drivers/input/joystick/twidjoy.c

   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
 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
 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
 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
 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 /*
 261  * The functions for inserting/removing us as a module.
 262  */
 263
 264 static int __init twidjoy_init(void)
 265 {
 266         return serio_register_driver(&twidjoy_drv);
 267 }
 268
 269 static void __exit twidjoy_exit(void)
 270 {
 271         serio_unregister_driver(&twidjoy_drv);
 272 }
 273
 274 module_init(twidjoy_init);
 275 module_exit(twidjoy_exit);