hid-ntrig.c revision dbf2b17de505d390b5ecf5b5944fc0c88f6d66fe 
1/*
2 *  HID driver for N-Trig touchscreens
3 *
4 *  Copyright (c) 2008 Rafi Rubin
5 *  Copyright (c) 2009 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/module.h>
19
20#include "hid-ids.h"
21
22#define NTRIG_DUPLICATE_USAGES	0x001
23
24#define nt_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
25					EV_KEY, (c))
26
27struct ntrig_data {
28	/* Incoming raw values for a single contact */
29	__u16 x, y, w, h;
30	__u16 id;
31	__u8 confidence;
32
33	bool reading_mt;
34	__u8 first_contact_confidence;
35
36	__u8 mt_footer[4];
37	__u8 mt_foot_count;
38};
39
40/*
41 * this driver is aimed at two firmware versions in circulation:
42 *  - dual pen/finger single touch
43 *  - finger multitouch, pen not working
44 */
45
46static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
47		struct hid_field *field, struct hid_usage *usage,
48		unsigned long **bit, int *max)
49{
50	/* No special mappings needed for the pen and single touch */
51	if (field->physical)
52		return 0;
53
54	switch (usage->hid & HID_USAGE_PAGE) {
55	case HID_UP_GENDESK:
56		switch (usage->hid) {
57		case HID_GD_X:
58			hid_map_usage(hi, usage, bit, max,
59					EV_ABS, ABS_MT_POSITION_X);
60			input_set_abs_params(hi->input, ABS_X,
61					field->logical_minimum,
62					field->logical_maximum, 0, 0);
63			return 1;
64		case HID_GD_Y:
65			hid_map_usage(hi, usage, bit, max,
66					EV_ABS, ABS_MT_POSITION_Y);
67			input_set_abs_params(hi->input, ABS_Y,
68					field->logical_minimum,
69					field->logical_maximum, 0, 0);
70			return 1;
71		}
72		return 0;
73
74	case HID_UP_DIGITIZER:
75		switch (usage->hid) {
76		/* we do not want to map these for now */
77		case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
78		case HID_DG_INPUTMODE:
79		case HID_DG_DEVICEINDEX:
80		case HID_DG_CONTACTMAX:
81			return -1;
82
83		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
84		case HID_DG_WIDTH:
85			hid_map_usage(hi, usage, bit, max,
86					EV_ABS, ABS_MT_TOUCH_MAJOR);
87			return 1;
88		case HID_DG_HEIGHT:
89			hid_map_usage(hi, usage, bit, max,
90					EV_ABS, ABS_MT_TOUCH_MINOR);
91			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
92					0, 1, 0, 0);
93			return 1;
94		}
95		return 0;
96
97	case 0xff000000:
98		/* we do not want to map these: no input-oriented meaning */
99		return -1;
100	}
101
102	return 0;
103}
104
105static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
106		struct hid_field *field, struct hid_usage *usage,
107		unsigned long **bit, int *max)
108{
109	/* No special mappings needed for the pen and single touch */
110	if (field->physical)
111		return 0;
112
113	if (usage->type == EV_KEY || usage->type == EV_REL
114			|| usage->type == EV_ABS)
115		clear_bit(usage->code, *bit);
116
117	return 0;
118}
119
120/*
121 * this function is called upon all reports
122 * so that we can filter contact point information,
123 * decide whether we are in multi or single touch mode
124 * and call input_mt_sync after each point if necessary
125 */
126static int ntrig_event (struct hid_device *hid, struct hid_field *field,
127		                        struct hid_usage *usage, __s32 value)
128{
129	struct input_dev *input = field->hidinput->input;
130	struct ntrig_data *nd = hid_get_drvdata(hid);
131
132	/* No special handling needed for the pen */
133	if (field->application == HID_DG_PEN)
134		return 0;
135
136        if (hid->claimed & HID_CLAIMED_INPUT) {
137		switch (usage->hid) {
138		case 0xff000001:
139			/* Tag indicating the start of a multitouch group */
140			nd->reading_mt = 1;
141			nd->first_contact_confidence = 0;
142			break;
143		case HID_DG_CONFIDENCE:
144			nd->confidence = value;
145			break;
146		case HID_GD_X:
147			nd->x = value;
148			/* Clear the contact footer */
149			nd->mt_foot_count = 0;
150			break;
151		case HID_GD_Y:
152			nd->y = value;
153			break;
154		case HID_DG_CONTACTID:
155			nd->id = value;
156			break;
157		case HID_DG_WIDTH:
158			nd->w = value;
159			break;
160		case HID_DG_HEIGHT:
161			nd->h = value;
162			/*
163			 * when in single touch mode, this is the last
164			 * report received in a finger event. We want
165			 * to emit a normal (X, Y) position
166			 */
167			if (!nd->reading_mt) {
168				input_event(input, EV_ABS, ABS_X, nd->x);
169				input_event(input, EV_ABS, ABS_Y, nd->y);
170			}
171			break;
172		case 0xff000002:
173			/*
174			 * we receive this when the device is in multitouch
175			 * mode. The first of the three values tagged with
176			 * this usage tells if the contact point is real
177			 * or a placeholder
178			 */
179
180			/* Shouldn't get more than 4 footer packets, so skip */
181			if (nd->mt_foot_count >= 4)
182				break;
183
184			nd->mt_footer[nd->mt_foot_count++] = value;
185
186			/* if the footer isn't complete break */
187			if (nd->mt_foot_count != 4)
188				break;
189
190			/* Pen activity signal, trigger end of touch. */
191			if (nd->mt_footer[2]) {
192				nd->confidence = 0;
193				break;
194			}
195
