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
  56#define DRIVER_DESC     "Handykey Twiddler keyboard as a joystick driver"
  57
  58MODULE_DESCRIPTION(DRIVER_DESC);
  59MODULE_LICENSE("GPL");
  60
  61/*
  62 * Constants.
  63 */
  64
  65#define TWIDJOY_MAX_LENGTH 5
  66
  67static struct twidjoy_button_spec {
  68        int bitshift;
  69        int bitmask;
  70        int buttons[3];
  71}
  72twidjoy_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
  90struct 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
 102static 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
 137static 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
 165static 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
 181static 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
 236static const 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
 246MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
 247
 248static 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
 259module_serio_driver(twidjoy_drv);
 260