2 * HID driver for eGalax dual-touch panels
4 * Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
15 #include <linux/device.h>
16 #include <linux/hid.h>
17 #include <linux/module.h>
18 #include <linux/usb.h>
19 #include <linux/slab.h>
20 #include "usbhid/usbhid.h"
22 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
23 MODULE_DESCRIPTION("eGalax dual-touch panel");
24 MODULE_LICENSE("GPL");
31 bool first; /* is this the first finger in the frame? */
32 bool valid; /* valid finger data, or just placeholder? */
33 bool activity; /* at least one active finger previously? */
34 __u16 lastx, lasty; /* latest valid (x, y) in the frame */
37 static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
38 struct hid_field *field, struct hid_usage *usage,
39 unsigned long **bit, int *max)
41 switch (usage->hid & HID_USAGE_PAGE) {
46 hid_map_usage(hi, usage, bit, max,
47 EV_ABS, ABS_MT_POSITION_X);
48 /* touchscreen emulation */
49 input_set_abs_params(hi->input, ABS_X,
50 field->logical_minimum,
51 field->logical_maximum, 0, 0);
54 hid_map_usage(hi, usage, bit, max,
55 EV_ABS, ABS_MT_POSITION_Y);
56 /* touchscreen emulation */
57 input_set_abs_params(hi->input, ABS_Y,
58 field->logical_minimum,
59 field->logical_maximum, 0, 0);
64 case HID_UP_DIGITIZER:
66 case HID_DG_TIPSWITCH:
67 /* touchscreen emulation */
68 hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
71 case HID_DG_CONFIDENCE:
72 case HID_DG_CONTACTCOUNT:
73 case HID_DG_CONTACTMAX:
75 case HID_DG_CONTACTID:
76 hid_map_usage(hi, usage, bit, max,
77 EV_ABS, ABS_MT_TRACKING_ID);
79 case HID_DG_TIPPRESSURE:
80 hid_map_usage(hi, usage, bit, max,
81 EV_ABS, ABS_MT_PRESSURE);
87 /* ignore others (from other reports we won't get anyway) */
91 static int egalax_input_mapped(struct hid_device *hdev, struct hid_input *hi,
92 struct hid_field *field, struct hid_usage *usage,
93 unsigned long **bit, int *max)
95 if (usage->type == EV_KEY || usage->type == EV_ABS)
96 clear_bit(usage->code, *bit);
102 * this function is called when a whole finger has been parsed,
103 * so that it can decide what to send to the input layer.
105 static void egalax_filter_event(struct egalax_data *td, struct input_dev *input)
107 td->first = !td->first; /* touchscreen emulation */
110 /* emit multitouch events */
111 input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
112 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
113 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
114 input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);
116 input_mt_sync(input);
119 * touchscreen emulation: store (x, y) as
120 * the last valid values in this frame
127 * touchscreen emulation: if this is the second finger and at least
128 * one in this frame is valid, the latest valid in the frame is
129 * the oldest on the panel, the one we want for single touch
131 if (!td->first && td->activity) {
132 input_event(input, EV_ABS, ABS_X, td->lastx);
133 input_event(input, EV_ABS, ABS_Y, td->lasty);
138 * touchscreen emulation: if the first finger is invalid
139 * and there previously was finger activity, this is a release
141 if (td->first && td->activity) {
142 input_event(input, EV_KEY, BTN_TOUCH, 0);
143 td->activity = false;
149 /* touchscreen emulation: if no previous activity, emit touch event */
151 input_event(input, EV_KEY, BTN_TOUCH, 1);
157 static int egalax_event(struct hid_device *hid, struct hid_field *field,
158 struct hid_usage *usage, __s32 value)
160 struct egalax_data *td = hid_get_drvdata(hid);
162 if (hid->claimed & HID_CLAIMED_INPUT) {
163 struct input_dev *input = field->hidinput->input;
165 switch (usage->hid) {
167 case HID_DG_CONFIDENCE:
168 /* avoid interference from generic hidinput handling */
170 case HID_DG_TIPSWITCH:
173 case HID_DG_TIPPRESSURE:
176 case HID_DG_CONTACTID:
184 /* this is the last field in a finger */
185 egalax_filter_event(td, input);
187 case HID_DG_CONTACTCOUNT:
188 /* touch emulation: this is the last field in a frame */
193 /* fallback to the generic hidinput handling */
198 /* we have handled the hidinput part, now remains hiddev */
199 if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
200 hid->hiddev_hid_event(hid, field, usage, value);
205 static int egalax_probe(struct hid_device *hdev, const struct hid_device_id *id)
208 struct egalax_data *td;
209 struct hid_report *report;
211 td = kmalloc(sizeof(struct egalax_data), GFP_KERNEL);
213 dev_err(&hdev->dev, "cannot allocate eGalax data\n");
216 hid_set_drvdata(hdev, td);
218 ret = hid_parse(hdev);
222 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
226 report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[5];
228 report->field[0]->value[0] = 2;
229 usbhid_submit_report(hdev, report, USB_DIR_OUT);
239 static void egalax_remove(struct hid_device *hdev)
242 kfree(hid_get_drvdata(hdev));
243 hid_set_drvdata(hdev, NULL);
246 static const struct hid_device_id egalax_devices[] = {
247 { HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
248 USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
251 MODULE_DEVICE_TABLE(hid, egalax_devices);
253 static const struct hid_usage_id egalax_grabbed_usages[] = {
254 { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
255 { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
258 static struct hid_driver egalax_driver = {
259 .name = "egalax-touch",
260 .id_table = egalax_devices,
261 .probe = egalax_probe,
262 .remove = egalax_remove,
263 .input_mapping = egalax_input_mapping,
264 .input_mapped = egalax_input_mapped,
265 .usage_table = egalax_grabbed_usages,
266 .event = egalax_event,
269 static int __init egalax_init(void)
271 return hid_register_driver(&egalax_driver);
274 static void __exit egalax_exit(void)
276 hid_unregister_driver(&egalax_driver);
279 module_init(egalax_init);
280 module_exit(egalax_exit);