xref: /linux/drivers/input/joystick/twidjoy.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * $Id: twidjoy.c,v 1.5 2002/01/22 20:31:53 vojtech Exp $
3  *
4  *  derived from CVS-ID "stinger.c,v 1.5 2001/05/29 12:57:18 vojtech Exp"
5  *
6  *  Copyright (c) 2001 Arndt Schoenewald
7  *  Copyright (c) 2000-2001 Vojtech Pavlik
8  *  Copyright (c) 2000 Mark Fletcher
9  *
10  *  Sponsored by Quelltext AG (http://www.quelltext-ag.de), Dortmund, Germany
11  */
12 
13 /*
14  * Driver to use Handykey's Twiddler (the first edition, i.e. the one with
15  * the RS232 interface) as a joystick under Linux
16  *
17  * The Twiddler is a one-handed chording keyboard featuring twelve buttons on
18  * the front, six buttons on the top, and a built-in tilt sensor. The buttons
19  * on the front, which are grouped as four rows of three buttons, are pressed
20  * by the four fingers (this implies only one button per row can be held down
21  * at the same time) and the buttons on the top are for the thumb. The tilt
22  * sensor delivers X and Y axis data depending on how the Twiddler is held.
23  * Additional information can be found at http://www.handykey.com.
24  *
25  * This driver does not use the Twiddler for its intended purpose, i.e. as
26  * a chording keyboard, but as a joystick: pressing and releasing a button
27  * immediately sends a corresponding button event, and tilting it generates
28  * corresponding ABS_X and ABS_Y events. This turns the Twiddler into a game
29  * controller with amazing 18 buttons :-)
30  *
31  * Note: The Twiddler2 (the successor of the Twiddler that connects directly
32  * to the PS/2 keyboard and mouse ports) is NOT supported by this driver!
33  *
34  * For questions or feedback regarding this driver module please contact:
35  * Arndt Schoenewald <arndt@quelltext.com>
36  */
37 
38 /*
39  * This program is free software; you can redistribute it and/or modify
40  * it under the terms of the GNU General Public License as published by
41  * the Free Software Foundation; either version 2 of the License, or
42  * (at your option) any later version.
43  *
44  * This program is distributed in the hope that it will be useful,
45  * but WITHOUT ANY WARRANTY; without even the implied warranty of
46  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
47  * GNU General Public License for more details.
48  *
49  * You should have received a copy of the GNU General Public License
50  * along with this program; if not, write to the Free Software
51  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
52  */
53 
54 #include <linux/kernel.h>
55 #include <linux/module.h>
56 #include <linux/slab.h>
57 #include <linux/input.h>
58 #include <linux/serio.h>
59 #include <linux/init.h>
60 
61 #define DRIVER_DESC	"Handykey Twiddler keyboard as a joystick driver"
62 
63 MODULE_DESCRIPTION(DRIVER_DESC);
64 MODULE_LICENSE("GPL");
65 
66 /*
67  * Constants.
68  */
69 
70 #define TWIDJOY_MAX_LENGTH 5
71 
72 static struct twidjoy_button_spec {
73 	int bitshift;
74 	int bitmask;
75 	int buttons[3];
76 }
77 twidjoy_buttons[] = {
78 	{  0, 3, { BTN_A,      BTN_B,     BTN_C    } },
79 	{  2, 3, { BTN_X,      BTN_Y,     BTN_Z    } },
80 	{  4, 3, { BTN_TL,     BTN_TR,    BTN_TR2  } },
81 	{  6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
82 	{  8, 1, { BTN_BASE5                       } },
83 	{  9, 1, { BTN_BASE                        } },
84 	{ 10, 1, { BTN_BASE3                       } },
85 	{ 11, 1, { BTN_BASE4                       } },
86 	{ 12, 1, { BTN_BASE2                       } },
87 	{ 13, 1, { BTN_BASE6                       } },
88 	{ 0,  0, { 0                               } }
89 };
90 
91 /*
92  * Per-Twiddler data.
93  */
94 
95 struct twidjoy {
96 	struct input_dev *dev;
97 	int idx;
98 	unsigned char data[TWIDJOY_MAX_LENGTH];
99 	char phys[32];
100 };
101 
102 /*
103  * twidjoy_process_packet() decodes packets the driver receives from the
104  * Twiddler. It updates the data accordingly.
