magellan.c

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

/*
 * Magellan and Space Mouse 6dof controller 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/input.h>
#include <linux/serio.h>
#include <linux/init.h>

#define DRIVER_DESC "Magellan and SpaceMouse 6dof controller driver"

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

/*
 * Definitions & global arrays.
 */

#define MAGELLAN_MAX_LENGTH 32

static int magellan_buttons[] = { BTN_0, BTN_1, BTN_2, BTN_3, BTN_4, BTN_5, BTN_6, BTN_7, BTN_8 };
static int magellan_axes[] = { ABS_X, ABS_Y, ABS_Z, ABS_RX, ABS_RY, ABS_RZ };

/*
 * Per-Magellan data.
 */

struct magellan {
    struct input_dev *dev;
    int idx;
    unsigned char data[MAGELLAN_MAX_LENGTH];
    char phys[32];
};

/*
 * magellan_crunch_nibbles() verifies that the bytes sent from the Magellan
 * have correct upper nibbles for the lower ones, if not, the packet will
 * be thrown away. It also strips these upper halves to simplify further
 * processing.
 */

static int magellan_crunch_nibbles(unsigned char *data, int count)
{
    static unsigned char nibbles[16] = "0AB3D56GH9:K<MN?";

    do {
        if (data[count] == nibbles[data[count] & 0xf])
            data[count] = data[count] & 0xf;
        else
            return -1;
    } while (--count);

    return 0;
}

static void magellan_process_packet(struct magellan* magellan)
{
    struct input_dev *dev = magellan->dev;
    unsigned char *data = magellan->data;
    int i, t;

    if (!magellan->idx) return;

    switch (magellan->data[0]) {

        case 'd':               /* Axis data */
            if (magellan->idx != 25) return;
            if (magellan_crunch_nibbles(data, 24)) return;
            for (i = 0; i < 6; i++)
                input_report_abs(dev, magellan_axes[i],
                    (data[(i << 2) + 1] << 12 | data[(i << 2) + 2] << 8 |
                     data[(i << 2) + 3] <<  4 | data[(i << 2) + 4]) - 32768);
            break;

        case 'k':               /* Button data */
            if (magellan->idx != 4) return;
            if (magellan_crunch_nibbles(data, 3)) return;
            t = (data[1] << 1) | (data[2] << 5) | data[3];
            for (i = 0; i < 9; i++) input_report_key(dev, magellan_buttons[i], (t >> i) & 1);
            break;
    }

    input_sync(dev);
}

static irqreturn_t magellan_interrupt(struct serio *serio,
        unsigned char data, unsigned int flags)
{
    struct magellan* magellan = serio_get_drvdata(serio);

    if (data == '\r') {
        magellan_process_packet(magellan);
        magellan->idx = 0;
    } else {
        if (magellan->idx < MAGELLAN_MAX_LENGTH)
            magellan->data[magellan->idx++] = data;
    }
    return IRQ_HANDLED;
}

/*
 * magellan_disconnect() is the opposite of magellan_connect()
 */

static void magellan_disconnect(struct serio *serio)
{
    struct magellan* magellan = serio_get_drvdata(serio);

    serio_close(serio);
    serio_set_drvdata(serio, NULL);
    input_unregister_device(magellan->dev);
    kfree(magellan);
}

/*
 * magellan_connect() is the routine that is called when someone adds a
 * new serio device that supports Magellan protocol and registers it as
 * an input device.
 */

static int magellan_connect(struct serio *serio, struct serio_driver *drv)
{
    struct magellan *magellan;
    struct input_dev *input_dev;
    int err = -ENOMEM;
    int i;

    magellan = kzalloc(sizeof(struct magellan), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!magellan || !input_dev)
        goto fail1;

    magellan->dev = input_dev;
    snprintf(magellan->phys, sizeof(magellan->phys), "%s/input0", serio->phys);

    input_dev->name = "LogiCad3D Magellan / SpaceMouse";
    input_dev->phys = magellan->phys;
    input_dev->id.bustype = BUS_RS232;
    input_dev->id.vendor = SERIO_MAGELLAN;
    input_dev->id.product = 0x0001;
    input_dev->id.version = 0x0100;
    input_dev->dev.parent = &serio->dev;

    input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);

    for (i = 0; i < 9; i++)
        set_bit(magellan_buttons[i], input_dev->keybit);

    for (i = 0; i < 6; i++)
        input_set_abs_params(input_dev, magellan_axes[i], -360, 360, 0, 0);

    serio_set_drvdata(serio, magellan);

    err = serio_open(serio, drv);
    if (err)
        goto fail2;

    err = input_register_device(magellan->dev);
    if (err)
        goto fail3;

    return 0;

 fail3: serio_close(serio);
 fail2: serio_set_drvdata(serio, NULL);
 fail1: input_free_device(input_dev);
    kfree(magellan);
    return err;
}

/*
 * The serio driver structure.
 */

static struct serio_device_id magellan_serio_ids[] = {
    {
        .type   = SERIO_RS232,
        .proto  = SERIO_MAGELLAN,
        .id = SERIO_ANY,
        .extra  = SERIO_ANY,
    },
    { 0 }
};

MODULE_DEVICE_TABLE(serio, magellan_serio_ids);

static struct serio_driver magellan_drv = {
    .driver     = {
        .name   = "magellan",
    },
    .description    = DRIVER_DESC,
    .id_table   = magellan_serio_ids,
    .interrupt  = magellan_interrupt,
    .connect    = magellan_connect,
    .disconnect = magellan_disconnect,
};

module_serio_driver(magellan_drv);