hid-ntrig.c revision 6549981bc54777c37eccf987e227aff47022ab7c 
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#define nt_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
28					EV_KEY, (c))
29
30struct ntrig_data {
31	/* Incoming raw values for a single contact */
32	__u16 x, y, w, h;
33	__u16 id;
34	__u8 confidence;
35
36	bool reading_mt;
37	__u8 first_contact_confidence;
38
39	__u8 mt_footer[4];
40	__u8 mt_foot_count;
41};
42
43/*
44 * this driver is aimed at two firmware versions in circulation:
45 *  - dual pen/finger single touch
46 *  - finger multitouch, pen not working
47 */
48
49static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
50		struct hid_field *field, struct hid_usage *usage,
51		unsigned long **bit, int *max)
52{
53	/* No special mappings needed for the pen and single touch */
54	if (field->physical)
55		return 0;
56
57	switch (usage->hid & HID_USAGE_PAGE) {
58	case HID_UP_GENDESK:
59		switch (usage->hid) {
60		case HID_GD_X:
61			hid_map_usage(hi, usage, bit, max,
62					EV_ABS, ABS_MT_POSITION_X);
63			input_set_abs_params(hi->input, ABS_X,
64					field->logical_minimum,
65					field->logical_maximum, 0, 0);
66			return 1;
67		case HID_GD_Y:
68			hid_map_usage(hi, usage, bit, max,
69					EV_ABS, ABS_MT_POSITION_Y);
70			input_set_abs_params(hi->input, ABS_Y,
71					field->logical_minimum,
72					field->logical_maximum, 0, 0);
73			return 1;
74		}
75		return 0;
76
77	case HID_UP_DIGITIZER:
78		switch (usage->hid) {
79		/* we do not want to map these for now */
80		case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
81		case HID_DG_INPUTMODE:
82		case HID_DG_DEVICEINDEX:
83		case HID_DG_CONTACTMAX:
84			return -1;
85
86		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
87		case HID_DG_WIDTH:
88			hid_map_usage(hi, usage, bit, max,
89					EV_ABS, ABS_MT_TOUCH_MAJOR);
90			return 1;
91		case HID_DG_HEIGHT:
92			hid_map_usage(hi, usage, bit, max,
93					EV_ABS, ABS_MT_TOUCH_MINOR);
94			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
95					0, 1, 0, 0);
96			return 1;
97		}
98		return 0;
99
100	case 0xff000000:
101		/* we do not want to map these: no input-oriented meaning */
102		return -1;
103	}
104
105	return 0;
106}
107
108static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
109		struct hid_field *field, struct hid_usage *usage,
110		unsigned long **bit, int *max)
111{
112	/* No special mappings needed for the pen and single touch */
113	if (field->physical)
114		return 0;
115
116	if (usage->type == EV_KEY || usage->type == EV_REL
117			|| usage->type == EV_ABS)
118		clear_bit(usage->code, *bit);
119
120	return 0;
121}
122
123/*
124 * this function is called upon all reports
125 * so that we can filter contact point information,
126 * decide whether we are in multi or single touch mode
127 * and call input_mt_sync after each point if necessary
128 */
129static int ntrig_event (struct hid_device *hid, struct hid_field *field,
130		                        struct hid_usage *usage, __s32 value)
131{
132	struct input_dev *input = field->hidinput->input;
133	struct ntrig_data *nd = hid_get_drvdata(hid);
134
135	/* No special handling needed for the pen */
136	if (field->application == HID_DG_PEN)
137		return 0;
138
139        if (hid->claimed & HID_CLAIMED_INPUT) {
140		switch (usage->hid) {
141		case 0xff000001:
142			/* Tag indicating the start of a multitouch group */
143			nd->reading_mt = 1;
144			nd->first_contact_confidence = 0;
145			break;
146		case HID_DG_TIPSWITCH:
