1 /**
2 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions, and the following disclaimer,
9 * without modification.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The names of the above-listed copyright holders may not be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
16 *
17 * ALTERNATIVELY, this software may be distributed under the terms of the
18 * GNU General Public License ("GPL") version 2, as published by the Free
19 * Software Foundation.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include "vchiq_connected.h"
35 #include "vchiq_core.h"
36
37 #define MAX_CALLBACKS 10
38
39 static int g_connected;
40 static int g_num_deferred_callbacks;
41 static VCHIQ_CONNECTED_CALLBACK_T g_deferred_callback[MAX_CALLBACKS];
42 static int g_once_init;
43 static struct mutex g_connected_mutex;
44
45 /****************************************************************************
46 *
47 * Function to initialize our lock.
48 *
49 ***************************************************************************/
50
connected_init(void)51 static void connected_init(void)
52 {
53 if (!g_once_init) {
54 lmutex_init(&g_connected_mutex);
55 g_once_init = 1;
56 }
57 }
58
59 /****************************************************************************
60 *
61 * This function is used to defer initialization until the vchiq stack is
62 * initialized. If the stack is already initialized, then the callback will
63 * be made immediately, otherwise it will be deferred until
64 * vchiq_call_connected_callbacks is called.
65 *
66 ***************************************************************************/
67
vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)68 void vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)
69 {
70 connected_init();
71
72 if (lmutex_lock_interruptible(&g_connected_mutex) != 0)
73 return;
74
75 if (g_connected)
76 /* We're already connected. Call the callback immediately. */
77
78 callback();
79 else {
80 if (g_num_deferred_callbacks >= MAX_CALLBACKS)
81 vchiq_log_error(vchiq_core_log_level,
82 "There are already %d callbacks registered - "
83 "please increase MAX_CALLBACKS",
84 g_num_deferred_callbacks);
85 else {
86 g_deferred_callback[g_num_deferred_callbacks] =
87 callback;
88 g_num_deferred_callbacks++;
89 }
90 }
91 lmutex_unlock(&g_connected_mutex);
92 }
93
94 /****************************************************************************
95 *
96 * This function is called by the vchiq stack once it has been connected to
97 * the videocore and clients can start to use the stack.
98 *
99 ***************************************************************************/
100
vchiq_call_connected_callbacks(void)101 void vchiq_call_connected_callbacks(void)
102 {
103 int i;
104
105 connected_init();
106
107 if (lmutex_lock_interruptible(&g_connected_mutex) != 0)
108 return;
109
110 for (i = 0; i < g_num_deferred_callbacks; i++)
111 g_deferred_callback[i]();
112
113 g_num_deferred_callbacks = 0;
114 g_connected = 1;
115 lmutex_unlock(&g_connected_mutex);
116 }
117 EXPORT_SYMBOL(vchiq_add_connected_callback);
118