tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * WUSB cluster reservation management
4 *
5 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
6 */
7#include <linux/kernel.h>
8#include <linux/uwb.h>
9
10#include "wusbhc.h"
11
12/*
13 * WUSB cluster reservations are multicast reservations with the
14 * broadcast cluster ID (BCID) as the target DevAddr.
15 *
16 * FIXME: consider adjusting the reservation depending on what devices
17 * are attached.
18 */
19
20static int wusbhc_bwa_set(struct wusbhc *wusbhc, u8 stream,
21 const struct uwb_mas_bm *mas)
22{
23 if (mas == NULL)
24 mas = &uwb_mas_bm_zero;
25 return wusbhc->bwa_set(wusbhc, stream, mas);
26}
27
28/**
29 * wusbhc_rsv_complete_cb - WUSB HC reservation complete callback
30 * @rsv: the reservation
31 *
32 * Either set or clear the HC's view of the reservation.
33 *
34 * FIXME: when a reservation is denied the HC should be stopped.
35 */
36static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
37{
38 struct wusbhc *wusbhc = rsv->pal_priv;
39 struct device *dev = wusbhc->dev;
40 struct uwb_mas_bm mas;
41
42 dev_dbg(dev, "%s: state = %d\n", __func__, rsv->state);
43 switch (rsv->state) {
44 case UWB_RSV_STATE_O_ESTABLISHED:
45 uwb_rsv_get_usable_mas(rsv, &mas);
46 dev_dbg(dev, "established reservation: %*pb\n",
47 UWB_NUM_MAS, mas.bm);
48 wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
49 break;
50 case UWB_RSV_STATE_NONE:
51 dev_dbg(dev, "removed reservation\n");
52 wusbhc_bwa_set(wusbhc, 0, NULL);
53 break;
54 default:
55 dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
56 break;
57 }
58}
59
60
61/**
62 * wusbhc_rsv_establish - establish a reservation for the cluster
63 * @wusbhc: the WUSB HC requesting a bandwidth reservation
64 */
65int wusbhc_rsv_establish(struct wusbhc *wusbhc)
66{
67 struct uwb_rc *rc = wusbhc->uwb_rc;
68 struct uwb_rsv *rsv;
69 struct uwb_dev_addr bcid;
70 int ret;
71
72 if (rc == NULL)
73 return -ENODEV;
74
75 rsv = uwb_rsv_create(rc, wusbhc_rsv_complete_cb, wusbhc);
76 if (rsv == NULL)
77 return -ENOMEM;
78
79 bcid.data[0] = wusbhc->cluster_id;
80 bcid.data[1] = 0;
81
82 rsv->target.type = UWB_RSV_TARGET_DEVADDR;
83 rsv->target.devaddr = bcid;
84 rsv->type = UWB_DRP_TYPE_PRIVATE;
85 rsv->max_mas = 256; /* try to get as much as possible */
86 rsv->min_mas = 15; /* one MAS per zone */
87 rsv->max_interval = 1; /* max latency is one zone */
88 rsv->is_multicast = true;
89
90 ret = uwb_rsv_establish(rsv);
91 if (ret == 0)
92 wusbhc->rsv = rsv;
93 else
94 uwb_rsv_destroy(rsv);
95 return ret;
96}
97
98
99/**
100 * wusbhc_rsv_terminate - terminate the cluster reservation
101 * @wusbhc: the WUSB host whose reservation is to be terminated
102 */
103void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
104{
105 if (wusbhc->rsv) {
106 uwb_rsv_terminate(wusbhc->rsv);
107 uwb_rsv_destroy(wusbhc->rsv);
108 wusbhc->rsv = NULL;
109 }
110}