147			/* Prevent emission of touch until validated */
148			return 1;
149		case HID_DG_CONFIDENCE:
150			nd->confidence = value;
151			break;
152		case HID_GD_X:
153			nd->x = value;
154			/* Clear the contact footer */
155			nd->mt_foot_count = 0;
156			break;
157		case HID_GD_Y:
158			nd->y = value;
159			break;
160		case HID_DG_CONTACTID:
161			nd->id = value;
162			break;
163		case HID_DG_WIDTH:
164			nd->w = value;
165			break;
166		case HID_DG_HEIGHT:
167			nd->h = value;
168			/*
169			 * when in single touch mode, this is the last
170			 * report received in a finger event. We want
171			 * to emit a normal (X, Y) position
172			 */
173			if (!nd->reading_mt) {
174				input_report_key(input, BTN_TOOL_DOUBLETAP,
175						 (nd->confidence != 0));
176				input_event(input, EV_ABS, ABS_X, nd->x);
177				input_event(input, EV_ABS, ABS_Y, nd->y);
178			}
179			break;
180		case 0xff000002:
181			/*
182			 * we receive this when the device is in multitouch
183			 * mode. The first of the three values tagged with
184			 * this usage tells if the contact point is real
185			 * or a placeholder
186			 */
187
188			/* Shouldn't get more than 4 footer packets, so skip */
189			if (nd->mt_foot_count >= 4)
190				break;
191
192			nd->mt_footer[nd->mt_foot_count++] = value;
193
194			/* if the footer isn't complete break */
195			if (nd->mt_foot_count != 4)
196				break;
197
198			/* Pen activity signal, trigger end of touch. */
199			if (nd->mt_footer[2]) {
200				nd->confidence = 0;
201				break;
202			}
203
204			/* If the contact was invalid */
205			if (!(nd->confidence && nd->mt_footer[0])
206					|| nd->w <= 250
207					|| nd->h <= 190) {
208				nd->confidence = 0;
209				break;
210			}
211
212			/* emit a normal (X, Y) for the first point only */
213			if (nd->id == 0) {
214				nd->first_contact_confidence = nd->confidence;
215				input_event(input, EV_ABS, ABS_X, nd->x);
216				input_event(input, EV_ABS, ABS_Y, nd->y);
217			}
218			input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
219			input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
220			if (nd->w > nd->h) {
221				input_event(input, EV_ABS,
222						ABS_MT_ORIENTATION, 1);
223				input_event(input, EV_ABS,
224						ABS_MT_TOUCH_MAJOR, nd->w);
225				input_event(input, EV_ABS,
226						ABS_MT_TOUCH_MINOR, nd->h);
227			} else {
228				input_event(input, EV_ABS,
229						ABS_MT_ORIENTATION, 0);
230				input_event(input, EV_ABS,
231						ABS_MT_TOUCH_MAJOR, nd->h);
232				input_event(input, EV_ABS,
233						ABS_MT_TOUCH_MINOR, nd->w);
234			}
235			input_mt_sync(field->hidinput->input);
236			break;
237
238		case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
239			if (!nd->reading_mt)
240				break;
241
242			nd->reading_mt = 0;
243
244			if (nd->first_contact_confidence) {
245				switch (value) {
246				case 0:	/* for single touch devices */
247				case 1:
248					input_report_key(input,
249							BTN_TOOL_DOUBLETAP, 1);
250					break;
251				case 2:
252					input_report_key(input,
253							BTN_TOOL_TRIPLETAP, 1);
254					break;
255				case 3:
256				default:
257					input_report_key(input,
258							BTN_TOOL_QUADTAP, 1);
259				}
260				input_report_key(input, BTN_TOUCH, 1);
261			} else {
262				input_report_key(input,
263						BTN_TOOL_DOUBLETAP, 0);
264				input_report_key(input,
265						BTN_TOOL_TRIPLETAP, 0);
266				input_report_key(input,
267						BTN_TOOL_QUADTAP, 0);
268				input_report_key(input, BTN_TOUCH, 0);
269			}
270			break;
271
272		default:
273			/* fallback to the generic hidinput handling */
