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