/*
 * $Id: iforce-serio.c,v 1.4 2002/01/28 22:45:00 jdeneux Exp $
 *
 *  Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
 *  Copyright (c) 2001 Johann Deneux <deneux@ifrance.com>
 *
 *  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 <vojtech@ucw.cz>, 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)
{
	iforce_serial_xmit((struct iforce *)serio->private);
}

static irqreturn_t iforce_serio_irq(struct serio *serio,
		unsigned char data, unsigned int flags, struct pt_regs *regs)
{
	struct iforce* iforce = serio->private;

	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, regs);
		iforce->pkt = 0;
		iforce->id  = 0;
		iforce->len = 0;
		iforce->idx = 0;
		iforce->csum = 0;
	}
out:
	return IRQ_HANDLED;
}

static void iforce_serio_connect(struct serio *serio, struct serio_dev *dev)
{
	struct iforce *iforce;
	if (serio->type != (SERIO_RS232 | SERIO_IFORCE))
		return;

	if (!(iforce = kmalloc(sizeof(struct iforce), GFP_KERNEL))) return;
	memset(iforce, 0, sizeof(struct iforce));

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

	if (serio_open(serio, dev)) {
		kfree(iforce);
		return;
	}

	if (iforce_init_device(iforce)) {
		serio_close(serio);
		kfree(iforce);
		return;
	}
}

static void iforce_serio_disconnect(struct serio *serio)
{
	struct iforce* iforce = serio->private;

	input_unregister_device(&iforce->dev);
	serio_close(serio);
	kfree(iforce);
}

struct serio_dev iforce_serio_dev = {
	.write_wakeup =	iforce_serio_write_wakeup,
	.interrupt =	iforce_serio_irq,
	.connect =	iforce_serio_connect,
	.disconnect =	iforce_serio_disconnect,
};