/***
 *
 *  rtmac/nomac/nomac_proto.c
 *
 *  RTmac - real-time networking media access control subsystem
 *  Copyright (C) 2002      Marc Kleine-Budde <kleine-budde@gmx.de>,
 *                2003-2005 Jan Kiszka <Jan.Kiszka@web.de>
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/init.h>

#include <rtdev.h>
#include <rtmac/rtmac_proto.h>
#include <rtmac/nomac/nomac.h>

static struct rtskb_queue nrt_rtskb_queue;
static rtdm_task_t wrapper_task;
static rtdm_event_t wakeup_sem;

int nomac_rt_packet_tx(struct rtskb *rtskb, struct rtnet_device *rtdev)
{
	/* unused here, just to demonstrate access to the discipline state
    struct nomac_priv   *nomac =
        (struct nomac_priv *)rtdev->mac_priv->disc_priv; */
	int ret;

	rtcap_mark_rtmac_enqueue(rtskb);

	/* no MAC: we simply transmit the packet under xmit_lock */
	rtdm_mutex_lock(&rtdev->xmit_mutex);
	ret = rtmac_xmit(rtskb);
	rtdm_mutex_unlock(&rtdev->xmit_mutex);

	return ret;
}

int nomac_nrt_packet_tx(struct rtskb *rtskb)
{
	struct rtnet_device *rtdev = rtskb->rtdev;
	/* unused here, just to demonstrate access to the discipline state
    struct nomac_priv   *nomac =
        (struct nomac_priv *)rtdev->mac_priv->disc_priv; */
	int ret;

	rtcap_mark_rtmac_enqueue(rtskb);

	/* note: this routine may be called both in rt and non-rt context
     *       => detect and wrap the context if necessary */
	if (!rtdm_in_rt_context()) {
		rtskb_queue_tail(&nrt_rtskb_queue, rtskb);
		rtdm_event_signal(&wakeup_sem);
		return 0;
	} else {
		/* no MAC: we simply transmit the packet under xmit_lock */
		rtdm_mutex_lock(&rtdev->xmit_mutex);
		ret = rtmac_xmit(rtskb);
		rtdm_mutex_unlock(&rtdev->xmit_mutex);

		return ret;
	}
}

void nrt_xmit_task(void *arg)
{
	struct rtskb *rtskb;
	struct rtnet_device *rtdev;

	while (!rtdm_task_should_stop()) {
		if (rtdm_event_wait(&wakeup_sem) < 0)
			break;

		while ((rtskb = rtskb_dequeue(&nrt_rtskb_queue))) {
			rtdev = rtskb->rtdev;

			/* no MAC: we simply transmit the packet under xmit_lock */
			rtdm_mutex_lock(&rtdev->xmit_mutex);
			rtmac_xmit(rtskb);
			rtdm_mutex_unlock(&rtdev->xmit_mutex);
		}
	}
}

int nomac_packet_rx(struct rtskb *rtskb)
{
	/* actually, NoMAC doesn't expect any control packet */
	kfree_rtskb(rtskb);

	return 0;
}

int __init nomac_proto_init(void)
{
	int ret;

	rtskb_queue_init(&nrt_rtskb_queue);
	rtdm_event_init(&wakeup_sem, 0);

	ret = rtdm_task_init(&wrapper_task, "rtnet-nomac", nrt_xmit_task, 0,
			     RTDM_TASK_LOWEST_PRIORITY, 0);
	if (ret < 0) {
		rtdm_event_destroy(&wakeup_sem);
		return ret;
	}

	return 0;
}

void nomac_proto_cleanup(void)
{
	rtdm_event_destroy(&wakeup_sem);
	rtdm_task_destroy(&wrapper_task);
}