linux/drivers/input/joystick/twidjoy.c
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   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
  59MODULE_DESCRIPTION(DRIVER_DESC);
  60MODULE_LICENSE("GPL");
  61
  62/*
  63 * Constants.
  64 */
  65
  66#define TWIDJOY_MAX_LENGTH 5
  67
  68static struct twidjoy_button_spec {
  69        int bitshift;
  70        int bitmask;
  71        int buttons[3];
  72}
  73twidjoy_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
  91struct 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
 103static 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
 138static 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
 166static 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
 182static 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
 237static 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
 247MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
 248
 249static 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
 264static int __init twidjoy_init(void)
 265{
 266        return serio_register_driver(&twidjoy_drv);
 267}
 268
 269static void __exit twidjoy_exit(void)
 270{
 271        serio_unregister_driver(&twidjoy_drv);
 272}
 273
 274module_init(twidjoy_init);
 275module_exit(twidjoy_exit);
 276