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
  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);