xref: /openbmc/linux/drivers/input/joystick/twidjoy.c (revision 94cdda6b)
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 
56 #define DRIVER_DESC	"Handykey Twiddler keyboard as a joystick driver"
57 
58 MODULE_DESCRIPTION(DRIVER_DESC);
59 MODULE_LICENSE("GPL");
60 
61 /*
62  * Constants.
63  */
64 
65 #define TWIDJOY_MAX_LENGTH 5
66 
67 static struct twidjoy_button_spec {
68 	int bitshift;
69 	int bitmask;
70 	int buttons[3];
71 }
72 twidjoy_buttons[] = {
73 	{  0, 3, { BTN_A,      BTN_B,     BTN_C    } },
74 	{  2, 3, { BTN_X,      BTN_Y,     BTN_Z    } },
75 	{  4, 3, { BTN_TL,     BTN_TR,    BTN_TR2  } },
76 	{  6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
77 	{  8, 1, { BTN_BASE5                       } },
78 	{  9, 1, { BTN_BASE                        } },
79 	{ 10, 1, { BTN_BASE3                       } },
80 	{ 11, 1, { BTN_BASE4                       } },
81 	{ 12, 1, { BTN_BASE2                       } },
82 	{ 13, 1, { BTN_BASE6                       } },
83 	{ 0,  0, { 0                               } }
84 };
85 
86 /*
87  * Per-Twiddler data.
88  */
89 
90 struct twidjoy {
91 	struct input_dev *dev;
92 	int idx;
93 	unsigned char data[TWIDJOY_MAX_LENGTH];
94 	char phys[32];
95 };
96 
97 /*
98  * twidjoy_process_packet() decodes packets the driver receives from the
99  * Twiddler. It updates the data accordingly.
100  */
101 
102 static void twidjoy_process_packet(struct twidjoy *twidjoy)
103 {
104 	struct input_dev *dev = twidjoy->dev;
105 	unsigned char *data = twidjoy->data;
106 	struct twidjoy_button_spec *bp;
107 	int button_bits, abs_x, abs_y;
108 
109 	button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);
110 
111 	for (bp = twidjoy_buttons; bp->bitmask; bp++) {
112 		int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
113 		int i;
114 
115 		for (i = 0; i < bp->bitmask; i++)
116 			input_report_key(dev, bp->buttons[i], i+1 == value);
117 	}
118 
119 	abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
120 	if (data[4] & 0x08) abs_x -= 256;
121 
122 	abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
123 	if (data[3] & 0x02) abs_y -= 256;
124 
125 	input_report_abs(dev, ABS_X, -abs_x);
126 	input_report_abs(dev, ABS_Y, +abs_y);
127 
128 	input_sync(dev);
129 }
130 
131 /*
132  * twidjoy_interrupt() is called by the low level driver when characters
133  * are ready for us. We then buffer them for further processing, or call the
134  * packet processing routine.
135  */
136 
137 static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
138 {
139 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
140 
141 	/* All Twiddler packets are 5 bytes. The fact that the first byte
142 	 * has a MSB of 0 and all other bytes have a MSB of 1 can be used
143 	 * to check and regain sync. */
144 
145 	if ((data & 0x80) == 0)
146 		twidjoy->idx = 0;	/* this byte starts a new packet */
147 	else if (twidjoy->idx == 0)
148 		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */
149 
150 	if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
151 		twidjoy->data[twidjoy->idx++] = data;
152 
153 	if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
154 		twidjoy_process_packet(twidjoy);
155 		twidjoy->idx = 0;
156 	}
157 
158 	return IRQ_HANDLED;
159 }
160 
161 /*
162  * twidjoy_disconnect() is the opposite of twidjoy_connect()
163  */
164 
165 static void twidjoy_disconnect(struct serio *serio)
166 {
167 	struct twidjoy *twidjoy = serio_get_drvdata(serio);
168 
169 	serio_close(serio);
170 	serio_set_drvdata(serio, NULL);
171 	input_unregister_device(twidjoy->dev);
172 	kfree(twidjoy);
173 }
174 
175 /*
176  * twidjoy_connect() is the routine that is called when someone adds a
177  * new serio device. It looks for the Twiddler, and if found, registers
178  * it as an input device.
179  */
180 
181 static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
182 {
183 	struct twidjoy_button_spec *bp;
184 	struct twidjoy *twidjoy;
185 	struct input_dev *input_dev;
186 	int err = -ENOMEM;
187 	int i;
188 
189 	twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL);
190 	input_dev = input_allocate_device();
191 	if (!twidjoy || !input_dev)
192 		goto fail1;
193 
194 	twidjoy->dev = input_dev;
195 	snprintf(twidjoy->phys, sizeof(twidjoy->phys), "%s/input0", serio->phys);
196 
197 	input_dev->name = "Handykey Twiddler";
198 	input_dev->phys = twidjoy->phys;
199 	input_dev->id.bustype = BUS_RS232;
200 	input_dev->id.vendor = SERIO_TWIDJOY;
201 	input_dev->id.product = 0x0001;
202 	input_dev->id.version = 0x0100;
203 	input_dev->dev.parent = &serio->dev;
204 
205 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
206 	input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4);
207 	input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4);
208 
209 	for (bp = twidjoy_buttons; bp->bitmask; bp++)
210 		for (i = 0; i < bp->bitmask; i++)
211 			set_bit(bp->buttons[i], input_dev->keybit);
212 
213 	serio_set_drvdata(serio, twidjoy);
214 
215 	err = serio_open(serio, drv);
216 	if (err)
217 		goto fail2;
218 
219 	err = input_register_device(twidjoy->dev);
220 	if (err)
221 		goto fail3;
222 
223 	return 0;
224 
225  fail3:	serio_close(serio);
226  fail2:	serio_set_drvdata(serio, NULL);
227  fail1:	input_free_device(input_dev);
228 	kfree(twidjoy);
229 	return err;
230 }
231 
232 /*
233  * The serio driver structure.
234  */
235 
236 static struct serio_device_id twidjoy_serio_ids[] = {
237 	{
238 		.type	= SERIO_RS232,
239 		.proto	= SERIO_TWIDJOY,
240 		.id	= SERIO_ANY,
241 		.extra	= SERIO_ANY,
242 	},
243 	{ 0 }
244 };
245 
246 MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
247 
248 static struct serio_driver twidjoy_drv = {
249 	.driver		= {
250 		.name	= "twidjoy",
251 	},
252 	.description	= DRIVER_DESC,
253 	.id_table	= twidjoy_serio_ids,
254 	.interrupt	= twidjoy_interrupt,
255 	.connect	= twidjoy_connect,
256 	.disconnect	= twidjoy_disconnect,
257 };
258 
259 module_serio_driver(twidjoy_drv);
260