *buf, size_t count)
371 {
372 	struct hid_device *hdev = to_hid_device(dev);
373 	struct ntrig_data *nd = hid_get_drvdata(hdev);
374 
375 	unsigned long val;
376 
377 	if (kstrtoul(buf, 0, &val))
378 		return -EINVAL;
379 
380 	if (val > nd->sensor_physical_height)
381 		return -EINVAL;
382 
383 	nd->activation_height = val * nd->sensor_logical_height /
384 				      nd->sensor_physical_height;
385 
386 	return count;
387 }
388 
389 static DEVICE_ATTR(activation_height, S_IWUSR | S_IRUGO,
390 		   show_activation_height, set_activation_height);
391 
392 static ssize_t show_deactivate_slack(struct device *dev,
393 				     struct device_attribute *attr,
394 				     char *buf)
395 {
396 	struct hid_device *hdev = to_hid_device(dev);
397 	struct ntrig_data *nd = hid_get_drvdata(hdev);
398 
399 	return sprintf(buf, "%d\n", -nd->deactivate_slack);
400 }
401 
402 static ssize_t set_deactivate_slack(struct device *dev,
403 				    struct device_attribute *attr,
404 				    const char *buf, size_t count)
405 {
406 	struct hid_device *hdev = to_hid_device(dev);
407 	struct ntrig_data *nd = hid_get_drvdata(hdev);
408 
409 	unsigned long val;
410 
411 	if (kstrtoul(buf, 0, &val))
412 		return -EINVAL;
413 
414 	/*
415 	 * No more than 8 terminal frames have been observed so far
416 	 * and higher slack is highly likely to leave the single
417 	 * touch emulation stuck down.
418 	 */
419 	if (val > 7)
420 		return -EINVAL;
421 
422 	nd->deactivate_slack = -val;
423 
424 	return count;
425 }
426 
427 static DEVICE_ATTR(deactivate_slack, S_IWUSR | S_IRUGO, show_deactivate_slack,
428 		   set_deactivate_slack);
429 
430 static struct attribute *sysfs_attrs[] = {
431 	&dev_attr_sensor_physical_width.attr,
432 	&dev_attr_sensor_physical_height.attr,
433 	&dev_attr_sensor_logical_width.attr,
434 	&dev_attr_sensor_logical_height.attr,
435 	&dev_attr_min_height.attr,
436 	&dev_attr_min_width.attr,
437 	&dev_attr_activate_slack.attr,
438 	&dev_attr_activation_width.attr,
439 	&dev_attr_activation_height.attr,
440 	&dev_attr_deactivate_slack.attr,
441 	NULL
442 };
443 
444 static const struct attribute_group ntrig_attribute_group = {
445 	.attrs = sysfs_attrs
446 };
447 
448 /*
449  * this driver is aimed at two firmware versions in circulation:
450  *  - dual pen/finger single touch
451  *  - finger multitouch, pen not working
452  */
453 
454 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
455 			       struct hid_field *field, struct hid_usage *usage,
456 			       unsigned long **bit, int *max)
457 {
458 	struct ntrig_data *nd = hid_get_drvdata(hdev);
459 
460 	/* No special mappings needed for the pen and single touch */
461 	if (field->physical)
462 		return 0;
463 
464 	switch (usage->hid & HID_USAGE_PAGE) {
465 	case HID_UP_GENDESK:
466 		switch (usage->hid) {
467 		case HID_GD_X:
468 			hid_map_usage(hi, usage, bit, max,
469 					EV_ABS, ABS_MT_POSITION_X);
470 			input_set_abs_params(hi->input, ABS_X,
471 					field->logical_minimum,
472 					field->logical_maximum, 0, 0);
473 
474 			if (!nd->sensor_logical_width) {
475 				nd->sensor_logical_width =
476 					field->logical_maximum -
477 					field->logical_minimum;
478 				nd->sensor_physical_width =
479 					field->physical_maximum -
480 					field->physical_minimum;
481 				nd->activation_width = activation_width *
482 					nd->sensor_logical_width /
483 					nd->sensor_physical_width;
484 				nd->min_width = min_width *
485 					nd->sensor_logical_width /
486 					nd->sensor_physical_width;
487 			}
488 			return 1;
489 		case HID_GD_Y:
490 			hid_map_usage(hi, usage, bit, max,
491 					EV_ABS, ABS_MT_POSITION_Y);
492 			input_set_abs_params(hi->input, ABS_Y,
493 					field->logical_minimum,
494 					field->logical_maximum, 0, 0);
495 
