2 * HID driver for N-Trig touchscreens
4 * Copyright (c) 2008-2010 Rafi Rubin
5 * Copyright (c) 2009-2010 Stephane Chatty
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)
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>
25 #define NTRIG_DUPLICATE_USAGES 0x001
28 /* Incoming raw values for a single contact */
34 bool first_contact_touch;
43 * this driver is aimed at two firmware versions in circulation:
44 * - dual pen/finger single touch
45 * - finger multitouch, pen not working
48 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
49 struct hid_field *field, struct hid_usage *usage,
50 unsigned long **bit, int *max)
52 /* No special mappings needed for the pen and single touch */
56 switch (usage->hid & HID_USAGE_PAGE) {
60 hid_map_usage(hi, usage, bit, max,
61 EV_ABS, ABS_MT_POSITION_X);
62 input_set_abs_params(hi->input, ABS_X,
63 field->logical_minimum,
64 field->logical_maximum, 0, 0);
67 hid_map_usage(hi, usage, bit, max,
68 EV_ABS, ABS_MT_POSITION_Y);
69 input_set_abs_params(hi->input, ABS_Y,
70 field->logical_minimum,
71 field->logical_maximum, 0, 0);
76 case HID_UP_DIGITIZER:
78 /* we do not want to map these for now */
79 case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
80 case HID_DG_INPUTMODE:
81 case HID_DG_DEVICEINDEX:
82 case HID_DG_CONTACTMAX:
85 /* width/height mapped on TouchMajor/TouchMinor/Orientation */
87 hid_map_usage(hi, usage, bit, max,
88 EV_ABS, ABS_MT_TOUCH_MAJOR);
91 hid_map_usage(hi, usage, bit, max,
92 EV_ABS, ABS_MT_TOUCH_MINOR);
93 input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
100 /* we do not want to map these: no input-oriented meaning */
107 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
108 struct hid_field *field, struct hid_usage *usage,
109 unsigned long **bit, int *max)
111 /* No special mappings needed for the pen and single touch */
115 if (usage->type == EV_KEY || usage->type == EV_REL
116 || usage->type == EV_ABS)
117 clear_bit(usage->code, *bit);
123 * this function is called upon all reports
124 * so that we can filter contact point information,
125 * decide whether we are in multi or single touch mode
126 * and call input_mt_sync after each point if necessary
128 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
129 struct hid_usage *usage, __s32 value)
131 struct input_dev *input = field->hidinput->input;
132 struct ntrig_data *nd = hid_get_drvdata(hid);
134 /* No special handling needed for the pen */
135 if (field->application == HID_DG_PEN)
138 if (hid->claimed & HID_CLAIMED_INPUT) {
139 switch (usage->hid) {
141 /* Tag indicating the start of a multitouch group */
143 nd->first_contact_touch = 0;
145 case HID_DG_TIPSWITCH:
146 nd->tipswitch = value;
147 /* Prevent emission of touch until validated */
149 case HID_DG_CONFIDENCE:
150 nd->confidence = value;
154 /* Clear the contact footer */
155 nd->mt_foot_count = 0;
160 case HID_DG_CONTACTID:
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
173 if (!nd->reading_mt) {
175 * TipSwitch indicates the presence of a
176 * finger in single touch mode.
