xref: /openbmc/linux/drivers/input/joystick/twidjoy.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 char *twidjoy_name = "Handykey Twiddler";
73 
74 static struct twidjoy_button_spec {
75 	int bitshift;
76 	int bitmask;
77 	int buttons[3];
78 }
79 twidjoy_buttons[] = {
80 	{  0, 3, { BTN_A,      BTN_B,     BTN_C    } },
81 	{  2, 3, { BTN_X,      BTN_Y,     BTN_Z    } },
82 	{  4, 3, { BTN_TL,     BTN_TR,    BTN_TR2  } },
83 	{  6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
84 	{  8, 1, { BTN_BASE5                       } },
85 	{  9, 1, { BTN_BASE                        } },
86 	{ 10, 1, { BTN_BASE3                       } },
87 	{ 11, 1, { BTN_BASE4                       } },
88 	{ 12, 1, { BTN_BASE2                       } },
89 	{ 13, 1, { BTN_BASE6                       } },
90 	{ 0,  0, { 0                               } }
91 };
92 
93 /*
94  * Per-Twiddler data.
95  */
96 
97 struct twidjoy {
98 	struct input_dev dev;
99 	int idx;
100 	unsigned char data[TWIDJOY_MAX_LENGTH];
101 	char phys[32];
102 };
103 
104 /*
105  * twidjoy_process_packet() decodes packets the driver receives from the
106  * Twiddler. It updates the data accordingly.
107  */
108 
109 static void twidjoy_process_packet(struct twidjoy *twidjoy, struct pt_regs *regs)
110 {
111 	if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
112 		struct input_dev *dev = &twidjoy->dev;
113 		unsigned char *data = twidjoy->data;
114 		struct twidjoy_button_spec *bp;
115 		int button_bits, abs_x, abs_y;
116 
117 		button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);
118 
119 		input_regs(dev, regs);
120 
121 		for (bp = twidjoy_buttons; bp->bitmask; bp++) {
122 			int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
123 			int i;
124 
125 			for (i = 0; i < bp->bitmask; i++)
126 				input_report_key(dev, bp->buttons[i], i+1 == value);
127 		}
128 
129 		abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
130 		if (data[4] & 0x08) abs_x -= 256;
131 
132 		abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
133 		if (data[3] & 0x02) abs_y -= 256;
134 
135 		input_report_abs(dev, ABS_X, -abs_x);
136 		input_report_abs(dev, ABS_Y, +abs_y);
137 
138 		input_sync(dev);
139 	}
140 
141 	return;
142 }
143 
144 /*
145  * twidjoy_interrupt() is called by the low level driver when characters
146  * are ready for us. We then buffer them for further processing, or call the
147  * packet processing routine.
148  */
149 
150 static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags, struct pt_regs *regs)
151 {
152 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
153 
154 	/* All Twiddler packets are 5 bytes. The fact that the first byte
155 	 * has a MSB of 0 and all other bytes have a MSB of 1 can be used
156 	 * to check and regain sync. */
157 
158 	if ((data & 0x80) == 0)
159 		twidjoy->idx = 0;	/* this byte starts a new packet */
160 	else if (twidjoy->idx == 0)
161 		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */
162 
163 	if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
164 		twidjoy->data[twidjoy->idx++] = data;
165 
166 	if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
167 		twidjoy_process_packet(twidjoy, regs);
168 		twidjoy->idx = 0;
169 	}
170 
171 	return IRQ_HANDLED;
172 }
173 
174 /*
175  * twidjoy_disconnect() is the opposite of twidjoy_connect()
176  */
177 
178 static void twidjoy_disconnect(struct serio *serio)
179 {
180 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
181 
182 	input_unregister_device(&twidjoy->dev);
183 	serio_close(serio);
184 	serio_set_drvdata(serio, NULL);
185 	kfree(twidjoy);
186 }
187 
188 /*
189  * twidjoy_connect() is the routine that is called when someone adds a
190  * new serio device. It looks for the Twiddler, and if found, registers
191  * it as an input device.
192  */
193 
194 static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
195 {
196 	struct twidjoy_button_spec *bp;
197 	struct twidjoy *twidjoy;
198 	int i;
199 	int err;
200 
201 	if (!(twidjoy = kmalloc(sizeof(struct twidjoy), GFP_KERNEL)))
202 		return -ENOMEM;
203 
204 	memset(twidjoy, 0, sizeof(struct twidjoy));
205 
206 	sprintf(twidjoy->phys, "%s/input0", serio->phys);
207 
208 	init_input_dev(&twidjoy->dev);
209 	twidjoy->dev.name = twidjoy_name;
210 	twidjoy->dev.phys = twidjoy->phys;
211 	twidjoy->dev.id.bustype = BUS_RS232;
212 	twidjoy->dev.id.vendor = SERIO_TWIDJOY;
213 	twidjoy->dev.id.product = 0x0001;
214 	twidjoy->dev.id.version = 0x0100;
215 	twidjoy->dev.dev = &serio->dev;
216 
217 	twidjoy->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
218 
219 	for (bp = twidjoy_buttons; bp->bitmask; bp++) {
220 		for (i = 0; i < bp->bitmask; i++)
221 			set_bit(bp->buttons[i], twidjoy->dev.keybit);
222 	}
223 
224 	twidjoy->dev.absbit[0] = BIT(ABS_X) | BIT(ABS_Y);
225 
226 	for (i = 0; i < 2; i++) {
227 		twidjoy->dev.absmax[ABS_X+i] =  50;
228 		twidjoy->dev.absmin[ABS_X+i] = -50;
229 
230 		/* TODO: arndt 20010708: Are these values appropriate? */
231 		twidjoy->dev.absfuzz[ABS_X+i] = 4;
232 		twidjoy->dev.absflat[ABS_X+i] = 4;
233 	}
234 
235 	twidjoy->dev.private = twidjoy;
236 
237 	serio_set_drvdata(serio, twidjoy);
238 
239 	err = serio_open(serio, drv);
240 	if (err) {
241 		serio_set_drvdata(serio, NULL);
242 		kfree(twidjoy);
243 		return err;
244 	}
245 
246 	input_register_device(&twidjoy->dev);
247 
248 	printk(KERN_INFO "input: %s on %s\n", twidjoy_name, serio->phys);
249 
250 	return 0;
251 }
252 
253 /*
254  * The serio driver structure.
255  */
256 
257 static struct serio_device_id twidjoy_serio_ids[] = {
258 	{
259 		.type	= SERIO_RS232,
260 		.proto	= SERIO_TWIDJOY,
261 		.id	= SERIO_ANY,
262 		.extra	= SERIO_ANY,
263 	},
264 	{ 0 }
265 };
266 
267 MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
268 
269 static struct serio_driver twidjoy_drv = {
270 	.driver		= {
271 		.name	= "twidjoy",
272 	},
273 	.description	= DRIVER_DESC,
274 	.id_table	= twidjoy_serio_ids,
275 	.interrupt	= twidjoy_interrupt,
276 	.connect	= twidjoy_connect,
277 	.disconnect	= twidjoy_disconnect,
278 };
279 
280 /*
281  * The functions for inserting/removing us as a module.
282  */
283 
284 int __init twidjoy_init(void)
285 {
286 	serio_register_driver(&twidjoy_drv);
287 	return 0;
288 }
289 
290 void __exit twidjoy_exit(void)
291 {
292 	serio_unregister_driver(&twidjoy_drv);
293 }
294 
295 module_init(twidjoy_init);
296 module_exit(twidjoy_exit);
297