reservation.c revision 90ff96f22426a9d1a06df97dead0a9098facb567 
1/*
2 * WUSB cluster reservation management
3 *
4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18#include <linux/kernel.h>
19#include <linux/uwb.h>
20
21#include "wusbhc.h"
22
23/*
24 * WUSB cluster reservations are multicast reservations with the
25 * broadcast cluster ID (BCID) as the target DevAddr.
26 *
27 * FIXME: consider adjusting the reservation depending on what devices
28 * are attached.
29 */
30
31static int wusbhc_bwa_set(struct wusbhc *wusbhc, u8 stream,
32	const struct uwb_mas_bm *mas)
33{
34	if (mas == NULL)
35		mas = &uwb_mas_bm_zero;
36	return wusbhc->bwa_set(wusbhc, stream, mas);
37}
38
39/**
40 * wusbhc_rsv_complete_cb - WUSB HC reservation complete callback
41 * @rsv:    the reservation
42 *
43 * Either set or clear the HC's view of the reservation.
44 *
45 * FIXME: when a reservation is denied the HC should be stopped.
46 */
47static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
48{
49	struct wusbhc *wusbhc = rsv->pal_priv;
50	struct device *dev = wusbhc->dev;
51	char buf[72];
52
53	switch (rsv->state) {
54	case UWB_RSV_STATE_O_ESTABLISHED:
55		bitmap_scnprintf(buf, sizeof(buf), rsv->mas.bm, UWB_NUM_MAS);
56		dev_dbg(dev, "established reservation: %s\n", buf);
57		wusbhc_bwa_set(wusbhc, rsv->stream, &rsv->mas);
58		break;
59	case UWB_RSV_STATE_NONE:
60		dev_dbg(dev, "removed reservation\n");
61		wusbhc_bwa_set(wusbhc, 0, NULL);
62		wusbhc->rsv = NULL;
63		break;
64	default:
65		dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
66		break;
67	}
68}
69
70
71/**
72 * wusbhc_rsv_establish - establish a reservation for the cluster
73 * @wusbhc: the WUSB HC requesting a bandwith reservation
74 */
75int wusbhc_rsv_establish(struct wusbhc *wusbhc)
76{
77	struct uwb_rc *rc = wusbhc->uwb_rc;
78	struct uwb_rsv *rsv;
79	struct uwb_dev_addr bcid;
80	int ret;
81
82	rsv = uwb_rsv_create(rc, wusbhc_rsv_complete_cb, wusbhc);
83	if (rsv == NULL)
84		return -ENOMEM;
85
86	bcid.data[0] = wusbhc->cluster_id;
87	bcid.data[1] = 0;
88
89	rsv->owner = &rc->uwb_dev;
90	rsv->target.type = UWB_RSV_TARGET_DEVADDR;
91	rsv->target.devaddr = bcid;
92	rsv->type = UWB_DRP_TYPE_PRIVATE;
93	rsv->max_mas = 256;
94	rsv->min_mas = 16;  /* one MAS per zone? */
95	rsv->sparsity = 16; /* at least one MAS in each zone? */
96	rsv->is_multicast = true;
97
98	ret = uwb_rsv_establish(rsv);
99	if (ret == 0)
100		wusbhc->rsv = rsv;
101	else
102		uwb_rsv_destroy(rsv);
103	return ret;
104}
105
106
107/**
108 * wusbhc_rsv_terminate - terminate any cluster reservation
109 * @wusbhc: the WUSB host whose reservation is to be terminated
110 */
111void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
112{
113	if (wusbhc->rsv)
114		uwb_rsv_terminate(wusbhc->rsv);
115}
116