aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/mtouch.c
blob: 4ec3b1f940c8f424560f4d5ebcc1bb060ce44162 (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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/*
 * MicroTouch (3M) serial touchscreen driver
 *
 * Copyright (c) 2004 Vojtech Pavlik
 */

/*
 * 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 Dan Streetman <ddstreet@ieee.org>
 *   Copied elo.c and edited for MicroTouch protocol
 */

#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	"MicroTouch serial touchscreen driver"

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80
#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40
#define MTOUCH_FORMAT_TABLET_LENGTH 5
#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01
#define MTOUCH_RESPONSE_END_BYTE 0x0d

/* todo: check specs for max length of all responses */
#define MTOUCH_MAX_LENGTH 16

#define MTOUCH_MIN_XC 0
#define MTOUCH_MAX_XC 0x3fff
#define MTOUCH_MIN_YC 0
#define MTOUCH_MAX_YC 0x3fff

#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])
#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])
#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])

/*
 * Per-touchscreen data.
 */

struct mtouch {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char data[MTOUCH_MAX_LENGTH];
	char phys[32];
};

static void mtouch_process_format_tablet(struct mtouch *mtouch)
{
	struct input_dev *dev = mtouch->dev;

	if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
		input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
		input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
		input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
		input_sync(dev);

		mtouch->idx = 0;
	}
}

static void mtouch_process_response(struct mtouch *mtouch)
{
	if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
		/* FIXME - process response */
		mtouch->idx = 0;
	} else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
		printk(KERN_ERR "mtouch.c: too many response bytes\n");
		mtouch->idx = 0;
	}
}

static irqreturn_t mtouch_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags)
{
	struct mtouch* mtouch = serio_get_drvdata(serio);

	mtouch->data[mtouch->idx] = data;

	if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
		mtouch_process_format_tablet(mtouch);
	else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
		mtouch_process_response(mtouch);
	else
		printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);

	return IRQ_HANDLED;
}

/*
 * mtouch_disconnect() is the opposite of mtouch_connect()
 */

static void mtouch_disconnect(struct serio *serio)
{
	struct mtouch* mtouch = serio_get_drvdata(serio);

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

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

static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
{
	struct mtouch *mtouch;
	struct input_dev *input_dev;
	int err;

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

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

	input_dev->name = "MicroTouch Serial TouchScreen";
	input_dev->phys = mtouch->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_MICROTOUCH;
	input_dev->id.product = 0;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;
	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
	input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
	input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);

	serio_set_drvdata(serio, mtouch);

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

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

	return 0;

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

/*
 * The serio driver structure.
 */

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

MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);

static struct serio_driver mtouch_drv = {
	.driver		= {
		.name	= "mtouch",
	},
	.description	= DRIVER_DESC,
	.id_table	= mtouch_serio_ids,
	.interrupt	= mtouch_interrupt,
	.connect	= mtouch_connect,
	.disconnect	= mtouch_disconnect,
};

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

static int __init mtouch_init(void)
{
	return serio_register_driver(&mtouch_drv);
}

static void __exit mtouch_exit(void)
{
	serio_unregister_driver(&mtouch_drv);
}

module_init(mtouch_init);
module_exit(mtouch_exit);