cobra.c

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/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 */

/*
 * Creative Labs Blaster GamePad Cobra driver for Linux
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <[email protected]>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/gameport.h>
#include <linux/input.h>
#include <linux/jiffies.h>

#define DRIVER_DESC "Creative Labs Blaster GamePad Cobra driver"

MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

#define COBRA_MAX_STROBE    45  /* 45 us max wait for first strobe */
#define COBRA_LENGTH        36

static int cobra_btn[] = { BTN_START, BTN_SELECT, BTN_TL, BTN_TR, BTN_X, BTN_Y, BTN_Z, BTN_A, BTN_B, BTN_C, BTN_TL2, BTN_TR2, 0 };

struct cobra {
    struct gameport *gameport;
    struct input_dev *dev[2];
    int reads;
    int bads;
    unsigned char exists;
    char phys[2][32];
};

static unsigned char cobra_read_packet(struct gameport *gameport, unsigned int *data)
{
    unsigned long flags;
    unsigned char u, v, w;
    __u64 buf[2];
    int r[2], t[2];
    int i, j, ret;

    int strobe = gameport_time(gameport, COBRA_MAX_STROBE);

    for (i = 0; i < 2; i++) {
        r[i] = buf[i] = 0;
        t[i] = COBRA_MAX_STROBE;
    }

    local_irq_save(flags);

    u = gameport_read(gameport);

    do {
        t[0]--; t[1]--;
        v = gameport_read(gameport);
        for (i = 0, w = u ^ v; i < 2 && w; i++, w >>= 2)
            if (w & 0x30) {
                if ((w & 0x30) < 0x30 && r[i] < COBRA_LENGTH && t[i] > 0) {
                    buf[i] |= (__u64)((w >> 5) & 1) << r[i]++;
                    t[i] = strobe;
                    u = v;
                } else t[i] = 0;
            }
    } while (t[0] > 0 || t[1] > 0);

    local_irq_restore(flags);

    ret = 0;

    for (i = 0; i < 2; i++) {

        if (r[i] != COBRA_LENGTH) continue;

        for (j = 0; j < COBRA_LENGTH && (buf[i] & 0x04104107f) ^ 0x041041040; j++)
            buf[i] = (buf[i] >> 1) | ((__u64)(buf[i] & 1) << (COBRA_LENGTH - 1));

        if (j < COBRA_LENGTH) ret |= (1 << i);

        data[i] = ((buf[i] >>  7) & 0x000001f) | ((buf[i] >>  8) & 0x00003e0)
            | ((buf[i] >>  9) & 0x0007c00) | ((buf[i] >> 10) & 0x00f8000)
            | ((buf[i] >> 11) & 0x1f00000);

    }

    return ret;
}

static void cobra_poll(struct gameport *gameport)
{
    struct cobra *cobra = gameport_get_drvdata(gameport);
    struct input_dev *dev;
    unsigned int data[2];
    int i, j, r;

    cobra->reads++;

    if ((r = cobra_read_packet(gameport, data)) != cobra->exists) {
        cobra->bads++;
        return;
    }

    for (i = 0; i < 2; i++)
        if (cobra->exists & r & (1 << i)) {

            dev = cobra->dev[i];

            input_report_abs(dev, ABS_X, ((data[i] >> 4) & 1) - ((data[i] >> 3) & 1));
            input_report_abs(dev, ABS_Y, ((data[i] >> 2) & 1) - ((data[i] >> 1) & 1));

            for (j = 0; cobra_btn[j]; j++)
                input_report_key(dev, cobra_btn[j], data[i] & (0x20 << j));

            input_sync(dev);

        }
}

static int cobra_open(struct input_dev *dev)
{
    struct cobra *cobra = input_get_drvdata(dev);

    gameport_start_polling(cobra->gameport);
    return 0;
}

static void cobra_close(struct input_dev *dev)
{
    struct cobra *cobra = input_get_drvdata(dev);

    gameport_stop_polling(cobra->gameport);
}

static int cobra_connect(struct gameport *gameport, struct gameport_driver *drv)
{
    struct cobra *cobra;
    struct input_dev *input_dev;
    unsigned int data[2];
    int i, j;
    int err;

    cobra = kzalloc(sizeof(struct cobra), GFP_KERNEL);
    if (!cobra)
        return -ENOMEM;

    cobra->gameport = gameport;

    gameport_set_drvdata(gameport, cobra);

    err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
    if (err)
        goto fail1;

    cobra->exists = cobra_read_packet(gameport, data);

    for (i = 0; i < 2; i++)
        if ((cobra->exists >> i) & data[i] & 1) {
            printk(KERN_WARNING "cobra.c: Device %d on %s has the Ext bit set. ID is: %d"
                " Contact [email protected]\n", i, gameport->phys, (data[i] >> 2) & 7);
            cobra->exists &= ~(1 << i);
        }

    if (!cobra->exists) {
        err = -ENODEV;
        goto fail2;
    }

    gameport_set_poll_handler(gameport, cobra_poll);
    gameport_set_poll_interval(gameport, 20);

    for (i = 0; i < 2; i++) {
        if (~(cobra->exists >> i) & 1)
            continue;

        cobra->dev[i] = input_dev = input_allocate_device();
        if (!input_dev) {
            err = -ENOMEM;
            goto fail3;
        }

        snprintf(cobra->phys[i], sizeof(cobra->phys[i]),
             "%s/input%d", gameport->phys, i);

        input_dev->name = "Creative Labs Blaster GamePad Cobra";
        input_dev->phys = cobra->phys[i];
        input_dev->id.bustype = BUS_GAMEPORT;
        input_dev->id.vendor = GAMEPORT_ID_VENDOR_CREATIVE;
        input_dev->id.product = 0x0008;
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = &gameport->dev;

        input_set_drvdata(input_dev, cobra);

        input_dev->open = cobra_open;
        input_dev->close = cobra_close;

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
        input_set_abs_params(input_dev, ABS_X, -1, 1, 0, 0);
        input_set_abs_params(input_dev, ABS_Y, -1, 1, 0, 0);
        for (j = 0; cobra_btn[j]; j++)
            set_bit(cobra_btn[j], input_dev->keybit);

        err = input_register_device(cobra->dev[i]);
        if (err)
            goto fail4;
    }

    return 0;

 fail4: input_free_device(cobra->dev[i]);
 fail3: while (--i >= 0)
        if (cobra->dev[i])
            input_unregister_device(cobra->dev[i]);
 fail2: gameport_close(gameport);
 fail1: gameport_set_drvdata(gameport, NULL);
    kfree(cobra);
    return err;
}

static void cobra_disconnect(struct gameport *gameport)
{
    struct cobra *cobra = gameport_get_drvdata(gameport);
    int i;

    for (i = 0; i < 2; i++)
        if ((cobra->exists >> i) & 1)
            input_unregister_device(cobra->dev[i]);
    gameport_close(gameport);
    gameport_set_drvdata(gameport, NULL);
    kfree(cobra);
}

static struct gameport_driver cobra_drv = {
    .driver     = {
        .name   = "cobra",
    },
    .description    = DRIVER_DESC,
    .connect    = cobra_connect,
    .disconnect = cobra_disconnect,
};

module_gameport_driver(cobra_drv);