178 input_report_key(input, BTN_TOUCH,
180 input_report_key(input, BTN_TOOL_DOUBLETAP,
182 input_event(input, EV_ABS, ABS_X, nd->x);
183 input_event(input, EV_ABS, ABS_Y, nd->y);
188 * we receive this when the device is in multitouch
189 * mode. The first of the three values tagged with
190 * this usage tells if the contact point is real
194 /* Shouldn't get more than 4 footer packets, so skip */
195 if (nd->mt_foot_count >= 4)
198 nd->mt_footer[nd->mt_foot_count++] = value;
200 /* if the footer isn't complete break */
201 if (nd->mt_foot_count != 4)
204 /* Pen activity signal, trigger end of touch. */
205 if (nd->mt_footer[2]) {
210 /* If the contact was invalid */
211 if (!(nd->confidence && nd->mt_footer[0])
218 /* emit a normal (X, Y) for the first point only */
221 * TipSwitch is superfluous in multitouch
222 * mode. The footer events tell us
223 * if there is a finger on the screen or
226 nd->first_contact_touch = nd->confidence;
227 input_event(input, EV_ABS, ABS_X, nd->x);
228 input_event(input, EV_ABS, ABS_Y, nd->y);
230 input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
231 input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
233 input_event(input, EV_ABS,
234 ABS_MT_ORIENTATION, 1);
235 input_event(input, EV_ABS,
236 ABS_MT_TOUCH_MAJOR, nd->w);
237 input_event(input, EV_ABS,
238 ABS_MT_TOUCH_MINOR, nd->h);
240 input_event(input, EV_ABS,
241 ABS_MT_ORIENTATION, 0);
242 input_event(input, EV_ABS,
243 ABS_MT_TOUCH_MAJOR, nd->h);
244 input_event(input, EV_ABS,
245 ABS_MT_TOUCH_MINOR, nd->w);
247 input_mt_sync(field->hidinput->input);
250 case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
256 if (nd->first_contact_touch) {
257 input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
258 input_report_key(input, BTN_TOUCH, 1);
260 input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
261 input_report_key(input, BTN_TOUCH, 0);
266 /* fallback to the generic hidinput handling */
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);
278 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
281 struct ntrig_data *nd;
282 struct hid_input *hidinput;
283 struct input_dev *input;
284 struct hid_report *report;
287 hdev->quirks |= HID_QUIRK_MULTI_INPUT;
289 nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
291 dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
296 hid_set_drvdata(hdev, nd);
298 ret = hid_parse(hdev);
300 dev_err(&hdev->dev, "parse failed\n");
304 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
306 dev_err(&hdev->dev, "hw start failed\n");
311 list_for_each_entry(hidinput, &hdev->inputs, list) {
312 if (hidinput->report->maxfield < 1)
315 input = hidinput->input;
316 switch (hidinput->report->field[0]->application) {
318 input->name = "N-Trig Pen";
320 case HID_DG_TOUCHSCREEN:
321 /* These keys are redundant for fingers, clear them
322 * to prevent incorrect identification */
323 __clear_bit(BTN_TOOL_PEN, input->keybit);
324 __clear_bit(BTN_TOOL_FINGER, input->keybit);
325 __clear_bit(BTN_0, input->keybit);
326 __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
328 * The physical touchscreen (single touch)
329 * input has a value for physical, whereas
330 * the multitouch only has logical input
334 (hidinput->report->field[0]
336 "N-Trig Touchscreen" :
342 /* This is needed for devices with more recent firmware versions */
343 report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
345 usbhid_submit_report(hdev, report, USB_DIR_OUT);
354 static void ntrig_remove(struct hid_device *hdev)
357 kfree(hid_get_drvdata(hdev));
360 static const struct hid_device_id ntrig_devices[] = {
361 { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
362 .driver_data = NTRIG_DUPLICATE_USAGES },
365 MODULE_DEVICE_TABLE(hid, ntrig_devices);
367 static const struct hid_usage_id ntrig_grabbed_usages[] = {
368 { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
369 { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
372 static struct hid_driver ntrig_driver = {
374 .id_table = ntrig_devices,
375 .probe = ntrig_probe,
376 .remove = ntrig_remove,
377 .input_mapping = ntrig_input_mapping,
378 .input_mapped = ntrig_input_mapped,
379 .usage_table = ntrig_grabbed_usages,
380 .event = ntrig_event,
383 static int __init ntrig_init(void)
385 return hid_register_driver(&ntrig_driver);
388 static void __exit ntrig_exit(void)
390 hid_unregister_driver(&ntrig_driver);
393 module_init(ntrig_init);
394 module_exit(ntrig_exit);
395 MODULE_LICENSE("GPL");