1 /*
2 * Copyright (c) 2001 Arndt Schoenewald
3 * Copyright (c) 2000-2001 Vojtech Pavlik
4 * Copyright (c) 2000 Mark Fletcher
5 *
6 * Sponsored by Quelltext AG (http://www.quelltext-ag.de), Dortmund, Germany
7 */
8
9 /*
10 * Driver to use Handykey's Twiddler (the first edition, i.e. the one with
11 * the RS232 interface) as a joystick under Linux
12 *
13 * The Twiddler is a one-handed chording keyboard featuring twelve buttons on
14 * the front, six buttons on the top, and a built-in tilt sensor. The buttons
15 * on the front, which are grouped as four rows of three buttons, are pressed
16 * by the four fingers (this implies only one button per row can be held down
17 * at the same time) and the buttons on the top are for the thumb. The tilt
18 * sensor delivers X and Y axis data depending on how the Twiddler is held.
19 * Additional information can be found at http://www.handykey.com.
20 *
21 * This driver does not use the Twiddler for its intended purpose, i.e. as
22 * a chording keyboard, but as a joystick: pressing and releasing a button
23 * immediately sends a corresponding button event, and tilting it generates
24 * corresponding ABS_X and ABS_Y events. This turns the Twiddler into a game
25 * controller with amazing 18 buttons :-)
26 *
27 * Note: The Twiddler2 (the successor of the Twiddler that connects directly
28 * to the PS/2 keyboard and mouse ports) is NOT supported by this driver!
29 *
30 * For questions or feedback regarding this driver module please contact:
31 * Arndt Schoenewald <arndt@quelltext.com>
32 */
33
34 /*
35 * This program is free software; you can redistribute it and/or modify
36 * it under the terms of the GNU General Public License as published by
37 * the Free Software Foundation; either version 2 of the License, or
38 * (at your option) any later version.
39 *
40 * This program is distributed in the hope that it will be useful,
41 * but WITHOUT ANY WARRANTY; without even the implied warranty of
42 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
43 * GNU General Public License for more details.
44 *
45 * You should have received a copy of the GNU General Public License
46 * along with this program; if not, write to the Free Software
47 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
48 */
49
50 #include <linux/kernel.h>
51 #include <linux/module.h>
52 #include <linux/slab.h>
53 #include <linux/input.h>
54 #include <linux/serio.h>
55 #include <linux/init.h>
56
57 #define DRIVER_DESC "Handykey Twiddler keyboard as a joystick driver"
58
59 MODULE_DESCRIPTION(DRIVER_DESC);
60 MODULE_LICENSE("GPL");
61
62 /*
63 * Constants.
64 */
65
66 #define TWIDJOY_MAX_LENGTH 5
67
68 static struct twidjoy_button_spec {
69 int bitshift;
70 int bitmask;
71 int buttons[3];
72 }
73 twidjoy_buttons[] = {
74 { 0, 3, { BTN_A, BTN_B, BTN_C } },
75 { 2, 3, { BTN_X, BTN_Y, BTN_Z } },
76 { 4, 3, { BTN_TL, BTN_TR, BTN_TR2 } },
77 { 6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
78 { 8, 1, { BTN_BASE5 } },
79 { 9, 1, { BTN_BASE } },
80 { 10, 1, { BTN_BASE3 } },
81 { 11, 1, { BTN_BASE4 } },
82 { 12, 1, { BTN_BASE2 } },
83 { 13, 1, { BTN_BASE6 } },
84 { 0, 0, { 0 } }
85 };
86
87 /*
88 * Per-Twiddler data.
89 */
90
91 struct twidjoy {
92 struct input_dev *dev;
93 int idx;
94 unsigned char data[TWIDJOY_MAX_LENGTH];
95 char phys[32];
96 };
97
98 /*
99 * twidjoy_process_packet() decodes packets the driver receives from the
100 * Twiddler. It updates the data accordingly.
101 */
102
twidjoy_process_packet(struct twidjoy * twidjoy)103 static void twidjoy_process_packet(struct twidjoy *twidjoy)
104 {
105 struct input_dev *dev = twidjoy->dev;
106 unsigned char *data = twidjoy->data;
107 struct twidjoy_button_spec *bp;
108 int button_bits, abs_x, abs_y;
109
110 button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);
111
112 for (bp = twidjoy_buttons; bp->bitmask; bp++) {
113 int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
114 int i;
115
116 for (i = 0; i < bp->bitmask; i++)
117 input_report_key(dev, bp->buttons[i], i+1 == value);
118 }
119
120 abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
121 if (data[4] & 0x08) abs_x -= 256;
122
123 abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
124 if (data[3] & 0x02) abs_y -= 256;
125
126 input_report_abs(dev, ABS_X, -abs_x);
127 input_report_abs(dev, ABS_Y, +abs_y);
128
129 input_sync(dev);
130 }
131
132 /*
133 * twidjoy_interrupt() is called by the low level driver when characters
134 * are ready for us. We then buffer them for further processing, or call the
135 * packet processing routine.
