hid-ntrig.c revision 57fd637ad9ac6b13c1c47b9a0ced4ee99bb26e76 
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	__s32 x, y, id, w, h;
29	char reading_a_point, found_contact_id;
30};
31
32/*
33 * this driver is aimed at two firmware versions in circulation:
34 *  - dual pen/finger single touch
35 *  - finger multitouch, pen not working
36 */
37
38static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
39		struct hid_field *field, struct hid_usage *usage,
40		unsigned long **bit, int *max)
41{
42	switch (usage->hid & HID_USAGE_PAGE) {
43
44	case HID_UP_GENDESK:
45		switch (usage->hid) {
46		case HID_GD_X:
47			hid_map_usage(hi, usage, bit, max,
48					EV_ABS, ABS_MT_POSITION_X);
49			input_set_abs_params(hi->input, ABS_X,
50					field->logical_minimum,
51					field->logical_maximum, 0, 0);
52			return 1;
53		case HID_GD_Y:
54			hid_map_usage(hi, usage, bit, max,
55					EV_ABS, ABS_MT_POSITION_Y);
56			input_set_abs_params(hi->input, ABS_Y,
57					field->logical_minimum,
58					field->logical_maximum, 0, 0);
59			return 1;
60		}
61		return 0;
62
63	case HID_UP_DIGITIZER:
64		switch (usage->hid) {
65		/* we do not want to map these for now */
66		case HID_DG_INVERT: /* value is always 0 */
67		case HID_DG_ERASER: /* value is always 0 */
68		case HID_DG_CONTACTID: /* value is useless */
69		case HID_DG_BARRELSWITCH:  /* doubtful */
70		case HID_DG_INPUTMODE:
71		case HID_DG_DEVICEINDEX:
72		case HID_DG_CONTACTCOUNT:
73		case HID_DG_CONTACTMAX:
74			return -1;
75
76		/* original mapping by Rafi Rubin */
77		case HID_DG_CONFIDENCE:
78			nt_map_key_clear(BTN_TOOL_DOUBLETAP);
79			return 1;
80
81		/* width/height mapped on TouchMajor/TouchMinor/Orientation */
82		case HID_DG_WIDTH:
83			hid_map_usage(hi, usage, bit, max,
84					EV_ABS, ABS_MT_TOUCH_MAJOR);
85			return 1;
86		case HID_DG_HEIGHT:
87			hid_map_usage(hi, usage, bit, max,
88					EV_ABS, ABS_MT_TOUCH_MINOR);
89			input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
90					0, 1, 0, 0);
91			return 1;
92		}
93		return 0;
94
95	case 0xff000000:
96		/* we do not want to map these: no input-oriented meaning */
97		return -1;
98	}
99
100	return 0;
101}
102
103static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
104		struct hid_field *field, struct hid_usage *usage,
105		unsigned long **bit, int *max)
106{
107	if (usage->type == EV_KEY || usage->type == EV_REL
108			|| usage->type == EV_ABS)
109		clear_bit(usage->code, *bit);
110
111	return 0;
112}
113
114/*
115 * this function is called upon all reports
116 * so that we can filter contact point information,
117 * decide whether we are in multi or single touch mode
118 * and call input_mt_sync after each point if necessary
119 */
120static int ntrig_event (struct hid_device *hid, struct hid_field *field,
121		                        struct hid_usage *usage, __s32 value)
122{
123	struct input_dev *input = field->hidinput->input;
124	struct ntrig_data *nd = hid_get_drvdata(hid);
125
126        if (hid->claimed & HID_CLAIMED_INPUT) {
127		switch (usage->hid) {
128		case HID_GD_X:
129			nd->x = value;
130			nd->reading_a_point = 1;
131			break;
132		case HID_GD_Y:
133			nd->y = value;
134			break;
135		case HID_DG_CONTACTID:
136			nd->id = value;
137			/* we receive this only when in multitouch mode */
138			nd->found_contact_id = 1;
139			break;
140		case HID_DG_WIDTH:
141			nd->w = value;
142			break;
143		case HID_DG_HEIGHT:
144			nd->h = value;
145			/*
146			 * when in single touch mode, this is the last
147			 * report received in a finger event. We want
148			 * to emit a normal (X, Y) position
149			 */
150			if (! nd->found_contact_id) {
151				input_event(input, EV_ABS, ABS_X, nd->x);
