1 /*
2 * HID driver for Cando dual-touch panels
3 *
4 * Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
5 *
6 */
7
8 /*
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)
12 * any later version.
13 */
14
15 #include <linux/device.h>
16 #include <linux/hid.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19
20 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
21 MODULE_DESCRIPTION("Cando dual-touch panel");
22 MODULE_LICENSE("GPL");
23
24 #include "hid-ids.h"
25
26 struct cando_data {
27 __u16 x, y;
28 __u8 id;
29 __s8 oldest; /* id of the oldest finger in previous frame */
30 bool valid; /* valid finger data, or just placeholder? */
31 bool first; /* is this the first finger in this frame? */
32 __s8 firstid; /* id of the first finger in the frame */
33 __u16 firstx, firsty; /* (x, y) of the first finger in the frame */
34 };
35
cando_input_mapping(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)36 static int cando_input_mapping(struct hid_device *hdev, struct hid_input *hi,
37 struct hid_field *field, struct hid_usage *usage,
38 unsigned long **bit, int *max)
39 {
40 switch (usage->hid & HID_USAGE_PAGE) {
41
42 case HID_UP_GENDESK:
43 switch (usage->hid) {
44 case HID_GD_X:
45 hid_map_usage(hi, usage, bit, max,
46 EV_ABS, ABS_MT_POSITION_X);
47 /* touchscreen emulation */
48 input_set_abs_params(hi->input, ABS_X,
49 field->logical_minimum,
50 field->logical_maximum, 0, 0);
51 return 1;
52 case HID_GD_Y:
53 hid_map_usage(hi, usage, bit, max,
54 EV_ABS, ABS_MT_POSITION_Y);
55 /* touchscreen emulation */
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 case HID_DG_TIPSWITCH:
66 case HID_DG_CONTACTMAX:
67 return -1;
68 case HID_DG_INRANGE:
69 /* touchscreen emulation */
70 hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
71 return 1;
72 case HID_DG_CONTACTID:
73 hid_map_usage(hi, usage, bit, max,
74 EV_ABS, ABS_MT_TRACKING_ID);
75 return 1;
76 }
77 return 0;
78 }
79
80 return 0;
81 }
82
cando_input_mapped(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)83 static int cando_input_mapped(struct hid_device *hdev, struct hid_input *hi,
84 struct hid_field *field, struct hid_usage *usage,
85 unsigned long **bit, int *max)
86 {
87 if (usage->type == EV_KEY || usage->type == EV_ABS)
88 clear_bit(usage->code, *bit);
89
90 return 0;
91 }
92
93 /*
94 * this function is called when a whole finger has been parsed,
95 * so that it can decide what to send to the input layer.
96 */
cando_filter_event(struct cando_data * td,struct input_dev * input)97 static void cando_filter_event(struct cando_data *td, struct input_dev *input)
98 {
99 td->first = !td->first; /* touchscreen emulation */
100
101 if (!td->valid) {
102 /*
103 * touchscreen emulation: if this is the second finger and
104 * the first was valid, the first was the oldest; if the
105 * first was not valid and there was a valid finger in the
106 * previous frame, this is a release.
107 */
108 if (td->first) {
109 td->firstid = -1;
110 } else if (td->firstid >= 0) {
111 input_event(input, EV_ABS, ABS_X, td->firstx);
112 input_event(input, EV_ABS, ABS_Y, td->firsty);
113 td->oldest = td->firstid;
114 } else if (td->oldest >= 0) {
115 input_event(input, EV_KEY, BTN_TOUCH, 0);
116 td->oldest = -1;
117 }
118
119 return;
120 }
121
122 input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
123 input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
124 input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
125
126 input_mt_sync(input);
127
128 /*
129 * touchscreen emulation: if there was no touching finger previously,
130 * emit touch event
131 */
132 if (td->oldest < 0) {
133 input_event(input, EV_KEY, BTN_TOUCH, 1);
134 td->oldest = td->id;
135 }
136
137 /*
138 * touchscreen emulation: if this is the first finger, wait for the
139 * second; the oldest is then the second if it was the oldest already
140 * or if there was no first, the first otherwise.