274			return 0;
275		}
276	}
277
278	/* we have handled the hidinput part, now remains hiddev */
279	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
280		hid->hiddev_hid_event(hid, field, usage, value);
281
282	return 1;
283}
284
285static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
286{
287	int ret;
288	struct ntrig_data *nd;
289	struct hid_input *hidinput;
290	struct input_dev *input;
291	struct hid_report *report;
292
293	if (id->driver_data)
294		hdev->quirks |= HID_QUIRK_MULTI_INPUT;
295
296	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
297	if (!nd) {
298		dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
299		return -ENOMEM;
300	}
301
302	nd->reading_mt = 0;
303	hid_set_drvdata(hdev, nd);
304
305	ret = hid_parse(hdev);
306	if (ret) {
307		dev_err(&hdev->dev, "parse failed\n");
308		goto err_free;
309	}
310
311	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
312	if (ret) {
313		dev_err(&hdev->dev, "hw start failed\n");
314		goto err_free;
315	}
316
317
318	list_for_each_entry(hidinput, &hdev->inputs, list) {
319		if (hidinput->report->maxfield < 1)
320			continue;
321
322		input = hidinput->input;
323		switch (hidinput->report->field[0]->application) {
324		case HID_DG_PEN:
325			input->name = "N-Trig Pen";
326			break;
327		case HID_DG_TOUCHSCREEN:
328			/* These keys are redundant for fingers, clear them
329			 * to prevent incorrect identification */
330			__clear_bit(BTN_TOOL_PEN, input->keybit);
331			__clear_bit(BTN_TOOL_FINGER, input->keybit);
332			__clear_bit(BTN_0, input->keybit);
333			/*
334			 * A little something special to enable
335			 * two and three finger taps.
336			 */
337			__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
338			__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
339			__set_bit(BTN_TOOL_QUADTAP, input->keybit);
340			/*
341			 * The physical touchscreen (single touch)
342			 * input has a value for physical, whereas
343			 * the multitouch only has logical input
344			 * fields.
345			 */
346			input->name =
347				(hidinput->report->field[0]
348				 ->physical) ?
349				"N-Trig Touchscreen" :
350				"N-Trig MultiTouch";
351			break;
352		}
353	}
354
355	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
356	if (report)
357		usbhid_submit_report(hdev, report, USB_DIR_OUT);
358
359
360	return 0;
361err_free:
362	kfree(nd);
363	return ret;
364}
365
366static void ntrig_remove(struct hid_device *hdev)
367{
368	hid_hw_stop(hdev);
369	kfree(hid_get_drvdata(hdev));
370}
371
372static const struct hid_device_id ntrig_devices[] = {
373	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
374		.driver_data = NTRIG_DUPLICATE_USAGES },
375	{ }
376};
377MODULE_DEVICE_TABLE(hid, ntrig_devices);
378
379static const struct hid_usage_id ntrig_grabbed_usages[] = {
380	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
381	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
382};
383
384static struct hid_driver ntrig_driver = {
385	.name = "ntrig",
386	.id_table = ntrig_devices,
387	.probe = ntrig_probe,
388	.remove = ntrig_remove,
389	.input_mapping = ntrig_input_mapping,
390	.input_mapped = ntrig_input_mapped,
391	.usage_table = ntrig_grabbed_usages,
392	.event = ntrig_event,
393};
394
395static int __init ntrig_init(void)
396{
397	return hid_register_driver(&ntrig_driver);
398}
399
400static void __exit ntrig_exit(void)
401{
402	hid_unregister_driver(&ntrig_driver);
403}
404
405module_init(ntrig_init);
406module_exit(ntrig_exit);
407MODULE_LICENSE("GPL");
408