xref: /linux/drivers/hid/hid-ntrig.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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 
27 struct 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 
46 static 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 
105 static 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  */
126 static 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_report_key(input, BTN_TOOL_DOUBLETAP,
169 						 (nd->confidence != 0));
170 				input_event(input, EV_ABS, ABS_X, nd->x);
171 				input_event(input, EV_ABS, ABS_Y, nd->y);
172 			}
173 			break;
174 		case 0xff000002:
175 			/*
176 			 * we receive this when the device is in multitouch
177 			 * mode. The first of the three values tagged with
178 			 * this usage tells if the contact point is real
179 			 * or a placeholder
180 			 */
181 
182 			/* Shouldn't get more than 4 footer packets, so skip */
183 			if (nd->mt_foot_count >= 4)
184 				break;
185 
186 			nd->mt_footer[nd->mt_foot_count++] = value;
187 
188 			/* if the footer isn't complete break */
189 			if (nd->mt_foot_count != 4)
190 				break;
191 
192 			/* Pen activity signal, trigger end of touch. */
193 			if (nd->mt_footer[2]) {
194 				nd->confidence = 0;
195 				break;
196 			}
197 
198 			/* If the contact was invalid */
199 			if (!(nd->confidence && nd->mt_footer[0])
200 					|| nd->w <= 250
201 					|| nd->h <= 190) {
202 				nd->confidence = 0;
203 				break;
204 			}
205 
206 			/* emit a normal (X, Y) for the first point only */
207 			if (nd->id == 0) {
208 				nd->first_contact_confidence = nd->confidence;
209 				input_event(input, EV_ABS, ABS_X, nd->x);
210 				input_event(input, EV_ABS, ABS_Y, nd->y);
211 			}
212 			input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
213 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
214 			if (nd->w > nd->h) {
215 				input_event(input, EV_ABS,
216 						ABS_MT_ORIENTATION, 1);
217 				input_event(input, EV_ABS,
218 						ABS_MT_TOUCH_MAJOR, nd->w);
219 				input_event(input, EV_ABS,
220 						ABS_MT_TOUCH_MINOR, nd->h);
221 			} else {
222 				input_event(input, EV_ABS,
223 						ABS_MT_ORIENTATION, 0);
224 				input_event(input, EV_ABS,
225 						ABS_MT_TOUCH_MAJOR, nd->h);
226 				input_event(input, EV_ABS,
227 						ABS_MT_TOUCH_MINOR, nd->w);
228 			}
229 			input_mt_sync(field->hidinput->input);
230 			break;
231 
232 		case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
233 			if (!nd->reading_mt)
234 				break;
235 
236 			nd->reading_mt = 0;
237 
238 			if (nd->first_contact_confidence) {
239 				switch (value) {
240 				case 0:	/* for single touch devices */
241 				case 1:
242 					input_report_key(input,
243 							BTN_TOOL_DOUBLETAP, 1);
244 					break;
245 				case 2:
246 					input_report_key(input,
247 							BTN_TOOL_TRIPLETAP, 1);
248 					break;
249 				case 3:
250 				default:
251 					input_report_key(input,
252 							BTN_TOOL_QUADTAP, 1);
253 				}
254 				input_report_key(input, BTN_TOUCH, 1);
255 			} else {
256 				input_report_key(input,
257 						BTN_TOOL_DOUBLETAP, 0);
258 				input_report_key(input,
259 						BTN_TOOL_TRIPLETAP, 0);
260 				input_report_key(input,
261 						BTN_TOOL_QUADTAP, 0);
262 			}
263 			break;
264 
265 		default:
266 			/* fallback to the generic hidinput handling */
267 			return 0;
268 		}
269 	}
270 
271 	/* we have handled the hidinput part, now remains hiddev */
272 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
273 		hid->hiddev_hid_event(hid, field, usage, value);
274 
275 	return 1;
276 }
277 
278 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
279 {
280 	int ret;
281 	struct ntrig_data *nd;
282 	struct hid_input *hidinput;
283 	struct input_dev *input;
284 
285 	if (id->driver_data)
286 		hdev->quirks |= HID_QUIRK_MULTI_INPUT;
287 
288 	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
289 	if (!nd) {
290 		dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
291 		return -ENOMEM;
292 	}
293 
294 	nd->reading_mt = 0;
295 	hid_set_drvdata(hdev, nd);
296 
297 	ret = hid_parse(hdev);
298 	if (ret) {
299 		dev_err(&hdev->dev, "parse failed\n");
300 		goto err_free;
301 	}
302 
303 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
304 	if (ret) {
305 		dev_err(&hdev->dev, "hw start failed\n");
306 		goto err_free;
307 	}
308 
309 
310 	list_for_each_entry(hidinput, &hdev->inputs, list) {
311 		input = hidinput->input;
312 		switch (hidinput->report->field[0]->application) {
313 		case HID_DG_PEN:
314 			input->name = "N-Trig Pen";
315 			break;
316 		case HID_DG_TOUCHSCREEN:
317 			__clear_bit(BTN_TOOL_PEN, input->keybit);
318 			/*
319 			 * A little something special to enable
320 			 * two and three finger taps.
321 			 */
322 			__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
323 			__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
324 			__set_bit(BTN_TOOL_QUADTAP, input->keybit);
325 			/*
326 			 * The physical touchscreen (single touch)
327 			 * input has a value for physical, whereas
328 			 * the multitouch only has logical input
329 			 * fields.
330 			 */
331 			input->name =
332 				(hidinput->report->field[0]
333 				 ->physical) ?
334 				"N-Trig Touchscreen" :
335 				"N-Trig MultiTouch";
336 			break;
337 		}
338 	}
339 
340 	return 0;
341 err_free:
342 	kfree(nd);
343 	return ret;
344 }
345 
346 static void ntrig_remove(struct hid_device *hdev)
347 {
348 	hid_hw_stop(hdev);
349 	kfree(hid_get_drvdata(hdev));
350 }
351 
352 static const struct hid_device_id ntrig_devices[] = {
353 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
354 		.driver_data = NTRIG_DUPLICATE_USAGES },
355 	{ }
356 };
357 MODULE_DEVICE_TABLE(hid, ntrig_devices);
358 
359 static const struct hid_usage_id ntrig_grabbed_usages[] = {
360 	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
361 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
362 };
363 
364 static struct hid_driver ntrig_driver = {
365 	.name = "ntrig",
366 	.id_table = ntrig_devices,
367 	.probe = ntrig_probe,
368 	.remove = ntrig_remove,
369 	.input_mapping = ntrig_input_mapping,
370 	.input_mapped = ntrig_input_mapped,
371 	.usage_table = ntrig_grabbed_usages,
372 	.event = ntrig_event,
373 };
374 
375 static int __init ntrig_init(void)
376 {
377 	return hid_register_driver(&ntrig_driver);
378 }
379 
380 static void __exit ntrig_exit(void)
381 {
382 	hid_unregister_driver(&ntrig_driver);
383 }
384 
385 module_init(ntrig_init);
386 module_exit(ntrig_exit);
387 MODULE_LICENSE("GPL");
388