tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
63MODULE_DESCRIPTION(DRIVER_DESC);
64MODULE_LICENSE("GPL");
65
66/*
67 * Constants.
68 */
69
70#define TWIDJOY_MAX_LENGTH 5
71
72static struct twidjoy_button_spec {
73 int bitshift;
74 int bitmask;
75 int buttons[3];
76}
77twidjoy_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
95struct 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
107static 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
144static 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
172static 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
188static 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
241static 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
251MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
252
253static 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
268static int __init twidjoy_init(void)
269{
270 serio_register_driver(&twidjoy_drv);
271 return 0;
272}
273
274static void __exit twidjoy_exit(void)
275{
276 serio_unregister_driver(&twidjoy_drv);
277}
278
279module_init(twidjoy_init);
280module_exit(twidjoy_exit);