496 			if (!nd->sensor_logical_height) {
497 				nd->sensor_logical_height =
498 					field->logical_maximum -
499 					field->logical_minimum;
500 				nd->sensor_physical_height =
501 					field->physical_maximum -
502 					field->physical_minimum;
503 				nd->activation_height = activation_height *
504 					nd->sensor_logical_height /
505 					nd->sensor_physical_height;
506 				nd->min_height = min_height *
507 					nd->sensor_logical_height /
508 					nd->sensor_physical_height;
509 			}
510 			return 1;
511 		}
512 		return 0;
513 
514 	case HID_UP_DIGITIZER:
515 		switch (usage->hid) {
516 		/* we do not want to map these for now */
517 		case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
518 		case HID_DG_INPUTMODE:
519 		case HID_DG_DEVICEINDEX:
520 		case HID_DG_CONTACTMAX:
521 			return -1;
522 
523 		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
524 		case HID_DG_WIDTH:
525 			hid_map_usage(hi, usage, bit, max,
526 				      EV_ABS, ABS_MT_TOUCH_MAJOR);
527 			return 1;
528 		case HID_DG_HEIGHT:
529 			hid_map_usage(hi, usage, bit, max,
530 				      EV_ABS, ABS_MT_TOUCH_MINOR);
531 			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
532 					     0, 1, 0, 0);
533 			return 1;
534 		}
535 		return 0;
536 
537 	case 0xff000000:
538 		/* we do not want to map these: no input-oriented meaning */
539 		return -1;
540 	}
541 
542 	return 0;
543 }
544 
545 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
546 			      struct hid_field *field, struct hid_usage *usage,
547 			      unsigned long **bit, int *max)
548 {
549 	/* No special mappings needed for the pen and single touch */
550 	if (field->physical)
551 		return 0;
552 
553 	if (usage->type == EV_KEY || usage->type == EV_REL
554 			|| usage->type == EV_ABS)
555 		clear_bit(usage->code, *bit);
556 
557 	return 0;
558 }
559 
560 /*
561  * this function is called upon all reports
562  * so that we can filter contact point information,
563  * decide whether we are in multi or single touch mode
564  * and call input_mt_sync after each point if necessary
565  */
566 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
567 			struct hid_usage *usage, __s32 value)
568 {
569 	struct ntrig_data *nd = hid_get_drvdata(hid);
570 	struct input_dev *input;
571 
572 	/* Skip processing if not a claimed input */
573 	if (!(hid->claimed & HID_CLAIMED_INPUT))
574 		goto not_claimed_input;
575 
576 	/* This function is being called before the structures are fully
577 	 * initialized */
578 	if(!(field->hidinput && field->hidinput->input))
579 		return -EINVAL;
580 
581 	input = field->hidinput->input;
582 
583 	/* No special handling needed for the pen */
584 	if (field->application == HID_DG_PEN)
585 		return 0;
586 
587 	switch (usage->hid) {
588 	case 0xff000001:
589 		/* Tag indicating the start of a multitouch group */
590 		nd->reading_mt = true;
591 		nd->first_contact_touch = false;
592 		break;
593 	case HID_DG_TIPSWITCH:
594 		nd->tipswitch = value;
595 		/* Prevent emission of touch until validated */
596 		return 1;
597 	case HID_DG_CONFIDENCE:
598 		nd->confidence = value;
599 		break;
600 	case HID_GD_X:
601 		nd->x = value;
602 		/* Clear the contact footer */
603 		nd->mt_foot_count = 0;
604 		break;
605 	case HID_GD_Y:
606 		nd->y = value;
607 		break;
608 	case HID_DG_CONTACTID:
609 		nd->id = value;
610 		break;
611 	case HID_DG_WIDTH:
612 		nd->w = value;
613 		break;
614 	case HID_DG_HEIGHT:
615 		nd->h = value;
616 		/*
617 		 * when in single touch mode, this is the last
618 		 * report received in a finger event. We want
619 		 * to emit a normal (X, Y) position
620 		 */
621 		if (!nd->reading_mt) {
622 			/*
623 			 * TipSwitch indicates the presence of a
624 			 * finger in single touch mode.
