reservation.c

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/*
 * WUSB cluster reservation management
 *
 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/uwb.h>

#include "wusbhc.h"

/*
 * WUSB cluster reservations are multicast reservations with the
 * broadcast cluster ID (BCID) as the target DevAddr.
 *
 * FIXME: consider adjusting the reservation depending on what devices
 * are attached.
 */

static int wusbhc_bwa_set(struct wusbhc *wusbhc, u8 stream,
    const struct uwb_mas_bm *mas)
{
    if (mas == NULL)
        mas = &uwb_mas_bm_zero;
    return wusbhc->bwa_set(wusbhc, stream, mas);
}

static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
{
    struct wusbhc *wusbhc = rsv->pal_priv;
    struct device *dev = wusbhc->dev;
    struct uwb_mas_bm mas;
    char buf[72];

    switch (rsv->state) {
    case UWB_RSV_STATE_O_ESTABLISHED:
        uwb_rsv_get_usable_mas(rsv, &mas);
        bitmap_scnprintf(buf, sizeof(buf), mas.bm, UWB_NUM_MAS);
        dev_dbg(dev, "established reservation: %s\n", buf);
        wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
        break;
    case UWB_RSV_STATE_NONE:
        dev_dbg(dev, "removed reservation\n");
        wusbhc_bwa_set(wusbhc, 0, NULL);
        break;
    default:
        dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
        break;
    }
}


int wusbhc_rsv_establish(struct wusbhc *wusbhc)
{
    struct uwb_rc *rc = wusbhc->uwb_rc;
    struct uwb_rsv *rsv;
    struct uwb_dev_addr bcid;
    int ret;

    rsv = uwb_rsv_create(rc, wusbhc_rsv_complete_cb, wusbhc);
    if (rsv == NULL)
        return -ENOMEM;

    bcid.data[0] = wusbhc->cluster_id;
    bcid.data[1] = 0;

    rsv->target.type = UWB_RSV_TARGET_DEVADDR;
    rsv->target.devaddr = bcid;
    rsv->type = UWB_DRP_TYPE_PRIVATE;
    rsv->max_mas = 256; /* try to get as much as possible */
    rsv->min_mas = 15;  /* one MAS per zone */
    rsv->max_interval = 1; /* max latency is one zone */
    rsv->is_multicast = true;

    ret = uwb_rsv_establish(rsv);
    if (ret == 0)
        wusbhc->rsv = rsv;
    else
        uwb_rsv_destroy(rsv);
    return ret;
}


void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
{
    if (wusbhc->rsv) {
        uwb_rsv_terminate(wusbhc->rsv);
        uwb_rsv_destroy(wusbhc->rsv);
        wusbhc->rsv = NULL;
    }
}