iforce-serio.c

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/*
 *  Copyright (c) 2000-2001 Vojtech Pavlik <[email protected]>
 *  Copyright (c) 2001, 2007 Johann Deneux <[email protected]>
 *
 *  USB/RS232 I-Force joysticks and wheels.
 */

/*
 * 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 "iforce.h"

void iforce_serial_xmit(struct iforce *iforce)
{
    unsigned char cs;
    int i;
    unsigned long flags;

    if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
        set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
        return;
    }

    spin_lock_irqsave(&iforce->xmit_lock, flags);

again:
    if (iforce->xmit.head == iforce->xmit.tail) {
        clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
        spin_unlock_irqrestore(&iforce->xmit_lock, flags);
        return;
    }

    cs = 0x2b;

    serio_write(iforce->serio, 0x2b);

    serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
    cs ^= iforce->xmit.buf[iforce->xmit.tail];
    XMIT_INC(iforce->xmit.tail, 1);

    for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
        serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
        cs ^= iforce->xmit.buf[iforce->xmit.tail];
        XMIT_INC(iforce->xmit.tail, 1);
    }

    serio_write(iforce->serio, cs);

    if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
        goto again;

    clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);

    spin_unlock_irqrestore(&iforce->xmit_lock, flags);
}

static void iforce_serio_write_wakeup(struct serio *serio)
{
    struct iforce *iforce = serio_get_drvdata(serio);

    iforce_serial_xmit(iforce);
}

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

    if (!iforce->pkt) {
        if (data == 0x2b)
            iforce->pkt = 1;
        goto out;
    }

    if (!iforce->id) {
        if (data > 3 && data != 0xff)
            iforce->pkt = 0;
        else
            iforce->id = data;
        goto out;
    }

    if (!iforce->len) {
        if (data > IFORCE_MAX_LENGTH) {
            iforce->pkt = 0;
            iforce->id = 0;
        } else {
            iforce->len = data;
        }
        goto out;
    }

    if (iforce->idx < iforce->len) {
        iforce->csum += iforce->data[iforce->idx++] = data;
        goto out;
    }

    if (iforce->idx == iforce->len) {
        iforce_process_packet(iforce, (iforce->id << 8) | iforce->idx, iforce->data);
        iforce->pkt = 0;
        iforce->id  = 0;
        iforce->len = 0;
        iforce->idx = 0;
        iforce->csum = 0;
    }
out:
    return IRQ_HANDLED;
}

static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
{
    struct iforce *iforce;
    int err;

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

    iforce->bus = IFORCE_232;
    iforce->serio = serio;

    serio_set_drvdata(serio, iforce);

    err = serio_open(serio, drv);
    if (err)
        goto fail1;

    err = iforce_init_device(iforce);
    if (err)
        goto fail2;

    return 0;

 fail2: serio_close(serio);
 fail1: serio_set_drvdata(serio, NULL);
    kfree(iforce);
    return err;
}

static void iforce_serio_disconnect(struct serio *serio)
{
    struct iforce *iforce = serio_get_drvdata(serio);

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

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

MODULE_DEVICE_TABLE(serio, iforce_serio_ids);

struct serio_driver iforce_serio_drv = {
    .driver     = {
        .name   = "iforce",
    },
    .description    = "RS232 I-Force joysticks and wheels driver",
    .id_table   = iforce_serio_ids,
    .write_wakeup   = iforce_serio_write_wakeup,
    .interrupt  = iforce_serio_irq,
    .connect    = iforce_serio_connect,
    .disconnect = iforce_serio_disconnect,
};