625 			 */
626 			input_report_key(input, BTN_TOUCH,
627 					 nd->tipswitch);
628 			input_report_key(input, BTN_TOOL_DOUBLETAP,
629 					 nd->tipswitch);
630 			input_event(input, EV_ABS, ABS_X, nd->x);
631 			input_event(input, EV_ABS, ABS_Y, nd->y);
632 		}
633 		break;
634 	case 0xff000002:
635 		/*
636 		 * we receive this when the device is in multitouch
637 		 * mode. The first of the three values tagged with
638 		 * this usage tells if the contact point is real
639 		 * or a placeholder
640 		 */
641 
642 		/* Shouldn't get more than 4 footer packets, so skip */
643 		if (nd->mt_foot_count >= 4)
644 			break;
645 
646 		nd->mt_footer[nd->mt_foot_count++] = value;
647 
648 		/* if the footer isn't complete break */
649 		if (nd->mt_foot_count != 4)
650 			break;
651 
652 		/* Pen activity signal. */
653 		if (nd->mt_footer[2]) {
654 			/*
655 			 * When the pen deactivates touch, we see a
656 			 * bogus frame with ContactCount > 0.
657 			 * We can
658 			 * save a bit of work by ensuring act_state < 0
659 			 * even if deactivation slack is turned off.
660 			 */
661 			nd->act_state = deactivate_slack - 1;
662 			nd->confidence = false;
663 			break;
664 		}
665 
666 		/*
667 		 * The first footer value indicates the presence of a
668 		 * finger.
669 		 */
670 		if (nd->mt_footer[0]) {
671 			/*
672 			 * We do not want to process contacts under
673 			 * the size threshold, but do not want to
674 			 * ignore them for activation state
675 			 */
676 			if (nd->w < nd->min_width ||
677 			    nd->h < nd->min_height)
678 				nd->confidence = false;
679 		} else
680 			break;
681 
682 		if (nd->act_state > 0) {
683 			/*
684 			 * Contact meets the activation size threshold
685 			 */
686 			if (nd->w >= nd->activation_width &&
687 			    nd->h >= nd->activation_height) {
688 				if (nd->id)
689 					/*
690 					 * first contact, activate now
691 					 */
692 					nd->act_state = 0;
693 				else {
694 					/*
695 					 * avoid corrupting this frame
696 					 * but ensure next frame will
697 					 * be active
698 					 */
699 					nd->act_state = 1;
700 					break;
701 				}
702 			} else
703 				/*
704 				 * Defer adjusting the activation state
705 				 * until the end of the frame.
706 				 */
707 				break;
708 		}
709 
710 		/* Discarding this contact */
711 		if (!nd->confidence)
712 			break;
713 
714 		/* emit a normal (X, Y) for the first point only */
715 		if (nd->id == 0) {
716 			/*
717 			 * TipSwitch is superfluous in multitouch
718 			 * mode.  The footer events tell us
719 			 * if there is a finger on the screen or
720 			 * not.