136 */
137
twidjoy_interrupt(struct serio * serio,unsigned char data,unsigned int flags)138 static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
139 {
140 struct twidjoy *twidjoy = serio_get_drvdata(serio);
141
142 /* All Twiddler packets are 5 bytes. The fact that the first byte
143 * has a MSB of 0 and all other bytes have a MSB of 1 can be used
144 * to check and regain sync. */
145
146 if ((data & 0x80) == 0)
147 twidjoy->idx = 0; /* this byte starts a new packet */
148 else if (twidjoy->idx == 0)
149 return IRQ_HANDLED; /* wrong MSB -- ignore this byte */
150
151 if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
152 twidjoy->data[twidjoy->idx++] = data;
153
154 if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
155 twidjoy_process_packet(twidjoy);
156 twidjoy->idx = 0;
157 }
158
159 return IRQ_HANDLED;
160 }
161
162 /*
163 * twidjoy_disconnect() is the opposite of twidjoy_connect()
164 */
165
twidjoy_disconnect(struct serio * serio)166 static void twidjoy_disconnect(struct serio *serio)
167 {
168 struct twidjoy *twidjoy = serio_get_drvdata(serio);
169
170 serio_close(serio);
171 serio_set_drvdata(serio, NULL);
172 input_unregister_device(twidjoy->dev);
173 kfree(twidjoy);
174 }
175
176 /*
177 * twidjoy_connect() is the routine that is called when someone adds a
178 * new serio device. It looks for the Twiddler, and if found, registers
179 * it as an input device.
180 */
181
twidjoy_connect(struct serio * serio,struct serio_driver * drv)182 static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
183 {
184 struct twidjoy_button_spec *bp;
185 struct twidjoy *twidjoy;
186 struct input_dev *input_dev;
187 int err = -ENOMEM;
188 int i;
189
190 twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL);
191 input_dev = input_allocate_device();
192 if (!twidjoy || !input_dev)
193 goto fail1;
194
195 twidjoy->dev = input_dev;
196 snprintf(twidjoy->phys, sizeof(twidjoy->phys), "%s/input0", serio->phys);
197
198 input_dev->name = "Handykey Twiddler";
199 input_dev->phys = twidjoy->phys;
200 input_dev->id.bustype = BUS_RS232;
201 input_dev->id.vendor = SERIO_TWIDJOY;
202 input_dev->id.product = 0x0001;
203 input_dev->id.version = 0x0100;
204 input_dev->dev.parent = &serio->dev;
205
206 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
207 input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4);
208 input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4);
209
210 for (bp = twidjoy_buttons; bp->bitmask; bp++)
211 for (i = 0; i < bp->bitmask; i++)
212 set_bit(bp->buttons[i], input_dev->keybit);
213
214 serio_set_drvdata(serio, twidjoy);
215
216 err = serio_open(serio, drv);
217 if (err)
218 goto fail2;
219
220 err = input_register_device(twidjoy->dev);
221 if (err)
222 goto fail3;
223
224 return 0;
225
226 fail3: serio_close(serio);
227 fail2: serio_set_drvdata(serio, NULL);
228 fail1: input_free_device(input_dev);
229 kfree(twidjoy);
230 return err;
231 }
232
233 /*
234 * The serio driver structure.
235 */
236
237 static struct serio_device_id twidjoy_serio_ids[] = {
238 {
239 .type = SERIO_RS232,
240 .proto = SERIO_TWIDJOY,
241 .id = SERIO_ANY,
242 .extra = SERIO_ANY,
243 },
244 { 0 }
245 };
246
247 MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
248
249 static struct serio_driver twidjoy_drv = {
250 .driver = {
251 .name = "twidjoy",
252 },
253 .description = DRIVER_DESC,
254 .id_table = twidjoy_serio_ids,
255 .interrupt = twidjoy_interrupt,
256 .connect = twidjoy_connect,
257 .disconnect = twidjoy_disconnect,
258 };
259
260 module_serio_driver(twidjoy_drv);
261