aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/touchwin.c
blob: a7b4c755958e3a2fe2775a9263c3ea7d0d7de453 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
 * Touchwindow serial touchscreen driver
 *
 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
 *
 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
 * Copyright (c) 2004 Vojtech Pavlik
 * and Dan Streetman <ddstreet@ieee.org>
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

/*
 * 2005/02/19 Rick Koch:
 *   The Touchwindow I used is made by Edmark Corp. and
 *   constantly outputs a stream of 0's unless it is touched.
 *   It then outputs 3 bytes: X, Y, and a copy of Y.
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>

#define DRIVER_DESC	"Touchwindow serial touchscreen driver"

MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

#define TW_LENGTH 3

#define TW_MIN_XC 0
#define TW_MAX_XC 0xff
#define TW_MIN_YC 0
#define TW_MAX_YC 0xff

/*
 * Per-touchscreen data.
 */

struct tw {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	int touched;
	unsigned char data[TW_LENGTH];
	char phys[32];
};

static irqreturn_t tw_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags, struct pt_regs *regs)
{
	struct tw *tw = serio_get_drvdata(serio);
	struct input_dev *dev = tw->dev;

	if (data) {		/* touch */
		tw->touched = 1;
		tw->data[tw->idx++] = data;
		/* verify length and that the two Y's are the same */
		if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
			input_regs(dev, regs);
			input_report_abs(dev, ABS_X, tw->data[0]);
			input_report_abs(dev, ABS_Y, tw->data[1]);
			input_report_key(dev, BTN_TOUCH, 1);
			input_sync(dev);
			tw->idx = 0;
		}
	} else if (tw->touched) {	/* untouch */
		input_report_key(dev, BTN_TOUCH, 0);
		input_sync(dev);
		tw->idx = 0;
		tw->touched = 0;
	}

	return IRQ_HANDLED;
}

/*
 * tw_disconnect() is the opposite of tw_connect()
 */

static void tw_disconnect(struct serio *serio)
{
	struct tw *tw = serio_get_drvdata(serio);

	input_get_device(tw->dev);
	input_unregister_device(tw->dev);
	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_put_device(tw->dev);
	kfree(tw);
}

/*
 * tw_connect() is the routine that is called when someone adds a
 * new serio device that supports the Touchwin protocol and registers it as
 * an input device.
 */

static int tw_connect(struct serio *serio, struct serio_driver *drv)
{
	struct tw *tw;
	struct input_dev *input_dev;
	int err;

	tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!tw || !input_dev) {
		err = -ENOMEM;
		goto fail1;
	}

	tw->serio = serio;
	tw->dev = input_dev;
	snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);

	input_dev->private = tw;
	input_dev->name = "Touchwindow Serial TouchScreen";
	input_dev->phys = tw->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_TOUCHWIN;
	input_dev->id.product = 0;
	input_dev->id.version = 0x0100;
	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
	input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
	input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);

	serio_set_drvdata(serio, tw);

	err = serio_open(serio, drv);
	if (err)
		goto fail2;

	err = input_register_device(tw->dev);
	if (err)
		goto fail3;

	return 0;

 fail3:	serio_close(serio);
 fail2:	serio_set_drvdata(serio, NULL);
 fail1:	input_free_device(input_dev);
	kfree(tw);
	return err;
}

/*
 * The serio driver structure.
 */

static struct serio_device_id tw_serio_ids[] = {
	{
		.type	= SERIO_RS232,
		.proto	= SERIO_TOUCHWIN,
		.id	= SERIO_ANY,
		.extra	= SERIO_ANY,
	},
	{ 0 }
};

MODULE_DEVICE_TABLE(serio, tw_serio_ids);

static struct serio_driver tw_drv = {
	.driver		= {
		.name	= "touchwin",
	},
	.description	= DRIVER_DESC,
	.id_table	= tw_serio_ids,
	.interrupt	= tw_interrupt,
	.connect	= tw_connect,
	.disconnect	= tw_disconnect,
};

/*
 * The functions for inserting/removing us as a module.
 */

static int __init tw_init(void)
{
	serio_register_driver(&tw_drv);
	return 0;
}

static void __exit tw_exit(void)
{
	serio_unregister_driver(&tw_drv);
}

module_init(tw_init);
module_exit(tw_exit);