196			/* If the contact was invalid */
197			if (!(nd->confidence && nd->mt_footer[0])
198					|| nd->w <= 250
199					|| nd->h <= 190) {
200				nd->confidence = 0;
201				break;
202			}
203
204			/* emit a normal (X, Y) for the first point only */
205			if (nd->id == 0) {
206				nd->first_contact_confidence = nd->confidence;
207				input_event(input, EV_ABS, ABS_X, nd->x);
208				input_event(input, EV_ABS, ABS_Y, nd->y);
209			}
210			input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
211			input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
212			if (nd->w > nd->h) {
213				input_event(input, EV_ABS,
214						ABS_MT_ORIENTATION, 1);
215				input_event(input, EV_ABS,
216						ABS_MT_TOUCH_MAJOR, nd->w);
217				input_event(input, EV_ABS,
218						ABS_MT_TOUCH_MINOR, nd->h);
219			} else {
220				input_event(input, EV_ABS,
221						ABS_MT_ORIENTATION, 0);
222				input_event(input, EV_ABS,
223						ABS_MT_TOUCH_MAJOR, nd->h);
224				input_event(input, EV_ABS,
225						ABS_MT_TOUCH_MINOR, nd->w);
226			}
227			input_mt_sync(field->hidinput->input);
228			break;
229
230		case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
231			if (!nd->reading_mt)
232				break;
233
234			nd->reading_mt = 0;
235
236			if (nd->first_contact_confidence) {
237				switch (value) {
238				case 0:	/* for single touch devices */
239				case 1:
240					input_report_key(input,
241							BTN_TOOL_DOUBLETAP, 1);
242					break;
243				case 2:
244					input_report_key(input,
245							BTN_TOOL_TRIPLETAP, 1);
246					break;
247				case 3:
248				default:
249					input_report_key(input,
250							BTN_TOOL_QUADTAP, 1);
251				}
252				input_report_key(input, BTN_TOUCH, 1);
253			} else {
254				input_report_key(input,
255						BTN_TOOL_DOUBLETAP, 0);
256				input_report_key(input,
257						BTN_TOOL_TRIPLETAP, 0);
258				input_report_key(input,
259						BTN_TOOL_QUADTAP, 0);
260			}
261			break;
262
263		default:
264			/* fallback to the generic hidinput handling */
265			return 0;
266		}
267	}
268
269	/* we have handled the hidinput part, now remains hiddev */
270	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
271		hid->hiddev_hid_event(hid, field, usage, value);
272
273	return 1;
274}
275
276static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
277{
278	int ret;
279	struct ntrig_data *nd;
280	struct hid_input *hidinput;
281	struct input_dev *input;
282
283	if (id->driver_data)
284		hdev->quirks |= HID_QUIRK_MULTI_INPUT;
285
286	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
287	if (!nd) {
288		dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
289		return -ENOMEM;
290	}
291
292	nd->reading_mt = 0;
293	hid_set_drvdata(hdev, nd);
294
295	ret = hid_parse(hdev);
296	if (ret) {
297		dev_err(&hdev->dev, "parse failed\n");
298		goto err_free;
299	}
300
301	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
302	if (ret) {
303		dev_err(&hdev->dev, "hw start failed\n");
304		goto err_free;
305	}
306
307
308	list_for_each_entry(hidinput, &hdev->inputs, list) {
309		input = hidinput->input;
310		switch (hidinput->report->field[0]->application) {
311		case HID_DG_PEN:
312			input->name = "N-Trig Pen";
313			break;
314		case HID_DG_TOUCHSCREEN:
315			__clear_bit(BTN_TOOL_PEN, input->keybit);
316			/*
317			 * A little something special to enable
318			 * two and three finger taps.
319			 */
320			__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
321			__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
322			__set_bit(BTN_TOOL_QUADTAP, input->keybit);
323			/*
324			 * The physical touchscreen (single touch)
325			 * input has a value for physical, whereas
326			 * the multitouch only has logical input
327			 * fields.
328			 */
329			input->name =
330				(hidinput->report->field[0]
331				 ->physical) ?
332				"N-Trig Touchscreen" :
333				"N-Trig MultiTouch";
334			break;
335		}
336	}
337
338	return 0;
339err_free:
340	kfree(nd);
341	return ret;
342}
343
344static void ntrig_remove(struct hid_device *hdev)
345{
346	hid_hw_stop(hdev);
347	kfree(hid_get_drvdata(hdev));
348}
349
350static const struct hid_device_id ntrig_devices[] = {
351	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
352		.driver_data = NTRIG_DUPLICATE_USAGES },
353	{ }
354};
355MODULE_DEVICE_TABLE(hid, ntrig_devices);
356
357static const struct hid_usage_id ntrig_grabbed_usages[] = {
358	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
359	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
360};
361
362static struct hid_driver ntrig_driver = {
363	.name = "ntrig",
364	.id_table = ntrig_devices,
365	.probe = ntrig_probe,
366	.remove = ntrig_remove,
367	.input_mapping = ntrig_input_mapping,
368	.input_mapped = ntrig_input_mapped,
369	.usage_table = ntrig_grabbed_usages,
370	.event = ntrig_event,
371};
372
373static int __init ntrig_init(void)
374{
375	return hid_register_driver(&ntrig_driver);
376}
377
378static void __exit ntrig_exit(void)
379{
380	hid_unregister_driver(&ntrig_driver);
381}
382
383module_init(ntrig_init);
384module_exit(ntrig_exit);
385MODULE_LICENSE("GPL");
386