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 #include "vchiq_killable.h"
37
38 #define MAX_CALLBACKS 10
39
40 static int g_connected;
41 static int g_num_deferred_callbacks;
42 static VCHIQ_CONNECTED_CALLBACK_T g_deferred_callback[MAX_CALLBACKS];
43 static int g_once_init;
44 static struct mutex g_connected_mutex;
45
46 /****************************************************************************
47 *
48 * Function to initialize our lock.
49 *
50 ***************************************************************************/
51
connected_init(void)52 static void connected_init(void)
53 {
54 if (!g_once_init) {
55 lmutex_init(&g_connected_mutex);
56 g_once_init = 1;
57 }
58 }
59
60 /****************************************************************************
61 *
62 * This function is used to defer initialization until the vchiq stack is
63 * initialized. If the stack is already initialized, then the callback will
64 * be made immediately, otherwise it will be deferred until
65 * vchiq_call_connected_callbacks is called.
66 *
67 ***************************************************************************/
68
vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)69 void vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)
70 {
71 connected_init();
72
73 if (lmutex_lock_interruptible(&g_connected_mutex) != 0)
74 return;
75
76 if (g_connected)
77 /* We're already connected. Call the callback immediately. */
78
79 callback();
80 else {
81 if (g_num_deferred_callbacks >= MAX_CALLBACKS)
82 vchiq_log_error(vchiq_core_log_level,
83 "There are already %d callbacks registered - "
84 "please increase MAX_CALLBACKS",
85 g_num_deferred_callbacks);
86 else {
87 g_deferred_callback[g_num_deferred_callbacks] =
88 callback;
89 g_num_deferred_callbacks++;
90 }
91 }
92 lmutex_unlock(&g_connected_mutex);
93 }
94
95 /****************************************************************************
96 *
97 * This function is called by the vchiq stack once it has been connected to
98 * the videocore and clients can start to use the stack.
99 *
100 ***************************************************************************/
101
vchiq_call_connected_callbacks(void)102 void vchiq_call_connected_callbacks(void)
103 {
104 int i;
105
106 connected_init();
107
108 if (lmutex_lock_interruptible(&g_connected_mutex) != 0)
109 return;
110
111 for (i = 0; i < g_num_deferred_callbacks; i++)
112 g_deferred_callback[i]();
113
114 g_num_deferred_callbacks = 0;
115 g_connected = 1;
116 lmutex_unlock(&g_connected_mutex);
117 }
118 EXPORT_SYMBOL(vchiq_add_connected_callback);
119