aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/joystick/twidjoy.c
blob: 7f7e5ab3f9e303871de01d681f0453af1bb3e52a (plain) (blame)
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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 *  Copyright (c) 2001 Arndt Schoenewald
 *  Copyright (c) 2000-2001 Vojtech Pavlik
 *  Copyright (c) 2000 Mark Fletcher
 *
 *  Sponsored by Quelltext AG (http://www.quelltext-ag.de), Dortmund, Germany
 */

/*
 * Driver to use Handykey's Twiddler (the first edition, i.e. the one with
 * the RS232 interface) as a joystick under Linux
 *
 * The Twiddler is a one-handed chording keyboard featuring twelve buttons on
 * the front, six buttons on the top, and a built-in tilt sensor. The buttons
 * on the front, which are grouped as four rows of three buttons, are pressed
 * by the four fingers (this implies only one button per row can be held down
 * at the same time) and the buttons on the top are for the thumb. The tilt
 * sensor delivers X and Y axis data depending on how the Twiddler is held.
 * Additional information can be found at http://www.handykey.com.
 *
 * This driver does not use the Twiddler for its intended purpose, i.e. as
 * a chording keyboard, but as a joystick: pressing and releasing a button
 * immediately sends a corresponding button event, and tilting it generates
 * corresponding ABS_X and ABS_Y events. This turns the Twiddler into a game
 * controller with amazing 18 buttons :-)
 *
 * Note: The Twiddler2 (the successor of the Twiddler that connects directly
 * to the PS/2 keyboard and mouse ports) is NOT supported by this driver!
 *
 * For questions or feedback regarding this driver module please contact:
 * Arndt Schoenewald <arndt@quelltext.com>
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

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

#define DRIVER_DESC	"Handykey Twiddler keyboard as a joystick driver"

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Constants.
 */

#define TWIDJOY_MAX_LENGTH 5

static struct twidjoy_button_spec {
	int bitshift;
	int bitmask;
	int buttons[3];
}
twidjoy_buttons[] = {
	{  0, 3, { BTN_A,      BTN_B,     BTN_C    } },
	{  2, 3, { BTN_X,      BTN_Y,     BTN_Z    } },
	{  4, 3, { BTN_TL,     BTN_TR,    BTN_TR2  } },
	{  6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
	{  8, 1, { BTN_BASE5                       } },
	{  9, 1, { BTN_BASE                        } },
	{ 10, 1, { BTN_BASE3                       } },
	{ 11, 1, { BTN_BASE4                       } },
	{ 12, 1, { BTN_BASE2                       } },
	{ 13, 1, { BTN_BASE6                       } },
	{ 0,  0, { 0                               } }
};

/*
 * Per-Twiddler data.
 */

struct twidjoy {
	struct input_dev *dev;
	int idx;
	unsigned char data[TWIDJOY_MAX_LENGTH];
	char phys[32];
};

/*
 * twidjoy_process_packet() decodes packets the driver receives from the
 * Twiddler. It updates the data accordingly.
 */

static void twidjoy_process_packet(struct twidjoy *twidjoy)
{
	struct input_dev *dev = twidjoy->dev;
	unsigned char *data = twidjoy->data;
	struct twidjoy_button_spec *bp;
	int button_bits, abs_x, abs_y;

	button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);

	for (bp = twidjoy_buttons; bp->bitmask; bp++) {
		int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
		int i;

		for (i = 0; i < bp->bitmask; i++)
			input_report_key(dev, bp->buttons[i], i+1 == value);
	}

	abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
	if (data[4] & 0x08) abs_x -= 256;

	abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
	if (data[3] & 0x02) abs_y -= 256;

	input_report_abs(dev, ABS_X, -abs_x);
	input_report_abs(dev, ABS_Y, +abs_y);

	input_sync(dev);
}

/*
 * twidjoy_interrupt() is called by the low level driver when characters
 * are ready for us. We then buffer them for further processing, or call the
 * packet processing routine.
 */

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

	/* All Twiddler packets are 5 bytes. The fact that the first byte
	 * has a MSB of 0 and all other bytes have a MSB of 1 can be used
	 * to check and regain sync. */

	if ((data & 0x80) == 0)
		twidjoy->idx = 0;	/* this byte starts a new packet */
	else if (twidjoy->idx == 0)
		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */

	if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
		twidjoy->data[twidjoy->idx++] = data;

	if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
		twidjoy_process_packet(twidjoy);
		twidjoy->idx = 0;
	}

	return IRQ_HANDLED;
}

/*
 * twidjoy_disconnect() is the opposite of twidjoy_connect()
 */

static void twidjoy_disconnect(struct serio *serio)
{
	struct twidjoy *twidjoy = serio_get_drvdata(serio);

	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_unregister_device(twidjoy->dev);
	kfree(twidjoy);
}

/*
 * twidjoy_connect() is the routine that is called when someone adds a
 * new serio device. It looks for the Twiddler, and if found, registers
 * it as an input device.
 */

static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
{
	struct twidjoy_button_spec *bp;
	struct twidjoy *twidjoy;
	struct input_dev *input_dev;
	int err = -ENOMEM;
	int i;

	twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!twidjoy || !input_dev)
		goto fail1;

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

	input_dev->name = "Handykey Twiddler";
	input_dev->phys = twidjoy->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_TWIDJOY;
	input_dev->id.product = 0x0001;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4);
	input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4);

	for (bp = twidjoy_buttons; bp->bitmask; bp++)
		for (i = 0; i < bp->bitmask; i++)
			set_bit(bp->buttons[i], input_dev->keybit);

	serio_set_drvdata(serio, twidjoy);

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

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

	return 0;

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

/*
 * The serio driver structure.
 */

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

MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);

static struct serio_driver twidjoy_drv = {
	.driver		= {
		.name	= "twidjoy",
	},
	.description	= DRIVER_DESC,
	.id_table	= twidjoy_serio_ids,
	.interrupt	= twidjoy_interrupt,
	.connect	= twidjoy_connect,
	.disconnect	= twidjoy_disconnect,
};

module_serio_driver(twidjoy_drv);