1/*
  2 *  HID driver for Quanta Optical Touch dual-touch panels
  3 *
  4 *  Copyright (c) 2009-2010 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
 20MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
 21MODULE_DESCRIPTION("Quanta dual-touch panel");
 22MODULE_LICENSE("GPL");
 23
 24#include "hid-ids.h"
 25
 26struct quanta_data {
 27	__u16 x, y;
 28	__u8 id;
 29	bool valid;		/* valid finger data, or just placeholder? */
 30	bool first;		/* is this the first finger in this frame? */
 31	bool activity_now;	/* at least one active finger in this frame? */
 32	bool activity;		/* at least one active finger previously? */
 33};
 34
 35static int quanta_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 36		struct hid_field *field, struct hid_usage *usage,
 37		unsigned long **bit, int *max)
 38{
 39	switch (usage->hid & HID_USAGE_PAGE) {
 40
 41	case HID_UP_GENDESK:
 42		switch (usage->hid) {
 43		case HID_GD_X:
 44			hid_map_usage(hi, usage, bit, max,
 45					EV_ABS, ABS_MT_POSITION_X);
 46			/* touchscreen emulation */
 47			input_set_abs_params(hi->input, ABS_X,
 48						field->logical_minimum,
 49						field->logical_maximum, 0, 0);
 50			return 1;
 51		case HID_GD_Y:
 52			hid_map_usage(hi, usage, bit, max,
 53					EV_ABS, ABS_MT_POSITION_Y);
 54			/* touchscreen emulation */
 55			input_set_abs_params(hi->input, ABS_Y,
 56						field->logical_minimum,
 57						field->logical_maximum, 0, 0);
 58			return 1;
 59		}
 60		return 0;
 61
 62	case HID_UP_DIGITIZER:
 63		switch (usage->hid) {
 64		case HID_DG_CONFIDENCE:
 65		case HID_DG_TIPSWITCH:
 66		case HID_DG_INPUTMODE:
 67		case HID_DG_DEVICEINDEX:
 68		case HID_DG_CONTACTCOUNT:
 69		case HID_DG_CONTACTMAX:
 70		case HID_DG_TIPPRESSURE:
 71		case HID_DG_WIDTH:
 72		case HID_DG_HEIGHT:
 73			return -1;
 74		case HID_DG_INRANGE:
 75			/* touchscreen emulation */
 76			hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 77			return 1;
 78		case HID_DG_CONTACTID:
 79			hid_map_usage(hi, usage, bit, max,
 80					EV_ABS, ABS_MT_TRACKING_ID);
 81			return 1;
 82		}
 83		return 0;
 84
 85	case 0xff000000:
 86		/* ignore vendor-specific features */
 87		return -1;
 88	}
 89
 90	return 0;
 91}
 92
 93static int quanta_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 94		struct hid_field *field, struct hid_usage *usage,
 95		unsigned long **bit, int *max)
 96{
 97	if (usage->type == EV_KEY || usage->type == EV_ABS)
 98		clear_bit(usage->code, *bit);
 99
100	return 0;
101}
102
103/*
104 * this function is called when a whole finger has been parsed,
105 * so that it can decide what to send to the input layer.
106 */
107static void quanta_filter_event(struct quanta_data *td, struct input_dev *input)
108{
109	
110	td->first = !td->first; /* touchscreen emulation */
111
112	if (!td->valid) {
113		/*
114		 * touchscreen emulation: if no finger in this frame is valid
115		 * and there previously was finger activity, this is a release
116		 */ 
117		if (!td->first && !td->activity_now && td->activity) {
118			input_event(input, EV_KEY, BTN_TOUCH, 0);
119			td->activity = false;
120		}
121		return;
122	}
123
124	input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
125	input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
126	input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
127
128	input_mt_sync(input);
129	td->valid = false;
130
131	/* touchscreen emulation: if first active finger in this frame... */
132	if (!td->activity_now) {
133		/* if there was no previous activity, emit touch event */
134		if (!td->activity) {
135			input_event(input, EV_KEY, BTN_TOUCH, 1);
136			td->activity = true;
137		}
138		td->activity_now = true;
139		/* and in any case this is our preferred finger */
140		input_event(input, EV_ABS, ABS_X, td->x);
141		input_event(input, EV_ABS, ABS_Y, td->y);
142	}
143}
144
145
146static int quanta_event(struct hid_device *hid, struct hid_field *field,
147				struct hid_usage *usage, __s32 value)
148{
149	struct quanta_data *td = hid_get_drvdata(hid);
150
151	if (hid->claimed & HID_CLAIMED_INPUT) {
152		struct input_dev *input = field->hidinput->input;
153
154		switch (usage->hid) {
155		case HID_DG_INRANGE:
156			td->valid = !!value;
157			break;
158		case HID_GD_X:
159			td->x = value;
160			break;
161		case HID_GD_Y:
162			td->y = value;
163			quanta_filter_event(td, input);
164			break;
165		case HID_DG_CONTACTID:
166			td->id = value;
167			break;
168		case HID_DG_CONTACTCOUNT:
169			/* touch emulation: this is the last field in a frame */
170			td->first = false;
171			td->activity_now = false;
172			break;
173		case HID_DG_CONFIDENCE:
174		case HID_DG_TIPSWITCH:
175			/* avoid interference from generic hidinput handling */
176			break;
177
178		default:
179			/* fallback to the generic hidinput handling */
180			return 0;
181		}
182	}
183
184	/* we have handled the hidinput part, now remains hiddev */
185	if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
186		hid->hiddev_hid_event(hid, field, usage, value);
187
188	return 1;
189}
190
191static int quanta_probe(struct hid_device *hdev, const struct hid_device_id *id)
192{
193	int ret;
194	struct quanta_data *td;
195
196	td = kmalloc(sizeof(struct quanta_data), GFP_KERNEL);
197	if (!td) {
198		hid_err(hdev, "cannot allocate Quanta Touch data\n");
199		return -ENOMEM;
200	}
201	td->valid = false;
202	td->activity = false;
203	td->activity_now = false;
204	td->first = false;
205	hid_set_drvdata(hdev, td);
206
207	ret = hid_parse(hdev);
208	if (!ret)
209		ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
210
211	if (ret)
212		kfree(td);
213
214	return ret;
215}
216
217static void quanta_remove(struct hid_device *hdev)
218{
219	hid_hw_stop(hdev);
220	kfree(hid_get_drvdata(hdev));
221	hid_set_drvdata(hdev, NULL);
222}
223
224static const struct hid_device_id quanta_devices[] = {
225	{ HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
226			USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH) },
227	{ HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
228			USB_DEVICE_ID_PIXART_IMAGING_INC_OPTICAL_TOUCH_SCREEN) },
229	{ }
230};
231MODULE_DEVICE_TABLE(hid, quanta_devices);
232
233static const struct hid_usage_id quanta_grabbed_usages[] = {
234	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
235	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
236};
237
238static struct hid_driver quanta_driver = {
239	.name = "quanta-touch",
240	.id_table = quanta_devices,
241	.probe = quanta_probe,
242	.remove = quanta_remove,
243	.input_mapping = quanta_input_mapping,
244	.input_mapped = quanta_input_mapped,
245	.usage_table = quanta_grabbed_usages,
246	.event = quanta_event,
247};
248
249static int __init quanta_init(void)
250{
251	return hid_register_driver(&quanta_driver);
252}
253
254static void __exit quanta_exit(void)
255{
256	hid_unregister_driver(&quanta_driver);
257}
258
259module_init(quanta_init);
260module_exit(quanta_exit);
261