105  */
106 
107 static void twidjoy_process_packet(struct twidjoy *twidjoy, struct pt_regs *regs)
108 {
109 	struct input_dev *dev = twidjoy->dev;
110 	unsigned char *data = twidjoy->data;
111 	struct twidjoy_button_spec *bp;
112 	int button_bits, abs_x, abs_y;
113 
114 	button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);
115 
116 	input_regs(dev, regs);
117 
118 	for (bp = twidjoy_buttons; bp->bitmask; bp++) {
119 		int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
120 		int i;
121 
122 		for (i = 0; i < bp->bitmask; i++)
123 			input_report_key(dev, bp->buttons[i], i+1 == value);
124 	}
125 
126 	abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
127 	if (data[4] & 0x08) abs_x -= 256;
128 
129 	abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
130 	if (data[3] & 0x02) abs_y -= 256;
131 
132 	input_report_abs(dev, ABS_X, -abs_x);
133 	input_report_abs(dev, ABS_Y, +abs_y);
134 
135 	input_sync(dev);
136 }
137 
138 /*
139  * twidjoy_interrupt() is called by the low level driver when characters
140  * are ready for us. We then buffer them for further processing, or call the
141  * packet processing routine.
142  */
143 
144 static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags, struct pt_regs *regs)
145 {
146 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
147 
148 	/* All Twiddler packets are 5 bytes. The fact that the first byte
149 	 * has a MSB of 0 and all other bytes have a MSB of 1 can be used
150 	 * to check and regain sync. */
151 
152 	if ((data & 0x80) == 0)
153 		twidjoy->idx = 0;	/* this byte starts a new packet */
154 	else if (twidjoy->idx == 0)
155 		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */
156 
157 	if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
158 		twidjoy->data[twidjoy->idx++] = data;
159 
160 	if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
161 		twidjoy_process_packet(twidjoy, regs);
162 		twidjoy->idx = 0;
163 	}
164 
165 	return IRQ_HANDLED;
166 }
167 
168 /*
169  * twidjoy_disconnect() is the opposite of twidjoy_connect()
170  */
171 
172 static void twidjoy_disconnect(struct serio *serio)
173 {
174 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
175 
176 	serio_close(serio);
177 	serio_set_drvdata(serio, NULL);
178 	input_unregister_device(twidjoy->dev);
179 	kfree(twidjoy);
180 }
181 
182 /*
183  * twidjoy_connect() is the routine that is called when someone adds a
184  * new serio device. It looks for the Twiddler, and if found, registers
185  * it as an input device.
186  */
187 
188 static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
189 {
190 	struct twidjoy_button_spec *bp;
191 	struct twidjoy *twidjoy;
192 	struct input_dev *input_dev;
193 	int err = -ENOMEM;
194 	int i;
195 
196 	twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL);
197 	input_dev = input_allocate_device();
198 	if (!twidjoy || !input_dev)
199 		goto fail;
200 
201 	twidjoy->dev = input_dev;
202 	sprintf(twidjoy->phys, "%s/input0", serio->phys);
203 
204 	input_dev->name = "Handykey Twiddler";
205 	input_dev->phys = twidjoy->phys;
206 	input_dev->id.bustype = BUS_RS232;
207 	input_dev->id.vendor = SERIO_TWIDJOY;
208 	input_dev->id.product = 0x0001;
209 	input_dev->id.version = 0x0100;
210 	input_dev->cdev.dev = &serio->dev;
211 	input_dev->private = twidjoy;
212 
213 	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
214 	input_dev->absbit[0] = BIT(ABS_X) | BIT(ABS_Y);
215 	input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4);
216 	input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4);
217 
218 	for (bp = twidjoy_buttons; bp->bitmask; bp++)
219 		for (i = 0; i < bp->bitmask; i++)
220 			set_bit(bp->buttons[i], input_dev->keybit);
221 
222 	serio_set_drvdata(serio, twidjoy);
223 
224 	err = serio_open(serio, drv);
225 	if (err)
226 		goto fail;
227 
228 	input_register_device(twidjoy->dev);
229 	return 0;
230 
231  fail:	serio_set_drvdata(serio, NULL);
232 	input_free_device(input_dev);
233 	kfree(twidjoy);
234 	return err;
235 }
236 
237 /*
238  * The serio driver structure.
239  */
240 
241 static struct serio_device_id twidjoy_serio_ids[] = {
242 	{
243 		.type	= SERIO_RS232,
244 		.proto	= SERIO_TWIDJOY,
245 		.id	= SERIO_ANY,
246 		.extra	= SERIO_ANY,
247 	},
248 	{ 0 }
249 };
250 
251 MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
252 
253 static struct serio_driver twidjoy_drv = {
254 	.driver		= {
255 		.name	= "twidjoy",
256 	},
257 	.description	= DRIVER_DESC,
258 	.id_table	= twidjoy_serio_ids,
259 	.interrupt	= twidjoy_interrupt,
260 	.connect	= twidjoy_connect,
261 	.disconnect	= twidjoy_disconnect,
262 };
263 
264 /*
265  * The functions for inserting/removing us as a module.
266  */
267 
268 static int __init twidjoy_init(void)
269 {
270 	serio_register_driver(&twidjoy_drv);
271 	return 0;
272 }
273 
274 static void __exit twidjoy_exit(void)
275 {
276 	serio_unregister_driver(&twidjoy_drv);
277 }
278 
279 module_init(twidjoy_init);
280 module_exit(twidjoy_exit);
281