721 			 */
722 			nd->first_contact_touch = nd->confidence;
723 			input_event(input, EV_ABS, ABS_X, nd->x);
724 			input_event(input, EV_ABS, ABS_Y, nd->y);
725 		}
726 
727 		/* Emit MT events */
728 		input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
729 		input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
730 
731 		/*
732 		 * Translate from height and width to size
733 		 * and orientation.
734 		 */
735 		if (nd->w > nd->h) {
736 			input_event(input, EV_ABS,
737 					ABS_MT_ORIENTATION, 1);
738 			input_event(input, EV_ABS,
739 					ABS_MT_TOUCH_MAJOR, nd->w);
740 			input_event(input, EV_ABS,
741 					ABS_MT_TOUCH_MINOR, nd->h);
742 		} else {
743 			input_event(input, EV_ABS,
744 					ABS_MT_ORIENTATION, 0);
745 			input_event(input, EV_ABS,
746 					ABS_MT_TOUCH_MAJOR, nd->h);
747 			input_event(input, EV_ABS,
748 					ABS_MT_TOUCH_MINOR, nd->w);
749 		}
750 		input_mt_sync(field->hidinput->input);
751 		break;
752 
753 	case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
754 		if (!nd->reading_mt) /* Just to be sure */
755 			break;
756 
757 		nd->reading_mt = false;
758 
759 
760 		/*
761 		 * Activation state machine logic:
762 		 *
763 		 * Fundamental states:
764 		 *	state >  0: Inactive
765 		 *	state <= 0: Active
766 		 *	state <  -deactivate_slack:
767 		 *		 Pen termination of touch
768 		 *
769 		 * Specific values of interest
770 		 *	state == activate_slack
771 		 *		 no valid input since the last reset
772 		 *
773 		 *	state == 0
774 		 *		 general operational state
775 		 *
776 		 *	state == -deactivate_slack
777 		 *		 read sufficient empty frames to accept
778 		 *		 the end of input and reset
779 		 */
780 
781 		if (nd->act_state > 0) { /* Currently inactive */
782 			if (value)
783 				/*
784 				 * Consider each live contact as
785 				 * evidence of intentional activity.
786 				 */
787 				nd->act_state = (nd->act_state > value)
788 						? nd->act_state - value
789 						: 0;
790 			else
791 				/*
792 				 * Empty frame before we hit the
793 				 * activity threshold, reset.
794 				 */
795 				nd->act_state = nd->activate_slack;
796 
797 			/*
798 			 * Entered this block inactive and no
799 			 * coordinates sent this frame, so hold off
800 			 * on button state.
801 			 */
802 			break;
803 		} else { /* Currently active */
804 			if (value && nd->act_state >=
805 				     nd->deactivate_slack)
806 				/*
807 				 * Live point: clear accumulated
808 				 * deactivation count.
809 				 */
810 				nd->act_state = 0;
811 			else if (nd->act_state <= nd->deactivate_slack)
812 				/*
813 				 * We've consumed the deactivation
814 				 * slack, time to deactivate and reset.
815 				 */
816 				nd->act_state =
817 					nd->activate_slack;
818 			else { /* Move towards deactivation */
819 				nd->act_state--;
820 				break;
821 			}
822 		}
823 
824 		if (nd->first_contact_touch && nd->act_state <= 0) {
825 			/*
826 			 * Check to see if we're ready to start
827 			 * emitting touch events.
828 			 *
829 			 * Note: activation slack will decrease over
830 			 * the course of the frame, and it will be
831 			 * inconsistent from the start to the end of
832 			 * the frame.  However if the frame starts
833 			 * with slack, first_contact_touch will still
834 			 * be 0 and we will not get to this point.
