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
wusbhc_bwa_set(struct wusbhc * wusbhc,u8 stream,const struct uwb_mas_bm * mas)31 static 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 */
wusbhc_rsv_complete_cb(struct uwb_rsv * rsv)47 static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
48 {
49 struct wusbhc *wusbhc = rsv->pal_priv;
50 struct device *dev = wusbhc->dev;
51 struct uwb_mas_bm mas;
52
53 dev_dbg(dev, "%s: state = %d\n", __func__, rsv->state);
54 switch (rsv->state) {
55 case UWB_RSV_STATE_O_ESTABLISHED:
56 uwb_rsv_get_usable_mas(rsv, &mas);
57 dev_dbg(dev, "established reservation: %*pb\n",
58 UWB_NUM_MAS, mas.bm);
59 wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
60 break;
61 case UWB_RSV_STATE_NONE:
62 dev_dbg(dev, "removed reservation\n");
63 wusbhc_bwa_set(wusbhc, 0, NULL);
64 break;
65 default:
66 dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
67 break;
68 }
69 }
70
71
72 /**
73 * wusbhc_rsv_establish - establish a reservation for the cluster
74 * @wusbhc: the WUSB HC requesting a bandwidth reservation
75 */
wusbhc_rsv_establish(struct wusbhc * wusbhc)76 int wusbhc_rsv_establish(struct wusbhc *wusbhc)
77 {
78 struct uwb_rc *rc = wusbhc->uwb_rc;
79 struct uwb_rsv *rsv;
80 struct uwb_dev_addr bcid;
81 int ret;
82
83 if (rc == NULL)
84 return -ENODEV;
85
86 rsv = uwb_rsv_create(rc, wusbhc_rsv_complete_cb, wusbhc);
87 if (rsv == NULL)
88 return -ENOMEM;
89
90 bcid.data[0] = wusbhc->cluster_id;
91 bcid.data[1] = 0;
92
93 rsv->target.type = UWB_RSV_TARGET_DEVADDR;
94 rsv->target.devaddr = bcid;
95 rsv->type = UWB_DRP_TYPE_PRIVATE;
96 rsv->max_mas = 256; /* try to get as much as possible */
97 rsv->min_mas = 15; /* one MAS per zone */
98 rsv->max_interval = 1; /* max latency is one zone */
99 rsv->is_multicast = true;
100
101 ret = uwb_rsv_establish(rsv);
102 if (ret == 0)
103 wusbhc->rsv = rsv;
104 else
105 uwb_rsv_destroy(rsv);
106 return ret;
107 }
108
109
110 /**
111 * wusbhc_rsv_terminate - terminate the cluster reservation
112 * @wusbhc: the WUSB host whose reservation is to be terminated
113 */
wusbhc_rsv_terminate(struct wusbhc * wusbhc)114 void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
115 {
116 if (wusbhc->rsv) {
117 uwb_rsv_terminate(wusbhc->rsv);
118 uwb_rsv_destroy(wusbhc->rsv);
119 wusbhc->rsv = NULL;
120 }
121 }
122