141 */
142 if (td->first) {
143 td->firstx = td->x;
144 td->firsty = td->y;
145 td->firstid = td->id;
146 } else {
147 int x, y, oldest;
148 if (td->id == td->oldest || td->firstid < 0) {
149 x = td->x;
150 y = td->y;
151 oldest = td->id;
152 } else {
153 x = td->firstx;
154 y = td->firsty;
155 oldest = td->firstid;
156 }
157 input_event(input, EV_ABS, ABS_X, x);
158 input_event(input, EV_ABS, ABS_Y, y);
159 td->oldest = oldest;
160 }
161 }
162
163
cando_event(struct hid_device * hid,struct hid_field * field,struct hid_usage * usage,__s32 value)164 static int cando_event(struct hid_device *hid, struct hid_field *field,
165 struct hid_usage *usage, __s32 value)
166 {
167 struct cando_data *td = hid_get_drvdata(hid);
168
169 if (hid->claimed & HID_CLAIMED_INPUT) {
170 struct input_dev *input = field->hidinput->input;
171
172 switch (usage->hid) {
173 case HID_DG_INRANGE:
174 td->valid = value;
175 break;
176 case HID_DG_CONTACTID:
177 td->id = value;
178 break;
179 case HID_GD_X:
180 td->x = value;
181 break;
182 case HID_GD_Y:
183 td->y = value;
184 cando_filter_event(td, input);
185 break;
186 case HID_DG_TIPSWITCH:
187 /* avoid interference from generic hidinput handling */
188 break;
189
190 default:
191 /* fallback to the generic hidinput handling */
192 return 0;
193 }
194 }
195
196 /* we have handled the hidinput part, now remains hiddev */
197 if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
198 hid->hiddev_hid_event(hid, field, usage, value);
199
200 return 1;
201 }
202
cando_probe(struct hid_device * hdev,const struct hid_device_id * id)203 static int cando_probe(struct hid_device *hdev, const struct hid_device_id *id)
204 {
205 int ret;
206 struct cando_data *td;
207
208 td = kmalloc(sizeof(struct cando_data), GFP_KERNEL);
209 if (!td) {
210 hid_err(hdev, "cannot allocate Cando Touch data\n");
211 return -ENOMEM;
212 }
213 hid_set_drvdata(hdev, td);
214 td->first = false;
215 td->oldest = -1;
216 td->valid = false;
217
218 ret = hid_parse(hdev);
219 if (!ret)
220 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
221
222 if (ret)
223 kfree(td);
224
225 return ret;
226 }
227
cando_remove(struct hid_device * hdev)228 static void cando_remove(struct hid_device *hdev)
229 {
230 hid_hw_stop(hdev);
231 kfree(hid_get_drvdata(hdev));
232 hid_set_drvdata(hdev, NULL);
233 }
234
235 static const struct hid_device_id cando_devices[] = {
236 { HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
237 USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
238 { HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
239 USB_DEVICE_ID_CANDO_MULTI_TOUCH_10_1) },
240 { HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
241 USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) },
242 { HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
243 USB_DEVICE_ID_CANDO_MULTI_TOUCH_15_6) },
244 { }
245 };
246 MODULE_DEVICE_TABLE(hid, cando_devices);
247
248 static const struct hid_usage_id cando_grabbed_usages[] = {
249 { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
250 { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
251 };
252
253 static struct hid_driver cando_driver = {
254 .name = "cando-touch",
255 .id_table = cando_devices,
256 .probe = cando_probe,
257 .remove = cando_remove,
258 .input_mapping = cando_input_mapping,
259 .input_mapped = cando_input_mapped,
260 .usage_table = cando_grabbed_usages,
261 .event = cando_event,
262 };
263
cando_init(void)264 static int __init cando_init(void)
265 {
266 return hid_register_driver(&cando_driver);
267 }
268
cando_exit(void)269 static void __exit cando_exit(void)
270 {
271 hid_unregister_driver(&cando_driver);
272 }
273
274 module_init(cando_init);
275 module_exit(cando_exit);
276
277