835 			 */
836 			input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
837 			input_report_key(input, BTN_TOUCH, 1);
838 		} else {
839 			input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
840 			input_report_key(input, BTN_TOUCH, 0);
841 		}
842 		break;
843 
844 	default:
845 		/* fall-back to the generic hidinput handling */
846 		return 0;
847 	}
848 
849 not_claimed_input:
850 
851 	/* we have handled the hidinput part, now remains hiddev */
852 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
853 		hid->hiddev_hid_event(hid, field, usage, value);
854 
855 	return 1;
856 }
857 
858 static int ntrig_input_configured(struct hid_device *hid,
859 		struct hid_input *hidinput)
860 
861 {
862 	struct input_dev *input = hidinput->input;
863 
864 	if (hidinput->report->maxfield < 1)
865 		return 0;
866 
867 	switch (hidinput->report->field[0]->application) {
868 	case HID_DG_PEN:
869 		input->name = "N-Trig Pen";
870 		break;
871 	case HID_DG_TOUCHSCREEN:
872 		/* These keys are redundant for fingers, clear them
873 		 * to prevent incorrect identification */
874 		__clear_bit(BTN_TOOL_PEN, input->keybit);
875 		__clear_bit(BTN_TOOL_FINGER, input->keybit);
876 		__clear_bit(BTN_0, input->keybit);
877 		__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
878 		/*
879 		 * The physical touchscreen (single touch)
880 		 * input has a value for physical, whereas
881 		 * the multitouch only has logical input
882 		 * fields.
883 		 */
884 		input->name = (hidinput->report->field[0]->physical) ?
885 							"N-Trig Touchscreen" :
886 							"N-Trig MultiTouch";
887 		break;
888 	}
889 
890 	return 0;
891 }
892 
893 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
894 {
895 	int ret;
896 	struct ntrig_data *nd;
897 	struct hid_report *report;
898 
899 	if (id->driver_data)
900 		hdev->quirks |= HID_QUIRK_MULTI_INPUT
901 				| HID_QUIRK_NO_INIT_REPORTS;
902 
903 	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
904 	if (!nd) {
905 		hid_err(hdev, "cannot allocate N-Trig data\n");
906 		return -ENOMEM;
907 	}
908 
909 	nd->reading_mt = false;
910 	nd->min_width = 0;
911 	nd->min_height = 0;
912 	nd->activate_slack = activate_slack;
913 	nd->act_state = activate_slack;
914 	nd->deactivate_slack = -deactivate_slack;
915 	nd->sensor_logical_width = 1;
916 	nd->sensor_logical_height = 1;
917 	nd->sensor_physical_width = 1;
918 	nd->sensor_physical_height = 1;
919 
920 	hid_set_drvdata(hdev, nd);
921 
922 	ret = hid_parse(hdev);
923 	if (ret) {
924 		hid_err(hdev, "parse failed\n");
925 		goto err_free;
926 	}
927 
928 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
929 	if (ret) {
930 		hid_err(hdev, "hw start failed\n");
931 		goto err_free;
932 	}
933 
934 	/* This is needed for devices with more recent firmware versions */
935 	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
936 	if (report) {
937 		/* Let the device settle to ensure the wakeup message gets
938 		 * through */
939 		hid_hw_wait(hdev);
940 		hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
941 
942 		/*
943 		 * Sanity check: if the current mode is invalid reset it to
944 		 * something reasonable.
945 		 */
946 		if (ntrig_get_mode(hdev) >= 4)
947 			ntrig_set_mode(hdev, 3);
948 	}
949 
950 	ntrig_report_version(hdev);
951 
952 	ret = sysfs_create_group(&hdev->dev.kobj,
953 			&ntrig_attribute_group);
954 	if (ret)
955 		hid_err(hdev, "cannot create sysfs group\n");
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 	.input_configured = ntrig_input_configured,
1027 	.usage_table = ntrig_grabbed_usages,
1028 	.event = ntrig_event,
1029 };
1030 module_hid_driver(ntrig_driver);
1031 
1032 MODULE_LICENSE("GPL");
1033