152				input_event(input, EV_ABS, ABS_Y, nd->y);
153			}
154			break;
155		case HID_DG_TIPPRESSURE:
156			/*
157			 * when in single touch mode, this is the last
158			 * report received in a pen event. We want
159			 * to emit a normal (X, Y) position
160			 */
161			if (! nd->found_contact_id) {
162				input_event(input, EV_ABS, ABS_X, nd->x);
163				input_event(input, EV_ABS, ABS_Y, nd->y);
164				input_event(input, EV_ABS, ABS_PRESSURE, value);
165			}
166			break;
167		case 0xff000002:
168			/*
169			 * we receive this when the device is in multitouch
170			 * mode. The first of the three values tagged with
171			 * this usage tells if the contact point is real
172			 * or a placeholder
173			 */
174			if (!nd->reading_a_point || value != 1)
175				break;
176			/* emit a normal (X, Y) for the first point only */
177			if (nd->id == 0) {
178				input_event(input, EV_ABS, ABS_X, nd->x);
179				input_event(input, EV_ABS, ABS_Y, nd->y);
180			}
181			input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
182			input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
183			if (nd->w > nd->h) {
184				input_event(input, EV_ABS,
185						ABS_MT_ORIENTATION, 1);
186				input_event(input, EV_ABS,
187						ABS_MT_TOUCH_MAJOR, nd->w);
188				input_event(input, EV_ABS,
189						ABS_MT_TOUCH_MINOR, nd->h);
190			} else {
191				input_event(input, EV_ABS,
192						ABS_MT_ORIENTATION, 0);
193				input_event(input, EV_ABS,
194						ABS_MT_TOUCH_MAJOR, nd->h);
195				input_event(input, EV_ABS,
196						ABS_MT_TOUCH_MINOR, nd->w);
197			}
198			input_mt_sync(field->hidinput->input);
199			nd->reading_a_point = 0;
200			nd->found_contact_id = 0;
201			break;
202
203		default:
204			/* fallback to the generic hidinput handling */
205			return 0;
206		}
207	}
208
209	/* we have handled the hidinput part, now remains hiddev */
210        if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
211                hid->hiddev_hid_event(hid, field, usage, value);
212
213	return 1;
214}
215
216static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
217{
218	int ret;
219	struct ntrig_data *nd;
220
221	nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
222	if (!nd) {
223		dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
224		return -ENOMEM;
225	}
226	nd->reading_a_point = 0;
227	nd->found_contact_id = 0;
228	hid_set_drvdata(hdev, nd);
229
230	ret = hid_parse(hdev);
231	if (!ret)
232		ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
233
234	if (ret)
235		kfree (nd);
236	return ret;
237}
238
239static void ntrig_remove(struct hid_device *hdev)
240{
241	hid_hw_stop(hdev);
242	kfree(hid_get_drvdata(hdev));
243}
244
245static const struct hid_device_id ntrig_devices[] = {
246	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
247		.driver_data = NTRIG_DUPLICATE_USAGES },
248	{ }
249};
250MODULE_DEVICE_TABLE(hid, ntrig_devices);
251
252static const struct hid_usage_id ntrig_grabbed_usages[] = {
253	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
254	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
255};
256
257static struct hid_driver ntrig_driver = {
258	.name = "ntrig",
259	.id_table = ntrig_devices,
260	.probe = ntrig_probe,
261	.remove = ntrig_remove,
262	.input_mapping = ntrig_input_mapping,
263	.input_mapped = ntrig_input_mapped,
264	.usage_table = ntrig_grabbed_usages,
265	.event = ntrig_event,
266};
267
268static int ntrig_init(void)
269{
270	return hid_register_driver(&ntrig_driver);
271}
272
273static void ntrig_exit(void)
274{
275	hid_unregister_driver(&ntrig_driver);
276}
277
278module_init(ntrig_init);
279module_exit(ntrig_exit);
280MODULE_LICENSE("GPL");
281